STATE STREET INSTITUTIONAL INVESTMENT TRUST (Form: 485BPOS, Received: 04/29/2019 16:57:20)

NAME, ADDRESS,

AND YEAR OF BIRTH

POSITION(S)

HELD WITH

TRUST

TERM OF

OFFICE AND

LENGTH OF

TIME SERVED

PRINCIPAL OCCUPATION

DURING PAST FIVE YEARS

Khimmara Greer

State Street Bank and Trust Company

100 Summer Street,

7 ^th Floor

Boston, MA 02111

YOB: 1983

Assistant Secretary

Term: Indefinite

Elected: 5/16

Vice President and Counsel, State Street Bank and Trust Company (2015- present); Regulatory Advisor, JPMorgan (2014 – 2015).

As filed with the U.S. Securities and Exchange Commission on April 29, 2019

1933 Act File No. 333-30810

1940 Act File No. 811-09819

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM N-1A

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

☒

Post-Effective Amendment No. 256

☒

and

REGISTRATION STATEMENT

UNDER

THE INVESTMENT COMPANY ACT OF 1940

☒

Amendment No. 258

STATE STREET INSTITUTIONAL INVESTMENT TRUST

One Iron Street, Boston, Massachusetts 02210

(Address of Principal Executive Offices)

(617) 664-7037

(Registrant’s Telephone Number)

Joshua A. Weinberg, Esq.

Managing Director and Managing Counsel

c/o SSGA Funds Management, Inc.

One Iron Street

Boston, Massachusetts 02210

(Name and Address of Agent for Service)

Copy to:

Timothy W. Diggins, Esq.

Ropes & Gray LLP

Prudential Tower, 800 Boylston Street

Boston, Massachusetts 02199-3600

It is proposed that this filing will become effective (check appropriate box):

☐	Immediately upon filing pursuant to paragraph (b)

☒	On April 30, 2019 pursuant to paragraph (b)

☐	60 days after filing pursuant to paragraph (a)(1)

☐	On (date) pursuant to paragraph (a)(1) of Rule 485.

☐	75 days after filing pursuant to paragraph (a)(2)

☐	On (date) pursuant to paragraph (a)(2) of Rule 485.

If appropriate, check the following box:

☐	This post-effective amendment designates a new effective date for a previously filed post-effective amendment.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Equity 500 Index Fund

Class A (SSSVX) Class I (SSSWX) Class K (SSSYX)

State Street Aggregate Bond Index Fund

Class A (SSFCX) Class I (SSFDX) Class K (SSFEX)

State Street Global Equity ex-U.S. Index Fund

Class A (SSGHX) Class I (SSGJX) Class K (SSGLX)

State Street Small/Mid Cap Equity Index Fund

Class A (SSMJX) Class I (SSMLX) Class K (SSMKX)

Beginning on January 1, 2021, as permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of a Fund's annual and semi- annual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Fund (or from your financial intermediary, such as a broker-dealer or bank). Instead, the reports will be made available on the Fund's website (www.ssgafunds.com), and you will be notified by mail each time a report is posted, and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Funds electronically by calling (800) 647-7327.

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with a Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling (800) 647-7327. Your election to receive reports in paper will apply to all funds held in your account.

The U.S. Securities and Exchange Commission and the U.S. Commodity Futures Trading Commission have not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in any of the Funds offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Each Fund may offer multiple classes of shares. This Prospectus covers only the Class A, Class I and Class K Shares of the Funds.

TABLE OF CONTENTS

Fund Summaries	1
State Street Equity 500 Index Fund	1
State Street Aggregate Bond Index Fund	7
State Street Global Equity ex-U.S. Index Fund	14
State Street Small/Mid Cap Equity Index Fund	22
Additional Information About Investment Objectives, Principal Strategies and Risks	29
Additional Information About Non-Principal Investment Strategies and Risks	44
Portfolio Holdings Disclosure	46
Management and Organization	47
Shareholder Information	50
Dividends, Distributions and Tax Considerations	62
Financial Intermediary Arrangements	64
Financial Highlights	66
Index/Trademark Licenses/Disclaimers	79

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State Street Equity 500 Index Fund

Investment Objective

The investment objective of the State Street Equity 500 Index Fund (the “Equity 500 Index Fund” or sometimes referred to in context as the “Fund”) is to replicate as closely as possible, before expenses, the performance of the Standard & Poor's 500 Index (the “S&P 500” or sometimes referred to in context as the “Index”).

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). You may qualify for sales charge discounts on purchases of Class A shares if you agree to invest in the future, or if you and your family currently invest, at least $50,000 in State Street Funds that offer Class A shares. More information about these and other discounts is available from your financial professional and in Choosing a Share Class – Reducing Your Class A Sales Charge on page 52 of the Fund's Prospectus. The expenses shown in the table and the Example reflect the expenses of both the Fund and the Fund's proportionate share of the expenses of State Street Equity 500 Index II Portfolio (the “Equity 500 Index II Portfolio” or sometimes referred to in context as the “Portfolio”).

Shareholder Fees (fees paid directly from your investment)

	Class A	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	5.25%	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None ¹	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class A	Class I	Class K
Management Fee	0.02%	0.02%	0.02%
Distribution and/or Shareholder Service (12b-1) Fees	0.25%	0.00%	0.00%
Other Expenses ²	0.32%	0.32%	0.12%
Total Annual Fund Operating Expenses	0.59%	0.34%	0.14%
Less Fee Waivers and/or Expense Reimbursements ³	(0.12)%	(0.12)%	(0.12)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.47%	0.22%	0.02%

¹	A contingent deferred sales charge (“CDSC”) of 1.00% may be assessed on redemptions of Class A shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase as part of an investment of $1,000,000 or more.
²	Other Expenses have been restated to reflect current fees for Class A and Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020, separately with respect to each of the Fund and the Portfolio, (i) to waive up to the full amount of the advisory fee payable by the Fund or the Portfolio, and/or (ii) to reimburse the Fund or the Portfolio to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.02% of the Fund's or the Portfolio's average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund/Portfolio's Board of Trustees.

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Example:

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated, and then sell all of your Fund Shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The calculation of costs for the one-year period takes into account the effect of any current contractual fee waivers and/or reimbursements; and the calculation of costs for the remaining periods takes such fee waivers and/or reimbursements into account only for the first year of each such period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 year	3 years	5 years	10 years
Class A	$571	$693	$826	$1,213
Class I	$ 23	$ 97	$179	$ 419
Class K	$ 2	$ 33	$ 67	$ 167

Portfolio Turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). As a shareholder of the Equity 500 Index II Portfolio, the Fund bears its ratable share of the transaction costs associated with the portfolio turnover of the Portfolio. A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund Shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 8% of the average value of its portfolio.

Principal Investment Strategies

The Fund uses a passive management strategy designed to track the performance of the S&P 500. The Index is a well-known stock market index that includes common stocks of 500 companies from a number of sectors and that measures the performance of the large-cap sector of the U.S. equities market. As of February 28, 2019, a significant portion of the Index comprised companies in the information technology sector, although this may change from time to time.

The Fund is not managed according to traditional methods of “active” investment management, which involve the buying and selling of securities based upon economic, financial and market analysis and investment judgment. Instead, the Fund, using a “passive” or “indexing” investment approach, seeks to provide investment results that, before expenses, correspond generally to the total return of the S&P 500.

The Fund generally intends to invest in all stocks comprising the S&P 500 in approximate proportion to their weightings in the Index. However, under various circumstances, it may not be possible or practicable to purchase all stocks in those weightings. In those circumstances, the Fund may purchase a sample of the stocks in the Index in proportions expected by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, to match generally the performance of the Index as a whole. In addition, from time to time stocks are added to or removed from the Index. The Fund may sell securities that are represented in the Index, or purchase securities that are not yet represented in the Index, in anticipation of their removal from or addition to the Index. Under normal market conditions, the Fund will not invest less than 80% of its total assets in stocks in the Index. Shareholders will receive sixty (60) days' notice prior to a change in the 80% investment policy. For this purpose, “total assets” means net assets plus borrowings, if any. The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. In addition, the Fund may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

The Fund may at times purchase or sell futures contracts, or options on those futures, in lieu of investing directly in the stocks making up the Index. The Fund might do so, for example, in order to increase its investment exposure pending investment of cash in the stocks comprising the Index. Alternatively, the Fund might use futures or options on futures to reduce its investment exposure in situations where it intends to sell a portion of the stocks in its portfolio but the sale has not yet been completed. The Fund may also enter into other derivatives transactions, including the use of options or swap transactions, in lieu of investing directly in the stocks making up the Index. The Fund may also, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Fund (including funds advised by the Adviser).

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The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the Equity 500 Index II Portfolio, which has substantially similar investment policies to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio, and it participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Portfolio.

Principal Risks

In addition, the Fund is subject to the following risks:

Counterparty Risk: The Fund will be subject to credit risk with respect to the counterparties with which the Fund enters into derivatives contracts, repurchase agreements, reverse repurchase agreements, and other transactions. If a counterparty fails to meet its contractual obligations, the Fund may be unable to terminate or realize any gain on the investment or transaction, or to recover collateral posted to the counterparty, resulting in a loss to the Fund. If the Fund holds collateral posted by its counterparty, it may be delayed or prevented from realizing on the collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty.

Derivatives Risk: Derivative transactions can create investment leverage and may have significant volatility. It is possible that a derivative transaction will result in a much greater loss than the principal amount invested, and the Fund may not be able to close out a derivative transaction at a favorable time or price. The counterparty to a derivatives contract may be unable or unwilling to make timely settlement payments, return the Fund's margin, or otherwise honor its obligations. A derivatives transaction may not behave in the manner anticipated by the Adviser or may not have the effect on the Fund anticipated by the Adviser.

Equity Investing Risk: The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Indexing Strategy/Index Tracking Risk: The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. While the Adviser seeks to track the performance of the Index ( i.e. , achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. The Adviser may attempt to replicate the Index return by investing in fewer than all of the securities in the Index, or in some securities not included in the Index, potentially increasing the risk of divergence between the Fund's return and that of the Index.

Large-Capitalization Securities Risk: Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies. Larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or other market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies.

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Large Shareholder Risk: To the extent a large proportion of the shares of the Portfolio are held by a small number of shareholders (or a single shareholder), including funds or accounts over which the Adviser has investment discretion, the Portfolio is subject to the risk that these shareholders will purchase or redeem Portfolio shares in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of the Portfolio to conduct its investment program.

Liquidity Risk: Lack of a ready market or restrictions on resale may limit the ability of the Fund to sell a security at an advantageous time or price or at all. Illiquid securities may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value. Illiquidity of the Fund's holdings may limit the ability of the Fund to obtain cash to meet redemptions on a timely basis. In addition, the Fund, due to limitations on investments in any illiquid securities and/or the difficulty in purchasing and selling such investments, may be unable to achieve its desired level of exposure to a certain market or sector.

Market Risk: The Fund's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.

Master/Feeder Structure Risk : The Fund pursues its objective by investing substantially all of its assets in another pooled investment vehicle (a “master fund”). The ability of the Fund to meet its investment objective is directly related to the ability of the master fund to meet its investment objective. The Adviser serves as investment adviser to the master fund, leading to potential conflicts of interest. The Fund will bear its pro rata portion of the expenses incurred by the master fund. Substantial redemptions by other investors in a master fund may affect the master fund's investment program adversely and limit the ability of the master fund to achieve its objective.

Risk of Investment in Other Pools: If the Fund invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected and is exposed indirectly to all of the risks applicable to an investment in such other pool. The investment policies of the other pool may not be the same as those of the Fund; as a result, an investment in the other pool may be subject to additional or different risks than those to which the Fund is typically subject. The Fund bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Fund may invest, leading to potential conflicts of interest. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which the Fund does so.

Technology Sector Risk: Market or economic factors impacting technology companies and companies that rely heavily on technological advances could have a major effect on the value of the Fund's investments. The value of stocks of technology companies and companies that rely heavily on technology is particularly vulnerable to rapid changes in technology product cycles, rapid product obsolescence, government regulation and competition, both domestically and internationally, including competition from foreign competitors with lower production costs. Stocks of technology companies and companies that rely heavily on technology, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market. Technology companies are heavily dependent on patent and intellectual property rights, the loss or impairment of which may adversely affect profitability. Additionally, companies in the technology sector may face dramatic and often unpredictable changes in growth rates and competition for the services of qualified personnel.

Unconstrained Sector Risk: The Fund may invest a substantial portion of its assets within one or more economic sectors or industries, which may change from time to time. Greater investment focus on one or more sectors or industries increases the potential for volatility and the risk that events negatively affecting such sectors or industries could reduce returns, potentially causing the value of the Fund's Shares to decrease, perhaps significantly.

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Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of the Index. The bar chart shows how the Class A shares' returns have varied for each full calendar year shown. The effect of sales charges, applicable to Class A shares only, is not reflected in the bar chart; if these amounts were reflected, returns would be lower. For periods prior to September 17, 2014, the inception date for Class A shares, the performance information shown is that of the Administrative Shares of the Fund, adjusted to reflect the higher class-related operating fees and expenses of Class A shares. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 15.89% (Q2, 2009)
Lowest Quarterly Return: -14.06% (Q3, 2011)

Average Annual Total Returns (for periods ended 12/31/18)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. After-tax returns depend on an investor's tax situation and may differ from those shown below, and after-tax returns are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts (IRAs). For periods prior to September 17, 2014, the inception date for Class A and Class I shares, the performance information shown is that of the Administrative Shares of the Fund, adjusted to reflect the higher class-related operating fees and expenses of Class A and Class I. For periods prior to September 17, 2014, the inception date for Class K shares, the performance information shown is that of the Administrative Shares of the Fund.

	One Year	Five Years	Ten Years	Inception Date
Class A				9/17/2014
Return Before Taxes	-9.73%	6.78%	11.94%
Return After Taxes on Distributions	-10.75%	5.97%	11.28%
Return After Taxes on Distributions and Sale of Fund Shares	-5.06%	5.21%	9.82%
Class I	-4.45%	8.21%	12.83%	9/17/2014
Class K	-4.42%	8.35%	12.91%	9/17/2014
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	-4.38%	8.49%	13.12%

The Fund will make updated performance information, including its current net asset value, available at the Fund's website: www.ssgafunds.com.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund and the Portfolio.

The professionals primarily responsible for the day-to-day management of the Portfolio and the Fund are Michael Feehily, Karl Schneider and Amy Scofield. Michael Feehily has served on the Fund and the Portfolio/the prior master portfolio in which the Fund has invested since 2014. Karl Schneider has served on the Fund and the Portfolio/the prior master portfolio in which the Fund has invested since 2002. Amy Scofield has served on the Fund and the Portfolio/the prior master portfolio in which the Fund has invested since 2012.

Michael Feehily, CFA, is a Senior Managing Director of the Adviser and the Head of Global Equity Beta Solutions in the Americas. He worked at the Adviser from 1997 to 2006 and rejoined in 2010.

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Karl Schneider, CAIA, is a Managing Director of the Adviser and Deputy Head of Global Equity Beta Solutions in the Americas. He joined the Adviser in 1997.

Amy Scofield is a Principal of the Adviser and a Portfolio Manager in the Global Equity Beta Solutions Group. She joined the Adviser in 2010.

Purchase and Sale of Fund Shares

Purchase Minimums

Class A
To establish an account	$2,000
To add to an existing account	None
Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

If you wish to purchase or redeem Fund Shares through a broker, bank or other financial intermediary (“Financial Intermediary”), please contact that Financial Intermediary directly. Your Financial Intermediary may have different or additional requirements for opening an account and/or for the processing of purchase and redemption orders, or may be closed at times when the Fund is open. Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Tax Information

The Fund's distributions are expected to be taxed as ordinary income, qualified dividend income and/or capital gains, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or individual retirement account. Any withdrawals made from such tax-advantaged arrangement may be taxable to you.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase Fund Shares through a broker-dealer or other Financial Intermediary (such as a bank), the Adviser or its affiliates may pay the Financial Intermediary for certain activities related to the Fund, including educational training programs, conferences, the development of technology platforms and reporting systems, or other services related to the sale or promotion of the Fund. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your Financial Intermediary's website for more information.

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State Street Aggregate Bond Index Fund

Investment Objective

The State Street Aggregate Bond Index Fund (the “Aggregate Bond Index Fund” or the “Fund”) seeks to provide investment results that, before fees and expenses, correspond generally to the price and yield performance of an index that tracks the U.S. dollar denominated investment grade bond market over the long term.

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). You may qualify for sales charge discounts on purchases of Class A shares if you agree to invest in the future, or if you and your family currently invest, at least $100,000 in State Street Funds that offer Class A shares. More information about these and other discounts is available from your financial professional and in Choosing a Share Class – Reducing Your Class A Sales Charge on page 52 of the Fund's Prospectus. The expenses shown in the table and the Example reflect the expenses of both the Fund and the Fund's proportionate share of the expenses of State Street Aggregate Bond Index Portfolio (the “Aggregate Bond Index Portfolio” or sometimes referred to in context as the “Portfolio”).

Shareholder Fees (fees paid directly from your investment)

	Class A	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	3.75%	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None ¹	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class A	Class I	Class K
Management Fee ²	0.025%	0.025%	0.025%
Distribution and/or Shareholder Service (12b-1) Fees	0.250%	0.000%	0.000%
Other Expenses ³	0.461%	0.461%	0.261%
Total Annual Fund Operating Expenses	0.736%	0.486%	0.286%
Less Fee Waivers and/or Expense Reimbursements ^4,5	(0.261)%	(0.261)%	(0.261)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.475%	0.225%	0.025%

¹	A contingent deferred sales charge (“CDSC”) of 1.00% may be assessed on redemptions of Class A shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase as part of an investment of $1,000,000 or more.

²	Management Fees have been restated to reflect current fees.
³	Other Expenses have been restated to reflect current fees for Class A and Class I shares.
⁴	The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020, separately with respect to each of the Fund and the Portfolio, (i) to waive up to the full amount of the advisory fee payable by the Fund or the Portfolio, and/or (ii) to reimburse the Fund or the Portfolio to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.025% of the Fund's or the Portfolio's average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund/Portfolio's Board of Trustees.
⁵	SSGA FM is contractually obligated to waive up to the portion of the management fee and/or expenses attributable to acquired fund fees and expenses in connection with the Portfolio's investments in To Be Announced (“TBA”) securities. This fee waiver and/or expense reimbursement may only be terminated with approval of the Fund/Portfolio's Board of Trustees.

Example:

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and/or reimbursements; and the calculation of costs for the remaining periods takes such fee waivers and/or reimbursements into account only for the first year of each such period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 year	3 years	5 years	10 years
Class A	$422	$576	$744	$1,231
Class I	$ 23	$130	$246	$ 586
Class K	$ 3	$ 65	$134	$ 337

Portfolio Turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). As a shareholder of the Aggregate Bond Index Portfolio, the Fund bears its ratable share of the transaction costs associated with the portfolio turnover of the Portfolio. A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund Shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 90% of the average value of its portfolio.

Principal Investment Strategies

The Fund is an “index” fund that seeks to track, before fees and expenses, the total return performance of the Bloomberg Barclays U.S. Aggregate Bond Index (the “U.S. Aggregate Bond Index” or sometimes referred to in context as the “Index”) over the long term. As an “index” fund, the Fund is not managed according to traditional methods of “active” investment management, which involve the buying and selling of securities based upon economic, financial and market analysis and investment judgment.

In seeking to track the performance of the Index, the Fund employs a sampling strategy, which means that the Fund will not typically purchase all of the securities represented in the Index. Instead, the Fund may purchase a subset of the securities in the Index, or securities the Adviser considers to be comparable to securities in the Index, in an effort to hold a portfolio of securities with generally the same risk and return characteristics of the Index. The number of holdings in the Fund will be based on a number of factors, including asset size of the Fund. SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, generally expects the Fund to hold fewer than the total number of securities in the Index, but reserves the right to hold as many securities as it believes necessary to achieve the Fund's investment objective.

Under normal circumstances, the Fund generally invests substantially all, but at least 80%, of its net assets (plus borrowings, if any) in securities comprising the Index or in securities that the Adviser determines have economic characteristics that are comparable to the economic characteristics of securities that comprise the Index. The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. The Fund will provide shareholders with at least sixty (60) days' notice prior to any change in this 80% investment policy. The Fund may also invest in other debt securities, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

The Fund may at times purchase or sell futures contracts on fixed-income securities, or options on those futures, in lieu of investing directly in fixed-income securities themselves. The Fund may also purchase or sell futures contracts and related options on the Index (or other fixed-income securities indices). The Fund might do so, for example, in order to adjust the interest-rate sensitivity of the Fund to bring the characteristics of the Fund more closely in line with those of the Index. It might also do so to increase its investment exposure pending investment of cash in bonds or other investments or to reduce its investment exposure in situations where it intends to sell a portion of the securities in its portfolio but the sale has not yet been completed. The Fund may also enter into other derivatives transactions, including the use of options or swap transactions, in lieu of investing directly in the stocks making up the Index. The Fund may, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Fund (including funds advised by the Adviser).

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original aggregate transaction must have a minimum deal size of $500 million, and a minimum tranche size of $25 million; the aggregate outstanding transaction sizes must be at least $300 million to remain in the Index. In addition, the securities must be U.S. dollar denominated, fixed rate, non-convertible, and taxable. Certain types of securities, such as flower bonds, targeted investor notes, and state and local government series bonds are excluded from the Index. Also excluded from the Index are structured notes with embedded swaps or other special features, private placements, floating rate securities and Eurobonds. The Index is market capitalization weighted and the securities in the Index are updated on the last business day of each month. As of February 28, 2019, the modified adjusted duration of securities in the Index was approximately 5.91 years. It is not possible to invest directly in the Index.

The Fund expects typically to invest a significant portion of its assets in U.S. agency mortgage pass-through securities up to a total weight that is comparable to that of the Index. Most transactions in mortgage pass-through securities occur through standardized contracts for future delivery in which the exact mortgage pools to be delivered are not specified until a few days prior to settlement, referred to as a “to-be-announced transaction” or “TBA Transaction.” In a TBA Transaction, the buyer and seller agree upon general trade parameters such as agency, settlement date, par amount and price. The actual pools delivered generally are determined two days prior to the settlement date; however, it is not anticipated that the Fund will receive pools, but instead will participate in rolling TBA Transactions. The Fund expects to enter into such contracts on a regular basis.

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the Aggregate Bond Index Portfolio, which has substantially identical investment policies to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio and it participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Portfolio.

The Index is sponsored by Bloomberg Index Services Limited (the “Index Provider”) which is not affiliated with the Fund or the Adviser. The Index Provider determines the composition of the Index, relative weightings of the securities in the Index and publishes information regarding the market value of the Index.

Principal Risks

In addition, the Fund is subject to the following risks:

Debt Securities Risk: The values of debt securities may increase or decrease as a result of the following: market fluctuations, increases in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments or illiquidity in debt securities markets; the risk of low rates of return due to reinvestment of securities during periods of falling interest rates or repayment by issuers with higher coupon or interest rates; and/or the risk of low income due to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of the Fund's fixed income securities to decrease, an adverse impact on the liquidity of the Fund's fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Fund may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

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Income Risk: The Fund's income may decline due to falling interest rates or other factors. Issuers of securities held by the Fund may call or redeem the securities during periods of falling interest rates, and the Fund would likely be required to reinvest in securities paying lower interest rates. If an obligation held by the Fund is prepaid, the Fund may have to reinvest the prepayment in other obligations paying income at lower rates.

Mortgage-Related and Other Asset-Backed Securities Risk: Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed-income investments. The liquidity of mortgage-related and asset-backed securities may change over time. During periods of falling interest rates, mortgage- and asset-backed securities may be called or prepaid, which may result in the Fund having to reinvest proceeds in other investments at a lower interest rate. During periods of rising interest rates, the average life of mortgage- and asset-backed securities may extend, which may lock in a below-market interest rate, increase the security's duration and

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interest rate sensitivity, and reduce the value of the security. Enforcing rights against the underlying assets or collateral may be difficult, and the underlying assets or collateral may be insufficient if the issuer defaults.

U.S. Government Securities Risk: Certain U.S. government securities are supported by the full faith and credit of the United States; others are supported by the right of the issuer to borrow from the U.S. Treasury; others are supported by the discretionary authority of the U.S. government to purchase the agency's obligations; and still others are supported only by the credit of the issuing agency, instrumentality, or enterprise. Although U.S. government-sponsored enterprises such as the Federal Home Loan Mortgage Corporation (Freddie Mac) and the Federal National Mortgage Association (Fannie Mae) may be chartered or sponsored by Congress, they are not funded by Congressional appropriations, and their securities are not issued by the U.S. Treasury, are not supported by the full faith and credit of the U.S. government, and involve increased credit risks.

Valuation Risk: Some portfolio holdings, potentially a large portion of the Fund's investment portfolio, may be valued on the basis of factors other than market quotations. This may occur more often in times of market turmoil or reduced liquidity. There are multiple methods that can be used to value a portfolio holding when market quotations are not readily available. The value established for any portfolio holding at a point in time might differ from what would be produced using a different methodology or if it had been priced using market quotations. Portfolio holdings that are valued using techniques other than market quotations, including “fair valued” securities, may be subject to greater fluctuation in their valuations from one day to the next than if market quotations were used. In addition, there is no assurance that the Fund could sell or close out a portfolio position for the value established for it at any time, and it is possible that the Fund would incur a loss because a portfolio position is sold or closed out at a discount to the valuation established by the Fund at that time. Investors who purchase or redeem Fund Shares on days when the Fund is holding fair-valued investments may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the Fund had not fair-valued the holding(s) or had used a different valuation methodology.

When-Issued, TBA and Delayed Delivery Securities Risk: The Fund may purchase securities on a when-issued, to-be-announced (“TBA”) or delayed delivery basis and may purchase securities on a forward commitment basis. The purchase price of the securities is typically fixed at the time of the commitment, but delivery and payment can take place a month or more after the date of the commitment. At the time of delivery of the securities, the value may be more or less than the purchase or sale price. Purchase of securities on a when-issued, TBA, delayed delivery, or forward commitment basis may give rise to investment leverage, and may result in increased volatility of the Fund's net asset value. Default by, or bankruptcy of, a counterparty to a when-issued, TBA or delayed delivery transaction would expose the Fund to possible losses because of an adverse market action, expenses or delays in connection with the purchase or sale of the pools specified in such transaction. Recently finalized rules of the Financial Industry Regulatory Authority, Inc. would impose mandatory margin requirements for certain types of when-issued, TBA delayed delivery or forward commitment transactions, with limited exceptions. Such transactions historically have not been required to be collateralized, and, if those rules are implemented, mandatory collateralization could increase the cost of such transactions and impose added operational complexity.

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Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of the Index. The bar chart shows how the Class A shares' returns have varied for each full calendar year shown. The effect of sales charges, applicable to Class A shares only, is not reflected in the bar chart; if these amounts were reflected, returns would be lower. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 2.92% (Q1, 2016)
Lowest Quarterly Return: -3.25% (Q4, 2016)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
Class A			9/19/2014
Return Before Taxes	-4.10%	0.64%
Return After Taxes on Distributions	-5.03%	-0.45%
Return After Taxes on Distributions and Sale of Fund Shares	-2.43%	0.01%
Class I	-0.20%	1.83%	9/19/2014
Class K	-0.10%	1.86%	9/19/2014
Bloomberg Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)	0.01%	2.05%

The Fund will make updated performance information, including its current net asset value, available at the Fund's website: www.ssgafunds.com.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund and the Portfolio.

The professionals primarily responsible for the day-to-day management of the Portfolio and the Fund are Marc DiCosimo and Joanna Madden. They have served as portfolio managers of the Fund and the Portfolio since 2014 and 2016, respectively.

Marc DiCosimo, CFA, is a Vice President of the Adviser and a Senior Portfolio Manager in the Fixed Income Beta Solutions Group. He joined the Adviser in 2013.

Joanna Madden is a Vice President of the Adviser and a Portfolio Manager in the Fixed Income Beta Solutions Group. She joined the Adviser in 2003.

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Purchase and Sale of Fund Shares

Purchase Minimums

Class A
To establish an account	$2,000
To add to an existing account	None
Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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State Street Global Equity ex-U.S. Index Fund

Investment Objective

The State Street Global Equity ex-U.S. Index Fund (the “Global Equity ex-U.S. Index Fund” or the “Fund”) seeks to provide investment results that, before fees and expenses, correspond generally to the total return performance of a broad-based index of world (ex-U.S.) equity markets over the long term.

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). You may qualify for sales charge discounts on purchases of Class A shares if you agree to invest in the future, or if you and your family currently invest, at least $50,000 in State Street Funds that offer Class A shares. More information about these and other discounts is available from your financial professional and in Choosing a Share Class – Reducing Your Class A Sales Charge on page 52 of the Fund's Prospectus. The expenses shown in the table and the Example reflect the expenses of both the Fund and the Fund's proportionate share of the expenses of State Street Global Equity ex-U.S. Index Portfolio (the “Global Equity ex-U.S. Index Portfolio” or sometimes referred to in context as the “Portfolio”).

Shareholder Fees (fees paid directly from your investment)

	Class A	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	5.25%	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None ¹	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class A	Class I	Class K
Management Fee	0.060 %	0.060 %	0.060 %
Distribution and/or Shareholder Service (12b-1) Fees	0.250 %	0.000 %	0.000 %
Other Expenses ²	0.320 %	0.320 %	0.120 %
Total Annual Fund Operating Expenses	0.630 %	0.380 %	0.180 %
Less Fee Waivers and/or Expense Reimbursements ³	(0.1150)%	(0.1150)%	(0.1150)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.515 %	0.265 %	0.065 %

¹	A contingent deferred sales charge (“CDSC”) of 1.00% may be assessed on redemptions of Class A shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase as part of an investment of $1,000,000 or more.
²	Other Expenses have been restated to reflect current fees for Class A and Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) separately with respect to each of the Fund and the Portfolio (i) to waive up to the full amount of the advisory fee payable by the Fund or the Portfolio, and/or (ii) to reimburse the Fund/Portfolio to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees, with respect to the Fund, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees, and, with respect to the Portfolio, distribution, shareholder servicing and sub-transfer agency fees) exceed 0.015% of the Fund's and 0.08% of the Portfolio's average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's/Portfolio's Board of Trustees.

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Example:

	1 year	3 years	5 years	10 years
Class A	$575	$705	$847	$1,260
Class I	$ 27	$110	$202	$ 469
Class K	$ 7	$ 46	$ 90	$ 218

Portfolio Turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). As a shareholder of the Global Equity ex-U.S. Index Portfolio, the Fund bears its ratable share of the transaction costs associated with the portfolio turnover of the Portfolio. A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund Shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 4% of the average value of its portfolio.

Principal Investment Strategies

The Fund is an “index” fund that seeks to track, before fees and expenses, the total return performance of the MSCI ACWI ex USA Index (the “MSCI ACWI ex USA Index” or sometimes referred to in context as the “Index”) over the long term. As an “index” fund, the Fund is not managed according to traditional methods of “active” investment management, which involve the buying and selling of securities based upon economic, financial and market analysis and investment judgment. As of February 28, 2019, a significant portion of the Index comprised companies in the financial sector, although this may change from time to time. As of February 28, 2019, a significant portion of the Index comprised companies located in Japan and the United Kingdom and a significant portion of the Index constituents are denominated in the Yen and the Great Britain Pound although this may change from time to time.

Under normal circumstances, the Fund generally invests substantially all, but at least 80%, of its net assets (plus borrowings, if any) in securities comprising the Index or in American Depositary Receipts (“ADRs”) or Global Depositary Receipts (“GDRs”) providing exposure to securities comprising the Index. The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. The Fund will provide shareholders with at least sixty (60) days' notice prior to any change in this 80% investment policy. In addition, the Fund may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

The Fund may also purchase or sell futures contracts, or options on those futures, in lieu of investing directly in the stocks making up the Index. The Fund might do so, for example, in order to increase its investment exposure pending investment of cash in stocks or other investments. Alternatively, the Fund might use futures or options on futures to reduce its investment exposure in situations where it intends to sell a portion of the stocks in its portfolio but the sale has not yet been completed. The Fund may also enter into other derivatives transactions, including the use of options, forwards or swap transactions, in lieu of investing directly in the stocks making up the Index. The Fund may also, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Fund (including funds advised by the Adviser).

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The Index is a free float-adjusted market capitalization index that is designed to measure the combined equity market performance of large and mid-cap securities in developed and emerging market countries excluding the United States. All listed equity securities and listed securities that exhibit characteristics of equity securities, except mutual funds, ETFs, equity derivatives, limited partnerships and most investment trusts, are eligible for inclusion. Countries covered in the Index have historically included, among others, Australia, Austria, Belgium, Brazil, Canada, Chile, China, Colombia, Czech Republic, Denmark, Egypt, Finland, France, Germany, Greece, Hong Kong, Hungary, India, Indonesia, Ireland, Israel, Italy, Japan, Malaysia, Mexico, the Netherlands, New Zealand, Norway, Pakistan, Peru, Philippines, Poland, Portugal, Qatar, Russia, Singapore, South Africa, South Korea, Spain, Sweden, Switzerland, Taiwan, Thailand, Turkey, United Arab Emirates and the United Kingdom.It is not possible to invest directly in the Index.

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the Global Equity ex-U.S. Index Portfolio, which has substantially identical investment policies to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio and it participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Portfolio.

The Index is sponsored by Morgan Stanley Capital International Inc. (the “Index Provider”), which is not affiliated with the Fund or the Adviser. The Index Provider determines the composition of the Index, relative weightings of the securities in the Index and publishes information regarding the market value of the Index.

Principal Risks

In addition, the Fund is subject to the following risks:

Currency Risk: The value of the Fund's assets may be affected favorably or unfavorably by currency exchange rates, currency exchange control regulations, and delays, restrictions or prohibitions on the repatriation of foreign currencies. Foreign currency exchange rates may have significant volatility, and changes in the values of foreign currencies against the U.S. dollar may result in substantial declines in the values of the Fund's assets denominated in foreign currencies.

Depositary Receipts Risk: Investments in depositary receipts may be less liquid and more volatile than the underlying securities in their primary trading market. If a depositary receipt is denominated in a different currency than its underlying securities, the Fund will be subject to the currency risk of both the investment in the depositary receipt and the underlying security. Holders of depositary receipts may have limited or no rights to take action with respect to the underlying securities or to compel the issuer of the receipts to take action. The prices of depositary receipts may differ from the prices of securities upon which they are based. To the extent the Fund invests in depositary receipts based on securities included in the Index, such differences in prices may increase index tracking risk.

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Emerging Markets Risk: Risks of investing in emerging markets include, among others, greater political and economic instability, greater volatility in currency exchange rates, less developed securities markets, possible trade barriers, currency transfer restrictions, a more limited number of potential buyers and issuers, an emerging market country's dependence on revenue from particular commodities or international aid, less governmental supervision and regulation, unavailability of currency hedging techniques, differences in auditing and financial reporting standards, and less developed legal systems. There is also the potential for unfavorable action such as expropriation, nationalization, embargo, and acts of war. The securities of emerging market companies may trade less frequently and in smaller volumes than more widely held securities. Market disruptions or substantial market corrections may limit very significantly the liquidity of securities of certain companies in a particular country or geographic region, or of all companies in the country or region. The Fund may be unable to liquidate its positions in such securities at any time, or at a favorable price, in order to meet the Fund's obligations. These risks are generally greater for investments in frontier market countries, which typically have smaller economies or less developed capital markets than traditional emerging market countries.

Financial Sector Risk: Financial services companies are subject to extensive governmental regulation which may limit both the amounts and types of loans and other financial commitments they can make, the interest rates and fees they can charge, the scope of their activities, the prices they can charge and the amount of capital they must maintain. Profitability is largely dependent on the availability and cost of capital funds and can fluctuate significantly when interest rates change or due to increased competition. In addition, deterioration of the credit markets generally may cause an adverse impact in a broad range of markets, including U.S. and international credit and interbank money markets generally, thereby affecting a wide range of financial institutions and markets. Certain events in the financial sector may cause an unusually high degree of volatility in the financial markets, both domestic and foreign, and cause certain financial services companies to incur large losses. Securities of financial services companies may experience a dramatic decline in value when such companies experience substantial declines in the valuations of their assets, take action to raise capital (such as the issuance of debt or equity securities), or cease operations. Credit losses resulting from financial difficulties of borrowers and financial losses associated with investment activities can negatively impact the sector. Insurance companies may be subject to severe price competition. Adverse economic, business or political developments could adversely affect financial institutions engaged in mortgage finance or other lending or investing activities directly or indirectly connected to the value of real estate.

Geographic Focus Risk: The performance of a fund that is less diversified across countries or geographic regions will be closely tied to market, currency, economic, political, environmental, or regulatory conditions and developments in the countries or regions in which the fund invests, and may be more volatile than the performance of a more geographically-diversified fund.

Europe: Developed and emerging market countries in Europe will be significantly affected by the fiscal and monetary controls of the Economic and Monetary Union of the European Union (“EU”). Changes in regulations on trade, decreasing imports or exports, changes in the exchange rate of the euro and recessions among European countries may have a significant adverse effect on the economies of other European countries. In addition, one or more countries may abandon the euro and/or withdraw from the EU. For example, in June 2016, citizens of the United Kingdom voted in a referendum to leave the EU (known as “Brexit”), creating economic and political uncertainty in its wake. In March 2017, the United Kingdom formally notified the European Council of the United Kingdom's intention to withdraw from the EU pursuant to Article 50 of the Treaty on European Union. This formal notification began a two-year period of negotiations regarding the terms of the United Kingdom's exit from the EU. It is unclear how withdrawal negotiations will be conducted and what the potential consequences may be. Any exits from the EU, or the possibility of such exits, may have a significant impact on the United Kingdom, Europe, and global economies, which may result in increased volatility and illiquidity, new legal and regulatory uncertainties and potentially lower economic growth for such economies that could potentially have an adverse effect on the value of the Fund's investments. In addition, a number of countries in Europe have suffered terrorist attacks and additional attacks may occur in the future. Such attacks may cause uncertainty in financial markets and may adversely affect the performance of the issuers to which the Fund has exposure.

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political tension increase, it could adversely affect the economy, especially the export sector, and destabilize the region as a whole. Japan also remains heavily dependent on oil imports, and higher commodity prices could therefore have a negative impact on the economy. The Japanese yen has fluctuated widely at times and any increase in its value may cause a decline in exports that could weaken the Japanese economy. Japan has, in the past, intervened in the currency markets to attempt to maintain or reduce the value of the yen. Japanese intervention in the currency markets could cause the value of the yen to fluctuate sharply and unpredictably and could cause losses to investors. Japan has an aging workforce and has experienced a significant population decline in recent years. Japan's labor market appears to be undergoing fundamental structural changes, as a labor market traditionally accustomed to lifetime employment adjusts to meet the need for increased labor mobility, which may adversely affect Japan's economic competitiveness. Natural disasters, such as earthquakes, volcanoes, typhoons or tsunamis, could occur in Japan or surrounding areas and could negatively affect the Japanese economy and, in turn, the Fund.

United Kingdom: The United Kingdom has one of the largest economies in Europe, and the United States and other European countries are substantial trading partners of the United Kingdom. As a result, the British economy may be impacted by changes to the economic condition of the United States and other European countries. The British economy, along with certain other EU economies, experienced a significant economic slowdown during the recent financial crisis, and certain British financial institutions suffered significant losses, were severely under-capitalized and required government intervention to survive. The British economy relies heavily on the export of financial services to the United States and other European countries and, therefore, a prolonged slowdown in the financial services sector may have a negative impact on the British economy. Continued governmental involvement or control in certain sectors may stifle competition in certain sectors or cause adverse effects on economic growth.

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changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.

Non-U.S. Securities Risk: Non-U.S. securities (including depositary receipts) are subject to political, regulatory, and economic risks not present in domestic investments. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, legal and financial report standards comparable to those in the United States. Further, such entities and/or their securities may be subject to risks associated with currency controls; expropriation; changes in tax policy; greater market volatility; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. Securities traded on foreign markets may be less liquid (harder to sell) than securities traded domestically. Foreign governments may impose restrictions on the repatriation of capital to the U.S. In addition, to the extent that the Fund buys securities denominated in a foreign currency, there are special risks such as changes in currency exchange rates and the risk that a foreign government could regulate foreign exchange transactions. In addition, to the extent investments are made in a limited number of countries, events in those countries will have a more significant impact on the Fund. Investments in depositary receipts may be less liquid and more volatile than the underlying shares in their primary trading market.

Small-, Mid-, and Micro-Capitalization Securities Risk: The securities of small-, mid- and micro-capitalization companies may be more volatile and may involve more risk than the securities of larger companies. These companies may have limited product lines, markets or financial resources, may lack the competitive strength of larger companies, and may depend on a few key employees. In addition, these companies may have been recently organized and may have little or no track record of success. The securities of smaller companies may trade less frequently and in smaller volumes than more widely held securities. Some securities of smaller issuers may be illiquid or may be restricted as to resale, and their values may have significant volatility. The Fund may be unable to liquidate its positions in such securities at any time, or at a favorable price, in order to meet the Fund's obligations. Returns on investments in securities of small-, mid- and micro-capitalization companies could trail the returns on investments in securities of larger companies.

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Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of the Index. The bar chart shows how the Class A shares' returns have varied for each full calendar year shown. The effect of sales charges, applicable to Class A shares only, is not reflected in the bar chart; if these amounts were reflected, returns would be lower. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 7.67% (Q1, 2017)
Lowest Quarterly Return: -12.03% (Q3, 2015)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
Class A			9/17/2014
Return Before Taxes	-18.87%	-1.66%
Return After Taxes on Distributions	-20.26%	-2.41%
Return After Taxes on Distributions and Sale of Fund Shares	-10.13%	-1.21%
Class I	-14.18%	-0.18%	9/17/2014
Class K	-14.03%	-0.10%	9/17/2014
MSCI ACWI ex USA Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-14.20%	0.00%

The Fund will make updated performance information, including its current net asset value, available at the Fund's website: www.ssgafunds.com.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund and the Portfolio.

The professionals primarily responsible for the day-to-day management of the Portfolio and the Fund are Michael Feehily, Karl Schneider and Olga Winner. They have served on the Fund and the Portfolio since inception in 2014.

Michael Feehily, CFA, is a Senior Managing Director of the Adviser and the Head of Global Equity Beta Solutions in the Americas. He worked at the Adviser from 1997 to 2006 and rejoined in 2010.

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Karl Schneider, CAIA, is a Managing Director of the Adviser and Deputy Head of Global Equity Beta Solutions in the Americas. He joined the Adviser in 1997.

Olga Winner, CFA, is a Vice President of the Adviser and a Senior Portfolio Manager in the Global Equity Beta Solutions Group. She joined the Adviser in 2007.

Purchase and Sale of Fund Shares

Purchase Minimums

Class A
To establish an account	$2,000
To add to an existing account	None
Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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State Street Small/Mid Cap Equity Index Fund

Investment Objective

The State Street Small/Mid Cap Equity Index Fund (the “Small/Mid Cap Equity Index Fund” or the “Fund”) seeks to provide investment results that, before expenses, correspond generally to the total return of an index that tracks the performance of mid-to small- capitalization exchange traded U.S. equity securities.

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). You may qualify for sales charge discounts on purchases of Class A shares if you agree to invest in the future, or if you and your family currently invest, at least $50,000 in State Street Funds that offer Class A shares. More information about these and other discounts is available from your financial professional and in Choosing a Share Class – Reducing Your Class A Sales Charge on page 52 of the Fund's Prospectus. The expenses shown in the table and the Example reflect the expenses of both the Fund and the Fund's proportionate share of the expenses of State Street Small/Mid Cap Equity Index Portfolio (the “Small/Mid Cap Equity Index Portfolio” or sometimes referred to in context as the “Portfolio”).

Shareholder Fees (fees paid directly from your investment)

	Class A	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	5.25%	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None ¹	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class A	Class I	Class K
Management Fee	0.030%	0.030%	0.030%
Distribution and/or Shareholder Service (12b-1) Fees	0.250%	0.000%	0.000%
Other Expenses ²	0.750%	0.750%	0.550%
Total Annual Fund Operating Expenses	1.030%	0.780%	0.580%
Less Fee Waivers and/or Expense Reimbursements ³	(0.535)%	(0.535)%	(0.535)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.495%	0.245%	0.045%

¹	A contingent deferred sales charge (“CDSC”) of 1.00% may be assessed on redemptions of Class A shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase as part of an investment of $1,000,000 or more.
²	Other Expenses have been restated to reflect current fees for Class A and Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020, separately with respect to each of the Fund and the Portfolio, (i) to waive up to the full amount of the advisory fee payable by the Fund or the Portfolio, and/or (ii) to reimburse the Fund or the Portfolio to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees and, with respect to the Portfolio, acquired fund fees) exceed 0.045% of the Fund's and 0.03% of the Portfolio's average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund/Portfolio's Board of Trustees.

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Example:

	1 year	3 years	5 years	10 years
Class A	$573	$785	$1,014	$1,672
Class I	$ 25	$195	$ 381	$ 916
Class K	$ 5	$132	$ 270	$ 675

Portfolio Turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). As a shareholder of the Small/Mid Cap Equity Index Portfolio, the Fund bears its ratable share of the transaction costs associated with the portfolio turnover of the Portfolio. A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund Shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 22% of the average value of its portfolio.

Principal Investment Strategies

The Fund uses a passive management strategy designed to track the performance of the Russell Small Cap Completeness Index (the “Index”). The Index is a float-adjusted, market capitalization index which measures the performance of the Russell 3000 ^® Index companies excluding S&P 500 ^® constituents. The Index is constructed to provide a comprehensive and unbiased barometer of the extended broad market beyond the S&P 500 exposure. As of February 28, 2019, the market capitalization of the companies included in the Index ranged from $5.04 million to $43.74 billion. As of February 28, 2019, the Index comprised 2,480 securities. As of February 28, 2019, a significant portion of the Index comprised companies in the financial services and technology sectors, although this may change from time to time.

The Fund generally intends to invest in all stocks comprising the Index in approximate proportion to their weightings in the Index. However, under various circumstances, it may not be possible or practicable to purchase all stocks in those weightings. In those circumstances, the Fund may purchase a sample of the stocks in the Index in proportions expected by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, to match generally the performance of the Index as a whole. In addition, from time to time stocks are added to or removed from the Index. The Fund may sell securities that are represented in the Index, or purchase securities that are not yet represented in the Index, in anticipation of their removal from or addition to the Index. Under normal market conditions, the Portfolio invests at least 80% of its net assets (plus borrowings, if any) in stocks in the Index. The Fund will provide shareholders with at least sixty (60) days' notice prior to any change in this 80% investment policy. The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. In addition, the Fund may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

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enter into other derivatives transactions, including the use of options or swap transactions relating to the Index or any securities comprising the Index, in lieu of investing directly in the stocks making up the Index. The Fund may, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Fund (including funds advised by the Adviser).

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the State Street Small/Mid Cap Equity Index Portfolio, a separate series of the State Street Institutional Investment Trust, with an identical investment objective as the Fund and that has substantially identical investment policies, strategies and risks, to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio and it participates in the investment returns achieved by the Portfolio.

The Index is sponsored by Frank Russell Company (the “Index Provider”), which is not affiliated with the Fund or the Adviser. The Index Provider determines the composition of the Index, relative weightings of the securities in the Index and publishes information regarding the market value of the Index.

Principal Risks

In addition, the Fund is subject to the following risks:

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heavily on technology, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market. Technology companies are heavily dependent on patent and intellectual property rights, the loss or impairment of which may adversely affect profitability. Additionally, companies in the technology sector may face dramatic and often unpredictable changes in growth rates and competition for the services of qualified personnel.

Performance

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 7.03% (Q3, 2016)
Lowest Quarterly Return: -17.87% (Q4, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
Class A			10/15/2015
Return Before Taxes	-14.10%	4.44%
Return After Taxes on Distributions	-14.91%	3.45%
Return After Taxes on Distributions and Sale of Fund Shares	-8.00%	3.22%
Class I	-9.07%	6.50%	10/15/2015
Class K	-9.03%	4.72%	8/11/2015
Russell Small Cap Completeness Index (reflects no deduction for fees, expenses or taxes)	-9.21%	4.77%

The Fund will make updated performance information, including its current net asset value, available at the Fund's website: www.ssgafunds.com.

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Investment Adviser

SSGA FM serves as the investment adviser to the Fund and the Portfolio.

The professionals primarily responsible for the day-to-day management of the Portfolio and the Fund are Michael Feehily, Karl Schneider and Ted Janowsky each of which has served as a portfolio manager of the Fund and the Portfolio since inception in 2015.

Michael Feehily, CFA, is a Senior Managing Director of the Adviser and the Head of Global Equity Beta Solutions in the Americas. He worked at the Adviser from 1997 to 2006 and rejoined in 2010.

Karl Schneider, CAIA, is a Managing Director of the Adviser and Deputy Head of Global Equity Beta Solutions in the Americas. He joined the Adviser in 1997.

Ted Janowsky, CFA, is a Vice President of the Adviser and a Senior Portfolio Manager in the Global Equity Beta Solutions Group. He joined the Adviser in 2005.

Purchase and Sale of Fund Shares

Purchase Minimums

Class A
To establish an account	$2,000
To add to an existing account	None
Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

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Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objectives, Principal Strategies and Risks

Investment Objective

The Trust's Board of Trustees may change each Fund's investment strategies and other policies without shareholder approval, except as otherwise indicated. The Board of Trustees may change each Fund's investment objective without shareholder approval. If the Trustees were to approve a change to the Equity 500 Index Fund's investment objective, shareholders would receive advance notice.

State Street Equity 500 Index Fund

Principal Investment Strategies

The Fund generally intends to invest in all stocks comprising the S&P 500 in approximate proportion to their weightings in the Index. However, under various circumstances, it may not be possible or practicable to purchase all stocks in those weightings. In those circumstances, the Fund may purchase a sample of the stocks in the Index in proportions expected by SSGA FM to match generally the performance of the Index as a whole. In addition, from time to time stocks are added to or removed from the Index. The Fund may sell securities that are represented in the Index, or purchase securities that are not yet represented in the Index, in anticipation of their removal from or addition to the Index. Under normal market conditions, the Fund will not invest less than 80% of its total assets in stocks in the Index. Shareholders will receive sixty (60) days' notice prior to a change in the 80% investment policy. For this purpose, “total assets” means net assets plus borrowings, if any. The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. In addition, the Fund may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

Comparison Index . The S&P 500 measures the performance of the large-cap segment of the market, is comprised of the stocks of 500 industry-leading companies and is considered to be a proxy of the U.S. equity stock market in general. The S&P 500 is unmanaged and does not reflect the actual cost of investing in the instruments that compose the Index. Additionally, the returns of the S&P 500 do not reflect the effect of fees, expenses and taxes.

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viability and investable weight factor of each stock and its adequacy as a representation of stocks in a particular industry group, and may be changed from time to time. “S&P” and “S&P 500” are registered trademarks of Standard & Poor's Financial Services, LLC (“S&P”), a division of S&P Global, and have been licensed for use by the Fund and the Portfolio. The Fund and the Portfolio are not sponsored, endorsed, sold or marketed by S&P, and S&P makes no representation regarding the advisability of investing in the Fund and the Portfolio. It is not possible to invest directly in the S&P 500.

Index Futures Contracts and Related Options . The Fund may buy and sell futures contracts and options on those futures contracts. An “index futures” contract is a contract to buy or sell units of an index at an agreed price on a specified future date. Depending on the change in value of the Index between the time when the Fund enters into and closes out an index future or option transaction, the Fund realizes a gain or loss. Options and futures transactions involve risks. For example, it is possible that changes in the prices of futures contracts will not correlate precisely with changes in the value of the Index. In those cases, use of futures contracts and related options might decrease the correlation between the return of the Fund and the return of the Index. In addition, the Fund incurs transaction costs in entering into, and closing out, positions in futures contracts and related options. Funds that enter into contracts with counterparties run the risk that the counterparty will be unwilling or unable to make timely settlement payments or otherwise honor its obligations. This risk is typically less for exchange-traded derivatives, such as those the Fund may invest in.

These costs typically have the effect of reducing the correlation between the return of the Fund and the return of the Index. Because the secondary market for futures contracts and options may be illiquid, the Fund may have to hold a contract or option when the Adviser would otherwise have sold it, or it may only be able to sell at a price lower than what the Adviser believes is the fair value of the contract or option, thereby potentially reducing the return of the Fund.

Other Derivative Transactions . The Fund may enter into derivatives transactions involving options and swaps. These transactions involve many of the same risks as those described above under “Index Futures Contracts and Related Options.” In addition, since many of such transactions are conducted directly with counterparties, and not on an exchange or board of trade, the Fund's ability to realize any investment return on such transactions may depend on the counterparty's ability or willingness to meet its obligations.

Additional Index Information . The Index's components are reconstituted and rebalanced quarterly.

State Street Aggregate Bond Index Fund

Principal Investment Strategies

In seeking to track the performance of the Index, the Fund employs a sampling strategy, which means that the Fund will not typically purchase all of the securities represented in the Index. Instead, the Fund may purchase a subset of the securities in the Index, or securities the Adviser considers to be comparable to securities in the Index, in an effort to hold a portfolio of securities with generally the same risk and return characteristics of the Index. The number of holdings in the Fund will be based on a number of factors, including asset size of the Fund. SSGA FM generally expects the Fund to hold fewer than the total number of securities in the Index, but reserves the right to hold as many securities as it believes necessary to achieve the Fund's investment objective.

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derivatives transactions, including the use of options or swap transactions, in lieu of investing directly in the stocks making up the Index. The Fund may, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Fund (including funds advised by the Adviser).

The Index is designed to measure the performance of the U.S. dollar denominated investment grade bond market, which includes investment grade (must be Baa3/BBB- or higher using the middle rating of Moody's Investors Service, Inc., Standard & Poor's, and Fitch Inc.) government bonds, investment grade corporate bonds, mortgage pass-through securities, commercial mortgage backed securities and other asset backed securities that are publicly for sale in the United States. The securities in the Index must have at least 1 year remaining to maturity and must have $300 million or more of outstanding face value. Asset backed securities must have a minimum deal size of $500 million and a minimum tranche size of $25 million. For commercial mortgage backed securities, the original aggregate transaction must have a minimum deal size of $500 million, and a minimum tranche size of $25 million; the aggregate outstanding transaction sizes must be at least $300 million to remain in the Index. In addition, the securities must be U.S. dollar denominated, fixed rate, non-convertible, and taxable. Certain types of securities, such as flower bonds, targeted investor notes, and state and local government series bonds are excluded from the Index. Also excluded from the Index are structured notes with embedded swaps or other special features, private placements, floating rate securities and Eurobonds. The Index is market capitalization weighted and the securities in the Index are updated on the last business day of each month. As of February 28, 2019, the modified adjusted duration of securities in the Index was approximately 5.91 years. It is not possible to invest directly in the Index.

Additional Index Information . The components of the Index are reconstituted and rebalanced monthly.

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State Street Global Equity ex-U.S. Index Fund

Principal Investment Strategies

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Fund realizes a gain or loss. Options and futures transactions involve risks. For example, it is possible that changes in the prices of futures contracts will not correlate precisely with changes in the value of the Index. In those cases, use of futures contracts and related options might decrease the correlation between the return of the Fund and the return of the Index. In addition, the Fund incurs transaction costs in entering into, and closing out, positions in futures contracts and related options. Funds that enter into contracts with counterparties run the risk that the counterparty will be unwilling or unable to make timely settlement payments or otherwise honor its obligations. This risk is typically less for exchange-traded derivatives, such as those the Fund may invest in.

Additional Index Information . The Index's components are reconstituted on an ongoing, event-driven basis and are rebalanced quarterly. The Index Provider classifies each issuer in one country. The Index Provider generally determines the country classification of an issuer based on the issuer's country of incorporation and the primary listing of its securities. To the extent that an issuer is incorporated in a different country than the country in which its securities are principally traded, the Index Provider considers the following additional set of criteria to determine the issuer's country classification: (i) the secondary listings of the issuer's securities, if any; (ii) the geographic distribution of the issuer's shareholder base; (iii) the location of the issuer's headquarters; (iv) the geographic distribution of the issuer's operations (in terms of assets and revenues); (v) the issuer's history with respect to these criteria; and (vi) the country in which investors consider the issuer to be most appropriately classified based on communications between the Index Provider and investors.

State Street Small/Mid Cap Equity Index Fund

Principal Investment Strategies

The Fund generally intends to invest in all stocks comprising the Index in approximate proportion to their weightings in the Index. However, under various circumstances, it may not be possible or practicable to purchase all stocks in those weightings. In those circumstances, the Fund may purchase a sample of the stocks in the Index in proportions expected by SSGA FM to match generally the performance of the Index as a whole. In addition, from time to time stocks are added to or removed from the Index. The Fund may sell securities that are represented in the Index, or purchase securities that are not yet represented in the Index, in anticipation of their removal from or addition to the Index. Under normal market conditions, the Portfolio invests at least 80% of its net assets (plus borrowings, if any) in stocks in the Index. The Fund will provide shareholders with at least sixty (60) days' notice prior to any change in this 80% investment policy. The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. In addition, the Fund may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

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The Fund may purchase or sell futures contracts on the Index, or options on those futures, in lieu of investing directly in the stocks making up the Index. The Fund might do so, for example, in order to increase its investment exposure pending investment of cash in the stocks comprising the Index. Alternatively, the Fund might use futures or options on futures to reduce its investment exposure in situations where it intends to sell a portion of the stocks in its portfolio but the sale has not yet been completed. The Fund may also enter into other derivatives transactions, including the use of options or swap transactions relating to the Index or any securities comprising the Index, in lieu of investing directly in the stocks making up the Index. The Fund may, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Fund (including funds advised by the Adviser).

Additional Index Information . The Index's components are reconstituted annually and rebalanced monthly.

Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure.

Call/Prepayment Risk (principal risk for the Aggregate Bond Index Fund) . Call/prepayment risk is the risk that an issuer will exercise its right to pay principal on an obligation held by a Fund earlier than expected or required. This may occur, for example, when there is a decline in interest rates, and an issuer of bonds or preferred stock redeems the bonds or stock in order to replace them with obligations on which it is required to pay a lower interest or dividend rate. It may also occur when there is an unanticipated increase in the rate at which mortgages or other receivables underlying mortgage- or asset-backed securities held by a Fund are prepaid. In any such case, a Fund may be forced to invest the prepaid amounts in lower-yielding investments, resulting in a decline in the Fund's income.

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ment or transaction, resulting in a loss to the Fund. A Fund may experience significant delays in obtaining any recovery in an insolvency, bankruptcy, or other reorganization proceeding involving its counterparty (including recovery of any collateral posted by it) and may obtain only a limited recovery or may obtain no recovery in such circumstances. If a Fund holds collateral posted by its counterparty, it may be delayed or prevented from realizing on the collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty. Under applicable law or contractual provisions, including if a Fund enters into an investment or transaction with a financial institution and such financial institution (or an affiliate of the financial institution) experiences financial difficulties, then the Fund may in certain situations be prevented or delayed from exercising its rights to terminate the investment or transaction, or to realize on any collateral and may result in the suspension of payment and delivery obligations of the parties under such investment or transactions or in another institution being substituted for that financial institution without the consent of the Fund. Further, a Fund may be subject to “bail-in” risk under applicable law whereby, if required by the financial institution's authority, the financial institution's liabilities could be written down, eliminated or converted into equity or an alternative instrument of ownership. A bail-in of a financial institution may result in a reduction in value of some or all of its securities and, if a Fund holds such securities or has entered into a transaction with such a financial security when a bail-in occurs, such Fund may also be similarly impacted.

Credit Risk (principal risk for the Aggregate Bond Index Fund) . Credit risk is the risk that an issuer, guarantor or liquidity provider of a fixed-income security held by a Fund may be unable or unwilling, or may be perceived (whether by market participants, ratings agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. It includes the risk that the security will be downgraded by a credit rating agency; generally, lower credit quality issuers present higher credit risks. An actual or perceived decline in creditworthiness of an issuer of a fixed-income security held by a Fund may result in a decrease in the value of the security. It is possible that the ability of an issuer to meet its obligations will decline substantially during the period when a Fund owns securities of the issuer or that the issuer will default on its obligations or that the obligations of the issuer will be limited or restructured.

The credit rating assigned to any particular investment does not necessarily reflect the issuer's current financial condition and does not reflect an assessment of an investment's volatility or liquidity. Securities rated in the lowest category of investment-grade are considered to have speculative characteristics. If a security held by a Fund loses its rating or its rating is downgraded, the Fund may nonetheless continue to hold the security in the discretion of the Adviser. In the case of asset-backed or mortgage-related securities, changes in the actual or perceived ability of the obligors on the underlying assets or mortgages to make payments of interest and/or principal may affect the values of those securities.

Currency Risk (principal risk for the Global Equity ex-U.S. Index Fund). Investments in issuers in different countries are often denominated in currencies other than the U.S. dollar. Changes in the values of those currencies relative to the U.S. dollar may have a positive or negative effect on the values of a Fund's investments denominated in those currencies. The values of other currencies relative to the U.S. dollar may fluctuate in response to, among other factors, interest rate changes, intervention (or failure to intervene) by national governments, central banks, or supranational entities such as the International Monetary Fund, the imposition of currency controls, and other political or regulatory developments. Currency values can decrease significantly both in the short term and over the long term in response to these and other developments. Continuing uncertainty as to the status of the Euro and the Economic and Monetary Union of the European Union (the “EMU”) has created significant volatility in currency and financial markets generally. Any partial or complete dissolution of the EMU, or any continued uncertainty as to its status, could have significant adverse effects on currency and financial markets, and on the values of a Fund's portfolio investments.

Debt Securities Risk (principal risk for the Aggregate Bond Index Fund) . The values of debt securities may increase or decrease as a result of the following: market fluctuations, increases in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments or illiquidity in debt securities markets; the risk of low rates of return due to reinvestment of securities during periods of falling interest rates or repayment by issuers with higher coupon or interest rates; and/or the risk of low income due to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of a Fund's fixed income securities to decrease, an adverse impact on the liquidity of a Fund's fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by a Fund may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

Depositary Receipts Risk (principal risk for the Global Equity ex-U.S. Index Fund) . American Depositary Receipts (“ADRs”) are typically trust receipts issued by a U.S. bank or trust company that evidence an indirect interest in underlying securities issued by a foreign entity. Global Depositary Receipts (“GDRs”), European Depositary Receipts (“EDRs”), and other types of depositary receipts

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are typically issued by non-U.S. banks or financial institutions to evidence an interest in underlying securities issued by either a U.S. or a non-U.S. entity. Investments in non-U.S. issuers through ADRs, GDRs, EDRs, and other types of depositary receipts generally involve risks applicable to other types of investments in non-U.S. issuers. Investments in depositary receipts may be less liquid and more volatile than the underlying securities in their primary trading market. If a depositary receipt is denominated in a different currency than its underlying securities, the Portfolio and, therefore, the Fund will be subject to the currency risk of both the investment in the depositary receipt and the underlying security. There may be less publicly available information regarding the issuer of the securities underlying a depositary receipt than if those securities were traded directly in U.S. securities markets. Depositary receipts may or may not be sponsored by the issuers of the underlying securities, and information regarding issuers of securities underlying unsponsored depositary receipts may be more limited than for sponsored depositary receipts. The values of depositary receipts may decline for a number of reasons relating to the issuers or sponsors of the depositary receipts, including, but not limited to, insolvency of the issuer or sponsor. Holders of depositary receipts may have limited or no rights to take action with respect to the underlying securities or to compel the issuer of the receipts to take action. The prices of depositary receipts may differ from the prices of securities upon which they are based. To the extent the Fund invests in depositary receipts based on securities included in the Index, such differences in prices may increase index tracking risk.

Derivatives Risk. A derivative is a financial contract the value of which depends on, or is derived from, the value of an underlying asset, interest rate, or index. Derivative transactions typically involve leverage and may have significant volatility. It is possible that a derivative transaction will result in a loss greater than the principal amount invested, and a Fund may not be able to close out a derivative transaction at a favorable time or price. Risks associated with derivative instruments include potential changes in value in response to interest rate changes or other market developments or as a result of the counterparty's credit quality; the potential for the derivative transaction not to have the effect the Adviser anticipated or a different or less favorable effect than the Adviser anticipated; the failure of the counterparty to the derivative transaction to perform its obligations under the transaction or to settle a trade; possible mispricing or improper valuation of the derivative instrument; imperfect correlation in the value of a derivative with the asset, rate, or index underlying the derivative; the risk that a Fund may be required to post collateral or margin with its counterparty, and will not be able to recover the collateral or margin in the event of the counterparty's insolvency or bankruptcy; the risk that a Fund will experience losses on its derivatives investments and on its other portfolio investments, even when the derivatives investments may be intended in part or entirely to hedge those portfolio investments; the risks specific to the asset underlying the derivative instrument; lack of liquidity for the derivative instrument, including without limitation absence of a secondary trading market; the potential for reduced returns to a Fund due to losses on the transaction and an increase in volatility; the potential for the derivative transaction to have the effect of accelerating the recognition of gain; and legal risks arising from the documentation relating to the derivative transaction.

Emerging Markets Risk (principal risk for the Global Equity ex-U.S. Index Fund) . Investments in emerging markets are generally subject to a greater risk of loss than investments in developed markets. This may be due to, among other things, the possibility of greater market volatility, lower trading volume and liquidity, greater risk of expropriation, nationalization, and social, political and economic instability, greater reliance on a few industries, international trade or revenue from particular commodities, less developed accounting, legal and regulatory systems, higher levels of inflation, deflation or currency devaluation, greater risk of market shut down, and more significant governmental limitations on investment policy as compared to those typically found in a developed market. In addition, issuers (including governments) in emerging market countries may have less financial stability than in other countries. The securities of emerging market companies may trade less frequently and in smaller volumes than more widely held securities. Market disruptions or substantial market corrections may limit very significantly the liquidity of securities of certain companies in a particular country or geographic region, or of all companies in the country or region. A Fund may be unable to liquidate its positions in such securities at any time, or at a favorable price, in order to meet the Fund's obligations. There is also the potential for unfavorable action such as embargo and acts of war. As a result, there will tend to be an increased risk of price volatility in investments in emerging market countries, which may be magnified by currency fluctuations relative to the U.S. dollar. Settlement and asset custody practices for transactions in emerging markets may differ from those in developed markets. Such differences may include possible delays in settlement and certain settlement practices, such as delivery of securities prior to receipt of payment, which increase the likelihood of a “failed settlement.” Failed settlements can result in losses. For these and other reasons, investments in emerging markets are often considered speculative.

Equity Investing Risk (principal risk for the Equity 500 Index Fund, Global Equity ex-U.S. Index Fund and Small/Mid Cap Equity Index Fund) . The market prices of equity securities owned by a Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer, such as management performance, financial leverage, non-compliance with regulatory requirements, and reduced demand for the issuer's goods or services. The values

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of equity securities also may decline due to general industry or market conditions that are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates, or adverse investor sentiment generally. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Extension Risk (principal risk for the Aggregate Bond Index Fund). During periods of rising interest rates, the average life of certain types of securities may be extended because of slower-than-expected principal payments. This may increase the period of time during which an investment earns a below-market interest rate, increase the security's duration and reduce the value of the security. Extension risk may be heightened during periods of adverse economic conditions generally, as payment rates decline due to higher unemployment levels and other factors.

Financial Sector Risk (principal risk for the Global Equity ex-U.S. Index Fund and Small/Mid Cap Equity Index Fund). Financial services companies are subject to extensive governmental regulation which may limit both the amounts and types of loans and other financial commitments they can make, the interest rates and fees they can charge, the scope of their activities, the prices they can charge and the amount of capital they must maintain. Profitability is largely dependent on the availability and cost of capital funds and can fluctuate significantly when interest rates change or due to increased competition. In addition, deterioration of the credit markets generally may cause an adverse impact in a broad range of markets, including U.S. and international credit and interbank money markets generally, thereby affecting a wide range of financial institutions and markets. Certain events in the financial sector may cause an unusually high degree of volatility in the financial markets, both domestic and foreign, and cause certain financial services companies to incur large losses. Securities of financial services companies may experience a dramatic decline in value when such companies experience substantial declines in the valuations of their assets, take action to raise capital (such as the issuance of debt or equity securities), or cease operations. Credit losses resulting from financial difficulties of borrowers and financial losses associated with investment activities can negatively impact the sector. Insurance companies may be subject to severe price competition. Adverse economic, business or political developments could adversely affect financial institutions engaged in mortgage finance or other lending or investing activities directly or indirectly connected to the value of real estate.

Geographic Focus Risk (principal risk for the Global Equity ex-U.S. Index Fund) . The performance of a fund that is less diversified across countries or geographic regions will be closely tied to market, currency, economic, political, environmental, or regulatory conditions and developments in the countries or regions in which the fund invests, and may be more volatile than the performance of a more geographically-diversified fund.

Europe . The Economic and Monetary Union of the EU requires compliance with restrictions on inflation rates, deficits, interest rates, debt levels and fiscal and monetary controls, each of which may significantly affect every country in Europe. Decreasing imports or exports, changes in governmental or EU regulations on trade, changes in the exchange rate of the euro (the common currency of certain EU countries), the default or threat of default by an EU member country on its sovereign debt, and/or an economic recession in an EU member country may have a significant adverse effect on the economies of EU member countries and their trading partners. The European financial markets have recently experienced volatility and adverse trends due to concerns about economic downturns or rising government debt levels in several European countries, including Greece, Ireland, Italy, Portugal and Spain. These events have adversely affected the exchange rate of the euro and may continue to significantly affect every country in Europe, including countries that do not use the euro.

Responses to the financial problems by European governments, central banks and others, including austerity measures and reforms, may not produce the desired results, may result in social unrest and may limit future growth and economic recovery or have other unintended consequences. Further defaults or restructurings by governments and other entities of their debt could have additional adverse effects on economies, financial markets and asset valuations around the world. In addition, one or more countries may abandon the euro and/or withdraw from the EU. For example, in June 2016, citizens of the United Kingdom voted in a referendum to leave the EU (known as “Brexit”), creating economic and political uncertainty in its wake and resulting in S&P downgrading the EU's credit rating from “AA+” to “AA” in the days following the vote. The country's referendum vote sparked depreciation in the value of the British pound, short-term declines in the stock markets and heightened risk of continued economic volatility worldwide. In March 2017, the United Kingdom formally notified the European Council of the United Kingdom's intention to withdraw from the EU pursuant to Article 50 of the Treaty on European Union. This formal notification began a two-year period of negotiations regarding the terms of the United Kingdom's exit from the EU. It is unclear how withdrawal negotiations will be conducted and what the potential consequences may be. Any exits from the EU, or the possibility of such exits, may have a significant impact on the United Kingdom, Europe, and global economies, which may result in increased volatility and illiquidity, new legal and regulatory uncertainties and potentially lower economic growth for such economies that could potentially have an adverse effect on the value of the Fund's investments. In addition, a number of countries in Europe

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have suffered terrorist attacks and additional attacks may occur in the future. Such attacks may cause uncertainty in financial markets and may adversely affect the performance of the issuers to which the Fund has exposure.

Japan. The growth of Japan's economy has historically lagged that of its Asian neighbors and other major developed economies. The Japanese economy is heavily dependent on international trade and has been adversely affected by trade tariffs, other protectionist measures, competition from emerging economies and the economic conditions of its trading partners. China has become an important trading partner with Japan, yet the countries' political relationship has become strained. Should political tension increase, it could adversely affect the economy, especially the export sector, and destabilize the region as a whole. Japan also remains heavily dependent on oil imports, and higher commodity prices could therefore have a negative impact on the economy. The Japanese economy faces several other concerns, including a financial system with large levels of nonperforming loans, over-leveraged corporate balance sheets, extensive cross-ownership by major corporations, a changing corporate governance structure, and large government deficits. These issues may cause a slowdown of the Japanese economy. The Japanese yen has fluctuated widely at times and any increase in its value may cause a decline in exports that could weaken the Japanese economy. Japan has, in the past, intervened in the currency markets to attempt to maintain or reduce the value of the yen. Japanese intervention in the currency markets could cause the value of the yen to fluctuate sharply and unpredictably and could cause losses to investors. Japan has an aging workforce and has experienced a significant population decline in recent years. Japan's labor market appears to be undergoing fundamental structural changes, as a labor market traditionally accustomed to lifetime employment adjusts to meet the need for increased labor mobility, which may adversely affect Japan's economic competitiveness.

The nuclear power plant catastrophe in Japan in March 2011 may have short- and long-term effects on the Japanese economy and its nuclear energy industry. Natural disasters, such as earthquakes, volcanoes, typhoons or tsunamis, could occur in Japan or surrounding areas and could negatively affect the Japanese economy and, in turn, a Fund.

United Kingdom. The United Kingdom has one of the largest economies in Europe, and the United States and other European countries are substantial trading partners of the United Kingdom. As a result, the British economy may be impacted by changes to the economic condition of the United States and other European countries. The British economy, along with certain other EU economies, experienced a significant economic slowdown during the recent financial crisis, and certain British financial institutions suffered significant losses, were severely under-capitalized and required government intervention to survive. The British economy relies heavily on the export of financial services to the United States and other European countries and, therefore, a prolonged slowdown in the financial services sector may have a negative impact on the British economy. Continued governmental involvement or control in certain sectors may stifle competition in certain sectors or cause adverse effects on economic growth. In the past, the United Kingdom has been a target of terrorism. Acts of terrorism in the United Kingdom or against British interests abroad may cause uncertainty in the British financial markets and adversely affect the performance of the issuers to which a Fund has exposure.

Income Risk (principal risk for the Aggregate Bond Index Fund). A Fund's income may decline due to falling interest rates or other factors. Issuers of securities held by a Fund may call or redeem the securities during periods of falling interest rates, and the Fund would likely be required to reinvest in securities paying lower interest rates. If an obligation held by a Fund is prepaid, the Fund may have to reinvest the prepayment in other obligations paying income at lower rates. A reduction in the income earned by a Fund may limit the Fund's ability to achieve its objective.

Indexing Strategy/Index Tracking Risk . Each Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities. Each Fund will seek to replicate Index returns, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. Each Fund generally will buy and will not sell a security included in the Index as long as the security is part of the Index regardless of any sudden or material decline in value or foreseeable material decline in value of the security, even though the Adviser may make a different investment decision for other actively managed accounts or portfolios that hold the security. As a result, a Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index (in absolute terms and by comparison with other indices) and, consequently, the performance, volatility, and risk of a Fund. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), a Fund's return may not match the return of the Index for a number of reasons. For example, the return on the sample of securities purchased by a Fund (or the return on securities not included in the Index) to replicate the performance of the Index may not correlate precisely with the return of the Index. Each Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, a Fund may not be fully invested at times, either as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. The Adviser may attempt to replicate the Index return by investing in fewer than all of the securities in the Index, or in some securities not included in the Index, potentially increasing the risk of divergence between a Fund's

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return and that of the Index. Changes in the composition of the Index and regulatory requirements also may impact a Fund's ability to match the return of the Index. The Adviser may apply one or more “screens” or investment techniques to refine or limit the number or types of issuers included in the Index in which a Fund may invest. Application of such screens or techniques may result in investment performance below that of the Index and may not produce results expected by the Adviser. Index tracking risk may be heightened during times of increased market volatility or other unusual market conditions.

Inflation Risk (principal risk for the Aggregate Bond Index Fund) . Inflation risk is the risk that the value of assets or income from investments will be less in the future as inflation decreases the value of money. As inflation increases, the values of a Fund's assets can decline.

Interest Rate Risk (principal risk for the Aggregate Bond Index Fund) . Interest rate risk is the risk that the securities held by a Fund will decline in value because of increases in market interest rates. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. Debt securities with longer durations tend to be more sensitive to changes in interest rates, usually making them more volatile than debt securities with shorter durations. For example, the value of a security with a duration of five years would be expected to decrease by 5% for every 1% increase in interest rates. Falling interest rates also create the potential for a decline in a Fund's income and yield. Interest-only and principal-only securities are especially sensitive to interest rate changes, which can affect not only their prices but can also change the income flows and repayment assumptions about those investments. Variable and floating rate securities also generally increase or decrease in value in response to changes in interest rates, although generally to a lesser degree than fixed-rate securities. A substantial increase in interest rates may also have an adverse impact on the liquidity of a security, especially those with longer durations. Changes in governmental policy, including changes in central bank monetary policy, could cause interest rates to rise rapidly, or cause investors to expect a rapid rise in interest rates. This could lead to heightened levels of interest rate, volatility and liquidity risks for the fixed income markets generally and could have a substantial and immediate effect on the values of a Fund's investments.

Large-Capitalization Securities Risk (principal risk for the Equity 500 Index Fund and the Global Equity ex-U.S. Index Fund) . Securities issued by large-capitalization companies may present risks not present in smaller companies. For example, larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or other market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies, especially during strong economic periods. Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies.

Large Shareholder Risk . To the extent a large proportion of the shares of a Portfolio are highly concentrated or held by a small number of shareholders (or a single shareholder), including funds or accounts over which the Adviser has investment discretion, a Portfolio is subject to the risk that these shareholders will purchase or redeem Portfolio shares in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of a Portfolio to conduct its investment program. For example, they could require a Portfolio to sell portfolio securities or purchase portfolio securities unexpectedly and incur substantial transaction costs and/or accelerate the realization of taxable income and/or gains to shareholders, or a Portfolio may be required to sell its more liquid portfolio investments to meet a large redemption, in which case a Portfolio's remaining assets may be less liquid, more volatile, and more difficult to price. A Portfolio may hold a relatively large proportion of its assets in cash in anticipation of large redemptions, diluting its investment returns.

Leveraging Risk . Borrowing transactions, reverse repurchase agreements, certain derivatives transactions, securities lending transactions and other investment transactions such as when-issued, delayed-delivery, or forward commitment transactions may create investment leverage. If a Fund engages in transactions that have a leveraging effect on the Fund's investment portfolio, the value of the Fund will be potentially more volatile and all other risks will tend to be compounded. This is because leverage generally creates investment risk with respect to a larger base of assets than a Fund would otherwise have and so magnifies the effect of any increase or decrease in the value of the Fund's underlying assets. The use of leverage is considered to be a speculative investment practice and may result in losses to a Fund. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. The use of leverage may cause a Fund to liquidate positions when it may not be advantageous to do so to satisfy repayment, interest payment, or margin obligations or to meet asset segregation or coverage requirements.

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conditions of a particular issuer. Disposal of illiquid securities may entail registration expenses and other transaction costs that are higher than those for liquid securities. A Fund may seek to borrow money to meet its obligations (including among other things redemption obligations) if it is unable to dispose of illiquid investments, resulting in borrowing expenses and possible leveraging of the Fund. In some cases, due to unanticipated levels of illiquidity a Fund may choose to meet its redemption obligations wholly or in part by distributions of assets in-kind.

The term “illiquid securities” for this purpose means securities that a Fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the securities. If any Fund determines at any time that it owns illiquid securities in excess of 15% of its net assets, it will cease to undertake new commitments to acquire illiquid securities until its holdings are no longer in excess of 15% of its NAV, report the occurrence in compliance with Rule 30b1-10 under the 1940 Act and, depending on circumstances, may take additional steps to reduce its holdings of illiquid securities.

In compliance with the U.S. Securities and Exchange Commission's (“SEC”) new liquidity risk management rule applicable to open-end mutual funds, the Funds recently established a liquidity risk management program. The rule's impact on the Fund, and on the open-end fund industry in general, is not yet fully known, but the rule could affect a Fund's performance and its ability to achieve its investment objectives. While the liquidity risk management program attempts to assess and manage liquidity risk, there is no guarantee it will be effective in its operations and may not reduce the liquidity risk inherent in a Fund's investments.

Market Disruption and Geopolitical Risk. A Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets. War, terrorism, and related geopolitical events have led, and in the future may lead, to increased short-term market volatility and may have adverse long-term effects on U.S. and world economies and markets generally. Likewise, natural and environmental disasters and systemic market dislocations may be highly disruptive to economies and markets. Those events as well as other changes in foreign and domestic economic and political conditions also could adversely affect individual issuers or related groups of issuers, securities markets, interest rates, credit ratings, inflation, investor sentiment, and other factors affecting the value of a Fund's investments. Given the increasing interdependence among global economies and markets, conditions in one country, market, or region might adversely affect markets, issuers, and/or foreign exchange rates in other countries, including the U.S. Any partial or complete dissolution of the Economic and Monetary Union of the European Union, or any increased uncertainty as to its status, could have significant adverse effects on currency and financial markets, and on the values of a Fund's investments. Securities and financial markets may be susceptible to market manipulation or other fraudulent trade practices, which could disrupt the orderly functioning of these markets or adversely affect the values of investments traded in these markets, including investments held by a Fund. To the extent a Fund has focused its investments in the market or index of a particular region, adverse geopolitical and other events could have a disproportionate impact on the Fund.

Market Risk . Market prices of investments held by a Fund will go up or down, sometimes rapidly or unpredictably. A Fund's investments are subject to changes in general economic conditions, general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in actual or perceived creditworthiness of issuers and general market liquidity. Even if general economic conditions do not change, the value of an investment in a Fund could decline if the particular industries, sectors or companies in which the Fund invests do not perform well or are adversely affected by events. Further, legal, political, regulatory and tax changes also may cause fluctuations in markets and securities prices.

Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject a Fund to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and a Fund's investment program in particular can be uncertain. In recent periods, governmental and non-governmental issuers have defaulted on, or have been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including, without limitation, in Europe or Asia. Defaults or restructurings by governments or others of their debts could have substantial adverse effects on economies, financial markets, and asset valuations around the world. Further Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, or investor perception that these efforts are not succeeding, could negatively affect financial markets generally as well as the values and liquidity of certain securities.

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Master/Feeder Structure Risk. Each Fund pursues its objective by investing substantially all of its assets in another pooled investment vehicle (a “master fund”). The ability of a Fund to meet its investment objective is directly related to the ability of the master fund to meet its investment objective. The ability of a Fund to meet its objective may be adversely affected by the purchase and redemption activities of other investors in the master fund. The ability of a Fund to meet redemption requests will depend on its ability to redeem its interest in the master fund. The Adviser or an affiliate serves as investment adviser to the master fund, leading to potential conflicts of interest. For example, the Adviser or its affiliates will receive fees based on the amount of assets invested in the master fund. Investment by a Fund in the master fund may be beneficial in the management of the master fund, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest a Fund's assets in a master fund sponsored or managed by the Adviser or its affiliates in lieu of investments by a Fund directly in portfolio securities, or may have an incentive to invest in such master fund over a master fund sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by a Fund in a master fund sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a master fund sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Fund does so. A Fund will bear its pro rata portion of the expenses incurred by the master fund.

Mortgage-Related and Other Asset-Backed Securities Risk (principal risk for the Aggregate Bond Index Fund) . Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed income investments. The liquidity of mortgage-related and asset-backed securities may change over time. Mortgage-related securities represent a participation in, or are secured by, mortgage loans. Other asset-backed securities are typically structured like mortgage-related securities, but instead of mortgage loans or interests in mortgage loans, the underlying assets may include, for example, items such as motor vehicle installment sales or installment loan contracts, leases on various types of real and personal property, and receivables from credit card agreements. During periods of falling interest rates, mortgage-related and other asset-backed securities, which typically provide the issuer with the right to prepay the security prior to maturity, may be prepaid, which may result in a Fund having to reinvest the proceeds in other investments at lower interest rates. During periods of rising interest rates, the average life of mortgage-related and other asset-backed securities may extend because of slower-than expected principal payments. This may lock in a below market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. As a result, mortgage-related and other asset-backed securities may have less potential for capital appreciation during periods of declining interest rates than other debt securities of comparable maturities, although they may have a similar risk of decline in market values during periods of rising interest rates. Prepayment rates are difficult to predict and the potential impact of prepayments on the value of a mortgage-related or other asset-backed security depends on the terms of the instrument and can result in significant volatility. The price of a mortgage-related or other asset-backed security also depends on the credit quality and adequacy of the underlying assets or collateral. Mortgage-related or other asset-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) will generally entail greater credit risk than obligations guaranteed by the U.S. Government. Defaults on the underlying assets, if any, may impair the value of a mortgage-related or other asset-backed security. For some asset-backed securities in which a Fund invests, such as those backed by credit card receivables, the underlying cash flows may not be supported by a security interest in a related asset. Moreover, the values of mortgage-related and other asset-backed securities may be substantially dependent on the servicing of the underlying asset pools, and are therefore subject to risks associated with the negligence or malfeasance by their servicers and to the credit risk of their servicers. In certain situations, the mishandling of related documentation may also affect the rights of securities holders in and to the underlying collateral. There may be legal and practical limitations on the enforceability of any security interest granted with respect to underlying assets, or the value of the underlying assets, if any, may be insufficient if the issuer defaults.

In a “forward roll” transaction, a Fund will sell a mortgage-related security to a bank or other permitted entity and simultaneously agree to purchase a similar security from the institution at a later date at an agreed upon price. The mortgage securities that are purchased will bear the same interest rate as those sold, but generally will be collateralized by different pools of mortgages with different prepayment histories than those sold. The values of such transactions will be affected by many of the same factors that affect the values of mortgage-related securities generally. In addition, forward roll transactions may have the effect of creating investment leverage in a Fund.

Non-U.S. Securities Risk (principal risk for the Global Equity ex-U.S. Index Fund) . Investments in securities of non-U.S. issuers (including depositary receipts) entail risks not typically associated with investing in securities of U.S. issuers. Similar risks may apply to securities traded on a U.S. securities exchange that are issued by entities with significant exposure to non-U.S. countries. In certain countries, legal remedies available to investors may be more limited than those available with regard to U.S. investments. Because non-U.S. securities are typically denominated and traded in currencies other than the U.S. dollar, the value of the Fund's assets, to the extent they are non-U.S. dollar denominated, may be affected favorably or unfavorably by currency exchange rates, exchange control regulations, and restrictions or prohibitions on the repatriation of non-U.S. currencies. Income and gains with

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respect to investments in certain countries may be subject to withholding and other taxes. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, and financial reporting standards, regulatory framework and practices comparable to those in the United States. The securities of some non-U.S. entities are less liquid and at times more volatile than securities of comparable U.S. entities, and could become subject to sanctions or embargoes that adversely affect a Fund's investment. Non-U.S. transaction costs, such as brokerage commissions and custody costs may be higher than in the U.S. In addition, there may be a possibility of nationalization or expropriation of assets, imposition of currency exchange controls, confiscatory taxation, and diplomatic developments that could adversely affect the values of a Fund's investments in certain non-U.S. countries. Investments in securities of non-U.S. issuers also are subject to foreign political and economic risk not associated with U.S. investments, meaning that political events (civil unrest, national elections, changes in political conditions and foreign relations, imposition of exchange controls and repatriation restrictions), social and economic events (labor strikes, rising inflation) and natural disasters occurring in a country where a Fund invests could cause the Fund's investments in that country to experience gains or losses.

Reinvestment Risk (principal risk for the Aggregate Bond Index Fund). Income from a Fund's portfolio may decline when the Fund invests the proceeds from investment income, sales of portfolio securities or matured, traded or called debt obligations. For instance, during periods of declining interest rates, an issuer of debt obligations may exercise an option to redeem securities prior to maturity, forcing a Fund to reinvest the proceeds in lower-yielding securities. A decline in income received by a Fund from its investments is likely to have a negative effect on the yield and total return of the Fund Shares.

Risk of Investment in Other Pools . If a Fund invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected. A Fund is exposed indirectly to all of the risks applicable to an investment in such other pool. In addition, lack of liquidity in the underlying pool could result in its value being more volatile than the underlying portfolio of securities, and may limit the ability of a Fund to sell or redeem its interest in the pool at a time or at a price it might consider desirable. The investment policies and limitations of the other pool may not be the same as those of the Fund; as a result, the Fund may be subject to additional or different risks, or may achieve a reduced investment return, as a result of its investment in another pool. If a pool is an exchange-traded fund or other product traded on a securities exchange or otherwise actively traded, its shares may trade at a premium or discount to their NAV, an effect that might be more pronounced in less liquid markets. A Fund bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Fund may invest, leading to potential conflicts of interest. For example, the Adviser or its affiliates may receive fees based on the amount of assets invested in the pool. Investment by a Fund in the pool may be beneficial to the Adviser or an affiliate in the management of the pool, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest a Fund's assets in a pool sponsored or managed by the Adviser or its affiliates in lieu of investments by the Fund directly in portfolio securities, or may have an incentive to invest in the pool over a pool sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by a Fund in a pool sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Fund does so.

Settlement Risk (principal risk for the Global Equity ex-U.S. Index Fund) . Markets in different countries have different clearance and settlement procedures and in certain markets there have been times when settlements have been unable to keep pace with the volume of transactions. Delays in settlement may increase credit risk to a Fund, limit the ability of a Fund to reinvest the proceeds of a sale of securities, hinder the ability of a Fund to lend its portfolio securities, and potentially subject a Fund to penalties for its failure to deliver to on-purchasers of securities whose delivery to a Fund was delayed. Delays in the settlement of securities purchased by a Fund may limit the ability of a Fund to sell those securities at times and prices it considers desirable, and may subject a Fund to losses and costs due to its own inability to settle with subsequent purchasers of the securities from it. A Fund may be required to borrow monies it had otherwise expected to receive in connection with the settlement of securities sold by it, in order to meet its obligations to others. Limits on the ability of a Fund to purchase or sell securities due to settlement delays could increase any variance between a Fund's performance and that of its benchmark index.

Small-, Mid- and Micro-Capitalization Securities Risk (principal risk for the Global Equity ex-U.S. Index Fund and Small/Mid Cap Equity Index Fund) . The securities of small-, mid- and micro-capitalization companies may be more volatile and may involve more risk than the securities of larger companies. These companies may have limited product lines, markets or financial resources, may lack the competitive strength of larger companies, and may depend on a few key employees. In addition, these companies may have been recently organized and may have little or no track record of success. The securities of smaller companies may trade less frequently and in smaller volumes than more widely held securities. The prices of these securities may fluctuate more sharply than those of other securities, and a Fund may experience some difficulty in establishing or closing out positions in these securities at prevailing market prices. There may be less publicly available information about the issuers of these securities or less market interest in

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these securities than in the case of larger companies, both of which can cause significant price volatility. Some securities of smaller issuers may be illiquid or may be restricted as to resale. A Fund may be unable to liquidate its positions in such securities at any time, or at a favorable price, in order to meet a Fund's obligations. Returns on investments in securities of small-, mid- and micro-capitalization companies could trail the returns on investments in securities of larger companies.

Special Risk Considerations of Investing in China (principal risk for the Global Equity ex-U.S. Index Fund) . Investing in securities of Chinese issuers, including by investing in A Shares, involves certain risks and considerations not typically associated with investing in securities of U.S. issuers, including, among others, (i) more frequent (and potentially widespread) trading suspensions and government interventions with respect to Chinese issuers, resulting in a lack of liquidity and in price volatility, (ii) currency revaluations and other currency exchange rate fluctuations or blockage, (iii) the nature and extent of intervention by the Chinese government in the Chinese securities markets, whether such intervention will continue and the impact of such intervention or its discontinuation, (iv) the risk of nationalization or expropriation of assets, (v) the risk that the Chinese government may decide not to continue to support economic reform programs, (vi) limitations on the use of brokers, (vii) potentially higher rates of inflation, (viii) the unavailability of consistently-reliable economic data, (ix) the relatively small size and absence of operating history of many Chinese companies, (x) accounting, auditing and financial reporting standards in China are different from U.S. standards and, therefore, disclosure of certain material information may not be available, (xi) greater political, economic, social, legal and tax-related uncertainty, (xii) higher market volatility caused by any potential regional territorial conflicts or natural disasters, (xiii) higher dependence on exports and international trade, (xiv) the risk of increased trade tariffs, embargoes and other trade limitations, (xv) restrictions on foreign ownership, and (xvi) custody risks associated with investing through programs to access Chinese securities. Significant portions of the Chinese securities markets may become rapidly illiquid, as Chinese issuers have the ability to suspend the trading of their equity securities, and have shown a willingness to exercise that option in response to market volatility and other events. The liquidity of Chinese securities may shrink or disappear suddenly and without warning as a result of adverse economic, market or political events, or adverse investor perceptions, whether or not accurate.

Technology Sector Risk (principal risk for the Equity 500 Index Fund and Small/Mid Cap Equity Index Fund). Market or economic factors impacting technology companies and companies that rely heavily on technological advances could have a major effect on the value of the Fund's investments. The value of stocks of technology companies and companies that rely heavily on technology is particularly vulnerable to rapid changes in technology product cycles, rapid product obsolescence, government regulation and competition, both domestically and internationally, including competition from foreign competitors with lower production costs. Stocks of technology companies and companies that rely heavily on technology, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market. Technology companies are heavily dependent on patent and intellectual property rights, the loss or impairment of which may adversely affect profitability. Additionally, companies in the technology sector may face dramatic and often unpredictable changes in growth rates and competition for the services of qualified personnel.

Unconstrained Sector Risk . A Fund may invest a substantial portion of its assets within one or more economic sectors or industries, which may change from time to time. When a Fund focuses its investments in a particular industry or sector, financial, economic, business, and other developments affecting issuers in that industry, market, or economic sector will have a greater effect on the Fund than if it had not focused its assets in that industry, market, or economic sector, which may increase the volatility of the Fund. Any such investment focus may also limit the liquidity of the Fund. In addition, investors may buy or sell substantial amounts of the Fund's shares in response to factors affecting or expected to affect an industry, market, or economic sector in which the Fund focuses its investments, resulting in extreme inflows or outflows of cash into and out of the Fund. Such extreme cash inflows or outflows might affect management of the Fund adversely.

U.S. Government Securities Risk (principal risk for the Aggregate Bond Index Fund) . U.S. government securities, such as Treasury bills, notes and bonds and mortgage-backed securities guaranteed by the Government National Mortgage Association (“Ginnie Mae”), are supported by the full faith and credit of the United States; others are supported by the right of the issuer to borrow from the U.S. Treasury; others are supported by the discretionary authority of the U.S. government to purchase the agency's obligations; and still others are supported only by the credit of the issuing agency, instrumentality, or enterprise. Although U.S. government-sponsored enterprises such as the Federal Home Loan Mortgage Corporation (“Freddie Mac”) and the Federal National Mortgage Association (“Fannie Mae”) may be chartered or sponsored by Congress, they are not funded by Congressional appropriations, and their securities are not issued by the U.S. Treasury nor supported by the full faith and credit of the U.S. government. There is no assurance that the U.S. government would provide financial support to its agencies and instrumentalities if not required to do so. In addition, certain governmental entities have been subject to regulatory scrutiny regarding their accounting policies and practices and other concerns that may result in legislation, changes in regulatory oversight and/or other consequences that could adversely affect the credit quality, availability, or investment character of securities issued by these entities. The value and liquidity of U.S. government securities may be affected adversely by changes in the ratings of those securities. Securities issued by the U.S. Treasury historically have

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been considered to present minimal credit risk. The downgrade in the long-term U.S. credit rating by at least one major rating agency has introduced greater uncertainty about the ability of the U.S. to repay its obligations. A further credit rating downgrade or a U.S. credit default could decrease the value and increase the volatility of a Fund's investments.

Valuation Risk (principal risk for the Aggregate Bond Index Fund, Global Equity ex-U.S. Index Fund and Small/Mid Cap Equity Index Fund) . Some portfolio holdings, potentially a large portion of a Fund's investment portfolio, may be valued on the basis of factors other than market quotations. This may occur more often in times of market turmoil or reduced liquidity. There are multiple methods that can be used to value a portfolio holding when market quotations are not readily available. The value established for any portfolio holding at a point in time might differ from what would be produced using a different methodology or if it had been priced using market quotations. Portfolio holdings that are valued using techniques other than market quotations, including “fair valued” securities, may be subject to greater fluctuation in their valuations from one day to the next than if market quotations were used. Technological issues or other service disruption issues involving third-party service providers may cause a Fund to value its investments incorrectly. In addition, there is no assurance that a Fund could sell or close out a portfolio position for the value established for it at any time, and it is possible that a Fund would incur a loss because a portfolio position is sold or closed out at a discount to the valuation established by a Fund at that time. Investors who purchase or redeem Fund Shares on days when a Fund is holding fair-valued investments may receive fewer or more shares or lower or higher redemption proceeds than they would have received if a Fund had not fair-valued the holding(s) or had used a different valuation methodology.

When-Issued, TBA and Delayed Delivery Securities Risk (principal risk for the Aggregate Bond Index Fund). A Fund may purchase securities on a when-issued, TBA or delayed delivery basis and may purchase securities on a forward commitment basis. The purchase price of the securities is typically fixed at the time of the commitment, but delivery and payment can take place a month or more after the date of the commitment. The prices of the securities so purchased or sold are subject to market fluctuations. At the time of delivery of the securities, the value may be more or less than the purchase or sale price. Purchase of securities on a when-issued, TBA, delayed delivery, or forward commitment basis may give rise to investment leverage, and may result in increased volatility of a Fund's net asset value. Default by, or bankruptcy of, a counterparty to a when-issued, TBA or delayed delivery transaction would expose a Fund to possible losses because of an adverse market action, expenses or delays in connection with the purchase or sale of the pools specified in such transaction. Recently finalized rules of the Financial Industry Regulatory Authority, Inc. would impose mandatory margin requirements for certain types of when-issued, TBA delayed delivery or forward commitment transactions, with limited exceptions. Such transactions historically have not been required to be collateralized, and, if those rules are implemented, mandatory collateralization could increase the cost of such transactions and impose added operational complexity.

Additional Information About Non-Principal Investment Strategies and Risks

Conflicts of Interest Risk. An investment in a Fund will be subject to a number of actual or potential conflicts of interest. For example, the Adviser or its affiliates may provide services to a Fund, such as securities lending agency services, custodial, administrative, bookkeeping, and accounting services, transfer agency and shareholder servicing, securities brokerage services, and other services for which the Fund would compensate the Adviser and/or such affiliates. The Funds may invest in other pooled investment vehicles sponsored, managed, or otherwise affiliated with the Adviser. There is no assurance that the rates at which a Fund pays fees or expenses to the Adviser or its affiliates, or the terms on which it enters into transactions with the Adviser or its affiliates will be the most favorable available in the market generally or as favorable as the rates the Adviser makes available to other clients. Because of its financial interest, the Adviser will have an incentive to enter into transactions or arrangements on behalf of a Fund with itself or its affiliates in circumstances where it might not have done so in the absence of that interest, provided that the Adviser will comply with applicable regulatory requirements.

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Funds. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for a Fund and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by a Fund. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Funds) or otherwise using such information for the benefit of its clients or itself.

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The foregoing does not purport to be a comprehensive list or complete explanation of all potential conflicts of interests which may affect a Fund. A Fund may encounter circumstances, or enter into transactions, in which conflicts of interest that are not listed or discussed above may arise.

Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Funds) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, a Fund, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect a Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect a Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject a Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of a Fund inaccessible or inaccurate or incomplete. A Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. A Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. Each Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Funds. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which each Fund invests, which could result in material adverse consequences for such issuers, and may cause a Fund's investment in such securities to lose value.

Index Construction Risk . A security included in an Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

Index Licensing Risk . It is possible that the license under which the Adviser or a Fund is permitted to replicate or otherwise use an Index will be terminated or may be disputed, impaired or cease to remain in effect. In such a case, the Adviser may be required to replace the Index with another index which it considers to be appropriate in light of the investment strategy of a Fund. The use of any such substitute index may have an adverse impact on a Fund's performance. In the event that the Adviser is unable to identify a suitable replacement for the Index, it may determine to terminate a Fund.

Money Market Risk . An investment in a money market fund is not a deposit of any bank and is not insured or guaranteed by the FDIC or any other government agency. Certain money market funds seek to preserve the value of their shares at $1.00 per share, although there can be no assurance that they will do so, and it is possible to lose money by investing in such a money market fund. A major or unexpected increase in interest rates or a decline in the credit quality of an issuer or entity providing credit support, an inactive trading market for money market instruments, or adverse market, economic, industry, political, regulatory, geopolitical, and other conditions could cause the share price of such a money market fund to fall below $1.00. It is possible that such a money market fund will issue and redeem shares at $1.00 per share at times when the fair value of the money market fund's portfolio per share is more or less than $1.00. None of State Street Corporation, State Street Bank and Trust Company (“State Street”), State Street Global Advisors (“SSGA”), SSGA FM or their affiliates (“State Street Entities”) guarantee the value of an investment in a money market fund at $1.00 per share. Investors should have no expectation of capital support to a money market fund from State Street Entities. Other money market funds price and transact at a “floating” NAV that will fluctuate along with changes in the market-based value of fund assets. Shares sold utilizing a floating NAV may be worth more or less than their original purchase price. Recent changes in the regulation of money market funds may affect the operations and structures of money market funds. A money market fund may be permitted or required to impose redemption fees or to impose limitations on redemptions during periods of high illiquidity in the markets for the investments held by it.

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Portfolio Turnover Risk (risk for the Aggregate Bond Index Fund) . A Fund may engage in frequent trading of its portfolio securities. Fund turnover generally involves a number of direct and indirect costs and expenses to a Fund, including, for example, brokerage commissions, dealer mark-ups and bid/asked spreads, and transaction costs on the sale of securities and reinvestment in other securities. The costs related to increased portfolio turnover have the effect of reducing a Fund's investment return, and the sale of securities by a Fund may result in the realization of taxable capital gains, including short-term capital gains, which are taxed to individuals as ordinary income.

Securities Lending Risk . Each Fund may lend portfolio securities in an amount not to exceed 40% of the value of its net assets. For these purposes, net assets shall exclude the value of all assets received as collateral for the loan. Such loans may be terminated at any time. Any such loans must be continuously secured by collateral maintained on a current basis in an amount at least equal to the market value of the securities loaned by a Fund, marked to market each trading day. In a loan transaction, as compensation for lending its securities, a Fund will receive a portion of the dividends or interest accrued on the securities held as collateral or, in the case of cash collateral, a portion of the income from the investment of such cash. In addition, a Fund will receive the amount of all dividends, interest and other distributions on the loaned securities. However, the borrower has the right to vote the loaned securities. A Fund will call loans to vote proxies if a material issue affecting the investment is to be voted upon. Efforts to recall such securities promptly may be unsuccessful, especially for foreign securities or thinly traded securities, and may involve expenses to a Fund. Securities lending involves the risk that the Fund may lose money because the borrower of the loaned securities fails to return the securities in a timely manner or at all. Should the borrower of the securities fail financially, a Fund may experience delays in recovering the securities or exercising its rights in the collateral. Loans are made only to borrowers that are deemed by the securities lending agent to be of good financial standing. In a loan transaction, a Fund will also bear the risk of any decline in value of securities acquired with cash collateral. Each Fund expects to invest cash collateral in a pooled investment vehicle advised by the Adviser. With respect to index funds, to the extent the collateral provided or investments made with cash collateral differ from securities included in the relevant Index, such collateral or investments may have a greater risk of loss than the securities included in the Index. In addition, a Fund will be subject to the risk that any income generated by reinvesting cash collateral is lower than any fees the Fund has agreed to pay a borrower.

Portfolio Holdings Disclosure

The Funds' portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

Each Fund is a separate, diversified series of the State Street Institutional Investment Trust (the “Trust”), which is an open-end management investment company organized as a business trust under the laws of The Commonwealth of Massachusetts.

Each Fund invests as part of a “master/feeder” structure. Each Fund currently seeks to achieve its investment objective by investing substantially all of its investable assets in a corresponding Portfolio, a separate mutual fund, that has substantially identical investment objective, investment policies, and risks as the Fund. All discussions about a Fund's investment objective, policies and risks should be understood to refer also to the investment objectives, policies and risks of the corresponding Portfolio.

Each Portfolio's shares are offered exclusively to investors (including without limitation, registered investment companies, private investment pools, bank collective funds, and investment separate accounts) that, like the Fund, pay fees to SSGA FM or its affiliates. The fees paid by those investment vehicles to SSGA FM (or its affiliates) vary depending on a number of factors, including by way of example, the services provided, the risks borne by SSGA FM (or its affiliates), fee rates paid by competitive investment vehicles, and in some cases direct negotiation with investors in the Portfolio.

A Fund can withdraw its investment in a Portfolio if, at any time, the Fund's Board of Trustees determines that it would be in the best interests of the Fund's shareholders, or if the investment objectives of the corresponding Portfolio changed so that they were inconsistent with the objectives of the Fund. If a Fund withdraws its investment from a Portfolio, the Fund may invest all of its assets in another mutual fund that has the same investment objective as the Fund, the Adviser may directly manage the Fund's assets, or the Board may take such other action it deems appropriate and in the best interests of shareholders of the Fund, which may include liquidation of the Fund.

Investment Adviser

SSGA FM serves as the investment adviser to each Fund and, subject to the oversight of the Board, is responsible for the investment management of each Fund. The Adviser provides an investment management program for each Fund and manages the investment of each Fund's assets. The Adviser is a wholly-owned subsidiary of State Street Global Advisors, Inc., which itself is a wholly-owned subsidiary of State Street Corporation. The Adviser is registered with the U.S. Securities and Exchange Commission (“SEC”) under the Investment Advisers Act of 1940, as amended. The Adviser and certain other affiliates of State Street Corporation make up SSGA. SSGA is one of the world's largest institutional money managers and the investment management arm of State Street Corporation. As of December 31, 2018, the Adviser managed approximately $452.10 billion in assets and SSGA managed approximately $2.51 trillion in assets. The Adviser's principal business address is One Iron Street, Boston, Massachusetts 02210.

Each Fund has entered into an investment advisory agreement with the Adviser, pursuant to which the Adviser will manage the Fund's assets, for compensation paid at an annual rate of 0.025% of the Aggregate Bond Index Fund's average daily net assets, 0.02% of the Equity 500 Index Fund's average daily net assets, 0.06% of the Global Equity ex-U.S. Index Fund's average daily net assets and 0.03% of the Small/Mid Cap Equity Index Fund's average daily net assets. For the year ended December 31, 2018, Equity 500 Index Fund's effective management fee paid was 0.00%, Aggregate Bond Fund's effective management fee paid was 0.00%, Global Equity ex-U.S. Index Fund's effective management fee paid was 0.00%, and Small/Mid Cap Equity Index Fund's effective management fee paid was 0.00%, each as a percentage of the Fund's average daily net assets. The Portfolios pay no investment advisory fees to SSGA FM.

Total Annual Fund Operating Expense Waivers . SSGA FM, as the investment adviser to each of the Equity 500 Index Fund, the Aggregate Bond Index Fund and the Small/Mid Cap Equity Index Fund, is contractually obligated, through April 30, 2020, (i) to waive up to the full amount of the advisory fee payable by a Fund, and/or (ii) to reimburse a Fund for expenses to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing and sub-transfer agency fees) exceed average daily net assets on an annual basis of 0.02% for the Equity 500 Index Fund, 0.025% for the Aggregate Bond Index Fund and 0.045% for the Small/Mid Cap Equity Index Fund. SSGA FM, as the investment adviser to the Global Equity ex-U.S. Index Fund, is contractually obligated, through April 30, 2020, (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund for expenses to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees, any class-specific expenses such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed average daily net assets on an annual basis of 0.015% for the Global Equity ex-U.S. Index Fund. These waiver and/or reimbursement agreements may not be terminated prior to April 30, 2020 except with approval of the Funds' Board of Trustees.

A discussion regarding the Board's consideration of the Funds' Investment Advisory Agreement is provided in the Funds' Semi-Annual Report to Shareholders for the period ended June 30, 2018.

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Portfolio Management

The Adviser manages the Funds using a team of investment professionals. The team approach is used to create an environment that encourages the flow of investment ideas. The portfolio managers within the team work together in a cohesive manner to develop and enhance techniques that drive the investment process for the respective investment strategy. This approach requires portfolio managers to share a variety of responsibilities including investment strategy and analysis while retaining responsibility for the implementation of the strategy within any particular portfolio. The approach also enables the team to draw upon the resources of other groups within SSGA. Each portfolio management team is overseen by the SSGA Investment Committee.

The table below identifies the professionals primarily responsible for the day-to-day management of each Fund and Portfolio:

Portfolio Managers		Portfolios and Funds
Michael Feehily, Karl Schneider and Amy Scofield		Equity 500 Index Fund and Equity 500 Index II Portfolio
Marc DiCosimo and Joanna Madden		Aggregate Bond Index Fund and Aggregate Bond Index Portfolio
Michael Feehily, Olga Winner and Karl Schneider		Global Equity ex-U.S. Index Fund and Global Equity ex-U.S. Index Portfolio
Michael Feehily, Ted Janowsky and Karl Schneider		Small/Mid Cap Equity Index Fund and Small/Mid Cap Equity Index Portfolio

Marc DiCosimo, CFA is a Vice President of SSGA and the Adviser and a Senior Portfolio Manager in the Fixed Income Beta Solutions Group within the Fixed Income, Cash and Currency Team. Prior to joining SSGA in 2013, Mr. DiCosimo worked at Wellington Management as a fixed income portfolio analyst on the Mortgage Backed Securities Team. Mr. DiCosimo has twenty years of fixed income experience working at Loomis Sayles and Saxon Mortgage Capital. Mr. DiCosimo graduated from the University of Richmond with a degree in Accounting. He is a Chartered Financial Analyst (CFA) and is a member of the CFA Institute and CFA Society Boston, Inc. He is a co-chair of the Mortgage Securitization Council of the Association of Institutional Investors.

Michael Feehily, CFA, is a Senior Managing Director of SSGA and the Adviser and the Head of Global Equity Beta Solutions in the Americas. He is also a member of the Senior Leadership Team and is a voting member on the firm's Trade Management Oversight Committee and the North America Product Committee. Mr. Feehily rejoined SSGA in 2010 after spending four years in State Street Global Markets, LLC, where he helped to build the Global Exposure Solutions business. This group created and managed portfolios that were designed to meet the short-term market exposure needs of institutional clients. Prior to this, Mr. Feehily had been Head of the U.S. Passive Equity Team within SSGA, which he originally joined in 1997. He began his career at State Street within the Global Services division in 1992. Mr. Feehily received a Bachelor of Science from Babson College in Finance, Investments, and Economics. He received a Master of Business Administration in Finance from Bentley College and also earned the Chartered Financial Analyst (CFA) designation. Mr. Feehily is a member of the CFA Institute and CFA Society Boston, Inc. He is also a former member of the Russell Index Client Advisory Board.

Olga Winner, CFA, is a Vice President of SSGA and the Adviser and a Senior Portfolio Manager in the Global Equity Beta Solutions Group. She is responsible for the management of several domestic, international developed and emerging market strategies, including separate accounts, commingled funds, mutual funds and ETFs. Additionally, Ms. Winner manages hedged and futures overlay strategies. Prior to joining SSGA, Ms. Winner worked as an acquisitions associate at Boston Capital Partners, a real estate investment firm, analyzing investment opportunities. She holds a Master of Business Administration and a Master of Science in Finance from the Carroll School of Management at Boston College and a Bachelor of Science in Finance from the University of Massachusetts. She also earned the Chartered Financial Analyst (CFA) designation and is a member of CFA Society Boston, Inc.

Ted Janowsky, CFA, is a Vice President of SSGA and the Adviser and a Senior Portfolio Manager in the Global Equity Beta Solutions Group. In this capacity, he manages a diverse group of equity and derivative-based index portfolios and has played a significant role designing proprietary portfolio management software. Additionally, Mr. Janowsky is head of the portfolio management team of SSGA's Company Stock Group, which manages all fiduciary transactions and company stock investments including employee stock ownership plans, 401(k) plans, defined benefit plans and non-qualified plans. Prior to joining the Global Equity Beta Solutions Group, he worked as an application developer in Investor Technology Services within State Street Corporation. He also worked as a business analyst in State Street's London and Sydney offices. Mr. Janowsky joined SSGA in 2005. Mr. Janowsky holds a Bachelor of Science in Business Administration from Bucknell University and a Master of Business Administration from the Carroll School of Management at Boston College. He has also earned the Chartered Financial Analyst (CFA) designation and is a member of the CFA Institute and CFA Society Boston, Inc.

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Joanna Madden is a Vice President of SSGA and the Adviser and a Portfolio Manager in the Fixed Income Beta Solutions Group since 2013. Previously, Ms. Madden was a portfolio manager in the U.S. Cash Management Group responsible for short-term liquidity investments across all the cash and securities lending portfolios managed in Boston. She joined the Boston group in April 2010 after working as a portfolio manager with the London Cash Management Group. Prior to her portfolio management role, she was a product analyst for the London Cash Management Group where she provided analytical and business support. Before joining SSGA in London, Ms. Madden worked as an operations specialist supporting the Boston Cash Management Group. Ms. Madden received a Bachelor of Science in Political Science from Loyola University of Chicago, Illinois.

Karl Schneider, CAIA, is a Managing Director of SSGA and the Adviser and Deputy Head of Global Equity Beta Solutions (GEBS) in the Americas, where he also serves as a Senior Portfolio Manager for a number of the group's passive equity portfolios. Previously within GEBS, he served as a portfolio manager and product specialist for U.S. equity strategies and synthetic beta strategies, including commodities, buy/write, and hedge fund replication. He is also a member of the S&P Dow Jones U.S. Equities Index Advisory Panel. Prior to joining the GEBS group, Mr. Schneider worked as a portfolio manager in SSGA's Currency Management Group, managing both active currency selection and traditional passive hedging overlay portfolios. He joined SSGA in 1997. Mr. Schneider holds a Bachelor of Science in Finance and Investments from Babson College and a Master of Science in Finance from the Carroll School of Management at Boston College. He has earned the Chartered Alternative Investment Analyst (CAIA) designation and is a member of the CAIA Association.

Amy Scofield is a Principal of SSGA and the Adviser and a Portfolio Manager in the Global Equity Beta Solutions Group. She is responsible for the management of various equity index funds, with domestic and international strategies. Ms. Scofield rejoined SSGA in November of 2010, after spending two years at Atlantic Trust Company, a private wealth management firm. In her role at Atlantic Trust Company, she specialized in asset allocation and performance analysis for high net worth clients. Prior to Atlantic Trust Company, Ms. Scofield was a compliance officer at SSGA, where she was responsible for ensuring equity portfolios met specified guidelines. She also worked as an operations associate in SSGA's International Structured Products Group. Ms. Scofield holds a Bachelor of Arts in Economics from Boston College.

Additional information about the portfolio managers' compensation, other accounts managed by the portfolio managers, and the portfolio managers' ownership of the Funds is available in the SAI.

Other Fund Services

The Administrator, Sub-Administrator and Custodian

The Adviser serves as administrator of each Fund. The amount of the fee paid to the Adviser for administrative services may vary by share class. Each Fund currently pays the Adviser an administrative fee at the annual rate of 0.05% with respect to each of its share classes. State Street, a subsidiary of State Street Corporation, serves as sub-administrator for the Funds for a fee that is paid by the Adviser. State Street also serves as custodian of the Funds for a separate fee that is paid by the Funds. SSGA FM serves as administrator of the Portfolios and State Street serves as sub-administrator and custodian of the Portfolios.

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Funds' transfer agent and dividend disbursing agent (the “Transfer Agent”).

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Funds' distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

Additional Information

The Trustees of the Trust oversee generally the operations of the Funds and the Trust. The Trust enters into contractual arrangements with various parties, including among others the Funds' investment adviser, custodian, transfer agent, and accountants, who provide services to the Funds. Shareholders are not parties to any such contractual arrangements or intended beneficiaries of those contractual arrangements, and those contractual arrangements are not intended to create in any shareholder any right to enforce them directly against the service providers or to seek any remedy under them directly against the service providers.

This Prospectus provides information concerning the Trust and the Funds that you should consider in determining whether to purchase shares of the Funds. Neither this Prospectus, nor the related SAI, is intended, or should be read, to be or to give rise to an agreement or contract between the Trust or the Funds and any investor, or to give rise to any rights in any shareholder or other person other than any rights under federal or state law that may not be waived.

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Shareholder Information

Determination of Net Asset Value

Each Fund determines its net asset value (“NAV”) per share once each business day as of the scheduled close of regular trading on the New York Stock Exchange (the “NYSE”). Pricing does not occur on NYSE holidays. A business day is one on which the NYSE is open for regular trading. The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. In unusual circumstances, such as an emergency or an unscheduled close or halt of trading on the NYSE, the time at which share prices are determined may be changed. The NAV per share is based on the market value of the investments held in a Fund. The NAV of each class of a Fund's Shares is calculated by dividing the value of the assets of the Fund attributable to that class less the liabilities of the Fund attributable to that class by the number of shares in the class outstanding. As noted in this Prospectus, each Fund may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when each Fund does not price its shares. Consequently, the NAV of each Fund's Shares may change on days when shareholders are not able to purchase or redeem the Fund's Shares. Purchase and redemption orders for Fund Shares are processed, respectively, at the NAV next determined after the Fund accepts a purchase order or receives a redemption request in good form. Each Fund values each security or other investment pursuant to guidelines adopted by the Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Funds' Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii) a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by a Fund occurs after the close of a related exchange but before the determination of a Fund's NAV. Attempts to determine the fair value of securities or other investments introduce an element of subjectivity to the pricing of securities or other investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the price a Fund would have received had it sold the investment. To the extent that a Fund invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the funds. The prospectuses of these funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

Investing in State Street Institutional Investment Trust Shares

Mutual funds advised by SSGA FM (the “State Street Funds”) and their service providers have a legal obligation to collect from you certain personal information about you at the time you open an account in order to verify your identity and the source of your payment. If you do not provide this information, you may not be able to open an account with the State Street Funds. If the State Street Funds believe that they have uncovered unlawful activity, the State Street Funds and their service providers may close your account and take any action they deem reasonable or required by law. The State Street Funds reserve the right to reject any purchase order.

This section of the Prospectus explains the basics of doing business with the State Street Funds. Carefully read each topic. The policies set forth below regarding the purchase, redemption and exchange of State Street Fund shares are in addition to the “Purchase and Sale of Fund Shares” section contained in the “Fund Summary” portion of this Prospectus. The State Street Funds reserve the right to change the following policies, without notice to shareholders; except that any modification or termination of the exchange privileges described in this Prospectus will be preceded by 60 days' advance notice to shareholders. Please call or check online for current information. Requests for transactions in the State Street Funds will be processed when they are received in “good order.” “Good order” means that the request is in an accurate and complete form, and all applicable documents have been received in such accurate and complete form (including typically, a signed application and medallion-guaranteed documents), and, for a purchase request, the check or wired funds have cleared.

Purchasing Shares

Choosing a Share Class

The Funds offer three classes of shares through this Prospectus: Class A, Class I and Class K, available to you subject to the eligibility requirements set forth below.

All classes of a Fund share the same investment objective and investments, but the different share classes have different expense structures and eligibility requirements. You should choose the class with the expense structure that best meets your needs and for which you are eligible. Some factors to consider are the amount you plan to invest, the time period before you expect to sell your shares, and whether you might invest more money in the Funds in the future. Your investment professional can help you choose the share class that best suits your investment needs.

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When you buy Class A shares, the initial sales load is deducted from the amount you invest, unless you qualify for an initial sales load waiver. This means that less money will be invested in a Fund immediately. Class A shares have a Rule 12b-1 fee of 0.25% per year. A contingent deferred sales charge (“CDSC”) of 1.00% may be assessed on redemptions of Class A shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase as part of an investment of $1,000,000 or more.

The chart below summarizes the features of the different share classes. This chart is only a general summary, and you should read the description of each Fund's expenses in each Fund Summary in this Prospectus.

The minimum purchase amount may be waived for specific investors or types of investors, including, without limitation, retirement plans, employees of State Street Corporation and its affiliates and their families. In the case of shareholders purchasing shares through a Financial Intermediary, the minimum purchase amount may be applied at the level of the Financial Intermediary.

	Class A	Class I	Class K
Availability	Available to the general public through certain Financial Intermediaries.	Limited to certain investors, including: • Certain banks, broker-dealers and other Financial Intermediaries. • Certain employer- sponsored retirement plans. • Certain employees or affiliates of State Street Corporation or its affiliates	Limited to certain investors, including certain qualified recordkeepers and employer-sponsored retirement plans.
Minimum Initial Investment	$2,000. The investment minimum may be modified, waived or reduced for certain types of investors ( e.g ., 401(k) or 403(b) plans) and investments as well as for certain fee-based programs where an agreement is in place.	$1,000,000. The investment minimum may be modified, waived or reduced for certain types of investors (e.g., 401(k) or 403(b) plans) and investments as well as for certain fee- based programs where an agreement is in place.	$10,000,000. The investment minimum may be modified, waived or reduced for certain types of investors ( e.g ., 401(k) or 403(b) plans) and investments as well as for certain fee- based programs where an agreement is in place.
Maximum Investment	None.	None.	None.
Initial (Front-End) Sales Charge	Yes. 5.25% for Equity Funds and 3.75% for Fixed Income Funds, payable at time of purchase. Lower sales charges are available for larger investments. See the chart under “Class A” section of this Prospectus.	No. Entire purchase price is invested in shares of a Fund.	No. Entire purchase price is invested in shares of a Fund.
Deferred (CDSC) Sales Charge	No, except for purchases of $1,000,000 or more that are redeemed within 18 months after purchase.	No.	No.
Distribution and Service (12b-1) Fees	0.25% annual fee.	No.	No.
Redemption Fees	No.	No.	No.

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The following pages cover additional details about each share class, including information about share class eligibility, initial and deferred sales charges, and sales charge reductions and waivers. Information about sales charges and sales charge reductions and waivers is also available free of charge on the Funds' website at www.ssgafunds.com.

Class A

Class A shares are available to the general public for investment through qualified recordkeepers with a distribution and/or fund servicing agreement maintained with SSGA FD.

When you buy Class A shares, you pay an initial (or front-end) sales charge at the time of your investment, which is included in the offering price, unless you qualify for a sales charge reduction or waiver. This fee is deducted from the amount you invest, and the remainder of your money is used to buy shares in the Fund. The tables below show the amount of sales charge you would pay at different levels of investment and the commissions paid to Financial Intermediaries at each level of investment. The actual sales charge you pay may vary slightly from the rates disclosed due to rounding.

Equity Funds (Equity Index 500 Fund, Global Equity ex-U.S. Index Fund Small/Mid Cap Equity Index Fund)

Amount of Purchase Payment	Sales Charge as a % of Offering Price	Sales Charge as a % of Net Amount Invested	Financial Intermediary Compensation as a % of Offering Price
Less than $50,000	5.25%	5.54%	4.75%
$50,000-$99,999	4.50%	4.71%	4.00%
$100,000-$249,999	3.50%	3.63%	3.25%
$250,000-$499,999	2.50%	2.56%	2.25%
$500,000-$999,999	2.00%	2.04%	1.75%
$1,000,000 or more	None	None	Advanced Commission ^{1, 2}

Fixed Income Funds (Aggregate Bond Index Fund)

Amount of Purchase Payment	Sales Charge as a % of Offering Price	Sales Charge as a % of Net Amount Invested	Financial Intermediary Compensation as a % of Offering Price
Less than $100,000	3.75%	3.90%	3.25%
$100,000-$249,999	3.25%	3.36%	3.00%
$250,000-$499,999	2.25%	2.30%	2.00%
$500,000-$999,999	1.75%	1.78%	1.50%
$1,000,000 or More	None	None	Advanced Commission ^{1, 2}

¹	Class A advanced commission for purchases over $1 million:

1.00%	First $3 million
Plus 0.50%	Next $12 million
Plus 0.25%	Over $15 million

If you purchase $1,000,000 or more of Class A shares of a Fund, you will not be assessed a sales charge at the time of purchase. SSGA FD pays broker-dealers advanced commissions that are calculated on a year-by-year basis based on the amounts invested during that year. Accordingly, with respect to additional purchase amounts, the advanced commission breakpoint resets annually to the first breakpoint on the anniversary of the first purchase. You may be charged a deferred sales charge of 1.00% of the lesser of the original cost of the shares being redeemed or your redemption proceeds if you redeem your shares within 18 months after purchase.

Reducing Your Class A Sales Charge

The Funds offer two principal ways for you to qualify for discounts on initial sales charges on Class A share purchases, often referred to as “breakpoint discounts”: Right of Accumulation or a Letter of Intent. Each of these methods is described below. In taking advantage of these methods for reducing the initial sales charge you will pay, you may link purchases of shares of all of the State Street Funds that offer Class A shares in which you invest (as described below) even if such State Street Funds are held in accounts with different Financial Intermediaries, as well as purchases of Class I and Class N shares of all State Street Funds (other than shares of money market funds) to be held in accounts owned by your spouse or domestic partner and children under the age of 21 who share your residential address. It is your responsibility when investing to inform your Financial Intermediary or the State Street Funds that you would like to have one or more of the State Street Funds linked together for purposes of reducing the initial sales charge .

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Right of Accumulation. You may qualify for a reduction in the sales charge you pay for purchases of Class A shares through Right of Accumulation. To calculate the sales charge applicable to your net purchase of Class A shares, you may aggregate your investment calculated as the higher of (a) the current value of your existing holdings or (b) the amount you invested (excluding capital appreciation) less any withdrawals of any Class A, Class I, and Class N shares of a State Street Fund (other than shares of money market funds) held in:

1.	Your account(s);
2.	Account(s) of your spouse or domestic partner;
3.	Account(s) of children under the age of 21 who share your residential address;
4.	Trust accounts established by any of the individuals in items (1) through (3) above. If the person(s) who established the trust is deceased, the trust account may be aggregated with the account(s) of the primary beneficiary of the trust;
5.	Solely controlled business accounts; and
6.	Single-participant retirement plans of any of the individuals in items (1) through (3) above.

In order to obtain any breakpoint reduction in the initial sales charge, you must, before purchasing Class A shares, inform your Financial Intermediary or the State Street Funds if you have any of the above types of accounts that can be aggregated with your current investment in Class A shares to reduce the applicable sales charge. In order to verify your eligibility for a reduced sales charge, you may be required to provide appropriate documentation, such as an account statement or the social security or tax identification number on an account, so that the State Street Funds may verify (1) the number of shares of the State Street Funds held in your account(s) with State Street Funds, (2) the number of shares of the State Street Funds held in your account(s) with a Financial Intermediary, and (3) the number of shares of the State Street Funds held in an account with a Financial Intermediary owned by your spouse or domestic partner and by children under the age of 21 who share your residential address.

Gifting of Shares . If you make a gift of shares, upon your request, you may combine purchases, if made at the same time, under right of accumulation of Class A, Class I and Class N shares of a State Street Fund (other than any shares of money market funds) at the sales charge discount allowed for the combined purchase. The receiver of the gift may also be entitled to a prospective reduction in sales charges in accordance with the Funds' right of accumulation or other provisions. You or the receiver of the gift must provide certain account information to State Street or their agents at the time of purchase to exercise this right.

Letter of Intent. In order to immediately reduce your Class A sales charge, you may sign a Letter of Intent stating your intention to buy a specified amount of Class A shares of one or more State Street Funds within a 13-month period at the reduced sales charge rates applicable to the aggregate amount of the intended purchases stated in the Letter. Purchases of Class A shares of one or more State Street Funds you make over the 13- month period will be combined and you will pay the same sales charge on the new Class A shares that you would have paid if all shares were purchased at once. The 13-month Letter of Intent period commences on the day that the Letter of Intent is received by the Funds or your Financial Intermediary. Purchases submitted not more than three months prior to the date the Letter of Intent is received are considered in determining the level of sales charge that will be paid pursuant to the Letter of Intent; however, the Letter of Intent will not result in any reduction in the amount of any previously paid sales charge. In addition, investors do not receive credit for shares purchased by the reinvestment of distributions.

The Letter of Intent is a non-binding commitment upon the investor to purchase the full amount indicated. Shares worth 5% of the amount of each purchase will be held in escrow (while remaining in your name) until the full amount covered by the Letter of Intent has been invested. If the terms of the Letter of Intent are not fulfilled by the end of the 13th month, you must pay SSGA FD the difference between the sales charges applicable to the purchases at the time they were made and the reduced sales charges previously paid or SSGA FD will liquidate sufficient escrowed shares to obtain the difference. Calculations made to determine whether a Letter of Intent commitment has been fulfilled will be made on the basis of the amount invested prior to the deduction of the applicable sales charge.

To take advantage of the Right of Accumulation and/or a Letter of Intent, complete the appropriate section of your Account Application or contact your Financial Intermediary. To determine if you are eligible for these programs, call (800) 647-7327. These programs may be terminated or amended at any time.

Waiver Of The Class A Sales Charge

A sales charge (“load”) may not be imposed on Class A shares of the Funds if the shares were:

1.	Acquired through the reinvestment of dividends and capital gain distributions.
2.	Acquired in exchange for shares of another Class A State Street Fund that were previously assessed a sales charge. However, if your shares are subject to CDSC, the CDSC will continue to apply to your new shares at the same CDSC rate.

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Bought in State Street Funds that do not offer Class N (no load) shares ¹ by officers, directors or trustees, retirees and employees and their immediate family members (i.e., spouses, domestic partners, children, grandchildren, parents, grandparents, and any dependent of the person, as defined in Section 152 of the Internal Revenue Code of 1986 (the “Code”)) of:

•	The State Street Funds
•	State Street Corporation and its subsidiaries and affiliates

4.	Bought by employees of:

•	DST Asset Manager Solutions, Inc. and its subsidiaries and affiliates.

•

Financial Intermediaries of financial institutions that have entered into selling agreements with the Funds or SSGA FD and their subsidiaries and affiliates (or otherwise have an arrangement with a Financial Intermediary or financial institution with respect to sales of Fund Shares). This waiver includes the employees' immediate family members (i.e., spouses, domestic partners, children, grandchildren, parents, grandparents and any dependent of the employee, as defined in Section 152 of the Code).

5.	Bought by:

•	Authorized retirement plans serviced or sponsored by a Financial Intermediary, provided that such Financial Intermediary has entered into an agreement with SSGA FD or with the Fund with respect to such purchases at NAV.
•	Investors who are directly rolling over or transferring shares from an established State Street Fund or State Street qualified retirement plan. Rolling over or transferring shares involves the transferring of shares (in-kind); there is no cash movement associated with the transaction.
•	Clients of Financial Intermediaries that (i) charge an ongoing fee for advisory, management, consulting or similar services, or (ii) have entered into an agreement with SSGA FD to offer Class A shares through a no-load network or platform, or self-directed brokerage accounts that may or may not charge transaction fees to customers.
•	Insurance company separate accounts.
•	Tuition Programs that qualify under Section 529 of the Code.

6.	Bought with proceeds from the sale of Class A shares of a State Street Fund, but only if the purchase is made within 90 days of the sale or distribution. Appropriate documentation may be required. Please refer to Class A Account Reinstatement Privileges below.
7.	Bought in connection with plans of reorganization of a State Street Fund, such as mergers, asset acquisitions and exchange offers to which a Fund is a party. However, you may pay a CDSC when you sell the Fund Shares you received in connection with the plan of reorganization.

Additional Sales Charge Waiver Disclosure

Sales charge waivers are available for eligible purchases of shares made directly though the State Street Funds advised by SSGA FM, and may be available for eligible purchases made through Financial Intermediaries that offer Class A shares on a load-waived basis to you and all similarly situated customers in accordance with the Financial Intermediary's policies and procedures.

Some Financial Intermediaries do not provide all of the sales charge waivers that are available when you purchase shares of the State Street Funds, including sales charge waivers for certain types of accounts, investors, relationships or transactions. Consult your financial advisor to determine which sales charge waivers, if any, you are entitled to receive when purchasing through your Financial Intermediary. You may need to invest directly through another Financial Intermediary in order to take advantage of a specific sales charge waiver offered by a Fund.

Similarly, when purchasing through a Financial Intermediary, your eligibility to receive sales charge waivers and reductions through reinstatement, rights of accumulation and letters of intent depends on the policies and procedures of the Financial Intermediary.

In all instances, it is the purchaser's responsibility to notify SSGA at (800) 647-7327 or the purchaser's Financial Intermediary of any relationship or other facts qualifying the purchaser for sales charge reduction or waivers. Waivers or reductions may be eliminated, modified, and added at any time without providing advance notice to shareholders.

¹	State Street Funds that offer Class N Shares include: State Street Dynamic Small Cap Fund (SVSCX), State Street Defensive Emerging Markets Equity Fund (SSEMX), State Street International Stock Selection Fund (SSAIX) and State Street S&P 500 Index Fund (SVSPX).

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How the CDSC is Calculated

The State Street Funds calculate the CDSC by treating all purchases made in a given month as though they were made on the first day of the month.

The CDSC will be multiplied by then current market value or the original cost of shares being redeemed, whichever is less. To minimize the CDSC, shares not subject to any charge, including share appreciation, or acquired through reinvestment of dividends or capital gain distributions, are redeemed first followed by shares held the longest time.

You should retain any records necessary to substantiate historical costs because SSGA FD, the Funds, the transfer agent and your Financial Intermediary may not maintain such information.

Waiver of the CDSC

In the following situations, no CDSC is imposed on redemptions of Class A shares of the Funds:

1.	If you participate in the Automatic Withdrawal Plan (AWP). Redemptions made on a regular periodic basis ( e.g . monthly) will not be subject to any applicable CDSC if they are, in the aggregate, less than or equal to 10% annually of the current market value of the account balance. Redemptions made as part of a required minimum distribution are also included in calculating amounts eligible for this waiver. For information on the Automatic Withdrawal Plan, please see Service Options.
2.	If you are a registered participant or beneficial owner of an account and you die or become disabled (as defined in Section 72(m)(7) of the Code). This waiver is only available for accounts open prior to the shareholder's or beneficiary's death or disability, and the redemption must be made within one year of such event. Subsequent purchases into such account are not eligible for the CDSC waiver. In order to qualify for this waiver, SSGA FD must be notified of such death or disability at the time of the redemption order and be provided with satisfactory evidence of such death or disability.
3.	Redemptions that represent a required minimum distribution from your IRA Account or other qualifying retirement plan but only if you are at least age 70 1/2. If you maintain more than one IRA, only the assets credited to the IRA that is invested in one or more of the State Street Funds are considered when calculating that portion of your minimum required distribution that qualifies for the waiver.
4.	A distribution from a qualified retirement plan by reason of the participant's retirement.
5.	Redemptions that are involuntary and result from a failure to maintain the required minimum balance in an account.
6.	Exchanges in connection with plans of reorganization of a State Street Fund, such as mergers, asset acquisitions and exchange offers to which a Fund is a party. However, you may pay a sales charge when you redeem the Fund Shares you receive in connection with the plan of reorganization.
7.	Exchanges for shares of the same class of another State Street Fund. However, if your shares are subject to CDSC, the CDSC will continue to apply to your new shares. For purposes of the CDSC, shares will continue to age from the date of the original purchase of the Fund Shares.
8.	Redemption of shares purchased through employer sponsored retirement plans and deferred compensation plans. The CDSC, however, will not be waived if the plan redeems all of the shares that it owns on behalf of participants prior to the applicable CDSC period, as defined above.
9.	Redemptions as part of annual IRA custodial fees.
10.	Acquired through the reinvestment of dividends and capital gains distributions.

Appropriate documentation may be required. Please refer to Class A Account Reinstatement Privileges below.

Class A Account Reinstatement Privileges

You may purchase Class A shares at NAV within 90 days of the sale with no sales charge by reinstating all or part of your proceeds into the same account that the sale or distribution occurred. Any applicable CDSC in connection with the redemption in Class A shares will be credited and aging will begin at original purchase date. Please note that a redemption and reinstatement are considered to be a sale and purchase for tax-reporting purposes.

Class I

Class I shares are not subject to any sales charge. Only certain investors are eligible to buy Class I shares. Your Financial Intermediary can help you determine whether you are eligible to purchase Class I shares.

Class I shares are available to the following categories of investors and/or investments:

1.	Banks, broker-dealers and other financial institutions (including registered investment advisers and financial planners) purchasing shares on behalf of their clients in:

•	discretionary and non-discretionary advisory programs;

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•	fund supermarkets;
•	asset allocation programs;
•	other programs in which the client pays an asset-based fee for advice or for executing transactions in Fund Shares or for otherwise participating in the program; or
•	certain other investment programs that do not charge an asset-based fee;

2.	Qualified state tuition plans described in Section 529 of the Code and donor-advised charitable gift funds (subject to all applicable terms and conditions);
3.	Defined contribution, defined benefit and other employer-sponsored employee benefit plans, whether or not qualified under the Code;
4.	Certain other registered open-end investment companies whose shares are distributed by SSGA FD;
5.	Certain retirement and deferred compensation programs established by State Street Corporation or its affiliates for their employees or the Funds' Trustees;
6.	Current or retired Directors or Trustees of the State Street Funds, officers and employees of SSGA, and any of its subsidiaries, such persons' spouses, and children under the age of 21, and trust accounts for which any of such person is a beneficiary;
7.	Investments made in connection with certain mergers and/or reorganizations as approved by the Adviser;
8.	The reinvestment of dividends from Class I shares in additional Class I shares of a Fund; and
9.	Qualified recordkeepers with a distribution and/or fund servicing agreement maintained with SSGA FD.

The minimum investment for Class I shares is $1,000,000.

Class K

Class K shares are not subject to any sales charge. Only certain investors are eligible to buy Class K shares. Your Financial Intermediary can help you determine whether you are eligible to purchase Class K shares.

Class K shares are available to the following categories of investors:

1.	Qualified recordkeepers with an applicable agreement maintained with SSGA FD;
2.	Defined benefit plans, defined contribution plans, endowments and foundations with greater than $10,000,000 in a qualified tax-exempt plan;
3.	Employers with greater than $10,000,000 in the aggregate between qualified and non-qualified plans that they sponsor; and
4.	Defined contribution, defined benefit and other employer-sponsored employee benefit plans, whether or not qualified under the Code.

The minimum investment for Class K shares is $10,000,000.

How to Initiate a Purchase Request

Investing in the State Street Funds Through a Financial Intermediary

If you currently do not have an account with SSGA FM, you may establish a new account and purchase shares of the State Street Funds through a Financial Intermediary, such as a bank, broker, or investment adviser. Please consult your Financial Intermediary to determine which, if any, shares are available through that firm and to learn about other rules that may apply. You may also submit a New Account Application. To open certain types of accounts, such as IRAs, you will be required to submit an account-specific application. If you intend to add certain investor services offered by the State Street Funds, such as Automatic Investment and Withdrawals Plans, and check-writing on money market funds, you also will be required to submit a Service Option Form. See Service Options . If you are opening an account through a Financial Intermediary, such as a bank or broker, the Financial Intermediary should have the documents that you will need.

Account Applications and Other Documents . You may find many of the forms necessary to open an account online or by calling or writing to the State Street Funds. See Contacting the State Street Funds .

Opening Accounts and Purchasing By Telephone . You may call the State Street Funds to request that the account-opening forms be sent to you or for assistance in completing the necessary paperwork. Once an account has been established, you may also call the State Street Funds to request a purchase of shares. See Contacting the State Street Funds .

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Opening Accounts and Purchasing By Mail . You may send the State Street Funds your account registration form and check to open a new account. To add to an existing account, you may send your check with a written request. You also may send a written request to the State Street Funds to make an exchange. For the State Street Funds' addresses, see Contacting the State Street Funds .

Please be sure to check Exchanging Shares and Frequent-Trading Limits below.

How to Pay for a Purchase

By Wire . Please call the State Street Funds for instructions and policies on purchasing shares by wire. See Contacting the State Street Funds . All wires should be in U.S. dollars and immediately available funds.

By Check . You may send a check to make initial or additional purchases to your fund account. Make your check payable to “State Street Funds” and include the appropriate fund name and account number ( e.g ., “State Street Equity 500 Index Fund—a/c #xxx”) in the memo section of the check.

By Exchange . You may purchase shares of a State Street Fund, provided the Funds' minimum investment is met, using the proceeds from the simultaneous redemption of shares of another State Street Fund of the same class. You may initiate an exchange by telephone, or by mail. See Exchanging Shares below.

In-Kind Purchase of State Street Fund Shares . The State Street Funds, in their sole discretion, may permit you to purchase shares of a State Street Fund (“State Street Fund Shares”) through the exchange of other securities that you own. The market value of any securities exchanged, plus any cash, must be at least $25 million. Please contact the State Street Funds for more information, including additional restrictions. See Contacting the State Street Funds .

Trade Dates-Purchases

The trade date for any purchase request received in good order will depend on the day and time the State Street Funds receive your request, the manner in which you are paying, and the type of fund you are purchasing. Each State Street Fund's NAV is calculated only on business days, that is, those days that the NYSE is open for regular trading. Purchase orders are processed at the NAV next determined after the Fund accepts a purchase order.

For Purchases by Check, Exchange or Wire into all Funds : If the purchase request is received in good order by the State Street Funds on a business day before the close of regular trading on the NYSE (ordinarily 4 p.m., Eastern time), the trade date will be the same day. If the purchase request is received in good order on a business day after the close of regular trading on the NYSE, or on a non-business day, the trade date will be the next business day.

If your purchase request is not in good order, it may be rejected.

For further information about purchase transactions, consult our website at www.ssgafunds.com or see Contacting the State Street Funds.

Other Purchase Policies You Should Know

Check Purchases. All checks used to purchase State Street Fund Shares must be drawn on a U.S. bank and in U.S. dollars. The State Street Funds will not accept any third-party check used for an initial purchase of Fund Shares, or any check drawn on a credit card account for any purpose.

New Accounts. We are required by law to obtain from you certain personal information that we will use to verify your identity. If you do not provide the information, we may not be able to open your account. If we are unable to verify your identity, the State Street Funds reserve the right, without notice, to close your account or take such other steps as we deem reasonable.

Refused or Rejected Purchase Requests. The State Street Funds reserve the right to stop selling Fund Shares or to reject any purchase request at any time and without notice, including purchases requested by exchange from another State Street Fund. This right also includes the right to reject any purchase request because of a history of frequent trading by the investor or because the purchase may negatively affect a Fund's operation or performance.

Purchases Through Pension Plans . If you are purchasing State Street Fund Shares through a pension or other participation plan, you should contact your plan administrator for further information on purchases.

Redeeming Shares

By Telephone. You may call the State Street Funds to request a redemption of shares. See Contacting the State Street Funds .

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By Mail. You may send a written request to the State Street Funds to redeem from a Fund account or to make an exchange. See Contacting the State Street Funds .

If you wish to redeem Fund Shares through a Financial Intermediary, please contact that Financial Intermediary directly. Your Financial Intermediary may have different or additional requirements for the processing of redemption orders, or may be closed at times when the Fund is open. Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Please be sure to check Exchanging Shares and Frequent-Trading Limits below.

Trade Date-Redemptions

The trade date for any redemption request received in good order will depend on the day and time the State Street Funds receive your request in good order and the manner in which you are redeeming.

Your redemption will be executed using the NAV as calculated on the trade date. NAVs are calculated only on days that the NYSE is open for regular trading (a business day). If the redemption request is received in good order by the State Street Funds on a business day before the close of regular trading on the NYSE (ordinarily 4 p.m., Eastern time), the request will be processed the same day using that day's NAV. If the redemption request is received in good order on a business day after the close of regular trading on the NYSE, or on a non-business day, the request will be processed the next business day.

How to Receive Redemption Proceeds

Regardless of the method the Funds use to make a redemption payment, the Funds typically expect to pay out redemption proceeds on the next business day after a redemption request is received in good order. If you purchased State Street Fund Shares by check or an automatic investment program and you elect to redeem shares within 15 days of the purchase, you may experience delays in receiving redemption proceeds. In this case, the State Street Funds generally will postpone sending redemption proceeds until it can verify that the check or automatic investment program investment has been collected, but in no event will this delay exceed 15 days. There will be no such delay for redemptions following purchases paid by federal funds wire or by bank cashier's check, certified check or treasurer's check. The State Street Funds reserve the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect a Fund. The State Street Funds reserve the right to suspend the right of shareholder redemption or postpone the date of payment for more than seven days to the extent permitted by the 1940 Act.

The transfer agent may temporarily delay for more than seven days the disbursement of redemption proceeds from the Fund account of a “Specified Adult” (as defined in Financial Industry Regulatory Authority, Inc. (“FINRA”) Rule 2165) based on a reasonable belief that financial exploitation of the Specified Adult has occurred, is occurring, has been attempted, or will be attempted, subject to certain conditions.

Under normal circumstances, each Fund expects to meet redemption requests by using cash or cash equivalents in its portfolio and/or selling portfolio assets to generate cash. The Funds also may pay redemption proceeds using cash obtained through borrowing arrangements (including under the Funds' line of credit, which is shared across all registered funds advised by SSGA FM (other than money market funds)) that may be available from time to time.

A Fund may pay all or a portion of your redemption proceeds by giving you securities (for example, if the Fund reasonably believes that a cash redemption may have a substantial impact on the Fund and its remaining shareholders). You may pay transaction costs to dispose of the securities, and you may receive less for them than the price at which they were valued for purposes of the redemption. In addition, you will be subject to the market risks associated with such securities until such time as you choose to dispose of the security.

During periods of deteriorating or stressed market conditions, when an increased portion of a Fund's portfolio may be comprised of less liquid investments, or during extraordinary or emergency circumstances, a Fund may be more likely to pay redemption proceeds with cash obtained through short-term borrowing arrangements (if available) or by giving you securities.

By Electronic Bank Transfer . You may have the proceeds of a fund redemption sent directly to a designated bank account. To establish the electronic bank transfer option on an account, you must designate a bank account by completing a special form or filling out the appropriate section of your account registration form. After the option is set up on your account, you can redeem shares by electronic bank transfer on a regular schedule (Automatic Withdrawal Plan) or from time to time. Your redemption request can be initiated by telephone, or by mail.

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By Wire . When redeeming shares of a State Street Fund, you may instruct the State Street Funds to wire your redemption proceeds ($1,000 minimum) to a previously designated bank account. Shares will be redeemed from the account on the day that the redemption instructions are received in good order. The wire redemption option is not automatic; you must designate a bank account by completing a special form or filling out the appropriate section of your account registration form. The State Street Funds typically do not charge you a fee for wiring redemption proceeds, although it reserves the right to do so. Your bank may charge a fee for receiving a wire. You are encouraged to check with your bank before initiating any transaction.

By Exchange . You may have the proceeds of a State Street Fund redemption invested directly into shares of another State Street Fund of the same class. You may initiate an exchange by telephone, or by mail.

By Check . You may have the proceeds of a State Street Funds redemption paid by check and sent to the address shown on the State Street Funds registration record, provided that the address on the registration record has not changed within thirty (30) days of the redemption request. The State Street Funds will mail you a redemption check, generally payable to all registered account owners.

Other Redemption Policies that You Should Know

Address Changes. If your address of record has been changed within thirty (30) days of the redemption request, the request must be in writing and bear a medallion guarantee.

Significant/Unusual Economic or Market Activity. During periods of significant or unusual economic or market activity, you may encounter delays attempting to give instructions by phone.

Minimum Account Size. If, due to your redemptions or exchanges, your account balance for a Fund falls below a minimum amount set by the Fund (presently, the minimum initial investment of your selected share class), the Fund may choose to redeem the shares in the account and mail you the proceeds. You will receive 60 days' notice that your account will be closed unless an investment is made to increase the account balance to the required minimum. Failure to bring your account balance to the required minimum within the prescribed period may result in the Fund closing your account at the NAV next determined on the day the account is closed, and mailing the proceeds to you at the address shown on the Fund's records.

Large Redemptions. Requests for redemptions over $50,000 must be in writing and bear a medallion guarantee.

Exchanging Shares

An exchange occurs when you use the proceeds from the redemption of shares of one State Street Fund to simultaneously purchase shares of a different State Street Fund. Exchanges may be made within the same class ( i.e . Class A shares for Class A shares, Class I shares for Class I shares). Class N shares are also exchangeable for other share classes of State Street Funds and would be subject to the conditions for investing in the other class of shares described in the applicable prospectus. The account holding the original shares must be registered in the same name as the account holding the new shares received in the exchange. You may make exchange requests by telephone, or by mail. See Purchasing Shares and Redeeming Shares above.

Exchanges are subject to the terms applicable to the purchases of the Fund into which you are exchanging. Exchange privileges may not be available for all State Street Funds and may be suspended or rejected. Exchanging shares of a State Street Fund for shares of another fund is a taxable event and may result in capital gain or loss. See Tax Considerations below.

If the NYSE is open for regular trading (generally until 4 p.m. Eastern time, on a business day) at the time an exchange request is received in good order, the trade date generally will be the same day. Please note that the State Street Funds reserve the right to revise or terminate the exchange privilege, limit the amount of any exchange, or reject an exchange, at any time, for any reason; provided, that shareholders will be provided 60 days' advance notice of any modification or termination of the exchange privilege.

Share Class Conversions

You may be able to convert your shares to a different share class of the same Fund that has a lower expense ratio provided that you are eligible to buy that share class and that certain conditions are met. This conversion feature is intended for shares held through a Financial Intermediary offering a fee-based or wrap fee program that has an agreement with SSGA FD specific for this purpose. In such instance, your shares may be automatically converted under certain circumstances. Class N shares of a State Street Fund may be converted to Class I shares of the same State Street Fund. Not all share classes are available through all Financial Intermediaries. If your shares of a Fund are converted to a different share class of the same Fund, the transaction will be based on the respective net asset value of each class as of the trade date of the conversion. Consequently, you may receive fewer shares or more shares than originally owned, depending on that day's net asset values. The total value of the initially held shares, however, will equal the total

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value of the converted shares at the time of conversion. The conversion of shares of one class of a Fund into shares of another class of the same Fund is not taxable for federal income tax purposes and no gain or loss will be reported on the transaction. See the applicable prospectus for share class information. Please contact your Financial Intermediary regarding the tax consequences of any conversion and for additional information.

Frequent-Trading Limits

Frequent, short-term trading, abusive trading practices and market timing (together, “Excessive Trading”), often in response to short-term fluctuations in the market, are not knowingly permitted by the State Street Funds. The State Street Funds do not accommodate frequent purchases and redemptions of Fund Shares by Fund shareholders. Excessive Trading into and out of a State Street Fund may harm a Fund's performance by disrupting portfolio management strategies and by increasing expenses. These expenses are borne by all Fund shareholders, including long-term investors who do not generate such costs.

Excessive Trading activity is generally evaluated based on roundtrip transactions in an account. A “roundtrip” transaction is defined generally as a purchase or exchange into a Fund followed, or preceded, by a redemption or exchange out of the same Fund within 30 days. A State Street Fund may, in its discretion, determine to apply a time period other than 30 days in connection with identifying roundtrip transactions. Shareholders with one or more roundtrip transactions may, in the discretion of a State Street Fund, be blocked from making additional purchases or exchanges in any State Street Fund for a period of time. A State Street Fund has discretion to determine that action is not necessary if it determines that a pattern of trading is not abusive or harmful to the affected Fund in a material way. Fund size and/or transaction size may be considered in evaluating any roundtrip transaction.

The Board of Trustees of the State Street Funds has adopted a “Market Timing/Excessive Trading Policy” (the “Policy”) to discourage Excessive Trading. Under the Policy, the State Street Funds reserve the right to reject any exchanges or purchase orders by any shareholder engaging in Excessive Trading activities.

As a means to protect each State Street Fund and its shareholders from Excessive Trading:

•	The State Street Funds' transfer agent compiles, monitors and reports account-level information on omnibus and underlying shareholder/participant activity. Depending on the account type, monitoring will be performed on a daily, monthly, quarterly and/or annual basis;
•	The State Street Funds' distributor has obtained information from each Financial Intermediary holding shares in an omnibus account with the State Street Funds regarding whether the Financial Intermediary has adopted and maintains procedures that are reasonably designed to protect the Funds against harmful short-term trading; and
•	With respect to State Street Funds that invest in securities that trade on foreign markets, pursuant to the State Street Funds' fair valuation procedures, pricing adjustments may be made based on information received from a third-party, multi-factor fair valuation pricing service.

The State Street Funds' distributor has detailed procedures that document the transparency oversight and monitoring processes performed by the State Street Funds' transfer agent.

While the State Street Funds attempt to discourage Excessive Trading, there can be no guarantee that it will be able to identify investors who are engaging in Excessive Trading or limit their trading practices. Additionally, frequent trades of small amounts may not be detected. The State Street Funds recognize that it may not always be able to detect or prevent Excessive Trading or other activity that may disadvantage the Funds or their shareholders.

A State Street Fund shareholder's right to purchase shares through an automatic investment plan or redeem shares in full (or in part through a systematic withdrawal plan) are unaffected by Excessive Trading restrictions.

Service Options

Dividend and Capital Gain Distribution Option

You may set up your State Street Fund account to reinvest any dividend or capital gains distribution that you receive as a Fund shareholder into the same or a different State Street Fund, or have any dividend or capital gain distribution paid by check, by wire or by check to a special payee. No interest will accrue on the amounts represented by the uncashed distribution checks. If you have elected to receive distributions by check, and the postal or other delivery service is unable to deliver the checks because of an incorrect mailing address, or if a distribution check remains uncashed for six months, the uncashed distribution and all future distributions will be reinvested at the then-current net asset value of the Fund.

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Please refer to Dividends, Distributions and Tax Considerations below for additional information.

Automatic Withdrawal Plan

If your account balance is over $10,000, you may request periodic (monthly, quarterly, semi-annually, or annually) automatic cash withdrawals of $100 or more which can be mailed to you or any person you designate, or sent through ACH to your bank (at your selection). Proceeds from such withdrawals will be transmitted to the bank account you designate two business days after the trade is placed or executed automatically. No interest will accrue on the amounts represented by the uncashed redemption check(s). Ask your financial adviser or Financial Intermediary for details.

Telephone Redemptions and Exchanges

You may set up your State Street Fund account so that if you request over the telephone to redeem State Street Fund Shares, the redemption proceeds will automatically be wired to a designated bank account. You also may set up your account to permit the State Street Funds to act on your telephonic instructions to exchange State Street Funds shares or to establish a systematic exchange plan. You may choose the date, the frequency (monthly, quarterly or annually) of systematic exchanges of your shares in one State Street Fund to another State Street Fund of the same share class.

Automatic Investment Plan

Once the initial investment has been accepted, you may make subsequent investments of $100 or more monthly, quarterly or annually by direct deposit by debiting your bank checking or savings account. Once this option has been established, you may call the State Street Funds to make additional automatic purchases, to change the amount of the existing automatic purchase, or to stop it. Each State Street Fund reserves the right to cancel your automatic investment plan if any correspondence sent by the Fund is returned by the postal or other delivery service as “undeliverable.”

Additional Shareholder Information

Account Transfers

To effect a change in account registration (for example, to add a new joint owner), a shareholder of a State Street Fund may request to open a new account in the same State Street Fund (referred to as a “transfer”). To effect a transfer, the State Street Funds require a completed and signed new account application, including all necessary additional documents required by the form, and a letter of instruction. The letter of instruction must include the name of the State Street Fund and the original account number, and must be signed by all registered owners of the original account and include a medallion guarantee.

Responsibility for Fraud

The State Street Funds will not be responsible for any account losses because of fraud if we reasonably believe that the person transacting business on an account is authorized to do so. Please take precautions to protect yourself from fraud. Keep your account information private, and immediately review any account statements that we provide to you. It is important that you contact the State Street Funds immediately about any transactions or changes to your account that you believe to be unauthorized.

Right to Change Policies

In addition to the rights expressly stated elsewhere in this Prospectus, the State Street Funds reserve the right, in the future, to:

1.	Alter, add, or discontinue any conditions of purchase (including eligibility requirements), redemption, exchange, service, or privilege at any time;
2.	Accept initial purchases by telephone;
3.	Freeze any account and/or suspend account services if the State Street Funds has received reasonable notice of a dispute regarding the assets in an account, including notice of a dispute between the registered or beneficial account owners, or if we reasonably believe a fraudulent transaction may occur or has occurred;
4.	Temporarily freeze any account and/or suspend account services upon initial notification to the State Street Funds of the death of the shareholder until the State Street Funds receive required documentation in good order;
5.	Alter, impose, discontinue, or waive any redemption fee, account service fee, or other fees charged to a group of shareholders; and
6.	Redeem an account or suspend account privileges, without the owner's permission to do so, in cases of threatening conduct or activity the State Street Funds believe to be suspicious, fraudulent, or illegal.

Changes may affect any or all investors. These actions will be taken when, at the sole discretion of the SSGA FM management, we reasonably believe they are deemed to be in the best interest of the State Street Fund.

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Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If the Funds' transfer agent identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to a Fund (if you hold shares directly with a Fund) or to your financial intermediary (if you do not hold shares directly with a Fund).

Dividends, Distributions and Tax Considerations

Income and capital gains dividends of the Funds will be declared and paid at least annually. Any income and capital gains that have not been distributed by December of each calendar year are generally distributed at such time. When a Fund distributes income or capital gains, the NAV per share is reduced by the amount of the distribution.

Distribution Options. You can choose from four different distribution options as indicated on the application:

•	Reinvestment Option—Dividends and capital gain distributions will be automatically reinvested in additional shares of a Fund. If you do not indicate a choice on the application, this option will be automatically assigned.
•	Income-Earned Option—Capital gain distributions will be automatically reinvested, but a check, direct deposit or wire will be sent for each dividend distribution.
•	Cash Option—A check, wire or direct deposit will be sent for each dividend and capital gain distribution.
•	Direct Dividends Option—Dividends and capital gain distributions will be automatically invested in another identically registered State Street Fund of the same share class.

If you have elected to receive distributions by check, and the postal or other delivery service is unable to deliver the checks because of an incorrect mailing address, or if a distribution check remains uncashed for six months, the uncashed distribution and all future distributions will be reinvested at the then-current net asset value of the Fund.

Dividend Policy Upon Purchase . A shareholder will receive a dividend or capital gain distribution only if the shareholder purchased Fund Shares by the close of the record date of such dividend or capital gain distribution.

Delivery of Documents to Accounts Sharing an Address

To reduce expenses, we may mail only one copy of the Funds' Prospectus and each annual and semi-annual report to those addresses shared by two or more accounts. If you wish to receive individual copies of these documents, please call us at (800) 997-7327, or contact your financial institution. We will begin sending you individual copies thirty (30) days after receiving your request.

Tax Considerations

Each Fund invests substantially all of its assets in a corresponding Portfolio that is expected to be treated as a regulated investment company for federal income tax purposes, and so substantially all of a Fund's income will result from distributions or deemed distributions from the corresponding Portfolio. Therefore, as applicable, and except as otherwise stated, references in this section to the assets owned or income earned by a Fund will include such assets and income of the corresponding Portfolio. Each Fund has elected to be treated as a regulated investment company and intends each year to qualify and to be eligible to be treated as such. A regulated investment company generally is not subject to tax at the corporate level on income and gains that are timely distributed to share-

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holders. In order to qualify and be eligible for treatment as a regulated investment company, a Fund must, among other things, satisfy diversification, 90% gross income and distribution requirements. A Fund's failure to qualify and be eligible for treatment as a regulated investment company would result in corporate level taxation, and consequently, a reduction in income available for distribution to shareholders.

Each Fund generally expects to satisfy the requirements to qualify and be eligible to be treated as a regulated investment company, provided that the respective Portfolio also meets these requirements; each Fund currently expects that the relevant Portfolio will meet these requirements. Because each Fund will invest substantially all its assets in a Portfolio, if such Portfolio were to fail to satisfy the diversification, 90% gross income, or distribution requirement and were not to cure that failure, the Fund itself would be unable to satisfy the diversification requirement. Such a failure to qualify and be eligible for treatment as a regulated investment company could subject the Fund or the Portfolio to regular corporate income taxes.

For U.S. federal income tax purposes, distributions of investment income generally are taxable to you as ordinary income. Taxes on distributions of capital gains generally are determined by how long a Portfolio owned (or is deemed to have owned) the investments that generated them, rather than how long you have owned your Fund Shares. Distributions of net capital gains (that is, the excess of net long-term capital gains over net short-term capital losses) from the sale of investments that a Portfolio owned (or is deemed to have owned) for more than one year that are properly reported by the Portfolio and the Fund as capital gain dividends generally will be treated as long-term capital gain includible in your net capital gain and taxed to individuals at reduced rates. Distributions of gains from investments that a Portfolio owned (or is deemed to have owned) for one year or less generally will be taxable to you as ordinary income when distributed to you by the Fund. Distributions of investment income properly reported by a Portfolio and by a Fund as derived from “qualified dividend income,” which will not include income from the Fund's or the Portfolio's portfolio securities on loan, are taxed to individuals at the rates applicable to net capital gain, provided holding period and other requirements are met by the shareholder, the Fund, and the Portfolio. Distributions are taxable to you even if they are paid from income or gains earned by a Fund before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares.

Any gain resulting from the redemption or other taxable disposition of Fund Shares generally will also be taxable to you as either short-term or long-term capital gain, depending upon how long you held such Fund Shares.

An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by a Fund, including any capital gain dividends, and net gains recognized on the redemption of shares of a Fund.

A Portfolio's income from or the proceeds of dispositions of its investments in non-U.S. assets may be subject to non-U.S. withholding or other taxes, which will reduce the yield on those investments. In certain instances, a Portfolio and, in turn, a Fund may be entitled to elect to pass through to its shareholders a credit (or deduction, for a shareholder that itemizes deductions and so chooses) for foreign taxes (if any) borne with respect to foreign securities income earned by the Portfolio. If the Portfolio and the Fund so elect, shareholders will include in gross income from foreign sources their pro rata shares of such taxes, if any, treated as paid by the Fund. There can be no assurance that a Portfolio and a Fund will make such election, even if each is eligible to do so. If the Portfolio or the Fund does not qualify for or does not make such election, shareholders will not be entitled separately to claim a credit or deduction with respect to foreign taxes paid by the Portfolio; in that case the foreign tax will nonetheless reduce the Portfolio's taxable income. Even if a Portfolio and a Fund elect to pass through to shareholders foreign tax credits or deductions, tax-exempt shareholders and those who invest in the Fund through tax-advantaged accounts such as IRAs will not benefit from any such tax credit or deduction.

Certain of a Portfolio's investment practices, including derivative transactions and investments in debt obligations issued or purchased at a discount, will be subject to special and complex U.S. federal income tax provisions. These special rules may affect the timing, character, and/or amount of a Portfolio's distributions to a Fund, and, in turn, a Fund's distributions to shareholders, and may require the Fund or the Portfolio to sell its investments at a time when it is not advantageous to do so.

A Fund's investments in a Portfolio may cause the tax treatment of the Fund's gains, losses and distributions to differ from the tax treatment that would apply if the Fund invested directly in the types of securities held by the Portfolio. As a result, investors may receive taxable distributions earlier and recognize higher amounts of capital gain or ordinary income than they otherwise would.

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If you are not a U.S. person, dividends paid by a Fund that the Fund properly reports as capital gain dividends, short-term capital gain dividends, or interest-related dividends, each as further defined in the SAI, are not subject to withholding of U.S. federal income tax, provided that certain other requirements are met. A Fund is permitted, but is not required, to report any part of its dividends as are eligible for such treatment. A Fund's dividends other than those the Fund so reports as capital gain dividends, short-term capital gain dividends, or interest-related dividends generally will be subject to U.S. withholding tax at a 30% rate (or lower applicable treaty rate). See each Fund's SAI for further information.

The U.S. Treasury and IRS generally require a Fund to obtain information sufficient to identify the status of each shareholder under sections 1471-1474 of the Internal Revenue Code of 1986, as amended, and the U.S. Treasury and IRS guidance issued thereunder (collectively, the “Foreign Account Tax Compliance Act” or “FATCA”) or under an applicable intergovernmental agreement between the United States and a foreign government. Please see the SAI for more information on FATCA reporting requirements.

Cost Basis Reporting . Department of the Treasury regulations mandate cost basis reporting to shareholders and the IRS for redemptions of Fund Shares acquired on or after January 1, 2012 (“Post Effective Date Shares”). If you acquire and hold shares directly through the Funds and not through a Financial Intermediary, DST Asset Manager Solutions, Inc. will use a default average cost basis methodology for tracking and reporting your cost basis on Post Effective Date Shares, unless you request, in writing, another cost basis reporting methodology.

Financial Intermediary Arrangements

Distribution Arrangements and Rule 12b-1 Fees

The Funds have adopted a distribution plan pursuant to Rule 12b-1 under the 1940 Act under which a Fund may compensate SSGA FD (or others) for services in connection with the distribution of a Fund's Class A shares and for services provided to shareholders in that class (the “Plan”). The Plan calls for payments at an annual rate (based on average daily net assets) of 0.25% of each Fund's net assets attributable to its Class A shares. Because these fees are paid out of the assets of a Fund attributable to its Class A shares on an ongoing basis, they will increase the cost of your investment and may cost you more over time than paying other types of sales charges.

A Fund may pay distribution fees and other amounts described in this Prospectus at a time when shares of that Fund are unavailable for purchase.

Other Payments to Financial Intermediaries

In addition to payments under the Plan described above, the Funds may reimburse SSGA FD or its affiliates for payments made to Financial Intermediaries that provide certain administrative, recordkeeping, and account maintenance services. The amount of the reimbursement and the manner in which it is calculated are reviewed by the Trustees periodically.

Financial Intermediaries are firms that sell shares of mutual funds, including the Funds, and/or provide certain administrative and account maintenance services to mutual fund investors. Financial Intermediaries may include, among others, brokers, financial planners or advisers, banks, retirement plan recordkeepers and insurance companies.

In some cases, a Financial Intermediary may hold its clients' Fund Shares in nominee or street name and may utilize omnibus accounts. Shareholder services provided by a Financial Intermediary may (though they will not necessarily) include, among other things: establishing and maintaining shareholder account registrations; receiving and processing purchase and redemption orders, including aggregated orders and delivering orders to the Fund's transfer agent; processing and mailing trade confirmations, periodic statements, prospectuses, annual reports, semiannual reports, shareholder notices, and other SEC-required communications; capturing and processing tax data; issuing and mailing dividend checks to shareholders who have selected cash distributions; preparing record date shareholder lists for proxy solicitations; and collecting and posting distributions to shareholder accounts.

The Financial Intermediary is often compensated by SSGA FD or its affiliates for the services it performs and in such cases is typically paid continually over time, during the period when the Financial Intermediary's clients hold investments in the Funds. The amount of continuing compensation paid by SSGA FD or its affiliates to different Financial Intermediaries for distribution and/or shareholder services varies. Any compensation is typically a percentage of the value of the Financial Intermediary's clients' investments in the Funds or a per account fee. The variation in compensation may, but will not necessarily, reflect enhanced or additional services provided by the Financial Intermediary.

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If you invest through a Financial Intermediary and meet the eligibility criteria for more than one share class, you should discuss with your Financial Intermediary which share class is appropriate for you. Your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend one share class over another, when you are eligible to invest in more than one share class. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by the Funds or its affiliates with respect to the different share classes offered by the Funds.

SSGA FD and its affiliates (including SSGA FM), at their own expense and out of their own assets, may also provide other compensation to Financial Intermediaries in connection with sales of the Funds' shares or the servicing of shareholders or shareholder accounts. Such compensation may include, but is not limited to, financial assistance to Financial Intermediaries in connection with conferences, sales, or training programs for their employees; seminars for the public; advertising or sales campaigns; or other Financial Intermediary-sponsored special events. In some instances, this compensation may be made available only to certain Financial Intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the Funds' shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as Financial Industry Regulatory Authority, Inc.

If payments to Financial Intermediaries by the distributor or adviser for a particular mutual fund complex exceed payments by other mutual fund complexes, your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend that fund complex over others. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by SSGA FD and its affiliates and by sponsors of other mutual funds he or she may recommend to you. You should also consult disclosures made by your Financial Intermediary at the time of purchase.

Third-Party Transactions . The State Street Funds have authorized certain Financial Intermediaries to accept purchase, redemption and exchange orders on the State Street Funds' behalf. Orders received for a State Street Fund by a Financial Intermediary that has been authorized to accept orders on the Fund's behalf (or other Financial Intermediaries designated by the Financial Intermediary) will be deemed accepted by the Fund at the time they are received by the Financial Intermediary and will be priced based on the Fund's next NAV determination as long as the Financial Intermediary transmits the order in good form and in a timely manner to the applicable State Street Fund(s). The Financial Intermediary is responsible for transmitting your orders and associated funds in good form and in a timely manner to the applicable State Street Fund(s). The State Street Funds will not be responsible for delays by the Financial Intermediary in transmitting your orders, including timely transfer of payment, to a Fund.

If you are purchasing, selling, exchanging or holding State Street Fund shares through a program of services offered by a Financial Intermediary, you may be required by the Financial Intermediary to pay additional fees. You should contact the Financial Intermediary for information concerning what additional fees, if any, may be charged.

Table of Contents

Financial Highlights

The financial highlight tables are intended to help you understand each Fund's financial performance since each Fund's inception. Certain information reflects the performance results for a single Fund Share. The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in each Fund (assuming reinvestment of all dividends and distributions). This information has been audited by Ernst & Young LLP, the Trust's independent registered public accounting firm, whose report, along with each Fund's financial highlights and financial statements, is included in the annual report to shareholders, which is available upon request. Any references to Notes in these financial highlight tables refer to the “Notes to Financial Statements” section of each Fund's financial statements, and the financial information included in these tables should be read in conjunction with the financial statements incorporated by reference in the SAI.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET EQUITY 500 INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class A Shares
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/17/14* - 12/31/14
Net asset value, beginning of period	$ 21.63	$18.83	$17.17	$17.27	$17.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.64	0.16	0.68	0.25	0.11
Net realized and unrealized gain (loss)	(1.66)	3.82	0.29	(0.11)	0.45
Total from investment operations	(1.02)	3.98	1.97	0.14	0.56
Distributions to shareholders from:
Net investment income	(0.37)	(0.39)	(0.23)	(0.24)	(0.29)
Net realized gains	(0.60)	(0.79)	(0.08)	—	—
Total distributions	(0.97)	(1.18)	(0.31)	(0.24)	(0.29)
Net asset value, end of period	$ 19.64	$ 21.63	$ 18.83	$ 17.17	$ 17.27
Total return (b)	(4.72)%	21.12%	11.42%	0.78%	3.28%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$31,766	$6,293	$7,509	$ 60	$ 51
Ratios to Average Net Assets:
Total expenses	0.38%(c)	0.56%(c)	0.57%(c)	0.61%(c)	0.70%(c)(d)
Net expenses	0.28%(c)	0.48%(c)	0.48%(c)	0.48%(c)	0.51%(c)(d)
Net investment income (loss)	2.89%	0.79%	3.69%	1.43%	2.32%(d)
Portfolio turnover rate	8%(e)	30%(e)	5%(e)	5%(e)	4%(e)(f)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Ratio does not include the expenses of the State Street Equity 500 Index II Portfolio.
(d)	Annualized.
(e)	Portfolio turnover rate is from the State Street Equity 500 Index II Portfolio.
(f)	Not annualized.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET EQUITY 500 INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class I Shares
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/17/14* - 12/31/14
Net asset value, beginning of period	$ 21.63	$ 18.84	$17.17	$17.27	$17.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.44	0.89	2.86	0.29	0.13
Net realized and unrealized gain (loss)	(1.41)	3.14	(0.84)	(0.11)	0.44
Total from investment operations	(0.97)	4.03	2.02	0.18	0.57
Distributions to shareholders from:
Net investment income	(0.41)	(0.45)	(0.27)	(0.28)	(0.30)
Net realized gains	(0.60)	(0.79)	(0.08)	—	—
Total distributions	(1.01)	(1.24)	(0.35)	(0.28)	(0.30)
Net asset value, end of period	$ 19.65	$ 21.63	$ 18.84	$ 17.17	$ 17.27
Total return (b)	(4.45)%	21.35%	11.75%	1.03%	3.35%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$14,496	$16,084	$4,469	$ 50	$ 51
Ratios to Average Net Assets:
Total expenses	0.15%(c)	0.31%(c)	0.32%(c)	0.36%(c)	0.45%(c)(d)
Net expenses	0.05%(c)	0.23%(c)	0.23%(c)	0.23%(c)	0.26%(c)(d)
Net investment income (loss)	1.98%	4.21%	15.53%(e)	1.66%	2.57%(d)
Portfolio turnover rate	8%(f)	30%(f)	5%(f)	5%(f)	4%(f)(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Ratio does not include the expenses of the State Street Equity 500 Index II Portfolio.
(d)	Annualized.
(e)	The calculation of the net investment income ratio is affected by the timing and relative size of a class' shareholder activity during the period. As a result, the net investment income ratio may vary significantly from period to period.
(f)	Portfolio turnover rate is from the State Street Equity 500 Index II Portfolio.
(g)	Not annualized.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET EQUITY 500 INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class K Shares
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/17/14* - 12/31/14
Net asset value, beginning of period	$ 21.62	$ 18.83	$ 17.17	$ 17.27	$17.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.47	0.44	0.44	1.45	0.14
Net realized and unrealized gain (loss)	(1.43)	3.64	1.61	(1.23)	0.44
Total from investment operations	(0.96)	4.08	2.05	0.22	0.58
Distributions to shareholders from:
Net investment income	(0.42)	(0.50)	(0.31)	(0.32)	(0.31)
Net realized gains	(0.60)	(0.79)	(0.08)	—	—
Total distributions	(1.02)	(1.29)	(0.39)	(0.32)	(0.31)
Net asset value, end of period	$ 19.64	$ 21.62	$ 18.83	$ 17.17	$ 17.27
Total return (b)	(4.42)%	21.61%	11.92%	1.23%	3.41%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$485,040	$412,903	$369,915	$62,064	$ 51
Ratios to Average Net Assets:
Total expenses	0.12%(c)	0.11%(c)	0.12%(c)	0.16%(c)	0.27%(c)(d)
Net expenses	0.02%(c)	0.03%(c)	0.03%(c)	0.03%(c)	0.06%(c)(d)
Net investment income (loss)	2.08%	2.14%	2.42%	8.45%(e)	2.78%(d)
Portfolio turnover rate	8%(f)	30%(f)	5%(f)	5%(f)	4%(f)(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Ratio does not include the expenses of the State Street Equity 500 Index II Portfolio.
(d)	Annualized.
(e)	The calculation of the net investment income ratio is affected by the timing and relative size of a class' shareholder activity during the period. As a result, the net investment income ratio may vary significantly from period to period.
(f)	Portfolio turnover rate is from the State Street Equity 500 Index II Portfolio.
(g)	Not annualized.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET AGGREGATE BOND INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class A
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/19/14* - 12/31/14
Net asset value, beginning of period	$ 9.82	$ 9.75	$ 9.75	$10.14	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.26	0.21	0.16	0.21	0.02
Net realized and unrealized gain (loss)	(0.30)	0.08	0.03	(0.18)	0.16
Total from investment operations	(0.04)	0.29	0.19	0.03	0.18
Distributions to shareholders from:
Net investment income	(0.23)	(0.21)	(0.18)	(0.26)	(0.04)
Net realized gains	—	(0.01)	(0.01)	(0.14)	—
Return of Capital	—	—	—	(0.02)	—
Total distributions	(0.23)	(0.22)	(0.19)	(0.42)	(0.04)
Net asset value, end of period	$ 9.55	$ 9.82	$ 9.75	$ 9.75	$ 10.14
Total return (b)	(0.39)%	2.93%	1.91%	0.35%	1.85%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$1,121	$ 340	$ 211	$ 184	$ 51
Ratios to Average Net Assets:
Total expenses (c)	0.55%	0.58%	0.67%	0.66%	0.91%(d)
Net expenses (c)	0.31%	0.40%	0.40%	0.31%	0.52%(d)
Net investment income (loss)	2.74%	2.11%	1.65%	2.11%	0.58%(d)
Portfolio turnover rate (e)	90%	99%	194%	62%(f)	16%(f)(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Ratio does not include the expenses of the corresponding Portfolio.
(d)	Annualized.
(e)	Portfolio turnover rate is from the corresponding Portfolio.
(f)	Portfolio turnover rate excludes to-be-announced (“TBA”) transactions.
(g)	Not annualized.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET AGGREGATE BOND INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class I
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/19/14* - 12/31/14
Net asset value, beginning of period	$ 9.84	$ 9.76	$ 9.74	$10.13	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.27	0.23	0.18	0.20	0.08
Net realized and unrealized gain (loss)	(0.29)	0.09	0.06	(0.14)	0.09
Total from investment operations	(0.02)	0.32	0.24	0.06	0.17
Distributions to shareholders from:
Net investment income	(0.27)	(0.23)	(0.21)	(0.29)	(0.04)
Net realized gains	—	(0.01)	(0.01)	(0.14)	—
Return of Capital	—	—	—	(0.02)	—
Total distributions	(0.27)	(0.24)	(0.22)	(0.45)	(0.04)
Net asset value, end of period	$ 9.55	$ 9.84	$ 9.76	$ 9.74	$ 10.13
Total return (b)	(0.20)%	3.29%	2.37%	0.60%	1.82%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$10,598	$10,807	$12,370	$4,508	$4,484
Ratios to Average Net Assets:
Total expenses (c)	0.27%	0.26%	0.33%	0.41%	0.88%(d)
Net expenses (c)	0.04%	0.08%	0.06%	0.06%	0.28%(d)
Net investment income (loss)	2.78%	2.30%	1.83%	1.95%	2.91%(d)
Portfolio turnover rate (e)	90%	99%	194%	62%(f)	16%(f)(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Ratio does not include the expenses of the corresponding Portfolio.
(d)	Annualized.
(e)	Portfolio turnover rate is from the corresponding Portfolio.
(f)	Portfolio turnover rate excludes to-be-announced (“TBA”) transactions.
(g)	Not annualized.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET AGGREGATE BOND INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class K
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/19/14* - 12/31/14
Net asset value, beginning of period	$ 9.83	$ 9.75	$ 9.74	$ 10.14	$ 10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.27	0.23	0.20	0.20	0.04
Net realized and unrealized gain (loss)	(0.28)	0.09	0.03	(0.15)	0.15
Total from investment operations	(0.01)	0.32	0.23	0.05	0.19
Distributions to shareholders from:
Net investment income	(0.27)	(0.23)	(0.21)	(0.29)	(0.05)
Net realized gains	—	(0.01)	(0.01)	(0.14)	—
Return of Capital	—	—	—	(0.02)	—
Total distributions	(0.27)	(0.24)	(0.22)	(0.45)	(0.05)
Net asset value, end of period	$ 9.55	$ 9.83	$ 9.75	$ 9.74	$ 10.14
Total return (b)	(0.10)%	3.30%	2.27%	0.54%	1.97%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$127,817	$97,318	$76,429	$49,641	$70,950
Ratios to Average Net Assets:
Total expenses (c)	0.27%	0.26%	0.33%	0.41%	0.50%(d)
Net expenses (c)	0.04%	0.08%	0.06%	0.06%	0.09%(d)
Net investment income (loss)	2.83%	2.37%	1.98%	1.88%	1.33%(d)
Portfolio turnover rate (e)	90%	99%	194%	62%(f)	16%(f)(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Ratio does not include the expenses of the corresponding Portfolio.
(d)	Annualized.
(e)	Portfolio turnover rate is from the corresponding Portfolio.
(f)	Portfolio turnover rate excludes to-be-announced (“TBA”) transactions.
(g)	Not annualized.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET GLOBAL EQUITY EX-U.S. INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class A
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/17/14* - 12/31/14
Net asset value, beginning of period	$ 10.67	$ 8.74	$ 8.45	$ 9.17	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.36	0.08	0.31	0.15	0.04
Net realized and unrealized gain (loss)	(1.90)	2.25	0.09	(0.71)	(0.83)
Total from investment operations	(1.54)	2.33	0.40	(0.56)	(0.79)
Distributions to shareholders from:
Net investment income	(0.23)	(0.26)	(0.11)	(0.16)	(0.04)
Net realized gains	(0.44)	(0.14)	—	—	—
Total distributions	(0.67)	(0.40)	(0.11)	(0.16)	(0.04)
Net asset value, end of period	$ 8.46	$ 10.67	$ 8.74	$ 8.45	$ 9.17
Total return (b)	(14.38)%	26.68%	4.75%	(6.17)%	(7.88)%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 3,599	$ 927	$1,564	$ 42	$ 46
Ratios to Average Net Assets:
Total expenses (c)	0.57%	0.53%	0.58%	0.70%	1.17%(d)
Net expenses (c)	0.42%	0.44%	0.42%	0.32%	0.60%(d)
Net investment income (loss)	3.59%	0.79%	3.51%	1.64%	1.55%(d)
Portfolio turnover rate (e)	4%	2%	8%	3%	0%(f)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Ratio does not include the expenses of the corresponding Portfolio.
(d)	Annualized.
(e)	Portfolio turnover rate is from the corresponding Portfolio.
(f)	Not annualized.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET GLOBAL EQUITY EX-U.S. INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class I
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/17/14* - 12/31/14
Net asset value, beginning of period	$ 10.67	$ 8.74	$ 8.45	$ 9.17	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.23	0.21	0.17	0.18	0.05
Net realized and unrealized gain (loss)	(1.76)	2.14	0.25	(0.72)	(0.83)
Total from investment operations	(1.53)	2.35	0.42	(0.54)	(0.78)
Distributions to shareholders from:
Net investment income	(0.24)	(0.28)	(0.13)	(0.18)	(0.05)
Net realized gains	(0.44)	(0.14)	—	—	—
Total distributions	(0.68)	(0.42)	(0.13)	(0.18)	(0.05)
Net asset value, end of period	$ 8.46	$ 10.67	$ 8.74	$ 8.45	$ 9.17
Total return (b)	(14.18)%	27.00%	5.02%	(5.94)%	(7.81)%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 635	$ 999	$ 501	$ 42	$ 46
Ratios to Average Net Assets:
Total expenses (c)	0.43%	0.23%	0.32%	0.45%	0.92%(d)
Net expenses (c)	0.30%	0.15%	0.16%	0.06%	0.35%(d)
Net investment income (loss)	2.27%	2.12%	2.01%	1.89%	1.81%(d)
Portfolio turnover rate (e)	4%	2%	8%	3%	0%(f)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Ratio does not include the expenses of the corresponding Portfolio.
(d)	Annualized.
(e)	Portfolio turnover rate is from the corresponding Portfolio.
(f)	Not annualized.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET GLOBAL EQUITY EX-U.S. INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class K
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/17/14* - 12/31/14
Net asset value, beginning of period	$ 10.68	$ 8.74	$ 8.45	$ 9.17	$ 10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.26	0.32	0.20	0.24	0.05
Net realized and unrealized gain (loss)	(1.77)	2.04	0.22	(0.78)	(0.83)
Total from investment operations	(1.51)	2.36	0.42	(0.54)	(0.78)
Distributions to shareholders from:
Net investment income	(0.26)	(0.28)	(0.13)	(0.18)	(0.05)
Net realized gains	(0.44)	(0.14)	—	—	—
Total distributions	(0.70)	(0.42)	(0.13)	(0.18)	(0.05)
Net asset value, end of period	$ 8.47	$ 10.68	$ 8.74	$ 8.45	$ 9.17
Total return (b)	(14.03)%	27.11%	5.02%	(5.94)%	(7.76)%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$433,086	$456,567	$222,297	$57,219	$40,800
Ratios to Average Net Assets:
Total expenses (c)	0.18%	0.18%	0.23%	0.45%	0.73%(d)
Net expenses (c)	0.05%	0.10%	0.07%	0.06%	0.15%(d)
Net investment income (loss)	2.57%	3.16%	2.28%	2.59%	2.00%(d)
Portfolio turnover rate (e)	4%	2%	8%	3%	0%(f)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Ratio does not include the expenses of the corresponding Portfolio.
(d)	Annualized.
(e)	Portfolio turnover rate is from the corresponding Portfolio.
(f)	Not annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET SMALL/MID CAP EQUITY INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class A
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	For the Period 10/16/15* - 12/31/15
Net asset value, beginning of period	$11.95	$10.67	$ 9.30	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.32	0.53	0.07	0.05
Net realized and unrealized gain (loss)	(1.45)	1.37	1.41	(0.69)
Total from investment operations	(1.13)	1.90	1.48	(0.64)
Distributions to shareholders from:
Net investment income	(0.15)	(0.25)	(0.11)	(0.06)
Net realized gains	(0.20)	(0.37)	(0.00)(b)	—
Total distributions	(0.35)	(0.62)	(0.11)	(0.06)
Net asset value, end of period	$ 10.47	$ 11.95	$ 10.67	$ 9.30
Total return (c)	(9.35)%	17.87%	15.67%	(6.27)%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$9,274	$ 988	$ 114	$ 97
Ratios to Average Net Assets:
Total expenses (d)	0.80%	1.10%	2.48%	5.08%(e)
Net expenses (d)	0.29%	0.35%	0.30%	0.30%(e)
Net investment income (loss)	2.65%	4.60%	0.69%	2.55%(e)
Portfolio turnover rate (f)	22%	21%	21%	8%(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Ratio does not include the expenses of the corresponding Portfolio.
(e)	Annualized.
(f)	Portfolio turnover rate is from the corresponding Portfolio.
(g)	Not annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET SMALL/MID CAP EQUITY INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class I
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	For the Period 10/16/15* - 12/31/15
Net asset value, beginning of period	$11.95	$10.67	$ 9.30	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.20	0.40	0.14	0.06
Net realized and unrealized gain (loss)	(1.29)	1.53	1.37	(0.70)
Total from investment operations	(1.09)	1.93	1.51	(0.64)
Distributions to shareholders from:
Net investment income	(0.18)	(0.28)	(0.14)	(0.06)
Net realized gains	(0.20)	(0.37)	(0.00)(b)	—
Total distributions	(0.38)	(0.65)	(0.14)	(0.06)
Net asset value, end of period	$ 10.48	$ 11.95	$ 10.67	$ 9.30
Total return (c)	(9.07)%	18.16%	15.96%	(6.18)%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$5,038	$4,135	$ 297	$ 97
Ratios to Average Net Assets:
Total expenses (d)	0.61%	0.90%	2.22%	4.83%(e)
Net expenses (d)	0.07%	0.11%	0.05%	0.05%(e)
Net investment income (loss)	1.58%	3.42%	1.42%	2.80%(e)
Portfolio turnover rate (f)	22%	21%	21%	8%(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Ratio does not include the expenses of the corresponding Portfolio.
(e)	Annualized.
(f)	Portfolio turnover rate is from the corresponding Portfolio.
(g)	Not annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET SMALL/MID CAP EQUITY INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class K
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	For the Period 8/12/15* - 12/31/15
Net asset value, beginning of period	$ 11.95	$ 10.67	$ 9.30	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.29	0.15	0.15	0.06
Net realized and unrealized gain (loss)	(1.38)	1.78	1.36	(0.70)
Total from investment operations	(1.09)	1.93	1.51	(0.64)
Distributions to shareholders from:
Net investment income	(0.18)	(0.28)	(0.14)	(0.06)
Net realized gains	(0.20)	(0.37)	(0.00)(b)	—
Total distributions	(0.38)	(0.65)	(0.14)	(0.06)
Net asset value, end of period	$ 10.48	$ 11.95	$ 10.67	$ 9.30
Total return (c)	(9.03)%	18.16%	16.21%	(6.38)%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$38,195	$18,750	$14,098	$3,930
Ratios to Average Net Assets:
Total expenses (d)	0.55%	0.96%	2.21%	4.71%(e)
Net expenses (d)	0.04%	0.05%	0.05%	0.05%(e)
Net investment income (loss)	2.37%	1.29%	1.51%	1.49%(e)
Portfolio turnover rate (f)	22%	21%	21%	8%(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Ratio does not include the expenses of the corresponding Portfolio.
(e)	Annualized.
(f)	Portfolio turnover rate is from the corresponding Portfolio.
(g)	Not annualized.

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Index/Trademark Licenses/Disclaimers

The Index Providers are not affiliated with the Trust, the Adviser, the Funds' Administrator, Sub-Administrator, Custodian, Transfer Agent, SSGA FD or any of their respective affiliates. The Adviser (“Licensee”) has entered into license agreements with the Index Providers pursuant to which the Adviser pays a fee to use their respective Indices. The Adviser is sub-licensing rights to the Indices to the Funds at no charge.

S&P Index: “S&P” and “Standard & Poor's” are registered trademarks of Standard and Poor's Financial Services LLC (“S&P”), a division of S&P Global, and have been licensed for use by S&P Dow Jones Indices LLC (“SPDJI”) and sub-licensed for use by the Adviser. Dow Jones ^® is a registered trademark of Dow Jones Trademark Holdings LLC.

The State Street Equity 500 Index Fund is not sponsored, endorsed, sold or marketed by S&P Dow Jones Indices LLC, Dow Jones, S&P, any of their respective affiliates (collectively, “S&P Dow Jones Indices”). S&P Dow Jones Indices does not make any representation or warranty, express or implied, to the owners of the State Street Equity 500 Index Fund or any member of the public regarding the advisability of investing in securities generally or in the State Street Equity 500 Index Fund particularly or the ability of the Indices to track general market performance. S&P Dow Jones Indices licenses to Licensee the Index and certain trademarks, service marks and/or trade names of S&P Dow Jones Indices and/or its licensors. The Indices are determined, composed and calculated by S&P Dow Jones Indices without regard to Licensee or the State Street Equity 500 Index Fund. S&P Dow Jones Indices have no obligation to take the needs of Licensee or the owners of the State Street Equity 500 Index Fund into consideration in determining, composing or calculating the Indices. S&P Dow Jones Indices is not responsible for and has not participated in the determination of the prices, and amount of the State Street Equity 500 Index Fund or the timing of the issuance or sale of the State Street Equity 500 Index Fund or in the determination or calculation of the equation by which the State Street Equity 500 Index Fund are to be converted into cash, surrendered or redeemed, as the case may be. S&P Dow Jones Indices has no obligation or liability in connection with the administration, marketing or trading of the State Street Equity 500 Index Fund. S&P Dow Jones Indices LLC is not an investment or tax advisor. Inclusion of a security within an index is not a recommendation by S&P Dow Jones Indices to buy, sell, or hold such security, nor is it considered to be investment advice.

NEITHER S&P DOW JONES INDICES NOR THIRD PARTY LICENSOR GUARANTEES THE ADEQUACY, ACCURACY, TIMELINESS AND/OR THE COMPLETENESS OF THE INDICES OR ANY DATA RELATED THERETO OR ANY COMMUNICATION, INCLUDING BUT NOT LIMITED TO, ORAL OR WRITTEN COMMUNICATION (INCLUDING ELECTRONIC COMMUNICATIONS) WITH RESPECT THERETO. S&P DOW JONES INDICES AND THIRD PARTY LICENSOR SHALL NOT BE SUBJECT TO ANY DAMAGES OR LIABILITY FOR ANY ERRORS, OMISSIONS, OR DELAYS THEREIN. S&P DOW JONES INDICES AND THIRD PARTY LICENSOR MAKES NO EXPRESS OR IMPLIED WARRANTIES, AND EXPRESSLY DISCLAIMS ALL WARRANTIES, OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE OR AS TO RESULTS TO BE OBTAINED BY LICENSEE, OWNERS OF THE STATE STREET EQUITY 500 INDEX FUND, OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE INDICES OR WITH RESPECT TO ANY DATA RELATED THERETO. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT WHATSOEVER SHALL S&P DOW JONES INDICES OR THIRD PARTY LICENSOR BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES INCLUDING BUT NOT LIMITED TO, LOSS OF PROFITS, TRADING LOSSES, LOST TIME OR GOODWILL, EVEN IF THEY HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, WHETHER IN CONTRACT, TORT, STRICT LIABILITY, OR OTHERWISE. THERE ARE NO THIRD PARTY BENEFICIARIES OF ANY AGREEMENTS OR ARRANGEMENTS BETWEEN S&P DOW JONES INDICES AND LICENSEE, OTHER THAN THE LICENSORS OF S&P DOW JONES INDICES.

“BLOOMBERG ^® is a trademark and service mark of Bloomberg Finance L.P. BARCLAYS ^® is a trademark and service mark of Barclays Bank Plc, used under license. Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited ("BISL”) (collectively, “Bloomberg”), or Bloomberg's licensors own all proprietary rights in the “Bloomberg Barclays U.S. Aggregate Bond Index.”

Neither Barclays Bank PLC, Barclays Capital Inc., nor any affiliate (collectively “Barclays”) nor Bloomberg is the issuer or producer of State Street Aggregate Bond Index Portfolio and neither Bloomberg nor Barclays has any responsibilities, obligations or duties to investors in State Street Aggregate Bond Index Portfolio. The Bloomberg Barclays U.S. Aggregate Bond Index is licensed for use by State Street Global Advisors as the Issuer of State Street Aggregate Bond Index Portfolio. The only relationship of Bloomberg and Barclays with the Issuer in respect of Bloomberg Barclays U.S. Aggregate Bond Index is the licensing of the Bloomberg Barclays U.S. Aggregate Bond Index, which is determined, composed and calculated by BISL, or any successor thereto, without regard to the Issuer or the State Street Aggregate Bond Index Portfolio or the owners of the State Street Aggregate Bond Index Portfolio.

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Additionally, State Street Global Advisors of State Street Aggregate Bond Index Portfolio may for itself execute transaction(s) with Barclays in or relating to the Bloomberg Barclays U.S. Aggregate Bond Index in connection with State Street Aggregate Bond Index Portfolio. Investors acquire State Street Aggregate Bond Index Portfolio from State Street Global Advisors and investors neither acquire any interest in Bloomberg Barclays U.S. Aggregate Bond Index nor enter into any relationship of any kind whatsoever with Bloomberg or Barclays upon making an investment in State Street Aggregate Bond Index Portfolio. The State Street Aggregate Bond Index Portfolio are not sponsored, endorsed, sold or promoted by Bloomberg or Barclays. Neither Bloomberg nor Barclays makes any representation or warranty, express or implied, regarding the advisability of investing in the State Street Aggregate Bond Index Portfolio or the advisability of investing in securities generally or the ability of the Bloomberg Barclays U.S. Aggregate Bond Index to track corresponding or relative market performance. Neither Bloomberg nor Barclays has passed on the legality or suitability of the State Street Aggregate Bond Index Portfolio with respect to any person or entity. Neither Bloomberg nor Barclays is responsible for or has participated in the determination of the timing of, prices at, or quantities of the State Street Aggregate Bond Index Portfolio to be issued. Neither Bloomberg nor Barclays has any obligation to take the needs of the Issuer or the owners of the State Street Aggregate Bond Index Portfolio or any other third party into consideration in determining, composing or calculating the Bloomberg Barclays U.S. Aggregate Bond Index. Neither Bloomberg nor Barclays has any obligation or liability in connection with administration, marketing or trading of the State Street Aggregate Bond Index Portfolio.

The licensing agreement between Bloomberg and Barclays is solely for the benefit of Bloomberg and Barclays and not for the benefit of the owners of the State Street Aggregate Bond Index Portfolio, investors or other third parties. In addition, the licensing agreement between State Street Global Advisors and Bloomberg is solely for the benefit of State Street Global Advisors and Bloomberg and not for the benefit of the owners of the State Street Aggregate Bond Index Portfolio, investors or other third parties.

NEITHER BLOOMBERG NOR BARCLAYS SHALL HAVE ANY LIABILITY TO THE ISSUER, INVESTORS OR OTHER THIRD PARTIES FOR THE QUALITY, ACCURACY AND/OR COMPLETENESS OF THE BLOOMBERG BARCLAYS U.S. AGGREGATE BOND INDEX OR ANY DATA INCLUDED THEREIN OR FOR INTERRUPTIONS IN THE DELIVERY OF THE BLOOMBERG BARCLAYS U.S. AGGREGATE BOND INDEX. NEITHER BLOOMBERG NOR BARCLAYS MAKES ANY WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY THE ISSUER, THE INVESTORS OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE BLOOMBERG BARCLAYS U.S. AGGREGATE BOND INDEX OR ANY DATA INCLUDED THEREIN. NEITHER BLOOMBERG NOR BARCLAYS MAKES ANY EXPRESS OR IMPLIED WARRANTIES, AND EACH HEREBY EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO THE BLOOMBERG BARCLAYS U.S. AGGREGATE BOND INDEX OR ANY DATA INCLUDED THEREIN. BLOOMBERG RESERVES THE RIGHT TO CHANGE THE METHODS OF CALCULATION OR PUBLICATION, OR TO CEASE THE CALCULATION OR PUBLICATION OF THE BLOOMBERG BARCLAYS U.S. AGGREGATE BOND INDEX, AND NEITHER BLOOMBERG NOR BARCLAYS SHALL BE LIABLE FOR ANY MISCALCULATION OF OR ANY INCORRECT, DELAYED OR INTERRUPTED PUBLICATION WITH RESPECT TO ANY OF THE BLOOMBERG BARCLAYS U.S. AGGREGATE BOND INDEX. NEITHER BLOOMBERG NOR BARCLAYS SHALL BE LIABLE FOR ANY DAMAGES, INCLUDING, WITHOUT LIMITATION, ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY LOST PROFITS, EVEN IF ADVISED OF THE POSSIBLITY OF SUCH, RESULTING FROM THE USE OF THE BLOOMBERG BARCLAYS U.S. AGGREGATE BOND INDEX OR ANY DATA INCLUDED THEREIN OR WITH RESPECT TO THE STATE STREET AGGREGATE BOND INDEX PORTFOLIO.

None of the information supplied by Bloomberg or Barclays and used in this publication may be reproduced in any manner without the prior written permission of both Bloomberg and Barclays Capital, the investment banking division of Barclays Bank PLC. Barclays Bank PLC is registered in England No. 1026167, registered office 1 Churchill Place London E14 5HP."

THE STATE STREET GLOBAL EQUITY EX-U.S. INDEX FUND IS NOT SPONSORED, ENDORSED, SOLD OR PROMOTED BY MSCI INC. (“MSCI”), MSCI'S PARENT COMPANY, ANY OF MSCI'S OR MSCI'S PARENT COMPANY'S DIRECTLY OR INDIRECTLY HELD SUBSIDIARIES, ANY OF MSCI'S OR MSCI'S PARENT COMPANY'S INFORMATION PROVIDERS OR ANY THIRD PARTY INVOLVED IN, OR RELATED TO, COMPILING, COMPUTING OR CREATING ANY MSCI INDEX (COLLECTIVELY, THE “MSCI PARTIES”).THE MSCI INDICES ARE THE EXCLUSIVE PROPERTY OF MSCI. MSCI AND THE MSCI INDEX NAMES ARE SERVICE MARK(S) OF MSCI OR ITS AFFILIATES AND HAVE BEEN LICENSED FOR USE FOR CERTAIN PURPOSES BY THE LICENSEE. NONE OF THE MSCI PARTIES MAKES ANY REPRESENTATION OR WARRANTY, EXPRESS OR IMPLIED, TO THE ISSUER OR OWNERS OF THE MSCI FUNDS OR ANY OTHER PERSON OR ENTITY REGARDING THE ADVISABILITY OF INVESTING IN FUNDS GENERALLY OR IN THE MSCI FUNDS PARTICULARLY OR THE ABILITY OF ANY MSCI INDEX TO TRACK CORRESPONDING STOCK MARKET PERFORMANCE. MSCI OR ITS AFFILIATES ARE THE LICENSORS OF CERTAIN TRADEMARKS, SERVICE MARKS AND TRADE NAMES AND OF THE MSCI INDICES WHICH ARE DETERMINED, COMPOSED AND CALCULATED BY MSCI WITHOUT REGARD TO THE MSCI FUNDS OR THE ISSUER OR OWNERS OF THE MSCI FUNDS OR ANY OTHER PERSON OR ENTITY. NONE

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OF THE MSCI PARTIES HAS ANY OBLIGATION TO TAKE THE NEEDS OF THE ISSUER OR OWNERS OF THE MSCI FUNDS OR ANY OTHER PERSON OR ENTITY INTO CONSIDERATION IN DETERMINING, COMPOSING OR CALCULATING THE MSCI INDICES. NONE OF THE MSCI PARTIES IS RESPONSIBLE FOR OR HAS PARTICIPATED IN THE DETERMINATION OF THE TIMING OF, PRICES AT, OR QUANTITIES OF THE MSCI FUNDS TO BE ISSUED OR IN THE DETERMINATION OR CALCULATION OF THE EQUATION BY OR THE CONSIDERATION INTO WHICH THE MSCI FUNDS ARE REDEEMABLE. FURTHER, NONE OF THE MSCI PARTIES HAS ANY OBLIGATION OR LIABILITY TO THE ISSUER OR OWNERS OF THE MSCI FUNDS OR ANY OTHER PERSON OR ENTITY IN CONNECTION WITH THE ADMINISTRATION, MARKETING OR OFFERING OF THE MSCI FUNDS.

ALTHOUGH MSCI SHALL OBTAIN INFORMATION FOR INCLUSION IN OR FOR USE IN THE CALCULATION OF THE MSCI INDICES FROM SOURCES THAT MSCI CONSIDERS RELIABLE, NONE OF THE MSCI PARTIES WARRANTS OR GUARANTEES THE ORIGINALITY, ACCURACY AND/OR THE COMPLETENESS OF ANY MSCI INDEX OR ANY DATA INCLUDED THEREIN. NONE OF THE MSCI PARTIES MAKES ANY WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY THE ISSUER OF THE MSCI FUNDS, OWNERS OF THE FUNDS, OR ANY OTHER PERSON OR ENTITY, FROM THE USE OF ANY MSCI INDEX OR ANY DATA INCLUDED THEREIN. NONE OF THE MSCI PARTIES SHALL HAVE ANY LIABILITY FOR ANY ERRORS, OMISSIONS OR INTERRUPTIONS OF OR IN CONNECTION WITH ANY MSCI INDEX OR ANY DATA INCLUDED THEREIN. FURTHER, NONE OF THE MSCI PARTIES MAKES ANY EXPRESS OR IMPLIED WARRANTIES OF ANY KIND, AND THE MSCI PARTIES HEREBY EXPRESSLY DISCLAIM ALL WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, WITH RESPECT TO EACH MSCI INDEX AND ANY DATA INCLUDED THEREIN. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT SHALL ANY OF THE MSCI PARTIES HAVE ANY LIABILITY FOR ANY DIRECT, INDIRECT, SPECIAL, PUNITIVE, CONSEQUENTIAL OR ANY OTHER DAMAGES (INCLUDING LOST PROFITS) EVEN IF NOTIFIED OF THE POSSIBILITY OF SUCH DAMAGES.

NO PURCHASER, SELLER OR HOLDER OF THE MSCI FUNDS, OR ANY OTHER PERSON OR ENTITY, SHOULD USE OR REFER TO ANY MSCI TRADE NAME, TRADEMARK OR SERVICE MARK TO SPONSOR, ENDORSE, MARKET OR PROMOTE THESE FUNDS WITHOUT FIRST CONTACTING MSCI TO DETERMINE WHETHER MSCI'S PERMISSION IS REQUIRED. UNDER NO CIRCUMSTANCES MAY ANY PERSON OR ENTITY CLAIM ANY AFFILIATION WITH MSCI WITHOUT THE PRIOR WRITTEN PERMISSION OF MSCI.

RUSSELL DOES NOT GUARANTEE THE ACCURACY AND/OR THE COMPLETENESS OF ANY OF THE INDICES OR ANY DATA INCLUDED THEREIN AND RUSSELL SHALL HAVE NO LIABILITY FOR ANY ERRORS, OMISSIONS, OR INTERRUPTIONS THEREIN. RUSSELL MAKES NO WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY THE FUNDS, INVESTORS, OWNERS OF THE PRODUCTS, OR ANY OTHER PERSON OR ENTITY FROM THE USE OF ANY OF THE INDICES OR ANY DATA INCLUDED THEREIN. RUSSELL MAKES NO EXPRESS OR IMPLIED WARRANTIES, AND EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO ALL OF THE INDICES OR ANY DATA INCLUDED THEREIN. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT SHALL RUSSELL HAVE ANY LIABILITY FOR ANY SPECIAL, PUNITIVE, INDIRECT, OR CONSEQUENTIAL DAMAGES (INCLUDING LOST PROFITS), EVEN IF NOTIFIED OF THE POSSIBILITY OF SUCH DAMAGES.

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Contacting the State Street Funds

Online:	www.ssgafunds.com	24 hours a day, 7 days a week
Phone:	(800) 647-7327	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Overnight/ Registered, Express, Certified Mail
State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737	State Street Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407

The Funds do not consider the U.S. Postal Service or other independent delivery services to be their agents. Therefore, deposits in the mail or with such services, or receipt at the Funds' post office box, of purchase orders or redemption requests, do not constitute receipt by the Funds or Transfer Agent.

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For more information about the Funds:

The Funds' SAI includes additional information about the Funds and is incorporated by reference into this document. Additional information about the Funds' investments is available in the Funds' most recent annual and semi-annual reports to shareholders. In a Fund's annual report, you will find a discussion of the market conditions and investment strategies that significantly affected the Fund's performance during its last fiscal year. The Funds' SAI is available, without charge, upon request. The Funds' annual and semi-annual reports are available, without charge, upon request. Shareholders in the Funds may make inquiries to the Funds to receive such information by calling (800) 997-7327 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. Each Fund's Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, free of charge, on the Funds' website at www.ssgafunds.com.

Reports and other information about the Funds are available free of charge on the EDGAR Database on the SEC's Internet site at http://www.sec.gov. Copies of this information also may be obtained, after paying a duplicating fee, by electronic request at the following E-mail address: publicinfo@sec.gov.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

SSITEQABSTATPRO

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Emerging Markets Equity Index Fund

Class A (SSUEX) Class I (SSLEX) Class K (SSKEX)

Beginning on January 1, 2021, as permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of the Fund's annual and semi- annual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Fund (or from your financial intermediary, such as a broker-dealer or bank). Instead, the reports will be made available on the Fund's website (www.ssgafunds.com), and you will be notified by mail each time a report is posted, and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Fund electronically by calling (800) 647-7327.

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with the Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling (800) 647-7327. Your election to receive reports in paper will apply to all funds held in your account.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in the Fund offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

The Fund may offer multiple classes of shares. This Prospectus covers only the Class A, Class I and Class K Shares of the Fund.

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Fund Summary	1
State Street Emerging Markets Equity Index Fund	1
Additional Information About Investment Objectives, Principal Strategies and Risks	9
Additional Information About Non-Principal Investment Strategies and Risks	17
Portfolio Holdings Disclosure	19
Management and Organization	20
Shareholder Information	21
Dividends, Distributions and Tax Considerations	33
Financial Intermediary Arrangements	35
Financial Highlights	37

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State Street Emerging Markets Equity Index Fund

Investment Objective

The State Street Emerging Markets Equity Index Fund (the “Emerging Markets Equity Index Fund” or the “Fund”) seeks to provide investment results that, before fees and expenses, correspond generally to the total return of an index that tracks the performance of emerging market equity securities.

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment)

	Class A	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	5.25%	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None ¹	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class A	Class I	Class K
Management Fee	0.14%	0.14%	0.14%
Distribution and/or Shareholder Service (12b-1) Fees	0.25%	0.00%	0.00%
Other Expenses ²	0.39%	0.39%	0.19%
Total Annual Fund Operating Expenses	0.78%	0.53%	0.33%
Less Fee Waivers and/or Expense Reimbursements ³	(0.16%)	(0.16%)	(0.16%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.62%	0.37%	0.17%

¹	A contingent deferred sales charge (“CDSC”) of 1.00% may be assessed on redemptions of Class A shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase as part of an investment of $1,000,000 or more.
²	Other expenses are based on estimates for the current fiscal year for Class A and Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.12% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

	1 year		3 years		5 years		10 years
Class A	$585		$746		$921		$1,426

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	1 year	3 years	5 years	10 years
Class I	$38	$154	$280	$650
Class K	$17	$ 90	$169	$403

Portfolio Turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund Shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 7% of the average value of its portfolio.

Principal Investment Strategies

The Fund is an “index” fund that seeks to track, before fees and expenses, the total return of the MSCI Emerging Markets Index (the “Index”) over the long term. As an “index” fund, the Fund is not managed according to traditional methods of “active” investment management, which involve the buying and selling of securities based upon economic, financial and market analysis and investment judgment.

In seeking to track the performance of the Index, the Fund employs a sampling strategy, which means that the Fund is not required to purchase all of the securities represented in the Index. Instead, the Fund may purchase a subset of the securities in the Index in an effort to create a portfolio of securities with generally the same risk and return characteristics as those of the Index. The number of holdings in the Fund will be based on a number of factors, including asset size of the Fund. SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, may invest the Fund's assets in a subset of securities in the Index or may invest the Fund's assets in substantially all of the securities represented in the Index, in approximately the same proportions as the Index, but reserves the right to hold as many securities as it believes necessary to achieve the Fund's investment objective. In addition, from time to time stocks are added to or removed from the Index. The Fund may sell securities that are represented in the Index, or purchase securities that are not yet represented in the Index, in anticipation of their removal from or addition to the Index. Under normal circumstances, the Fund generally invests substantially all, but at least 80%, of its net assets (plus borrowings, if any) in securities included in the Index or in other securities of emerging market companies providing exposure comparable, in the Adviser's view, to securities comprising the Index. An “emerging market company” is any company domiciled or doing a substantial portion of its business in countries represented in the Index at the time of purchase. These securities may be represented by American Depositary Receipts (“ADRs”), Global Depositary Receipts (“GDRs”), Non- Voting Depositary Receipts (“NVDRs”) or Participatory Notes (“P-Notes”). The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. The Fund will provide shareholders with at least 60 days' notice prior to any change in this 80% investment policy. The Fund may invest a portion of its assets in cash and cash equivalents, repurchase agreements and money market instruments, such as money market funds (including money market funds advised by the Adviser).

The Fund may purchase or sell futures contracts, or options on those futures, in lieu of investing directly in the stocks making up the Index. The Fund might do so, for example, in order to increase its investment exposure pending investment of cash in stocks or other investments. Alternatively, the Fund might use futures or options on futures to reduce its investment exposure in situations where it intends to sell a portion of the stocks in its portfolio but the sale has not yet been completed. The Fund may enter into other derivatives transactions, including the use of options, forwards or swap transactions, in lieu of investing directly in the stocks making up the Index. The Fund may also, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Fund (including funds advised by the Adviser).

The Index is a free float-adjusted market capitalization index that is designed to measure equity market performance of emerging market countries. As of February 28, 2019, the Index comprised 1,125 securities covering large- and mid-cap companies across 24 countries and represented 88.97% of the market capitalization of MSCI Emerging Markets Investable Market Index (IMI), which is composed of large-, mid- and small-cap companies. As of February 28, 2019, the market capitalization of the companies included in the Index ranged from $35.87 million to $244.41 billion. Countries covered in the Index have historically included, among others, Brazil, Chile, China, Colombia, Czech Republic, Egypt, Greece, Hungary, India, Indonesia, Korea, Malaysia, Mexico, Pakistan, Peru, Philippines, Poland, Qatar, Russia, South Africa, Taiwan, Thailand, Turkey and United Arab Emirates. As of February 28, 2019, a significant portion of the Index comprised companies in the financial and information technology sectors, although this may change from time to time. As of February 28, 2019, a significant portion of the Index comprised companies located in China and South Korea and a significant portion of the Index constituents are denominated in Hong Kong Dollars and the South Korea Won, although this may change from time to time.

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The Index is sponsored by MSCI, Inc. (the “Index Provider”) which is not affiliated with the Fund or the Adviser. The Index Provider determines the composition of the Index, relative weightings of the securities in the Index and publishes information regarding the market value of the Index.

Principal Risks

In addition, the Fund is subject to the following risks:

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Financial Institutions Risk: Changes in the creditworthiness of financial institutions (such as banks and broker-dealers) may adversely affect the values of instruments of issuers in financial industries. Adverse developments in banking and other financial industries may cause the Fund to underperform relative to other funds that invest more broadly across different industries or have a smaller exposure to financial institutions. Changes in governmental regulation and oversight of financial institutions may have an adverse effect on the financial condition of a financial institution.

Frontier Markets Risk: Investments in frontier markets may be more volatile and less liquid than investments in more developed markets or in other emerging market countries. Risks that are characteristic of many emerging markets generally may be especially heightened in frontier markets due to political, economic, financial, or other factors.

Futures Contract Risks; Other Exchange-Traded Derivatives: The risk of loss relating to the use of futures contracts and other exchange-traded derivatives is potentially unlimited. There is no assurance that a liquid secondary market on an exchange will exist for any particular futures contract or other exchange-traded derivative or at any particular time. In the event no such market exists for a particular derivative, it might not be possible to effect closing transactions, and the Fund will be unable to terminate its exposure to the derivative. If the Fund uses futures contracts or other exchange-traded derivatives for hedging purposes, there is a risk of imperfect correlation between movements in the prices of the derivatives and movements in the securities or index underlying the derivatives or movements in the prices of the Fund's investments that are the subject of such hedge. Certain foreign futures contracts and other exchange-traded derivatives may be less liquid and more volatile than U.S. contracts. The Fund may be delayed or prevented from recovering margin or other amounts deposited with a futures commission merchant or futures clearinghouse.

China: The Chinese economy is generally considered an emerging market and can be significantly affected by economic and political conditions and policy in China and surrounding Asian countries. A relatively small number of Chinese companies represent a large portion of China's total market and thus may be more sensitive to adverse political or economic circumstances and market movements. The economy of China differs, often unfavorably, from the U.S. economy in such respects as structure, general development, government involvement, wealth distribution, rate of inflation, growth rate, allocation of resources and capital reinvestment, among others. Under China's political and economic system, the central government has historically exercised substantial control over virtually every sector of the Chinese economy through administrative regulation and/or state ownership. In addition, expropriation, including nationalization, confiscatory taxation, political, economic or social instability or other developments could adversely affect and significantly diminish the values of the Chinese companies in which the Fund invests. The Chinese economy and financial markets have experienced high levels of growth in recent years; any actual or perceived reduction or curtailment in those levels of growth in the future would likely have a substantial adverse impact on the values of Chinese companies. These factors and others could negatively affect the value and liquidity of the Fund. The Fund may invest in shares of Chinese companies traded on stock markets in Mainland China or Hong Kong. These stock markets have recently experienced high levels of volatility, which may continue in the future. The Hong Kong stock market may behave differently from the Mainland China stock market and there may be little to no correlation between the performance of the Hong Kong stock market and the Mainland China stock market.

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South Korea: Economic and political developments of South Korean neighbors may have an adverse effect on the South Korean economy. Substantial political tensions exist between North Korea and South Korea and, recently, these political tensions have escalated. The outbreak of hostilities between the two nations, or even the threat of such an outbreak, will likely adversely impact the South Korean economy. In addition, South Korea's economic growth potential has recently been on a decline, mainly because of a rapidly aging population and structural problems. Among these structural concerns are the country's underdeveloped financial markets and a general lack of regulatory transparency. The restructuring of the South Korean economy, including the creation of a mechanism for bankrupt firms to exit the market, remains an important unfinished task. These factors may adversely affect the South Korean economy and cause a diversion of corporate investment to China and other lower wage countries. South Korea's economic growth potential is susceptible to problems from large scale emigration, rigid labor regulations and ongoing labor relations issues.

Mid-Capitalization Securities Risk: The securities of mid-capitalization companies may be more volatile and may involve more risk than the securities of larger companies. These companies may have limited product lines, markets or financial resources, may lack the competitive strength of larger companies, and may depend on a few key employees. In addition, these companies may have been recently organized and may have little or no track record of success. The securities of mid-sized companies may trade less frequently and in smaller volumes than more widely held securities. Some securities of mid-sized issuers may be illiquid or may be restricted as to resale, and their values may be volatile.

Money Market Risk: An investment in a money market fund is not a deposit of any bank and is not insured or guaranteed by the FDIC or any other government agency. Certain money market funds seek to preserve the value of their shares at $1.00 per share, although there can be no assurance that they will do so, and it is possible to lose money by investing in such a money market fund. A major or unexpected increase in interest rates or a decline in the credit quality of an issuer or entity providing credit support, an inactive trading market for money market instruments, or adverse market, economic, industry, political, regulatory, geopolitical, and other conditions could cause the share price of such a money market fund to fall below $1.00. Other money market funds price and transact at a “floating” NAV that will fluctuate along with changes in the market-based value of fund

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assets. Shares sold utilizing a floating NAV may be worth more or less than their original purchase price. Recent changes in the regulation of money market funds may affect the operations and structures of money market funds.

Technology Sector Risk: The Fund's assets may be focused in the technology sector, which means the Fund will be more affected by the performance of the technology sector than a fund that is more diversified. Market or economic factors impacting technology companies and companies that rely heavily on technological advances could have a major effect on the value of the Fund's investments. The value of stocks of technology companies and companies that rely heavily on technology is particularly vulnerable to rapid changes in technology product cycles, rapid product obsolescence, government regulation and competition, both domestically and internationally, including competition from foreign competitors with lower production costs. Stocks of technology companies and companies that rely heavily on technology, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market. Technology companies are heavily dependent on patent and intellectual property rights, the loss or impairment of which may adversely affect profitability. Additionally, companies in the technology sector may face dramatic and often unpredictable changes in growth rates and competition for the services of qualified personnel.

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Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of the Index. The bar chart shows how the Class K shares' returns have varied for each full calendar year shown. Except for differences in returns resulting from differences in fees and expenses, all share classes would have substantially similar returns because all share classes invest in the same portfolio of securities. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Return (years ended 12/31)

Highest Quarterly Return: 11.46% (Q1, 2017)
Lowest Quarterly Return: -8.62% (Q2, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. After-tax returns depend on an investor's tax situation and may differ from those shown below, and after-tax returns are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts (IRAs). Except for differences in returns resulting from differences in fees, expenses, and sales charges (as applicable), all share classes would have substantially similar returns because all share classes invest in the same portfolio of securities.

	One Year	Since Inception	Inception Date
Class K			12/18/15
Return Before Taxes	-14.77%	8.95%
Return After Taxes on Distributions	-15.29%	8.29%
Return After Taxes on Distributions and Sale of Fund Shares	-8.25%	6.97%
MSCI Emerging Market Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-14.58%	9.40%

The Fund will make updated performance information, including its current net asset value, available at the Fund's website: www.ssgafunds.com.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

The professionals primarily responsible for the day-to-day management of the Fund are Michael Feehily, Thomas Coleman and Olga Winner, each of which has served as a portfolio manager of the Fund since inception in 2015.

Michael Feehily, CFA, is a Senior Managing Director of the Adviser and the Head of Global Equity Beta Solutions in the Americas. He worked at the Adviser from 1997 to 2006 and rejoined in 2010.

Thomas Coleman, CFA, is a Vice President of the Adviser and a Senior Portfolio Manager in the Global Equity Beta Solutions Group. He joined the Adviser in 1998.

Olga Winner, CFA, is a Vice President of the Adviser and a Senior Portfolio Manager in the Global Equity Beta Solutions Group. She joined the Adviser in 2007.

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Purchase and Sale of Fund Shares

Purchase Minimums

Class A
To establish an account	$2,000
To add to an existing account	None
Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objectives, Principal Strategies and Risks

Investment Objective

Principal Investment Strategies

In seeking to track the performance of the Index, the Fund employs a sampling strategy, which means that the Fund is not required to purchase all of the securities represented in the Index. Instead, the Fund may purchase a subset of the securities in the Index in an effort to create a portfolio of securities with generally the same risk and return characteristics as those of the Index. The number of holdings in the Fund will be based on a number of factors, including asset size of the Fund. SSGA FM may invest the Fund's assets in a subset of securities in the Index or may invest the Fund's assets in substantially all of the securities represented in the Index, in approximately the same proportions as the Index, but reserves the right to hold as many securities as it believes necessary to achieve the Fund's investment objective. In addition, from time to time stocks are added to or removed from the Index. The Fund may sell securities that are represented in the Index, or purchase securities that are not yet represented in the Index, in anticipation of their removal from or addition to the Index. Under normal circumstances, the Fund generally invests substantially all, but at least 80%, of its net assets (plus borrowings, if any) in securities included in the Index or in other securities of emerging market companies providing exposure comparable, in the Adviser's view, to securities comprising the Index. An “emerging market company” is any company domiciled or doing a substantial portion of its business in countries represented in the Index at the time of purchase. These securities may be represented by American Depositary Receipts (“ADRs”), Global Depositary Receipts (“GDRs”), Non- Voting Depositary Receipts (“NVDRs”) or Participatory Notes (“P-Notes”). The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. The Fund will provide shareholders with at least 60 days' notice prior to any change in this 80% investment policy. The Fund may invest a portion of its assets in cash and cash equivalents, repurchase agreements and money market instruments, such as money market funds (including money market funds advised by the Adviser).

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Additional Index Information . The Index's components are reconstituted and rebalanced semi-annually. The Index Provider classifies each issuer in one country. The Index Provider generally determines the country classification of an issuer based on the issuer's country of incorporation and the primary listing of its securities. To the extent that an issuer is incorporated in a different country than the country in which its securities are principally traded, the Index Provider considers the following additional set of criteria to determine the issuer's country classification: (i) the secondary listings of the issuer's securities, if any; (ii) the geographic distribution of the issuer's shareholder base; (iii) the location of the issuer's headquarters; (iv) the geographic distribution of the issuer's operations (in terms of assets and revenues); (v) the issuer's history with respect to these criteria; and (vi) the country in which investors consider the issuer to be most appropriately classified based on communications between the Index Provider and investors.

Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure.

Counterparty Risk . The Fund will be subject to credit risk with respect to the counterparties with which the Fund enters into derivatives contracts and other transactions such as repurchase agreements or reverse repurchase agreements. The Fund's ability to profit from these types of investments and transactions will depend on the willingness and ability of its counterparty to perform its obligations. If a counterparty fails to meet its contractual obligations, the Fund may be unable to terminate or realize any gain on the investment or transaction, resulting in a loss to the Fund. The Fund may experience significant delays in obtaining any recovery in an insolvency, bankruptcy, or other reorganization proceeding involving its counterparty (including recovery of any collateral posted by it) and may obtain only a limited recovery or may obtain no recovery in such circumstances. If the Fund holds collateral posted by its counterparty, it may be delayed or prevented from realizing on the collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty. Under applicable law or contractual provisions, including if the Fund enters into an investment or transaction with a financial institution and such financial institution (or an affiliate of the financial institution) experiences financial difficulties, then the Fund may in certain situations be prevented or delayed from exercising its rights to terminate the investment or transaction, or to realize on any collateral and may result in the suspension of payment and delivery obligations of the parties under such investment or transactions or in another institution being substituted for that financial institution without the consent of the Fund. Further, the Fund may be subject to “bail-in” risk under applicable law whereby, if required by the financial institution's authority, the financial institution's liabilities could be written down, eliminated or converted into equity or an alternative instrument of ownership. A bail-in of a financial institution may result in a reduction in value of some or all of its securities and, if the Fund holds such securities or has entered into a transaction with such a financial security when a bail-in occurs, such Fund may also be similarly impacted.

Currency Risk. Investments in issuers in different countries are often denominated in currencies other than the U.S. dollar. Changes in the values of those currencies relative to the U.S. dollar may have a positive or negative effect on the values of the Fund's investments denominated in those currencies. The values of other currencies relative to the U.S. dollar may fluctuate in response to, among other factors, interest rate changes, intervention (or failure to intervene) by national governments, central banks, or supranational entities such as the International Monetary Fund, the imposition of currency controls, and other political or regulatory developments. Currency values can decrease significantly both in the short term and over the long term in response to these and other developments. Continuing uncertainty as to the status of the Euro and the Economic and Monetary Union of the European Union (the “EMU”) has created significant volatility in currency and financial markets generally. Any partial or complete dissolution of the EMU, or any continued uncertainty as to its status, could have significant adverse effects on currency and financial markets, and on the values of the Fund's portfolio investments.

Depositary Receipts Risk . American Depositary Receipts (“ADRs”) are typically trust receipts issued by a U.S. bank or trust company that evidence an indirect interest in underlying securities issued by a foreign entity. Global Depositary Receipts (“GDRs”), European Depositary Receipts (“EDRs”), and other types of depositary receipts are typically issued by non-U.S. banks or financial institutions to evidence an interest in underlying securities issued by either a U.S. or a non-U.S. entity. Investments in non-U.S. issuers through ADRs, GDRs, EDRs, and other types of depositary receipts generally involve risks applicable to other types of investments in non-U.S. issuers. Investments in depositary receipts may be less liquid and more volatile than the underlying securities in their primary trading market. If a depositary receipt is denominated in a different currency than its underlying securities, the Fund will be subject to the currency risk of both the investment in the depositary receipt and the underlying security. There may be less publicly available information regarding the issuer of the securities underlying a depositary receipt than if those securities were traded directly in U.S. securities markets. Depositary receipts may or may not be sponsored by the issuers of the underlying securities, and information regarding issuers of securities underlying unsponsored depositary receipts may be more limited than for sponsored depositary receipts. The values of depositary receipts may decline for a number of reasons relating to the issuers or sponsors of the depositary receipts, including, but not limited to, insolvency of the issuer or sponsor. Holders of depositary receipts may have lim-

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ited or no rights to take action with respect to the underlying securities or to compel the issuer of the receipts to take action. The prices of depositary receipts may differ from the prices of securities upon which they are based. To the extent the Fund invests in depositary receipts based on securities included in the Index, such differences in prices may increase index tracking risk.

Derivatives Risk. A derivative is a financial contract the value of which depends on, or is derived from, the value of an underlying asset, interest rate, or index. Derivative transactions typically involve leverage and may have significant volatility. It is possible that a derivative transaction will result in a loss greater than the principal amount invested, and the Fund may not be able to close out a derivative transaction at a favorable time or price. Risks associated with derivative instruments include potential changes in value in response to interest rate changes or other market developments or as a result of the counterparty's credit quality; the potential for the derivative transaction not to have the effect the Adviser anticipated or a different or less favorable effect than the Adviser anticipated; the failure of the counterparty to the derivative transaction to perform its obligations under the transaction or to settle a trade; possible mispricing or improper valuation of the derivative instrument; imperfect correlation in the value of a derivative with the asset, rate, or index underlying the derivative; the risk that the Fund may be required to post collateral or margin with its counterparty, and will not be able to recover the collateral or margin in the event of the counterparty's insolvency or bankruptcy; the risk that the Fund will experience losses on its derivatives investments and on its other portfolio investments, even when the derivatives investments may be intended in part or entirely to hedge those portfolio investments; the risks specific to the asset underlying the derivative instrument; lack of liquidity for the derivative instrument, including without limitation absence of a secondary trading market; the potential for reduced returns to the Fund due to losses on the transaction and an increase in volatility; the potential for the derivative transaction to have the effect of accelerating the recognition of gain; and legal risks arising from the documentation relating to the derivative transaction.

Emerging Markets Risk . Investments in emerging markets are generally subject to a greater risk of loss than investments in developed markets. This may be due to, among other things, the possibility of greater market volatility, lower trading volume and liquidity, greater risk of expropriation, nationalization, and social, political and economic instability, greater reliance on a few industries, international trade or revenue from particular commodities, less developed accounting, legal and regulatory systems, higher levels of inflation, deflation or currency devaluation, greater risk of market shut down, and more significant governmental limitations on investment policy as compared to those typically found in a developed market. In addition, issuers (including governments) in emerging market countries may have less financial stability than in other countries. The securities of emerging market companies may trade less frequently and in smaller volumes than more widely held securities. Market disruptions or substantial market corrections may limit very significantly the liquidity of securities of certain companies in a particular country or geographic region, or of all companies in the country or region. The Fund may be unable to liquidate its positions in such securities at any time, or at a favorable price, in order to meet the Fund's obligations. There is also the potential for unfavorable action such as embargo and acts of war. As a result, there will tend to be an increased risk of price volatility in investments in emerging market countries, which may be magnified by currency fluctuations relative to the U.S. dollar. Settlement and asset custody practices for transactions in emerging markets may differ from those in developed markets. Such differences may include possible delays in settlement and certain settlement practices, such as delivery of securities prior to receipt of payment, which increase the likelihood of a “failed settlement.” Failed settlements can result in losses. For these and other reasons, investments in emerging markets are often considered speculative.

Equity Investing Risk . The market prices of equity securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer, such as management performance, financial leverage, non-compliance with regulatory requirements, and reduced demand for the issuer's goods or services. The values of equity securities also may decline due to general industry or market conditions that are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates, or adverse investor sentiment generally. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Financial Institutions Risk . Some instruments are issued or guaranteed by financial institutions, such as banks and brokers, or are collateralized by securities issued or guaranteed by financial institutions. Changes in the creditworthiness of any of these institutions may adversely affect the values of instruments of issuers in financial industries. Financial institutions may be particularly sensitive to certain economic factors such as interest rate changes, adverse developments in the real estate market, fiscal and monetary policy and general economic cycles. Adverse developments in banking and other financial industries may cause the Fund to underperform relative to other funds that invest more broadly across different industries or have a smaller exposure to financial institutions. Changes in governmental regulation and oversight of financial institutions may have an adverse effect on the financial condition or the earnings or operations of a financial institution and on the types and amounts of businesses in which a financial institution may engage. An investor may be delayed or prevented from exercising certain remedies against a financial institution. The amount of the Fund's assets that may be invested in any financial institution, or financial institutions generally, may be limited by applicable law.

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Financial Sector Risk. Financial services companies are subject to extensive governmental regulation which may limit both the amounts and types of loans and other financial commitments they can make, the interest rates and fees they can charge, the scope of their activities, the prices they can charge and the amount of capital they must maintain. Profitability is largely dependent on the availability and cost of capital funds and can fluctuate significantly when interest rates change or due to increased competition. In addition, deterioration of the credit markets generally may cause an adverse impact in a broad range of markets, including U.S. and international credit and interbank money markets generally, thereby affecting a wide range of financial institutions and markets. Certain events in the financial sector may cause an unusually high degree of volatility in the financial markets, both domestic and foreign, and cause certain financial services companies to incur large losses. Securities of financial services companies may experience a dramatic decline in value when such companies experience substantial declines in the valuations of their assets, take action to raise capital (such as the issuance of debt or equity securities), or cease operations. Credit losses resulting from financial difficulties of borrowers and financial losses associated with investment activities can negatively impact the sector. Insurance companies may be subject to severe price competition. Adverse economic, business or political developments could adversely affect financial institutions engaged in mortgage finance or other lending or investing activities directly or indirectly connected to the value of real estate.

Frontier Markets Risks . Investments in frontier markets may be more volatile and less liquid than investments in more developed markets or in other emerging market countries. Some of these markets may have relatively unstable governments, economies based on only a few industries and securities markets that trade only a limited number of securities. Many frontier markets do not have well-developed regulatory systems and disclosure standards may be less stringent than those of more developed markets. The risks of expropriation, nationalization, and social, political, and economic instability are greater in frontier markets than in more developed markets. These risks, which are characteristic of many emerging markets generally, may be especially heightened in frontier markets, due to political, economic, financial, or other factors.

Futures Contract Risk; Other Exchange-Traded Derivatives Risk . The risk of loss relating to the use of futures contracts and other exchange-traded derivatives is potentially unlimited. The ability to establish and close out positions in futures contracts and other exchange-traded derivatives will be subject to the development and maintenance of a liquid secondary market. There is no assurance that a liquid secondary market on an exchange will exist for any particular futures contract or other exchange-traded derivative or at any particular time. In the event no such market exists for a particular derivative, it might not be possible to effect closing transactions, and the Fund will be unable to terminate the derivative. In using futures contracts and other exchange-traded derivatives, the Fund will be reliant on the ability of the Adviser to predict market and price movements correctly; the skills needed to use such derivatives successfully are different from those needed for traditional portfolio management. If the Fund uses futures contracts or other exchange-traded derivatives for hedging purposes, there is a risk of imperfect correlation between movements in the prices of the derivatives and movements in the securities or index underlying the derivatives or movements in the prices of the Fund's investments that are the subject of such hedge. The prices of futures and other exchange-traded derivatives, for a number of reasons, may not correlate perfectly with movements in the securities or index underlying them. For example, participants in the futures markets and in markets for other exchange-traded derivatives are subject to margin deposit requirements. Such requirements may cause investors to take actions with respect to their derivatives positions that they would not otherwise take. The margin requirements in the derivatives markets may be less onerous than margin requirements in the securities markets in general, and as a result those markets may attract more speculators than the securities markets do. Increased participation by speculators in those markets may cause temporary price distortions. Due to the possibility of price distortion, even a correct forecast of general market trends by the Adviser still may not result in a successful derivatives activity over a very short time period. The risk of a position in a futures contract or other exchange-traded derivative may be very large compared to the relatively low level of margin the Fund is required to deposit. In many cases, a relatively small price movement in a futures contract may result in immediate and substantial loss or gain to the investor relative to the size of a required margin deposit. The Fund will incur brokerage fees in connection with its exchange-traded derivatives transactions. The Fund will typically be required to post margin with its futures commission merchant in connection with its transactions in futures contracts and other exchange-traded derivatives. In the event of an insolvency of the futures commission merchant or a clearing house, the Fund may not be able to recover all (or any) of the margin it has posted with the futures commission merchant, or to realize the value of any increase in the price of its positions, or it may experience a significant delay in doing so. The Fund also may be delayed or prevented from recovering margin or other amounts deposited with a futures commission merchant or futures clearinghouse. The Commodity Futures Trading Commission (the “CFTC”) and the various exchanges have established limits referred to as “speculative position limits” on the maximum net long or net short positions that any person and certain affiliated entities may hold or control in a particular futures contract. Trading limits are imposed on the number of contracts that any person may trade on a particular trading day. An exchange may order the liquidation of positions found to be in violation of these limits and it may impose sanctions or restrictions. In addition, the Dodd-Frank Act requires the CFTC to establish speculative position limits on certain commodity futures contracts and their economically equivalent futures, options and swaps. Regulatory action taken by the

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CFTC to establish these additional position limits may adversely affect the market liquidity of the futures, options and economically equivalent derivatives in which the Fund may invest. It is possible that, as a result of such limits, the Fund's adviser will be precluded from taking positions in certain futures contracts or over-the-counter derivatives as a result of positions held by other clients of the adviser or by the adviser or its affiliates themselves.

Futures contracts and other exchange-traded derivatives traded on markets outside the U.S. are not generally subject to the same level of regulation by the CFTC or other U.S. regulatory entities as contracts traded in the U.S., including without limitation as to the execution, delivery, and clearing of transactions. U.S. regulators neither regulate the activities of a foreign exchange, nor have the power to compel enforcement of the rules of the foreign exchange or the laws of the foreign country in question. Margin and other payments made by the Fund may not be afforded the same protections as are afforded those payments in the U.S., including in connection with the insolvency of an executing or clearing broker or a clearinghouse or exchange. Certain foreign futures contracts and other exchange-traded derivatives may be less liquid and more volatile than U.S. contracts.

Geographic Focus Risk . The performance of a fund that is less diversified across countries or geographic regions will be closely tied to market, currency, economic, political, environmental, or regulatory conditions and developments in the countries or regions in which the fund invests, and may be more volatile than the performance of a more geographically-diversified fund.

China . The economy of China differs, often unfavorably, from the U.S. economy in such respects as structure, general development, government involvement, wealth distribution, rate of inflation, growth rate, allocation of resources and capital reinvestment, among others. Under China's political and economic system, the central government has historically exercised substantial control over virtually every sector of the Chinese economy through administrative regulation and/or state ownership. Since 1978, the Chinese government has been, and is expected to continue, reforming its economic policies, which has resulted in less direct central and local government control over the business and production activities of Chinese enterprises and companies. Notwithstanding the economic reforms instituted by the Chinese government and the Chinese Communist Party, actions of the Chinese central and local government authorities continue to have a substantial effect on economic conditions in China, which could affect the public and private sector companies in which the Fund invests. In the past, the Chinese government has from time to time taken actions that influence the prices at which certain goods may be sold, encourage companies to invest or concentrate in particular industries, induce mergers between companies in certain industries and induce private companies to publicly offer their securities to increase or continue the rate of economic growth, control the rate of inflation or otherwise regulate economic expansion. It may do so in the future as well. Such actions and a variety of other centrally planned or determined activities by the Chinese government could have a significant adverse effect on economic conditions in China, the economic prospects for, and the market prices and liquidity of, the securities of Chinese companies and the payments of dividends and interest by Chinese companies. In addition, expropriation, including nationalization, confiscatory taxation, political, economic or social instability or other developments could adversely affect and significantly diminish the values of the Chinese companies in which the Fund invests. The Chinese economy and financial markets have experienced high levels of growth in recent years; any actual or perceived reduction or curtailment in those levels of growth in the future would likely have a substantial adverse impact on the values of Chinese companies. These factors and others could negatively affect the value and liquidity of the Fund. The Fund may invest in shares of Chinese companies traded on stock markets in Mainland China or Hong Kong. These stock markets have recently experienced high levels of volatility, which may continue in the future. The Hong Kong stock market may behave differently from the Mainland China stock market and there may be little to no correlation between the performance of the Hong Kong stock market and the Mainland China stock market.

From time to time, certain of the companies in which a Fund may invest may operate in, or have dealings with, countries subject to sanctions or embargoes imposed by the U.S. government and the United Nations and/or in countries identified by the U.S. government as state sponsors of terrorism. One or more of these companies may be subject to constraints under U.S. law or regulations which could negatively affect the company's performance. Additionally, one or more of these companies may suffer damage to its reputation if it is identified as a company which invests or deals with countries which are identified by the U.S. government as state sponsors of terrorism or subject to sanctions. As an investor in such companies, the Fund will be indirectly subject to these risks.

South Korea . In addition, economic and political developments of South Korean neighbors may have an adverse effect on the South Korean economy. Substantial political tensions exist between North Korea and South Korea and, recently, these political tensions have escalated. The outbreak of hostilities between the two nations, or even the threat of such an outbreak, will likely adversely impact the South Korean economy. In addition, South Korea's economic growth potential has recently been on a decline, mainly because of a rapidly aging population and structural problems. Among these structural concerns are the country's underdeveloped financial markets and a general lack of regulatory transparency. The restructuring of the South Korean economy, including the creation of a mechanism for bankrupt firms to exit the market, remains an important unfinished task.

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These factors may adversely affect the South Korean economy and cause a diversion of corporate investment to China and other lower wage countries. South Korea's economic growth potential is susceptible to problems from large scale emigration, rigid labor regulations and ongoing labor relations issues.

Indexing Strategy/Index Tracking Risk . The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities. The Fund will seek to replicate Index returns, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. The Fund generally will buy and will not sell a security included in the Index as long as the security is part of the Index regardless of any sudden or material decline in value or foreseeable material decline in value of the security, even though the Adviser may make a different investment decision for other actively managed accounts or portfolios that hold the security. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index (in absolute terms and by comparison with other indices) and, consequently, the performance, volatility, and risk of the Fund. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index for a number of reasons. For example, the return on the sample of securities purchased by the Fund (or the return on securities not included in the Index) to replicate the performance of the Index may not correlate precisely with the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, either as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. The Adviser may attempt to replicate the Index return by investing in fewer than all of the securities in the Index, or in some securities not included in the Index, potentially increasing the risk of divergence between the Fund's return and that of the Index. Changes in the composition of the Index and regulatory requirements also may impact the Fund's ability to match the return of the Index. The Adviser may apply one or more “screens” or investment techniques to refine or limit the number or types of issuers included in the Index in which the Fund may invest. Application of such screens or techniques may result in investment performance below that of the Index and may not produce results expected by the Adviser. Index tracking risk may be heightened during times of increased market volatility or other unusual market conditions.

Large-Capitalization Securities Risk . Securities issued by large-capitalization companies may present risks not present in smaller companies. For example, larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or other market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies, especially during strong economic periods. Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies.

Leveraging Risk . Borrowing transactions, reverse repurchase agreements, certain derivatives transactions, securities lending transactions and other investment transactions such as when-issued, delayed-delivery, or forward commitment transactions may create investment leverage. If the Fund engages in transactions that have a leveraging effect on the Fund's investment portfolio, the value of the Fund will be potentially more volatile and all other risks will tend to be compounded. This is because leverage generally creates investment risk with respect to a larger base of assets than the Fund would otherwise have and so magnifies the effect of any increase or decrease in the value of the Fund's underlying assets. The use of leverage is considered to be a speculative investment practice and may result in losses to the Fund. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. The use of leverage may cause the Fund to liquidate positions when it may not be advantageous to do so to satisfy repayment, interest payment, or margin obligations or to meet asset segregation or coverage requirements.

Liquidity Risk . Liquidity risk is the risk that the Fund may not be able to dispose of securities or close out derivatives transactions readily at a favorable time or prices (or at all) or at prices approximating those at which the Fund currently values them. For example, certain investments may be subject to restrictions on resale, may trade in the over-the-counter market or in limited volume, or may not have an active trading market. Illiquid securities may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value. It may be difficult for the Fund to value illiquid securities accurately. The market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. Disposal of illiquid securities may entail registration expenses and other transaction costs that are higher than those for liquid securities. The Fund may seek to borrow money to meet its obligations (including among other things redemption obligations) if it is unable to dispose of illiquid investments, resulting in borrowing expenses and possible leveraging of the Fund. In some cases, due to unanticipated levels of illiquidity the Fund may choose to meet its redemption obligations wholly or in part by distributions of assets in-kind.

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In compliance with the SEC's new liquidity risk management rule applicable to open-end mutual funds, the Fund recently established a liquidity risk management program. The rule's impact on the Fund, and on the open-end fund industry in general, is not yet fully known, but the rule could affect the Fund's performance and its ability to achieve its investment objectives. While the liquidity risk management program attempts to assess and manage liquidity risk, there is no guarantee it will be effective in its operations and may not reduce the liquidity risk inherent in the Fund's investments.

Market Disruption and Geopolitical Risk. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets. War, terrorism, and related geopolitical events have led, and in the future may lead, to increased short-term market volatility and may have adverse long-term effects on U.S. and world economies and markets generally. Likewise, natural and environmental disasters and systemic market dislocations may be highly disruptive to economies and markets. Those events as well as other changes in foreign and domestic economic and political conditions also could adversely affect individual issuers or related groups of issuers, securities markets, interest rates, credit ratings, inflation, investor sentiment, and other factors affecting the value of the Fund's investments. Given the increasing interdependence among global economies and markets, conditions in one country, market, or region might adversely affect markets, issuers, and/or foreign exchange rates in other countries, including the U.S. Any partial or complete dissolution of the Economic and Monetary Union of the European Union, or any increased uncertainty as to its status, could have significant adverse effects on currency and financial markets, and on the values of the Fund's investments. Securities and financial markets may be susceptible to market manipulation or other fraudulent trade practices, which could disrupt the orderly functioning of these markets or adversely affect the values of investments traded in these markets, including investments held by the Fund. To the extent the Fund has focused its investments in the market or index of a particular region, adverse geopolitical and other events could have a disproportionate impact on the Fund.

Market Risk . Market prices of investments held by the Fund will go up or down, sometimes rapidly or unpredictably. The Fund's investments are subject to changes in general economic conditions, general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in actual or perceived creditworthiness of issuers and general market liquidity. Even if general economic conditions do not change, the value of an investment in the Fund could decline if the particular industries, sectors or companies in which the Fund invests do not perform well or are adversely affected by events. Further, legal, political, regulatory and tax changes also may cause fluctuations in markets and securities prices.

Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject the Fund to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and the Fund's investment program in particular can be uncertain. In recent periods, governmental and non-governmental issuers have defaulted on, or have been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including, without limitation, in Europe or Asia. Defaults or restructurings by governments or others of their debts could have substantial adverse effects on economies, financial markets, and asset valuations around the world. Further Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, or investor perception that these efforts are not succeeding, could negatively affect financial markets generally as well as the values and liquidity of certain securities.

Mid-Capitalization Securities Risk . The securities of mid-capitalization companies may be more volatile and may involve more risk than the securities of larger companies. These companies may have limited product lines, markets or financial resources, may lack the competitive strength of larger companies, and may depend on a few key employees. In addition, these companies may have been recently organized and may have little or no track record of success. The securities of mid-sized companies may trade less frequently and in smaller volumes than more widely held securities. The prices of these securities may fluctuate more sharply than those of other securities, and the Fund may experience some difficulty in establishing or closing out positions in these securities at prevailing market prices. There may be less publicly available information about the issuers of these securities or less market interest in

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these securities than in the case of larger companies, both of which can cause significant price volatility. Some securities of mid-sized issuers may be illiquid or may be restricted as to resale. Returns on investments in securities of mid-capitalization companies could trail the returns on investments in securities of larger or smaller companies.

Non-U.S. Securities Risk . Investments in securities of non-U.S. issuers (including depositary receipts) entail risks not typically associated with investing in securities of U.S. issuers. Similar risks may apply to securities traded on a U.S. securities exchange that are issued by entities with significant exposure to non-U.S. countries. In certain countries, legal remedies available to investors may be more limited than those available with regard to U.S. investments. Because non-U.S. securities are typically denominated and traded in currencies other than the U.S. dollar, the value of the Fund's assets, to the extent they are non-U.S. dollar denominated, may be affected favorably or unfavorably by currency exchange rates, exchange control regulations, and restrictions or prohibitions on the repatriation of non-U.S. currencies. Income and gains with respect to investments in certain countries may be subject to withholding and other taxes. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, and financial reporting standards, regulatory framework and practices comparable to those in the United States. The securities of some non-U.S. entities are less liquid and at times more volatile than securities of comparable U.S. entities, and could become subject to sanctions or embargoes that adversely affect the Fund's investment. Non-U.S. transaction costs, such as brokerage commissions and custody costs may be higher than in the U.S. In addition, there may be a possibility of nationalization or expropriation of assets, imposition of currency exchange controls, confiscatory taxation, and diplomatic developments that could adversely affect the values of the Fund's investments in certain non-U.S. countries. Investments in securities of non-U.S. issuers also are subject to foreign political and economic risk not associated with U.S. investments, meaning that political events (civil unrest, national elections, changes in political conditions and foreign relations, imposition of exchange controls and repatriation restrictions), social and economic events (labor strikes, rising inflation) and natural disasters occurring in a country where the Fund invests could cause the Fund's investments in that country to experience gains or losses.

Risk of Investment in Other Pools . If the Fund invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected. The Fund is exposed indirectly to all of the risks applicable to an investment in such other pool. In addition, lack of liquidity in the underlying pool could result in its value being more volatile than the underlying portfolio of securities, and may limit the ability of the Fund to sell or redeem its interest in the pool at a time or at a price it might consider desirable. The investment policies and limitations of the other pool may not be the same as those of the Fund; as a result, the Fund may be subject to additional or different risks, or may achieve a reduced investment return, as a result of its investment in another pool. If a pool is an exchange-traded fund or other product traded on a securities exchange or otherwise actively traded, its shares may trade at a premium or discount to their NAV, an effect that might be more pronounced in less liquid markets. The Fund bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Fund may invest, leading to potential conflicts of interest. For example, the Adviser or its affiliates may receive fees based on the amount of assets invested in the pool. Investment by the Fund in the pool may be beneficial to the Adviser or an affiliate in the management of the pool, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest the Fund's assets in a pool sponsored or managed by the Adviser or its affiliates in lieu of investments by the Fund directly in portfolio securities, or may have an incentive to invest in the pool over a pool sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by the Fund in a pool sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which the Fund does so.

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Settlement Risk . Markets in different countries have different clearance and settlement procedures and in certain markets there have been times when settlements have been unable to keep pace with the volume of transactions. Delays in settlement may increase credit risk to the Fund, limit the ability of the Fund to reinvest the proceeds of a sale of securities, hinder the ability of the Fund to lend its portfolio securities, and potentially subject the Fund to penalties for its failure to deliver to on-purchasers of securities whose delivery to the Fund was delayed. Delays in the settlement of securities purchased by the Fund may limit the ability of the Fund to sell those securities at times and prices it considers desirable, and may subject the Fund to losses and costs due to its own inability to settle with subsequent purchasers of the securities from it. The Fund may be required to borrow monies it had otherwise expected to receive in connection with the settlement of securities sold by it, in order to meet its obligations to others. Limits on the ability of the Fund to purchase or sell securities due to settlement delays could increase any variance between the Fund's performance and that of its benchmark index.

Technology Sector Risk. The Fund's assets may be focused in the technology sector, which means the Fund will be more affected by the performance of the technology sector than a fund that is more diversified. Market or economic factors impacting technology companies and companies that rely heavily on technological advances could have a major effect on the value of the Fund's investments. The value of stocks of technology companies and companies that rely heavily on technology is particularly vulnerable to rapid changes in technology product cycles, rapid product obsolescence, government regulation and competition, both domestically and internationally, including competition from foreign competitors with lower production costs. Stocks of technology companies and companies that rely heavily on technology, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market. Technology companies are heavily dependent on patent and intellectual property rights, the loss or impairment of which may adversely affect profitability. Additionally, companies in the technology sector may face dramatic and often unpredictable changes in growth rates and competition for the services of qualified personnel.

Unconstrained Sector Risk . The Fund may invest a substantial portion of its assets within one or more economic sectors or industries, which may change from time to time. When the Fund focuses its investments in a particular industry or sector, financial, economic, business, and other developments affecting issuers in that industry, market, or economic sector will have a greater effect on the Fund than if it had not focused its assets in that industry, market, or economic sector, which may increase the volatility of the Fund. Any such investment focus may also limit the liquidity of the Fund. In addition, investors may buy or sell substantial amounts of the Fund's shares in response to factors affecting or expected to affect an industry, market, or economic sector in which the Fund focuses its investments, resulting in extreme inflows or outflows of cash into and out of the Fund. Such extreme cash inflows and outflows might affect management of the Fund adversely.

Valuation Risk . Some portfolio holdings, potentially a large portion of the Fund's investment portfolio, may be valued on the basis of factors other than market quotations. This may occur more often in times of market turmoil or reduced liquidity. There are multiple methods that can be used to value a portfolio holding when market quotations are not readily available. The value established for any portfolio holding at a point in time might differ from what would be produced using a different methodology or if it had been priced using market quotations. Portfolio holdings that are valued using techniques other than market quotations, including “fair valued” securities, may be subject to greater fluctuation in their valuations from one day to the next than if market quotations were used. Technological issues or other service disruption issues involving third-party service providers may cause the Fund to value its investments incorrectly. In addition, there is no assurance that the Fund could sell or close out a portfolio position for the value established for it at any time, and it is possible that the Fund would incur a loss because a portfolio position is sold or closed out at a discount to the valuation established by the Fund at that time. Investors who purchase or redeem Fund Shares on days when the Fund is holding fair-valued investments may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the Fund had not fair-valued the holding(s) or had used a different valuation methodology.

Additional Information About Non-Principal Investment Strategies and Risks

Conflicts of Interest Risk. An investment in the Fund will be subject to a number of actual or potential conflicts of interest. For example, the Adviser or its affiliates may provide services to the Fund, such as securities lending agency services, custodial, administrative, bookkeeping, and accounting services, transfer agency and shareholder servicing, securities brokerage services, and other services for which the Fund would compensate the Adviser and/or such affiliates. The Fund may invest in other pooled investment vehicles sponsored, managed, or otherwise affiliated with the Adviser. There is no assurance that the rates at which the Fund pays fees or expenses to the Adviser or its affiliates, or the terms on which it enters into transactions with the Adviser or its affiliates will be the most favorable available in the market generally or as favorable as the rates the Adviser makes available to other clients. Because of its financial interest, the Adviser will have an incentive to enter into transactions or arrangements on behalf of the Fund with itself or its affiliates in circumstances where it might not have done so in the absence of that interest, provided that the Adviser will comply with applicable regulatory requirements.

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The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Fund. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for the Fund and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by the Fund. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Fund) or otherwise using such information for the benefit of its clients or itself.

The foregoing does not purport to be a comprehensive list or complete explanation of all potential conflicts of interests which may affect the Fund. The Fund may encounter circumstances, or enter into transactions, in which conflicts of interest that are not listed or discussed above may arise.

Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Fund) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, the Fund, the Adviser, or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect the Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect the Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject the Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of the Fund inaccessible or inaccurate or incomplete. The Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. The Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. The Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Fund. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which the Fund invests, which could result in material adverse consequences for such issuers, and may cause the Fund's investment in such securities to lose value.

Index Construction Risk . A security included in the Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently the Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

Index Licensing Risk . It is possible that the license under which the Adviser or the Fund is permitted to replicate or otherwise use the Index will be terminated or may be disputed, impaired or cease to remain in effect. In such a case, the Adviser may be required to replace the Index with another index which it considers to be appropriate in light of the investment strategy of the Fund. The use of any such substitute index may have an adverse impact on the Fund's performance. In the event that the Adviser is unable to identify a suitable replacement for the Index, it may determine to terminate the Fund.

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securities in a timely manner or at all. Should the borrower of the securities fail financially, the Fund may experience delays in recovering the securities or exercising its rights in the collateral. Loans are made only to borrowers that are deemed by the securities lending agent to be of good financial standing. In a loan transaction, the Fund will also bear the risk of any decline in value of securities acquired with cash collateral. The Fund expects to invest cash collateral in a pooled investment vehicle advised by the Adviser. With respect to index funds, to the extent the collateral provided or investments made with cash collateral differ from securities included in the relevant Index, such collateral or investments may have a greater risk of loss than the securities included in the Index. In addition, the Fund will be subject to the risk that any income generated by reinvesting cash collateral is lower than any fees the Fund has agreed to pay a borrower.

Portfolio Holdings Disclosure

The Fund's portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

The Fund is a separate, diversified series of the State Street Institutional Investment Trust (the “Trust”), which is an open-end management investment company organized as a business trust under the laws of The Commonwealth of Massachusetts.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund and, subject to the oversight of the Board, is responsible for the investment management of the Fund. The Adviser provides an investment management program for the Fund and manages the investment of the Fund's assets. The Adviser is a wholly-owned subsidiary of State Street Global Advisors, Inc., which itself is a wholly-owned subsidiary of State Street Corporation. The Adviser is registered with the U.S. Securities and Exchange Commission (“SEC”) under the Investment Advisers Act of 1940, as amended. The Adviser and certain other affiliates of State Street Corporation make up SSGA. SSGA is one of the world's largest institutional money managers and the investment management arm of State Street Corporation. As of December 31, 2018, the Adviser managed approximately $452.10 billion in assets and SSGA managed approximately $2.51 trillion in assets. The Adviser's principal business address is One Iron Street, Boston, Massachusetts 02210.

The Fund has entered into an investment advisory agreement with the Adviser, pursuant to which the Adviser will manage the Fund's assets for compensation paid at the annual rate of 0.14% of the Fund's average daily net assets.

Total Annual Fund Operating Expense Waiver . SSGA FM, as the investment adviser to the Fund, is contractually obligated, through April 30, 2020, (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, extraordinary expenses, interest, taxes, extraordinary expenses, acquired fund fees, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.12% of average daily net assets on an annual basis. This waiver and/or reimbursement arrangement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

A discussion regarding the Board's consideration of the Fund's Investment Advisory Agreement is provided in the Fund's Semi-Annual Report to Shareholders for the period ended June 30, 2018.

The Adviser manages the Fund using a team of investment professionals. The team approach is used to create an environment that encourages the flow of investment ideas. The portfolio managers within the team work together in a cohesive manner to develop and enhance techniques that drive the investment process for the respective investment strategy. This approach requires portfolio managers to share a variety of responsibilities including investment strategy and analysis while retaining responsibility for the implementation of the strategy within any particular portfolio. The approach also enables the team to draw upon the resources of other groups within SSGA. The portfolio management team is overseen by the SSGA Investment Committee.

The professionals primarily responsible for the day-to-day management of the Fund include the following:

Thomas Coleman, CFA, is a Vice President of SSGA and the Adviser and a Senior Portfolio Manager in the Global Equity Beta Solutions Group. Within this group, Mr. Coleman is the Emerging Markets Strategy leader and as such, he is responsible for the management of a variety of commingled, segregated, and exchange traded products benchmarked to international indices, including MSCI Emerging Markets and ACWI indices, as well as S&P Emerging Markets indices. Mr. Coleman is also responsible for domestic strategies benchmarked to Russell, Standard & Poor's, and NASDAQ indices. Prior to assuming his current role in April 2004, he managed SSGA's International Structured Products Group Operations Team. Mr. Coleman holds a Bachelor of Science in Finance and Accounting from Boston College and a Master of Business Administration from Babson College. He also earned the Chartered Financial Analyst (CFA) designation and is a member of CFA Society Boston, Inc.

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Additional information about the portfolio managers' compensation, other accounts managed by the portfolio managers, and the portfolio managers' ownership of the Fund is available in the SAI.

Other Fund Services

The Administrator, Sub-Administrator and Custodian

The Adviser serves as administrator of the Fund. The amount of the fee paid to the Adviser for administrative services may vary by share class. The Fund currently pays the Adviser an administrative fee at the annual rate of 0.05% with respect to each of its share classes. State Street, a subsidiary of State Street Corporation, serves as sub-administrator for the Fund for a fee that is paid by the Adviser. State Street also serves as custodian of the Fund for a separate fee that is paid by the Fund.

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Fund's transfer agent and dividend disbursing agent (the “Transfer Agent”).

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Fund's distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

Additional Information

The Trustees of the Trust oversee generally the operations of the Fund and the Trust. The Trust enters into contractual arrangements with various parties, including among others the Fund's investment adviser, custodian, transfer agent, and accountants, who provide services to the Fund. Shareholders are not parties to any such contractual arrangements or intended beneficiaries of those contractual arrangements, and those contractual arrangements are not intended to create in any shareholder any right to enforce them directly against the service providers or to seek any remedy under them directly against the service providers.

This Prospectus provides information concerning the Trust and the Fund that you should consider in determining whether to purchase shares of the Fund. Neither this Prospectus, nor the related SAI, is intended, or should be read, to be or to give rise to an agreement or contract between the Trust or the Fund and any investor, or to give rise to any rights in any shareholder or other person other than any rights under federal or state law that may not be waived.

Shareholder Information

Determination of Net Asset Value

The Fund determines its net asset value (“NAV”) per share once each business day as of the scheduled close of regular trading on the New York Stock Exchange (the “NYSE”). Pricing does not occur on NYSE holidays. A business day is one on which the NYSE is open for regular trading. The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. In unusual circumstances, such as an emergency or an unscheduled close or halt of trading on the NYSE, the time at which share prices are determined may be changed. The NAV per share is based on the market value of the investments held in the Fund. The NAV of each class of the Fund's Shares is calculated by dividing the value of the assets of the Fund attributable to that class less the liabilities of the Fund attributable to that class by the number of shares in the class outstanding.As noted in this Prospectus, the Fund may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when the Fund does not price its shares. Consequently, the NAV of the Fund's Shares may change on days when shareholders are not able to purchase or redeem the Fund's Shares. Purchase and redemption orders for Fund Shares are processed, respectively, at the NAV next determined after the Fund accepts a purchase order or receives a redemption request in good form. The Fund values each security or other investment pursuant to guidelines adopted by the Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Fund's Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii)

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a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by the Fund occurs after the close of a related exchange but before the determination of the Fund's NAV. Attempts to determine the fair value of securities or other investments introduce an element of subjectivity to the pricing of securities or other investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the price the Fund would have received had it sold the investment. To the extent that the Fund invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the funds. The prospectuses of these funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

Investing in State Street Institutional Investment Trust Shares

Purchasing Shares

Choosing a Share Class

The Fund offers three classes of shares through this Prospectus: Class A, Class I and Class K, available to you subject to the eligibility requirements set forth below.

All classes of the Fund share the same investment objective and investments, but the different share classes have different expense structures and eligibility requirements. You should choose the class with the expense structure that best meets your needs and for which you are eligible. Some factors to consider are the amount you plan to invest, the time period before you expect to sell your shares, and whether you might invest more money in the Fund in the future. Your investment professional can help you choose the share class that best suits your investment needs.

When you buy Class A shares, the initial sales load is deducted from the amount you invest, unless you qualify for an initial sales load waiver. This means that less money will be invested in the Fund immediately. Class A shares have a Rule 12b-1 fee of 0.25% per year. A contingent deferred sales charge (“CDSC”) of 1.00% may be assessed on redemptions of Class A shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase as part of an investment of $1,000,000 or more.

The chart below summarizes the features of the different share classes. This chart is only a general summary, and you should read the description of the Fund's expenses in the Fund Summary in this Prospectus.

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	Class A	Class I	Class K
Availability	Available to the general public through certain Financial Intermediaries.	Limited to certain investors, including: • Certain banks, broker-dealers and other Financial Intermediaries. • Certain employer- sponsored retirement plans. • Certain employees or affiliates of State Street Corporation or its affiliates	Limited to certain investors, including certain qualified recordkeepers and employer-sponsored retirement plans.
Minimum Initial Investment	$2,000. The investment minimum may be modified, waived or reduced for certain types of investors ( e.g ., 401(k) or 403(b) plans) and investments as well as for certain fee-based programs where an agreement is in place.	$1,000,000. The investment minimum may be modified, waived or reduced for certain types of investors (e.g., 401(k) or 403(b) plans) and investments as well as for certain fee- based programs where an agreement is in place.	$10,000,000. The investment minimum may be modified, waived or reduced for certain types of investors ( e.g ., 401(k) or 403(b) plans) and investments as well as for certain fee- based programs where an agreement is in place.
Maximum Investment	None.	None.	None.
Initial (Front-End) Sales Charge	Yes. 5.25%, payable at time of purchase. Lower sales charges are available for larger investments. See the chart under “Class A” section of this Prospectus.	No. Entire purchase price is invested in shares of the Fund.	No. Entire purchase price is invested in shares of the Fund.
Deferred (CDSC) Sales Charge	No, except for purchases of $1,000,000 or more that are redeemed within 18 months after purchase.	No.	No.
Distribution and Service (Rule 12b-1) Fees	0.25% annual fee.	No.	No.
Redemption Fees	No.	No.	No.

Class A

Class A shares are available to the general public for investment through qualified recordkeepers with a distribution and/or fund servicing agreement maintained with SSGA FD.

When you buy Class A shares, you pay an initial (or front-end) sales charge at the time of your investment, which is included in the offering price, unless you qualify for a sales charge reduction or waiver. This fee is deducted from the amount you invest, and the remainder of your money is used to buy shares in the Fund. The table below shows the amount of sales charge you would pay at different levels of investment and the commissions paid to Financial Intermediaries at each level of investment. The actual sales charge you pay may vary slightly from the rates disclosed due to rounding.

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Amount of Purchase Payment	Sales Charge as a % of Offering Price	Sales Charge as a % of Net Amount Invested	Financial Intermediary Compensation as a % of Offering Price
Less than $50,000	5.25%	5.54%	4.75%
$50,000-$99,999	4.50%	4.71%	4.00%
$100,000-$249,999	3.50%	3.63%	3.25%
$250,000-$499,999	2.50%	2.56%	2.25%
$500,000-$999,999	2.00%	2.04%	1.75%
$1,000,000 or more	None	None	Advanced Commission ^{1, 2}

¹	Class A advanced commission for purchases over $1 million:

1.00%	First $3 million
Plus 0.50%	Next $12 million
Plus 0.25%	Over $15 million

If you purchase $1,000,000 or more of Class A shares of the Fund, you will not be assessed a sales charge at the time of purchase. SSGA FD pays broker-dealers advanced commissions that are calculated on a year-by-year basis based on the amounts invested during that year. Accordingly, with respect to additional purchase amounts, the advanced commission breakpoint resets annually to the first breakpoint on the anniversary of the first purchase. You may be charged a deferred sales charge of 1.00% of the lesser of the original cost of the shares being redeemed or your redemption proceeds if you redeem your shares within 18 months after purchase.

Reducing Your Class A Sales Charge

The Fund offers two principal ways for you to qualify for discounts on initial sales charges on Class A share purchases, often referred to as “breakpoint discounts”: Right of Accumulation or a Letter of Intent. Each of these methods is described below. In taking advantage of these methods for reducing the initial sales charge you will pay, you may link purchases of shares of all of the State Street Funds that offer Class A shares in which you invest (as described below) even if such State Street Funds are held in accounts with different Financial Intermediaries, as well as purchases of Class I and Class N shares of all State Street Funds (other than shares of money market funds) to be held in accounts owned by your spouse or domestic partner and children under the age of 21 who share your residential address. It is your responsibility when investing to inform your Financial Intermediary or the State Street Funds that you would like to have one or more of the State Street Funds linked together for purposes of reducing the initial sales charge .

1.	Your account(s);
2.	Account(s) of your spouse or domestic partner;
3.	Account(s) of children under the age of 21 who share your residential address;
4.	Trust accounts established by any of the individuals in items (1) through (3) above. If the person(s) who established the trust is deceased, the trust account may be aggregated with the account(s) of the primary beneficiary of the trust;
5.	Solely controlled business accounts; and
6.	Single-participant retirement plans of any of the individuals in items (1) through (3) above.

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Gifting of Shares . If you make a gift of shares, upon your request, you may combine purchases, if made at the same time, under right of accumulation of Class A, Class I and Class N shares of a State Street Fund (other than any shares of money market funds) at the sales charge discount allowed for the combined purchase. The receiver of the gift may also be entitled to a prospective reduction in sales charges in accordance with the Fund's right of accumulation or other provisions. You or the receiver of the gift must provide certain account information to State Street or their agents at the time of purchase to exercise this right.

Letter of Intent. In order to immediately reduce your Class A sales charge, you may sign a Letter of Intent stating your intention to buy a specified amount of Class A shares of one or more State Street Funds within a 13-month period at the reduced sales charge rates applicable to the aggregate amount of the intended purchases stated in the Letter. Purchases of Class A shares of one or more State Street Funds you make over the 13- month period will be combined and you will pay the same sales charge on the new Class A shares that you would have paid if all shares were purchased at once. The 13-month Letter of Intent period commences on the day that the Letter of Intent is received by the Fund or your Financial Intermediary. Purchases submitted not more than three months prior to the date the Letter of Intent is received are considered in determining the level of sales charge that will be paid pursuant to the Letter of Intent; however, the Letter of Intent will not result in any reduction in the amount of any previously paid sales charge. In addition, investors do not receive credit for shares purchased by the reinvestment of distributions.

Waiver Of The Class A Sales Charge

A sales charge (“load”) may not be imposed on Class A shares of the Fund if the shares were:

1.	Acquired through the reinvestment of dividends and capital gain distributions.
2.	Acquired in exchange for shares of another Class A State Street Fund that were previously assessed a sales charge. However, if your shares are subject to CDSC, the CDSC will continue to apply to your new shares at the same CDSC rate.
3.	Bought in State Street Funds that do not offer Class N (no load) shares ¹ by officers, directors or trustees, retirees and employees and their immediate family members (i.e., spouses, domestic partners, children, grandchildren, parents, grandparents, and any dependent of the person, as defined in Section 152 of the Internal Revenue Code of 1986 (the “Code”)) of:

•	The State Street Funds
•	State Street Corporation and its subsidiaries and affiliates

4.	Bought by employees of:

•	DST Asset Manager Solutions, Inc. and its subsidiaries and affiliates.

•

Financial Intermediaries of financial institutions that have entered into selling agreements with the Fund or SSGA FD and their subsidiaries and affiliates (or otherwise have an arrangement with a Financial Intermediary or financial institution with respect to sales of Fund Shares). This waiver includes the employees' immediate family members (i.e., spouses, domestic partners, children, grandchildren, parents, grandparents and any dependent of the employee, as defined in Section 152 of the Code).

5.	Bought by:

•	Authorized retirement plans serviced or sponsored by a Financial Intermediary, provided that such Financial Intermediary has entered into an agreement with SSGA FD or with the Fund with respect to such purchases at NAV.
•	Investors who are directly rolling over or transferring shares from an established State Street Fund or State Street qualified retirement plan. Rolling over or transferring shares involves the transferring of shares (in-kind); there is no cash movement associated with the transaction.

¹	State Street Funds that offer Class N Shares include: State Street Dynamic Small Cap Fund (SVSCX), State Street Defensive Emerging Markets Equity Fund (SSEMX), State Street International Stock Selection Fund (SSAIX) and State Street S&P 500 Index Fund (SVSPX).

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•	Clients of Financial Intermediaries that (i) charge an ongoing fee for advisory, management, consulting or similar services, or (ii) have entered into an agreement with SSGA FD to offer Class A shares through a no-load network or platform, or self-directed brokerage accounts that may or may not charge transaction fees to customers.
•	Insurance company separate accounts.
•	Tuition Programs that qualify under Section 529 of the Code.

6.	Bought with proceeds from the sale of Class A shares of a State Street Fund, but only if the purchase is made within 90 days of the sale or distribution. Appropriate documentation may be required. Please refer to Class A Account Reinstatement Privileges below.
7.	Bought in connection with plans of reorganization of a State Street Fund, such as mergers, asset acquisitions and exchange offers to which the Fund is a party. However, you may pay a CDSC when you sell the Fund Shares you received in connection with the plan of reorganization.

Additional Sales Charge Waiver Disclosure

How the CDSC is Calculated

The State Street Funds calculate the CDSC by treating all purchases made in a given month as though they were made on the first day of the month.

You should retain any records necessary to substantiate historical costs because SSGA FD, the Fund, the transfer agent and your Financial Intermediary may not maintain such information.

Waiver of the CDSC

In the following situations, no CDSC is imposed on redemptions of Class A shares of the Fund:

1.	If you participate in the Automatic Withdrawal Plan (AWP). Redemptions made on a regular periodic basis ( e.g . monthly) will not be subject to any applicable CDSC if they are, in the aggregate, less than or equal to 10% annually of the current market value of the account balance. Redemptions made as part of a required minimum distribution are also included in calculating amounts eligible for this waiver. For information on the Automatic Withdrawal Plan, please see Service Options.
2.	If you are a registered participant or beneficial owner of an account and you die or become disabled (as defined in Section 72(m)(7) of the Code). This waiver is only available for accounts open prior to the shareholder's or beneficiary's death or disability, and the redemption must be made within one year of such event. Subsequent purchases into such account are not eligible for the CDSC waiver. In order to qualify for this waiver, SSGA FD must be notified of such death or disability at the time of the redemption order and be provided with satisfactory evidence of such death or disability.
3.	Redemptions that represent a required minimum distribution from your IRA Account or other qualifying retirement plan but only if you are at least age 70 1/2. If you maintain more than one IRA, only the assets credited to the IRA that is invested in one or more of the State Street Funds are considered when calculating that portion of your minimum required distribution that qualifies for the waiver.
4.	A distribution from a qualified retirement plan by reason of the participant's retirement.

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5.	Redemptions that are involuntary and result from a failure to maintain the required minimum balance in an account.
6.	Exchanges in connection with plans of reorganization of a State Street Fund, such as mergers, asset acquisitions and exchange offers to which the Fund is a party. However, you may pay a sales charge when you redeem the Fund Shares you receive in connection with the plan of reorganization.
7.	Exchanges for shares of the same class of another State Street Fund. However, if your shares are subject to CDSC, the CDSC will continue to apply to your new shares. For purposes of the CDSC, shares will continue to age from the date of the original purchase of the Fund Shares.
8.	Redemption of shares purchased through employer sponsored retirement plans and deferred compensation plans. The CDSC, however, will not be waived if the plan redeems all of the shares that it owns on behalf of participants prior to the applicable CDSC period, as defined above.
9.	Redemptions as part of annual IRA custodial fees.
10.	Acquired through the reinvestment of dividends and capital gains distributions.

Appropriate documentation may be required. Please refer to Class A Account Reinstatement Privileges below.

Class A Account Reinstatement Privileges

Class I

Class I shares are available to the following categories of investors and/or investments:

1.	Banks, broker-dealers and other financial institutions (including registered investment advisers and financial planners) purchasing shares on behalf of their clients in:

•	discretionary and non-discretionary advisory programs;
•	fund supermarkets;
•	asset allocation programs;
•	other programs in which the client pays an asset-based fee for advice or for executing transactions in Fund Shares or for otherwise participating in the program; or
•	certain other investment programs that do not charge an asset-based fee;

2.	Qualified state tuition plans described in Section 529 of the Code and donor-advised charitable gift funds (subject to all applicable terms and conditions);
3.	Defined contribution, defined benefit and other employer-sponsored employee benefit plans, whether or not qualified under the Code;
4.	Certain other registered open-end investment companies whose shares are distributed by SSGA FD;
5.	Certain retirement and deferred compensation programs established by State Street Corporation or its affiliates for their employees or the Fund's Trustees;
6.	Current or retired Directors or Trustees of the State Street Funds, officers and employees of SSGA, and any of its subsidiaries, such persons' spouses, and children under the age of 21, and trust accounts for which any of such person is a beneficiary;
7.	Investments made in connection with certain mergers and/or reorganizations as approved by the Adviser;
8.	The reinvestment of dividends from Class I shares in additional Class I shares of the Fund; and
9.	Qualified recordkeepers with a distribution and/or fund servicing agreement maintained with SSGA FD.

The minimum investment for Class I shares is $1,000,000.

Class K

Class K shares are available to the following categories of investors:

1.	Qualified recordkeepers with an applicable agreement maintained with SSGA FD;

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2.	Defined benefit plans, defined contribution plans, endowments and foundations with greater than $10,000,000 in a qualified tax-exempt plan;
3.	Employers with greater than $10,000,000 in the aggregate between qualified and non-qualified plans that they sponsor; and
4.	Defined contribution, defined benefit and other employer-sponsored employee benefit plans, whether or not qualified under the Code.

The minimum investment for Class K shares is $10,000,000.

How to Initiate a Purchase Request

Investing in the State Street Funds Through a Financial Intermediary

Please be sure to check Exchanging Shares and Frequent-Trading Limits below.

How to Pay for a Purchase

By Check . You may send a check to make initial or additional purchases to your fund account. Make your check payable to “State Street Funds” and include the appropriate fund name and account number ( e.g ., “State Street Emerging Markets Equity Index Fund—a/c #xxx”) in the memo section of the check.

By Exchange . You may purchase shares of a State Street Fund, provided the Fund's minimum investment is met, using the proceeds from the simultaneous redemption of shares of another State Street Fund of the same class. You may initiate an exchange by telephone, or by mail. See Exchanging Shares below.

Trade Dates-Purchases

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If your purchase request is not in good order, it may be rejected.

For further information about purchase transactions, consult our website at www.ssgafunds.com or see Contacting the State Street Funds.

Other Purchase Policies You Should Know

Redeeming Shares

By Telephone. You may call the State Street Funds to request a redemption of shares. See Contacting the State Street Funds .

By Mail. You may send a written request to the State Street Funds to redeem from the Fund account or to make an exchange. See Contacting the State Street Funds .

Please be sure to check Exchanging Shares and Frequent-Trading Limits below.

Trade Date-Redemptions

The trade date for any redemption request received in good order will depend on the day and time the State Street Funds receive your request in good order and the manner in which you are redeeming.

How to Receive Redemption Proceeds

Regardless of the method the Fund uses to make a redemption payment, the Fund typically expects to pay out redemption proceeds on the next business day after a redemption request is received in good order. If you purchased State Street Fund Shares by check or an automatic investment program and you elect to redeem shares within 15 days of the purchase, you may experience delays in receiving redemption proceeds. In this case, the State Street Funds generally will postpone sending redemption proceeds until it can verify that the check or automatic investment program investment has been collected, but in no event will this delay exceed 15 days. There will be no such delay for redemptions following purchases paid by federal funds wire or by bank cashier's check, certified

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check or treasurer's check. The State Street Funds reserve the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Fund. The State Street Funds reserve the right to suspend the right of shareholder redemption or postpone the date of payment for more than seven days to the extent permitted by the 1940 Act.

Under normal circumstances, the Fund expects to meet redemption requests by using cash or cash equivalents in its portfolio and/or selling portfolio assets to generate cash. The Fund also may pay redemption proceeds using cash obtained through borrowing arrangements (including under the Fund's line of credit, which is shared across all registered funds advised by SSGA FM (other than money market funds)) that may be available from time to time.

The Fund may pay all or a portion of your redemption proceeds by giving you securities (for example, if the Fund reasonably believes that a cash redemption may have a substantial impact on the Fund and its remaining shareholders). You may pay transaction costs to dispose of the securities, and you may receive less for them than the price at which they were valued for purposes of the redemption. In addition, you will be subject to the market risks associated with such securities until such time as you choose to dispose of the security.

During periods of deteriorating or stressed market conditions, when an increased portion of the Fund's portfolio may be comprised of less liquid investments, or during extraordinary or emergency circumstances, the Fund may be more likely to pay redemption proceeds with cash obtained through short-term borrowing arrangements (if available) or by giving you securities.

By Electronic Bank Transfer . You may have the proceeds of the fund redemption sent directly to a designated bank account. To establish the electronic bank transfer option on an account, you must designate a bank account by completing a special form or filling out the appropriate section of your account registration form. After the option is set up on your account, you can redeem shares by electronic bank transfer on a regular schedule (Automatic Withdrawal Plan) or from time to time. Your redemption request can be initiated by telephone, or by mail.

Other Redemption Policies that You Should Know

Address Changes. If your address of record has been changed within thirty (30) days of the redemption request, the request must be in writing and bear a medallion guarantee.

Significant/Unusual Economic or Market Activity. During periods of significant or unusual economic or market activity, you may encounter delays attempting to give instructions by phone.

Minimum Account Size. If, due to your redemptions or exchanges, your account balance for the Fund falls below a minimum amount set by the Fund (presently, the minimum initial investment of your selected share class), the Fund may choose to redeem the shares in the account and mail you the proceeds. You will receive 60 days' notice that your account will be closed unless an investment is made to increase the account balance to the required minimum. Failure to bring your account balance to the required minimum within the prescribed period may result in the Fund closing your account at the NAV next determined on the day the account is closed, and mailing the proceeds to you at the address shown on the Fund's records.

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Large Redemptions. Requests for redemptions over $50,000 must be in writing and bear a medallion guarantee.

Exchanging Shares

Share Class Conversions

You may be able to convert your shares to a different share class of the same Fund that has a lower expense ratio provided that you are eligible to buy that share class and that certain conditions are met. This conversion feature is intended for shares held through a Financial Intermediary offering a fee-based or wrap fee program that has an agreement with SSGA FD specific for this purpose. In such instance, your shares may be automatically converted under certain circumstances. Class N shares of a State Street Fund may be converted to Class I shares of the same State Street Fund. Not all share classes are available through all Financial Intermediaries. If your shares of the Fund are converted to a different share class of the same Fund, the transaction will be based on the respective net asset value of each class as of the trade date of the conversion. Consequently, you may receive fewer shares or more shares than originally owned, depending on that day's net asset values. The total value of the initially held shares, however, will equal the total value of the converted shares at the time of conversion. The conversion of shares of one class of the Fund into shares of another class of the same Fund is not taxable for federal income tax purposes and no gain or loss will be reported on the transaction. See the applicable prospectus for share class information. Please contact your Financial Intermediary regarding the tax consequences of any conversion and for additional information.

Frequent-Trading Limits

Frequent, short-term trading, abusive trading practices and market timing (together, “Excessive Trading”), often in response to short-term fluctuations in the market, are not knowingly permitted by the State Street Funds. The State Street Funds do not accommodate frequent purchases and redemptions of Fund Shares by Fund shareholders. Excessive Trading into and out of a State Street Fund may harm the Fund's performance by disrupting portfolio management strategies and by increasing expenses. These expenses are borne by all Fund shareholders, including long-term investors who do not generate such costs.

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As a means to protect each State Street Fund and its shareholders from Excessive Trading:

•	The State Street Funds' transfer agent compiles, monitors and reports account-level information on omnibus and underlying shareholder/participant activity. Depending on the account type, monitoring will be performed on a daily, monthly, quarterly and/or annual basis;
•	The State Street Funds' distributor has obtained information from each Financial Intermediary holding shares in an omnibus account with the State Street Funds regarding whether the Financial Intermediary has adopted and maintains procedures that are reasonably designed to protect the Fund against harmful short-term trading; and
•	With respect to State Street Funds that invest in securities that trade on foreign markets, pursuant to the State Street Funds' fair valuation procedures, pricing adjustments may be made based on information received from a third-party, multi-factor fair valuation pricing service.

The State Street Funds' distributor has detailed procedures that document the transparency oversight and monitoring processes performed by the State Street Funds' transfer agent.

Service Options

Dividend and Capital Gain Distribution Option

Please refer to Dividends, Distributions and Tax Considerations below for additional information.

Automatic Withdrawal Plan

Telephone Redemptions and Exchanges

Automatic Investment Plan

Once the initial investment has been accepted, you may make subsequent investments of $100 or more monthly, quarterly or annually by direct deposit by debiting your bank checking or savings account. Once this option has been established, you may call the State Street Funds to make additional automatic purchases, to change the amount of the existing automatic purchase, or to stop it. The State Street Fund reserves the right to cancel your automatic investment plan if any correspondence sent by the Fund is returned by the postal or other delivery service as “undeliverable.”

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Additional Shareholder Information

Account Transfers

Responsibility for Fraud

Right to Change Policies

In addition to the rights expressly stated elsewhere in this Prospectus, the State Street Funds reserve the right, in the future, to:

1.	Alter, add, or discontinue any conditions of purchase (including eligibility requirements), redemption, exchange, service, or privilege at any time;
2.	Accept initial purchases by telephone;
3.	Freeze any account and/or suspend account services if the State Street Funds has received reasonable notice of a dispute regarding the assets in an account, including notice of a dispute between the registered or beneficial account owners, or if we reasonably believe a fraudulent transaction may occur or has occurred;
4.	Temporarily freeze any account and/or suspend account services upon initial notification to the State Street Funds of the death of the shareholder until the State Street Funds receive required documentation in good order;
5.	Alter, impose, discontinue, or waive any redemption fee, account service fee, or other fees charged to a group of shareholders; and
6.	Redeem an account or suspend account privileges, without the owner's permission to do so, in cases of threatening conduct or activity the State Street Funds believe to be suspicious, fraudulent, or illegal.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If the Fund's transfer agent identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

Dividends, Distributions and Tax Considerations

Income and capital gains dividends of the Fund will be declared and paid at least annually. Any income and capital gains that have not been distributed by December of each calendar year are generally distributed at such time. When the Fund distributes income or capital gains, the NAV per share is reduced by the amount of the distribution.

Distribution Options. You can choose from four different distribution options as indicated on the application:

•	Reinvestment Option—Dividends and capital gain distributions will be automatically reinvested in additional shares of the Fund. If you do not indicate a choice on the application, this option will be automatically assigned.

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•	Income-Earned Option—Capital gain distributions will be automatically reinvested, but a check, direct deposit or wire will be sent for each dividend distribution.
•	Cash Option—A check, wire or direct deposit will be sent for each dividend and capital gain distribution.
•	Direct Dividends Option—Dividends and capital gain distributions will be automatically invested in another identically registered State Street Fund of the same share class.

Delivery of Documents to Accounts Sharing an Address

To reduce expenses, we may mail only one copy of the Fund's Prospectus and the annual and semi-annual report to those addresses shared by two or more accounts. If you wish to receive individual copies of these documents, please call us at (800) 997-7327, or contact your financial institution. We will begin sending you individual copies thirty (30) days after receiving your request.

Tax Considerations

The following discussion is a summary of some important U.S. federal income tax considerations generally applicable to an investment in the Fund. Your investment in the Fund may have other tax implications. Please consult your tax advisor about federal, state, local, foreign or other tax laws applicable to you. Investors, including non-U.S. investors, may wish to consult the SAI tax section for additional disclosure.

The Fund has elected to be treated as a regulated investment company and intends each year to qualify and to be eligible to be treated as such. A regulated investment company generally is not subject to tax at the corporate level on income and gains that are timely distributed to shareholders. In order to qualify and be eligible for treatment as a regulated investment company, the Fund must, among other things, satisfy diversification, 90% gross income and distribution requirements. The Fund's failure to qualify as a regulated investment company would result in corporate level taxation, and consequently, a reduction in income available for distribution to shareholders.

For U.S. federal income tax purposes, distributions of investment income generally are taxable to you as ordinary income. Taxes on distributions of capital gains generally are determined by how long the applicable Fund owned (or is deemed to have owned) the investments that generated them, rather than how long you have owned your Fund Shares. Distributions of net capital gains (that is, the excess of net long-term capital gains over net short-term capital losses) from the sale of investments that the Fund owned (or is deemed to have owned) for more than one year that are properly reported by the Fund as capital gain dividends generally will be treated as long-term capital gain includible in your net capital gain and taxed to individuals at reduced rates. Distributions of gains from investments that the Fund owned (or is deemed to have owned) for one year or less generally will be taxable to you as ordinary income. Distributions of investment income properly reported by the Fund as derived from “qualified dividend income,” which will not include income from the Fund's portfolio securities on loan, are taxed to individuals at the rates applicable to net capital gain, provided holding period and other requirements are met by both the shareholder and the Fund. Distributions are taxable to you even if they are paid from income or gains earned by the Fund before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares.

An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by the Fund, including any capital gain dividends, and net gains recognized on the redemption of shares of the Fund.

The Fund's income from or the proceeds of dispositions of its investments in non-U.S. assets may be subject to non-U.S. withholding or other taxes, which will reduce the yield on those investments. In certain instances, the Fund may be entitled to elect to pass through to its shareholders a credit (or deduction, for a shareholder that itemizes deductions and so chooses) for foreign taxes (if any) borne with respect to foreign securities income earned by the Fund. If the Fund so elects, shareholders will include in gross income

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from foreign sources their pro rata shares of such taxes, if any, treated as paid by the Fund. There can be no assurance that the Fund will make such election, even if it is eligible to do so. If the Fund does not qualify for or does not make such election, shareholders will not be entitled separately to claim a credit or deduction with respect to foreign taxes paid by the Fund; in that case the foreign tax will nonetheless reduce the Fund's taxable income. Even if the Fund elects to pass through to shareholders foreign tax credits or deductions, tax-exempt shareholders and those who invest in the Fund through tax-advantaged accounts such as IRAs will not benefit from any such tax credit or deduction.

Certain of the Fund's investment practices, including derivative transactions and investments in debt obligations issued or purchased at a discount, will be subject to special and complex U.S. federal income tax provisions. These special rules may affect the timing, character, and/or amount of the Fund's distributions to shareholders and may require the Fund to sell its investments at a time when it is not advantageous to do so.

If you are not a U.S. person, dividends paid by the Fund that the Fund properly reports as capital gain dividends, short-term capital gain dividends, or interest-related dividends, each as further defined in the SAI, are not subject to withholding of U.S. federal income tax, provided that certain other requirements are met. The Fund is permitted, but is not required, to report any part of its dividends as are eligible for such treatment. The Fund's dividends other than those the Fund so reports as capital gain dividends, short-term capital gain dividends, or interest-related dividends generally will be subject to U.S. withholding tax at a 30% rate (or lower applicable treaty rate). See the Fund's SAI for further information.

The U.S. Treasury and IRS generally require the Fund to obtain information sufficient to identify the status of each shareholder under sections 1471-1474 of the Internal Revenue Code of 1986, as amended, and the U.S. Treasury and IRS guidance issued thereunder (collectively, the “Foreign Account Tax Compliance Act” or “FATCA”) or under an applicable intergovernmental agreement between the United States and a foreign government. Please see the SAI for more information on FATCA reporting requirements.

Cost Basis Reporting . Department of the Treasury regulations mandate cost basis reporting to shareholders and the IRS for redemptions of Fund Shares acquired on or after January 1, 2012 (“Post Effective Date Shares”). If you acquire and hold shares directly through the Fund and not through a Financial Intermediary, DST Asset Manager Solutions, Inc. will use a default average cost basis methodology for tracking and reporting your cost basis on Post Effective Date Shares, unless you request, in writing, another cost basis reporting methodology.

Financial Intermediary Arrangements

Distribution Arrangements and Rule 12b-1 Fees

The Fund has adopted a distribution plan pursuant to Rule 12b-1 under the 1940 Act under which the Fund may compensate SSGA FD (or others) for services in connection with the distribution of the Fund's Class A shares and for services provided to shareholders in that class (the “Plan”). The Plan calls for payments at an annual rate (based on average daily net assets) of 0.25% of the Fund's net assets attributable to its Class A shares. Because these fees are paid out of the assets of the Fund attributable to its Class A shares on an ongoing basis, they will increase the cost of your investment and may cost you more over time than paying other types of sales charges.

The Fund may pay distribution fees and other amounts described in this Prospectus at a time when shares of that Fund are unavailable for purchase.

Other Payments to Financial Intermediaries

In addition to payments under the Plan described above, the Fund may reimburse SSGA FD or its affiliates for payments made to Financial Intermediaries that provide certain administrative, recordkeeping, and account maintenance services. The amount of the reimbursement and the manner in which it is calculated are reviewed by the Trustees periodically.

Financial Intermediaries are firms that sell shares of mutual funds, including the Fund, and/or provide certain administrative and account maintenance services to mutual fund investors. Financial Intermediaries may include, among others, brokers, financial planners or advisers, banks, retirement plan recordkeepers and insurance companies.

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statements, prospectuses, annual reports, semiannual reports, shareholder notices, and other SEC-required communications; capturing and processing tax data; issuing and mailing dividend checks to shareholders who have selected cash distributions; preparing record date shareholder lists for proxy solicitations; and collecting and posting distributions to shareholder accounts.

The Financial Intermediary is often compensated by SSGA FD or its affiliates for the services it performs and in such cases is typically paid continually over time, during the period when the Financial Intermediary's clients hold investments in the Fund. The amount of continuing compensation paid by SSGA FD or its affiliates to different Financial Intermediaries for distribution and/or shareholder services varies. Any compensation is typically a percentage of the value of the Financial Intermediary's clients' investments in the Fund or a per account fee. The variation in compensation may, but will not necessarily, reflect enhanced or additional services provided by the Financial Intermediary.

If you invest through a Financial Intermediary and meet the eligibility criteria for more than one share class, you should discuss with your Financial Intermediary which share class is appropriate for you. Your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend one share class over another, when you are eligible to invest in more than one share class. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by the Fund or its affiliates with respect to the different share classes offered by the Fund.

SSGA FD and its affiliates (including SSGA FM), at their own expense and out of their own assets, may also provide other compensation to Financial Intermediaries in connection with sales of the Fund's shares or the servicing of shareholders or shareholder accounts. Such compensation may include, but is not limited to, financial assistance to Financial Intermediaries in connection with conferences, sales, or training programs for their employees; seminars for the public; advertising or sales campaigns; or other Financial Intermediary-sponsored special events. In some instances, this compensation may be made available only to certain Financial Intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the Fund's shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as Financial Industry Regulatory Authority, Inc.

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Financial Highlights

The financial highlight tables are intended to help you understand the Fund's financial performance since the Fund's inception. Certain information reflects the performance results for a single Fund Share. The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in the Fund (assuming reinvestment of all dividends and distributions). This information has been audited by Ernst & Young LLP, the Trust's independent registered public accounting firm, whose report, along with the Fund's financial highlights and financial statements, is included in the annual report to shareholders, which is available upon request. Any references to Notes in these financial highlight tables refer to the “Notes to Financial Statements” section of the Fund's financial statements, and the financial information included in these tables should be read in conjunction with the financial statements incorporated by reference in the SAI.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET EMERGING MARKETS EQUITY INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class K
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	For the Period 12/21/15* - 12/31/15
Net asset value, beginning of period	$ 14.46	$ 10.82	$ 9.99	$ 10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.32	0.29	0.21	0.02
Net realized and unrealized gain (loss)	(2.46)	3.72	0.87	(0.01)
Total from investment operations	(2.14)	4.01	1.08	0.01
Distributions to shareholders from:
Net investment income	(0.27)	(0.30)	(0.22)	(0.02)
Net realized gains	(0.09)	(0.07)	(0.03)	—
Total distributions	(0.36)	(0.37)	(0.25)	(0.02)
Net asset value, end of period	$ 11.96	$ 14.46	$ 10.82	$ 9.99
Total return (b)	(14.77)%	37.19%	10.81%	0.14%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$580,430	$607,947	$374,808	$165,807
Ratios to Average Net Assets:
Total expenses	0.33%	0.34%	0.56%	0.83%(c)
Net expenses	0.17%	0.17%	0.18%	0.17%(c)
Net investment income (loss)	2.36%	2.23%	1.98%	8.03%(c)
Portfolio turnover rate	7%	6%	14%	0%(d)(e)

*	Commencement of operations.
(a)	Per share numbers have been calculated using average shares outstanding, which more appropriately presents the per share data for the period.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Annualized.
(d)	Amount shown represents less than 0.5%.
(e)	Not annualized.

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Contacting the State Street Funds

Online:	www.ssgafunds.com	24 hours a day, 7 days a week
Phone:	(800) 647-7327	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Overnight/ Registered, Express, Certified Mail
State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737	State Street Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407

The Fund does not consider the U.S. Postal Service or other independent delivery services to be its agents. Therefore, deposits in the mail or with such services, or receipt at the Fund's post office box, of purchase orders or redemption requests, do not constitute receipt by the Fund or Transfer Agent.

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For more information about the Fund:

The Fund's SAI includes additional information about the Fund and is incorporated by reference into this document. Additional information about the Fund's investments is available in the Fund's most recent annual and semi-annual reports to shareholders. In the Fund's annual report, you will find a discussion of the market conditions and investment strategies that significantly affected the Fund's performance during its last fiscal year. The Fund's SAI is available, without charge, upon request. The Fund's annual and semi-annual reports are available, without charge, upon request. Shareholders in the Fund may make inquiries to the Fund to receive such information by calling (800) 997-7327 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. The Fund's Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, free of charge, on the Fund's website at www.ssgafunds.com.

Reports and other information about the Fund are available free of charge on the EDGAR Database on the SEC's Internet site at http://www.sec.gov. Copies of this information also may be obtained, after paying a duplicating fee, by electronic request at the following E-mail address: publicinfo@sec.gov.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

SSITEMCGSTATPRO

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Equity 500 Index Fund: Administrative Shares (STFAX)

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with the Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling (800) 647-7327. Your election to receive reports in paper will apply to all funds held in your account.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in the State Street Equity 500 Index Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

The Fund may offer multiple classes of shares. This Prospectus covers only the Administrative Shares.

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Fund Summary	1
State Street Equity 500 Index Fund	1
Additional Information About Investment Objective, Principal Strategies and Risks	7
Additional Information About Non-Principal Investment Strategies and Risks	12
Portfolio Holdings Disclosure	13
Management and Organization	14
Shareholder Information	16
Dividends, Distributions and Tax Considerations	19
Financial Intermediary Arrangements	20
Financial Highlights	22
Index/Trademark Licenses/Disclaimers	24

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State Street Equity 500 Index Fund

Investment Objective

Fees and Expenses of the Fund

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). The expenses shown in the table and the Example reflect the expenses of the Fund and the Fund's proportionate share of the expenses of the State Street Equity 500 Index II Portfolio (the “Equity 500 Index II Portfolio” or sometimes referred to in context as the “Portfolio”).

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	0.02%
Distribution and/or Shareholder Service (12b-1) Fees	0.15%
Other Expenses	0.12%
Total Annual Fund Operating Expenses	0.29%
Less Fee Waivers and/or Expense Reimbursements ¹	(0.12)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.17%

Example:

1 year		3 years		5 years		10 years
$17		$81		$151		$356

Portfolio Turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). As a shareholder of the Portfolio, the Fund bears its ratable share of the transaction costs associated with the portfolio turnover of the Portfolio. A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund Shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 8% of the average value of its portfolio.

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Principal Investment Strategies

Principal Risks

In addition, the Fund is subject to the following risks:

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Risk of Investment in Other Pools: When the Fund invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected and is exposed indirectly to all of the risks applicable to an investment in such other pool. The investment policies of the other pool may not be the same as those of the Fund; as a result, an investment in the other pool may be subject to additional or different risks than those to which the Fund is typically subject. The Fund bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Fund may invest, leading to potential conflicts of interest. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which the Fund does so.

Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's' returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of the Index. The bar chart shows how the Administrative Shares' returns have varied for each full calendar year shown. The Fund's past performance does not necessarily indicate how the Fund will perform in the future.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 15.89% (Q2, 2009)
Lowest Quarterly Return: -14.00% (Q3, 2011)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Five Years	Ten Years	Inception Date
Administrative Shares				4/18/2001
Return Before Taxes	-4.56%	8.22%	12.85%
Return After Taxes on Distributions	-5.67%	7.34%	12.15%
Return After Taxes on Distributions and Sale of Fund Shares	-1.94%	6.37%	10.62%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	-4.38%	8.49%	13.12%

The Fund will make updated performance information, including its current net asset value, available at the Fund's website: www.ssgafunds.com.

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Investment Adviser

SSGA FM serves as the investment adviser to the Fund and the Portfolio.

Michael Feehily, CFA, is a Senior Managing Director of the Adviser and the Head of Global Equity Beta Solutions in the Americas. He worked at the Adviser from 1997 to 2006 and rejoined in 2010.

Karl Schneider, CAIA, is a Managing Director of the Adviser and Deputy Head of Global Equity Beta Solutions in the Americas. He joined the Adviser in 1997.

Amy Scofield is a Principal of the Adviser and a Portfolio Manager in the Global Equity Beta Solutions Group. She joined the Adviser in 2010.

Purchase and Sale of Fund Shares

Purchase Minimums

To establish an account	$25,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

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Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objective, Principal Strategies and Risks

State Street Equity 500 Index Fund Administrative Shares

Investment Objective

The Trust's Board of Trustees may change the Fund's investment strategies and other policies without shareholder approval, except as otherwise indicated. The Board of Trustees may change the Fund's investment objective without shareholder approval. If the Trustees were to approve a change to the Equity 500 Index Fund's investment objective, shareholders would receive advance notice.

Principal Investment Strategies

The Fund generally intends to invest in all stocks comprising the S&P 500 in approximate proportion to their weightings in the Index. However, under various circumstances, it may not be possible or practicable to purchase all stocks in those weightings. In those circumstances, the Fund may purchase a sample of the stocks in the Index in proportions expected by SSGA FM to match generally the performance of the Index as a whole. In addition, from time to time stocks are added to or removed from the Index. The Fund may sell securities that are represented in the Index, or purchase securities that are not yet represented in the Index, in anticipation of their removal from or addition to the Index. Under normal market conditions, the Fund will not invest less than 80% of its total assets in stocks in the Index. Shareholders will receive sixty (60) days' notice prior to a change in the 80% investment policy. For this purpose, “total assets” means net assets plus borrowings, if any. The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. In addition, the Fund may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

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Additional Index Information . The Index's components are reconstituted and rebalanced quarterly.

Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure.

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derivative transaction not to have the effect the Adviser anticipated or a different or less favorable effect than the Adviser anticipated; the failure of the counterparty to the derivative transaction to perform its obligations under the transaction or to settle a trade; possible mispricing or improper valuation of the derivative instrument; imperfect correlation in the value of a derivative with the asset, rate, or index underlying the derivative; the risk that the Fund may be required to post collateral or margin with its counterparty, and will not be able to recover the collateral or margin in the event of the counterparty's insolvency or bankruptcy; the risk that the Fund will experience losses on its derivatives investments and on its other portfolio investments, even when the derivatives investments may be intended in part or entirely to hedge those portfolio investments; the risks specific to the asset underlying the derivative instrument; lack of liquidity for the derivative instrument, including without limitation absence of a secondary trading market; the potential for reduced returns to the Fund due to losses on the transaction and an increase in volatility; the potential for the derivative transaction to have the effect of accelerating the recognition of gain; and legal risks arising from the documentation relating to the derivative transaction.

Large-Capitalization Securities Risk. Securities issued by large-capitalization companies may present risks not present in smaller companies. For example, larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or other market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies, especially during strong economic periods. Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies.

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and/or gains to shareholders, or the Portfolio may be required to sell its more liquid portfolio investments to meet a large redemption, in which case the Portfolio's remaining assets may be less liquid, more volatile, and more difficult to price. The Portfolio may hold a relatively large proportion of its assets in cash in anticipation of large redemptions, diluting its investment returns.

Leveraging Risk . Borrowing transactions, reverse repurchase agreements, certain derivatives transactions, securities lending transactions and other investment transactions such as when-issued, delayed-delivery, or forward commitment transactions may create investment leverage. If the Fund engages in transactions that have a leveraging effect on the Fund's investment portfolio, the value of the Fund will be potentially more volatile and all other risks will tend to be compounded. This is because leverage generally creates investment risk with respect to a larger base of assets than the Fund would otherwise have and so magnifies the effect of any increase or decrease in the value of the Fund's underlying assets. The use of leverage is considered to be a speculative investment practice and may result in losses to the Fund. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. The use of leverage may cause the Fund to liquidate positions when it may not be advantageous to do so to satisfy repayment, interest payment, or margin obligations or to meet asset segregation or coverage requirements.

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including, but not limited to, economic growth or recession, changes in interest rates, changes in actual or perceived creditworthiness of issuers and general market liquidity. Even if general economic conditions do not change, the value of an investment in the Fund could decline if the particular industries, sectors or companies in which the Fund invests do not perform well or are adversely affected by events. Further, legal, political, regulatory and tax changes also may cause fluctuations in markets and securities prices.

Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject the Fund to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and the Fund's investment program in particular can be uncertain. In recent periods, governmental and non-governmental issuers have defaulted on, or have been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including, without limitation, in Europe or Asia. Defaults or restructurings by governments or others of their debts could have substantial adverse effects on economies, financial markets, and asset valuations around the world. Further Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, or investor perception that these efforts are not succeeding, could negatively affect financial markets generally as well as the values and liquidity of certain securities.

Master/Feeder Structure Risk. The Fund pursues its objective by investing substantially all of its assets in another pooled investment vehicle (a “master fund”). The ability of the Fund to meet its investment objective is directly related to the ability of the master fund to meet its investment objective. The ability of the Fund to meet its objective may be adversely affected by the purchase and redemption activities of other investors in the master fund. The ability of the Fund to meet redemption requests will depend on its ability to redeem its interest in the master fund. The Adviser or an affiliate serves as investment adviser to the master fund, leading to potential conflicts of interest. For example, the Adviser or its affiliates will receive fees based on the amount of assets invested in the master fund. Investment by the Fund in the master fund may be beneficial in the management of the master fund, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest the Fund's assets in a master fund sponsored or managed by the Adviser or its affiliates in lieu of investments by the Fund directly in portfolio securities, or may have an incentive to invest in such master fund over a master fund sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by the Fund in a master fund sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a master fund sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which the Fund does so. The Fund will bear its pro rata portion of the expenses incurred by the master fund.

Risk of Investment in Other Pools . When the Fund invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected. The Fund is exposed indirectly to all of the risks applicable to an investment in such other pool. In addition, lack of liquidity in the underlying pool could result in its value being more volatile than the underlying portfolio of securities, and may limit the ability of the Fund to sell or redeem its interest in the pool at a time or at a price it might consider desirable. The investment policies and limitations of the other pool may not be the same as those of the Fund; as a result, the Fund may be subject to additional or different risks, or may achieve a reduced investment return, as a result of its investment in another pool. If a pool is an exchange-traded fund or other product traded on a securities exchange or otherwise actively traded, its shares may trade at a premium or discount to their NAV, an effect that might be more pronounced in less liquid markets. The Fund bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Fund may invest, leading to potential conflicts of interest. For example, the Adviser or its affiliates may receive fees based on the amount of assets invested in the pool. Investment by the Fund in the pool may be beneficial to the Adviser or an affiliate in the management of the pool, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest the Fund's assets in a pool sponsored or managed by the Adviser or its affiliates in lieu of investments by the Fund directly in portfolio securities, or may have an incentive to invest in the pool over a pool sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by the Fund in a pool sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which the Fund does so.

Technology Sector Risk. Market or economic factors impacting technology companies and companies that rely heavily on technological advances could have a major effect on the value of the Fund's investments. The value of stocks of technology companies and companies that rely heavily on technology is particularly vulnerable to rapid changes in technology product cycles, rapid product obsolescence, government regulation and competition, both domestically and internationally, including competition from foreign

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competitors with lower production costs. Stocks of technology companies and companies that rely heavily on technology, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market. Technology companies are heavily dependent on patent and intellectual property rights, the loss or impairment of which may adversely affect profitability. Additionally, companies in the technology sector may face dramatic and often unpredictable changes in growth rates and competition for the services of qualified personnel.

Unconstrained Sector Risk . The Fund may invest a substantial portion of its assets within one or more economic sectors or industries, which may change from time to time. When the Fund focuses its investments in a particular industry or sector, financial, economic, business, and other developments affecting issuers in that industry, market, or economic sector will have a greater effect on the Fund than if it had not focused its assets in that industry, market, or economic sector, which may increase the volatility of the Fund. Any such investment focus may also limit the liquidity of the Fund. In addition, investors may buy or sell substantial amounts of the Fund's shares in response to factors affecting or expected to affect an industry, market, or economic sector in which the Fund focuses its investments, resulting in extreme inflows or outflows of cash into and out of the Fund. Such extreme cash inflows or outflows might affect management of the Fund adversely.

Additional Information About Non-Principal Investment Strategies and Risks

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Fund. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for the Fund and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by the Fund. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Fund) or otherwise using such information for the benefit of its clients or itself.

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result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. The Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Fund. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which the Fund invests, which could result in material adverse consequences for such issuers, and may cause the Fund's investment in such securities to lose value.

Securities Lending Risk . The Fund may lend portfolio securities in an amount not to exceed 40% of the value of its net assets. For these purposes, net assets shall exclude the value of all assets received as collateral for the loan. Such loans may be terminated at any time. Any such loans must be continuously secured by collateral maintained on a current basis in an amount at least equal to the market value of the securities loaned by the Fund, marked to market each trading day. In a loan transaction, as compensation for lending its securities, the Fund will receive a portion of the dividends or interest accrued on the securities held as collateral or, in the case of cash collateral, a portion of the income from the investment of such cash. In addition, the Fund will receive the amount of all dividends, interest and other distributions on the loaned securities. However, the borrower has the right to vote the loaned securities. The Fund will call loans to vote proxies if a material issue affecting the investment is to be voted upon. Efforts to recall such securities promptly may be unsuccessful, especially for foreign securities or thinly traded securities, and may involve expenses to the Fund. Securities lending involves the risk that the Fund may lose money because the borrower of the loaned securities fails to return the securities in a timely manner or at all. Should the borrower of the securities fail financially, the Fund may experience delays in recovering the securities or exercising its rights in the collateral. Loans are made only to borrowers that are deemed by the securities lending agent to be of good financial standing. In a loan transaction, the Fund will also bear the risk of any decline in value of securities acquired with cash collateral. The Fund expects to invest cash collateral in a pooled investment vehicle advised by the Adviser. With respect to index funds, to the extent the collateral provided or investments made with cash collateral differ from securities included in the relevant Index, such collateral or investments may have a greater risk of loss than the securities included in the Index. In addition, the Fund will be subject to the risk that any income generated by reinvesting cash collateral is lower than any fees the Fund has agreed to pay a borrower.

Portfolio Holdings Disclosure

The Fund's portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

The Fund invests as part of a “master/feeder” structure. The Fund currently seeks to achieve its investment objective by investing substantially all of its investable assets in the Portfolio, a separate mutual fund, that has substantially identical investment objective, investment policies, and risks as the Fund. All discussions about the Fund's investment objective, policies and risks should be understood to refer also to the investment objectives, policies and risks of the Portfolio.

The Portfolio's shares are offered exclusively to investors (including without limitation, registered investment companies, private investment pools, bank collective funds, and investment separate accounts) that, like the Fund, pay fees to SSGA FM or its affiliates. The fees paid by those investment vehicles to SSGA FM (or its affiliates) vary depending on a number of factors, including by way of example, the services provided, the risks borne by SSGA FM (or its affiliates), fee rates paid by competitive investment vehicles, and in some cases direct negotiation with investors in the Portfolio.

The Fund can withdraw its investment in the Portfolio if, at any time, the Fund's Board of Trustees determines that it would be in the best interests of the Fund's shareholders, or if the investment objectives of the Portfolio changed so that they were inconsistent with the objectives of the Fund. If the Fund withdraws its investment from the Portfolio, the Fund may invest all of its assets in another mutual fund that has the same investment objective as the Fund, the Adviser may directly manage the Fund's assets, or the Board may take such other action it deems appropriate and in the best interests of shareholders of the Fund, which may include liquidation of the Fund.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund and Portfolio and, subject to the oversight of the Board, is responsible for the investment management of the Fund. The Adviser provides an investment management program for the Fund and manages the investment of the Fund's assets. The Adviser is a wholly-owned subsidiary of State Street Global Advisors, Inc., which itself is a wholly-owned subsidiary of State Street Corporation. The Adviser is registered with the U.S. Securities and Exchange Commission (“SEC”) under the Investment Advisers Act of 1940, as amended. The Adviser and certain other affiliates of State Street Corporation make up SSGA. SSGA is one of the world's largest institutional money managers and the investment management arm of State Street Corporation. As of December 31, 2018, the Adviser managed approximately $452.10 billion in assets and SSGA managed approximately $2.51 trillion in assets. The Adviser's principal business address is One Iron Street, Boston, Massachusetts 02210.

The Fund has entered into an investment advisory agreement with the Adviser pursuant to which the Adviser will manage the Fund's assets, for compensation paid at an annual rate of 0.02% of the Fund's average daily net assets. For the year ended December 31, 2018, the Fund's effective management fee paid was 0.00% of average daily net assets. The Adviser places all orders for purchases and sales of the Portfolio's investments. The Portfolio pays no investment advisory fees to SSGA FM.

Total Annual Fund Operating Expense Waiver . SSGA FM, as the investment adviser to the Fund, is contractually obligated, through April 30, 2020, (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing and sub-transfer agency fees) exceed 0.02% of average daily net assets on an annual basis. This waiver and/or reimbursement arrangement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

A discussion regarding the Board's consideration of the Fund's Investment Advisory Agreement is provided in the Fund's Semi-Annual Report to Shareholders for the period ended June 30, 2018.

The Adviser manages the Fund and the Portfolio using a team of investment professionals. The team approach is used to create an environment that encourages the flow of investment ideas. The portfolio managers within the team work together in a cohesive manner to develop and enhance techniques that drive the investment process for the respective investment strategy. This approach requires portfolio managers to share a variety of responsibilities including investment strategy and analysis while retaining responsibility for the implementation of the strategy within any particular portfolio. The approach also enables the team to draw upon the resources of other groups within SSGA. The portfolio management team is overseen by the SSGA Investment Committee.

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The professionals primarily responsible for the day-to-day management of the Equity 500 Index II Portfolio and the Equity 500 Index Fund include the following:

Additional information about the portfolio managers' compensation, other accounts managed by the portfolio managers, and the portfolio managers' ownership of the Fund is available in the SAI.

Other Fund Services

The Administrator, Sub-Administrator and Custodian

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Fund's transfer agent and dividend disbursing agent (the “Transfer Agent”).

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Fund's distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

Additional Information

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Shareholder Information

Determination of Net Asset Value

The Fund determines its net asset value (“NAV”) per share once each business day as of the close of regular trading on the New York Stock Exchange (the “NYSE”). Pricing does not occur on NYSE holidays. A business day is one on which the NYSE is open for regular trading. The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. In unusual circumstances, such as an emergency or an unscheduled close or halt of trading on the NYSE, the time at which share prices are determined may be changed. The NAV per share is based on the market value of the investments held in the Fund. The NAV of the Fund's Administrative Shares is calculated by dividing the value of the assets of the Fund attributable to its Administrative Shares less the liabilities of the Fund attributable to its Administrative Shares by the number of Administrative Shares outstanding. As noted in this Prospectus, the Fund may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when the Fund does not price its shares. Consequently, the NAV of the Fund's shares may change on days when shareholders are not able to purchase or redeem the Fund's shares. Purchase and redemption orders for Fund Shares are processed, respectively, at the NAV next determined after the Fund accepts a purchase order or receives a redemption request in good form. The Fund values each security or other investment pursuant to guidelines adopted by the Fund's Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Portfolio's Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii) a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by the Fund occurs after the close of a related exchange but before the determination of the Fund's NAV. Attempts to determine the fair value of securities or other investments introduce an element of subjectivity to the pricing of securities or other investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the price the Fund would have received had it sold the investment. To the extent that the Fund invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the funds. The prospectuses of these funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

Investing in State Street Institutional Investment Trust Shares

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Purchasing Shares

Investors pay no sales load to invest in the Administrative Shares of the Fund. The price for Fund shares is the NAV per share. Orders received in good form (a purchase order is in good form if it meets the requirements implemented from time to time by the Fund or its Transfer Agent, and for new accounts includes submission of a completed and signed application and all documentation necessary to open an account) will be priced at the NAV next calculated after the order is accepted by the Fund.

The minimum initial investment in the Administrative Shares is $25 million, although the Adviser may waive the minimum in its discretion. There is no minimum subsequent investment. The Fund intends to be as fully invested as is practicable; therefore, investments must be made either in Federal Funds ( i.e ., monies credited to the account of the Fund's custodian bank by a Federal Reserve Bank) or securities (“in-kind”) acceptable to the Adviser. (Please consult your tax adviser regarding in-kind transactions.) (If you purchase shares by check, your order will not be in good form until the Transfer Agent receives federal funds for the check.) The Fund reserves the right to cease accepting investments at any time or to reject any purchase order.

In accordance with certain federal regulations, the Trust is required to obtain, verify and record information that identifies each entity that applies to open an account. For this reason, when you open (or change ownership of) an account, the Trust will request certain information, including your name, address and taxpayer identification number, which will be used to verify your identity. If you are unable to provide sufficient information to verify your identity, the Trust will not open an account for you. As required by law, the Trust may employ various procedures, such as comparing your information to fraud databases or requesting additional information and documentation from you, to ensure that the information supplied by you is correct. The Trust reserves the right to reject any purchase order for any reason, including failure to provide the Trust with information necessary to confirm your identity as required by law.

If you are purchasing through a Financial Intermediary, please contact your Financial Intermediary as their requirements may differ.

Redeeming Shares

An investor may redeem all or any portion of its investment at the NAV next determined after it submits a redemption request, in proper form, to the Fund. Regardless of the method the Fund uses to make a redemption payment, the Fund typically expects to pay out redemption proceeds on the next business day after a redemption request is received in good order. If you purchased State Street Fund shares by check or an automatic investment program and you elect to redeem shares within 15 days of the purchase, you may experience delays in receiving redemption proceeds. In this case, the State Street Funds generally will postpone sending redemption proceeds until it can verify that the check or automatic investment program investment has been collected, but in no event will this delay exceed 15 days. There will be no such delay for redemptions following purchases paid by federal funds wire or by bank cashier's check, certified check or treasurer's check. The State Street Funds reserve the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect a Fund. The State Street Funds reserve the right to suspend the right of shareholder redemption or postpone the date of payment for more than seven days to the extent permitted by the 1940 Act.

If your account is held through an Intermediary, please contact them for additional assistance and advice on how to redeem your shares.

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Cost Basis Reporting Upon the redemption of your shares in the Fund, the Fund or, if you purchase your shares through a Financial Intermediary, your Financial Intermediary, generally will be required to provide you and the IRS with cost basis and certain other related tax information about the Fund shares you redeemed. Please contact the Fund or consult your Financial Intermediary, as appropriate, for more information regarding available methods for cost basis reporting and how to select or change a particular method. Please consult your tax advisor to determine which available cost basis method is best for you.

About Mail Transactions

If you choose to purchase or redeem shares by sending instructions by regular mail, they will not be deemed received in good order until they are released by the post office and redelivered to the Transfer Agent's physical location at 430 W 7th Street Suite 219737 in Kansas City, MO 64105-1407. There will be a time lag, which may be one or more days, between regular mail receipt at the post office box and redelivery to such physical location and a Fund's net asset value may change over those days. You might consider using express rather than regular mail if you believe time of receipt of your transaction request to be sensitive.

Frequent-Trading Limits

As a means to protect each State Street Fund and its shareholders from Excessive Trading:

•	The State Street Funds' transfer agent compiles, monitors and reports account-level information on omnibus and underlying shareholder/participant activity. Depending on the account type, monitoring will be performed on a daily, monthly, quarterly and/or annual basis;
•	The State Street Funds' distributor has obtained information from each Financial Intermediary holding shares in an omnibus account with the State Street Funds regarding whether the Financial Intermediary has adopted and maintains procedures that are reasonably designed to protect the Funds against harmful short-term trading; and
•	With respect to State Street Funds that invest in securities that trade on foreign markets, pursuant to the State Street Funds' fair valuation procedures, pricing adjustments may be made based on information received from a third-party, multi-factor fair valuation pricing service.

The State Street Funds' distributor has detailed procedures that document the transparency oversight and monitoring processes performed by the State Street Funds' transfer agent.

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Delivery of Documents to Accounts Sharing an Address

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a State Street Fund identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Fund (if you hold shares directly with the Fund) or to your financial intermediary (if you do not hold shares directly with the Fund).

Dividends, Distributions and Tax Considerations

The Fund invests substantially all of its assets in the Portfolio, which is expected to be treated as a regulated investment company for federal income tax purposes, and so substantially all of the Fund's income will result from distributions or deemed distributions from the Portfolio. Therefore, as applicable, and except as otherwise stated, references in this section to the assets owned or income earned by the Fund will include such assets and income of the Portfolio. The Fund has elected to be treated as a regulated investment company and intends each year to qualify and to be eligible to be treated as such. A regulated investment company generally is not subject to tax at the corporate level on income and gains that are timely distributed to shareholders. In order to qualify and be eligible for treatment as a regulated investment company, the Fund must, among other things, satisfy diversification, 90% gross income and distribution requirements. The Fund's failure to qualify and be eligible for treatment as a regulated investment company would result in corporate level taxation, and consequently, a reduction in income available for distribution to shareholders.

The Fund generally expects to satisfy the requirements to qualify and be eligible to be treated as a regulated investment company, provided that the Portfolio also meets these requirements; the Fund currently expects that the Portfolio will meet these requirements. Because the Fund will invest substantially all its assets in the Portfolio, if the Portfolio were to fail to satisfy the diversification, 90% gross income, or distribution requirement and were not to cure that failure, the Fund itself would be unable to satisfy the diversification requirement. Such a failure to qualify and be eligible for treatment as a regulated investment company could subject the Fund or the Portfolio to regular corporate income taxes.

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Fund as derived from “qualified dividend income,” which will not include income from the Fund's or the Portfolio's portfolio securities on loan, are taxed to individuals at the rates applicable to net capital gain, provided holding period and other requirements are met by the shareholder, the Fund, and the Portfolio. Distributions are taxable to you even if they are paid from income or gains earned by the Fund before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares.

An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by the Fund, including any capital gain dividends, and net gains recognized on the redemption of shares of the Fund.

Certain of the Portfolio's investment practices, including derivative transactions and investments in debt obligations issued or purchased at a discount, will be subject to special and complex U.S. federal income tax provisions. These special rules may affect the timing, character, and/or amount of the Portfolio's distributions to the Fund, and, in turn, the Fund's distributions to shareholders, and may require the Fund or the Portfolio to sell its investments at a time when it is not advantageous to do so.

The Fund's investments in the Portfolio may cause the tax treatment of the Fund's gains, losses and distributions to differ from the tax treatment that would apply if the Fund invested directly in the types of securities held by the Portfolio. As a result, investors may receive taxable distributions earlier and recognize higher amounts of capital gain or ordinary income than they otherwise would.

Financial Intermediary Arrangements

Distribution Arrangements and Rule 12b-1 Fees

The Fund has adopted a distribution plan pursuant to Rule 12b-1 under the 1940 Act under which the Fund may compensate SSGA FD (or others) for services in connection with the distribution of the Fund's Administrative Shares and for services provided to Fund shareholders (the “Plan”). The Plan calls for payments at an annual rate (based on average daily net assets) of 0.15% of the Fund's net assets attributable to its Administrative Shares. Because these fees are paid out of the assets of the Fund attributable to its Administrative Shares on an ongoing basis, they will increase the cost of your investment and may cost you more over time than paying other types of sales charges.

The Fund may pay distribution fees and other amounts described in this Prospectus at a time when shares of the Fund are unavailable for purchase.

Other Payments to Financial Intermediaries

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The Financial Intermediary is often compensated by SSGA FD or its affiliates for the services it performs and in such cases is typically paid continually over time, during the period when the Financial Intermediary's clients hold investments in the Fund. The amount of continuing compensation paid by SSGA FD or its affiliates to different Financial Intermediaries for distribution and/or shareholder services varies. Any compensation is typically a percentage of the value of the Financial Intermediary's clients' investments in the Fund or a per account fee. The variation in compensation may, but will not necessarily, reflect enhanced or additional services provided by the Financial Intermediary.

If you invest through a Financial Intermediary and meet the eligibility criteria for more than one share class, you should discuss with your Financial Intermediary which share class is appropriate for you. Your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend one share class over another, when you are eligible to invest in more than one share class. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by the Fund or its affiliates with respect to the different share classes offered by the Fund.

SSGA FD and its affiliates (including SSGA FM), at their own expense and out of their own assets, may also provide other compensation to Financial Intermediaries in connection with sales of the Fund's shares or the servicing of shareholders or shareholder accounts. Such compensation may include, but is not limited to, financial assistance to Financial Intermediaries in connection with conferences, sales, or training programs for their employees; seminars for the public; advertising or sales campaigns; or other Financial Intermediary-sponsored special events. In some instances, this compensation may be made available only to certain Financial Intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the Fund's shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as Financial Industry Regulatory Authority, Inc.

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Financial Highlights

The financial highlight tables are intended to help you understand the Fund's Administrative Shares financial performance for the past five fiscal years. Certain information reflects the performance results for a single Fund Share. The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in the Fund (assuming reinvestment of all dividends and distributions). This information has been audited by Ernst & Young LLP, the Trust's independent registered public accounting firm, whose report, along with the Fund's financial highlights and financial statements, is included in the annual report to shareholders, which is available upon request. Any references to Notes in these financial highlight tables refer to the “Notes to Financial Statements” section of the Fund's financial statements, and the financial information included in these tables should be read in conjunction with the financial statements incorporated by reference in the SAI.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET EQUITY 500 INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Administrative Shares
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	Year Ended 12/31/14
Net asset value, beginning of period	$ 21.62	$ 18.83	$ 17.17	$ 17.27	$ 15.50
Income (loss) from investment operations:
Net investment income (loss) (a)	0.34	0.38	0.26	0.31	0.29
Net realized and unrealized gain (loss)	(1.33)	3.66	1.76	(0.12)	1.79
Total from investment operations	(0.99)	4.04	2.02	0.19	2.08
Distributions to shareholders from:
Net investment income	(0.39)	(0.46)	(0.28)	(0.29)	(0.31)
Net realized gains	(0.60)	(0.79)	(0.08)	—	—
Total distributions	(0.99)	(1.25)	(0.36)	(0.29)	(0.31)
Net asset value, end of period	$ 19.64	$ 21.62	$ 18.83	$ 17.17	$ 17.27
Total return (b)	(4.56)%	21.43%	11.75%	1.08%	13.41%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$213,270	$274,650	$277,141	$261,038	$248,180
Ratios to Average Net Assets:(c)
Total expenses	0.27%(d)	0.26%(d)	0.27%(d)	0.31%(d)	0.30%(e)
Net expenses	0.17%(d)	0.18%(d)	0.18%(d)	0.18%(d)	0.23%(e)
Net investment income (loss)	1.51%	1.83%	1.48%	1.76%	1.78%
Portfolio turnover rate	8%(f)	30%(f)	5%(f)	5%(f)	4%(g)

(a)	Net investment income per share is calculated using the average shares method.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Prior to August 11, 2014, the per shares amounts and percentages included the Fund's proportionate share of income and expenses of the State Street Equity 500 Index Portfolio.
(d)	Ratio does not include the expenses of the State Street Equity 500 Index II Portfolio.
(e)	Ratio includes expenses allocated from the State Street Equity 500 Index Portfolio from 1/1/2014 through 8/10/2014, and does not include the expenses of the State Street Equity 500 Index II Portfolio from 8/11/2014 through 12/31/2014.
(f)	Portfolio turnover rate is from the State Street Equity 500 Index II Portfolio.
(g)	Portfolio turnover rate is calculated from the State Street Equity 500 Index Portfolio (from 1/1/2014 to 8/10/2014) and the State Street Equity 500 Index II Portfolio (from 8/11/2014 to 12/31/2014).

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Index/Trademark Licenses/Disclaimers

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Contacting the State Street Funds

Online:	www.ssgafunds.com	24 hours a day, 7 days a week
Phone:	(800) 647-7327	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Overnight/ Registered, Express, Certified Mail
State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737	State Street Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407

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For more information about the Fund:

The Fund's SAI includes additional information about the Fund and is incorporated by reference into this document. Additional information about the Fund's investments is available in the Fund's most recent annual and semi-annual reports to shareholders. In a Fund's annual report, you will find a discussion of the market conditions and investment strategies that significantly affected the Fund's performance during its last fiscal year. The Fund's SAI is available, without charge, upon request. The Fund's annual and semi-annual reports are available, without charge, upon request. Shareholders in the Fund may make inquiries to the Fund to receive such information by calling (800) 997-7327 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. The Fund's Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, free of charge, on the Funds' website at www.ssgafunds.com.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

SSITEQ5ADSTATPRO

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Equity 500 Index Fund: Class R Shares (SSFRX)

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with the Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling (800) 647-7327. Your election to receive reports in paper will apply to all funds held in your account.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in the State Street Equity 500 Index Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

The Fund may offer multiple classes of shares. This Prospectus covers only the Class R Shares.

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Fund Summary	1
State Street Equity 500 Index Fund	1
Additional Information About Investment Objective, Principal Strategies and Risks	7
Additional Information About Non-Principal Investment Strategies and Risks	12
Portfolio Holdings Disclosure	13
Management and Organization	14
Shareholder Information	16
Dividends, Distributions and Tax Considerations	19
Financial Intermediary Arrangements	20
Financial Highlights	22
Index/Trademark Licenses/Disclaimers	24

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State Street Equity 500 Index Fund

Investment Objective

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	0.02%
Distribution and/or Shareholder Service (12b-1) Fees	0.60%
Other Expenses	0.12%
Total Annual Fund Operating Expenses	0.74%
Less Fee Waivers and/or Expense Reimbursements ¹	(0.12)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.62%

Example:

1 year		3 years		5 years		10 years
$63		$224		$400		$907

Portfolio Turnover:

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Principal Investment Strategies

Principal Risks

In addition, the Fund is subject to the following risks:

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Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's' returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of the Index. The bar chart shows how the Class R Shares' returns have varied for each full calendar year shown. The Fund's past performance does not necessarily indicate how the Fund will perform in the future.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 15.77% (Q2, 2009)
Lowest Quarterly Return: -14.13% (Q3, 2011)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Five Years	Ten Years	Inception Date
Class R Shares				6/7/2005
Return Before Taxes	-5.04%	7.73%	12.34%
Return After Taxes on Distributions	-6.04%	6.97%	11.77%
Return After Taxes on Distributions and Sale of Fund Shares	-2.29%	5.99%	10.22%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	-4.38%	8.49%	13.12%

The Fund will make updated performance information, including its current net asset value, available at the Fund's website: www.ssgafunds.com.

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Investment Adviser

SSGA FM serves as the investment adviser to the Fund and the Portfolio.

Michael Feehily, CFA, is a Senior Managing Director of the Adviser and the Head of Global Equity Beta Solutions in the Americas. He worked at the Adviser from 1997 to 2006 and rejoined in 2010.

Karl Schneider, CAIA, is a Managing Director of the Adviser and Deputy Head of Global Equity Beta Solutions in the Americas. He joined the Adviser in 1997.

Amy Scofield is a Principal of the Adviser and a Portfolio Manager in the Global Equity Beta Solutions Group. She joined the Adviser in 2010.

Purchase and Sale of Fund Shares

Purchase Minimums

To establish an account	$25,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

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Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objective, Principal Strategies and Risks

State Street Equity 500 Index Fund Class R

Investment Objective

Principal Investment Strategies

The Fund generally intends to invest in all stocks comprising the S&P 500 in approximate proportion to their weightings in the Index. However, under various circumstances, it may not be possible or practicable to purchase all stocks in those weightings. In those circumstances, the Fund may purchase a sample of the stocks in the Index in proportions expected by SSGA FM to match generally the performance of the Index as a whole. In addition, from time to time stocks are added to or removed from the Index. The Fund may sell securities that are represented in the Index, or purchase securities that are not yet represented in the Index, in anticipation of their removal from or addition to the Index. Under normal market conditions, the Fund will not invest less than 80% of its total assets in stocks in the Index. Shareholders will receive sixty (60) days' notice prior to a change in the 80% investment policy. For this purpose, “total assets” means net assets plus borrowings, if any. The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. In addition, the Fund may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

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Additional Index Information . The Index's components are reconstituted and rebalanced quarterly.

Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure.

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Large-Capitalization Securities Risk. Securities issued by large-capitalization companies may present risks not present in smaller companies. For example, larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or other market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies, especially during strong economic periods. Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies.

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Leveraging Risk . Borrowing transactions, reverse repurchase agreements, certain derivatives transactions, securities lending transactions and other investment transactions such as when-issued, delayed-delivery, or forward commitment transactions may create investment leverage. If the Fund engages in transactions that have a leveraging effect on the Fund's investment portfolio, the value of the Fund will be potentially more volatile and all other risks will tend to be compounded. This is because leverage generally creates investment risk with respect to a larger base of assets than the Fund would otherwise have and so magnifies the effect of any increase or decrease in the value of the Fund's underlying assets. The use of leverage is considered to be a speculative investment practice and may result in losses to the Fund. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. The use of leverage may cause the Fund to liquidate positions when it may not be advantageous to do so to satisfy repayment, interest payment, or margin obligations or to meet asset segregation or coverage requirements.

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Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject the Fund to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and the Fund's investment program in particular can be uncertain. In recent periods, governmental and non-governmental issuers have defaulted on, or have been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including, without limitation, in Europe or Asia. Defaults or restructurings by governments or others of their debts could have substantial adverse effects on economies, financial markets, and asset valuations around the world. Further Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, or investor perception that these efforts are not succeeding, could negatively affect financial markets generally as well as the values and liquidity of certain securities.

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Unconstrained Sector Risk . The Fund may invest a substantial portion of its assets within one or more economic sectors or industries, which may change from time to time. When the Fund focuses its investments in a particular industry or sector, financial, economic, business, and other developments affecting issuers in that industry, market, or economic sector will have a greater effect on the Fund than if it had not focused its assets in that industry, market, or economic sector, which may increase the volatility of the Fund. Any such investment focus may also limit the liquidity of the Fund. In addition, investors may buy or sell substantial amounts of the Fund's shares in response to factors affecting or expected to affect an industry, market, or economic sector in which the Fund focuses its investments, resulting in extreme inflows or outflows of cash into and out of the Fund. Such extreme cash inflows or outflows might affect management of the Fund adversely.

Additional Information About Non-Principal Investment Strategies and Risks

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Fund. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for the Fund and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by the Fund. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Fund) or otherwise using such information for the benefit of its clients or itself.

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Portfolio Holdings Disclosure

The Fund's portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

Investment Adviser

Total Annual Fund Operating Expense Waiver . SSGA FM, as the investment adviser to the Fund, is contractually obligated, through April 30, 2020, (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing and sub-transfer agency fees) exceed 0.02% of average daily net assets on an annual basis. This waiver and/or reimbursement arrangement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

A discussion regarding the Board's consideration of the Fund's Investment Advisory Agreement is provided in the Fund's Semi-Annual Report to Shareholders for the period ended June 30, 2018.

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The professionals primarily responsible for the day-to-day management of the Equity 500 Index II Portfolio and the Equity 500 Index Fund include the following:

Additional information about the portfolio managers' compensation, other accounts managed by the portfolio managers, and the portfolio managers' ownership of the Fund is available in the SAI.

Other Fund Services

The Administrator, Sub-Administrator and Custodian

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Fund's transfer agent and dividend disbursing agent (the “Transfer Agent”).

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Fund's distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

Additional Information

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Shareholder Information

Determination of Net Asset Value

The Fund determines its net asset value (“NAV”) per share once each business day as of the close of regular trading on the New York Stock Exchange (the “NYSE”). Pricing does not occur on NYSE holidays. A business day is one on which the NYSE is open for regular trading. The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. In unusual circumstances, such as an emergency or an unscheduled close or halt of trading on the NYSE, the time at which share prices are determined may be changed. The NAV per share is based on the market value of the investments held in the Fund. The NAV of the Fund's Class R Shares is calculated by dividing the value of the assets of the Fund attributable to its Class R Shares less the liabilities of the Fund attributable to its Class R Shares by the number of Class R Shares outstanding. As noted in this Prospectus, the Fund may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when the Fund does not price its shares. Consequently, the NAV of the Fund's shares may change on days when shareholders are not able to purchase or redeem the Fund's shares. Purchase and redemption orders for Fund Shares are processed, respectively, at the NAV next determined after the Fund accepts a purchase order or receives a redemption request in good form. The Fund values each security or other investment pursuant to guidelines adopted by the Fund's Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Portfolio's Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii) a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by the Fund occurs after the close of a related exchange but before the determination of the Fund's NAV. Attempts to determine the fair value of securities or other investments introduce an element of subjectivity to the pricing of securities or other investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the price the Fund would have received had it sold the investment. To the extent that the Fund invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the funds. The prospectuses of these funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

Investing in State Street Institutional Investment Trust Shares

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Purchasing Shares

Investors pay no sales load to invest in the Class R Shares of the Fund. The price for Fund shares is the NAV per share. Orders received in good form (a purchase order is in good form if it meets the requirements implemented from time to time by the Fund or its Transfer Agent, and for new accounts includes submission of a completed and signed application and all documentation necessary to open an account) will be priced at the NAV next calculated after the order is accepted by the Fund.

The minimum initial investment in the Class R Shares is $25 million, although the Adviser may waive the minimum in its discretion. There is no minimum subsequent investment. The Fund intends to be as fully invested as is practicable; therefore, investments must be made either in Federal Funds ( i.e ., monies credited to the account of the Fund's custodian bank by a Federal Reserve Bank) or securities (“in-kind”) acceptable to the Adviser. (Please consult your tax adviser regarding in-kind transactions.) (If you purchase shares by check, your order will not be in good form until the Transfer Agent receives federal funds for the check.) The Fund reserves the right to cease accepting investments at any time or to reject any purchase order.

If you are purchasing through a Financial Intermediary, please contact your Financial Intermediary as their requirements may differ.

Redeeming Shares

If your account is held through an Intermediary, please contact them for additional assistance and advice on how to redeem your shares.

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About Mail Transactions

Frequent-Trading Limits

As a means to protect each State Street Fund and its shareholders from Excessive Trading:

•	The State Street Funds' transfer agent compiles, monitors and reports account-level information on omnibus and underlying shareholder/participant activity. Depending on the account type, monitoring will be performed on a daily, monthly, quarterly and/or annual basis;
•	The State Street Funds' distributor has obtained information from each Financial Intermediary holding shares in an omnibus account with the State Street Funds regarding whether the Financial Intermediary has adopted and maintains procedures that are reasonably designed to protect the Funds against harmful short-term trading; and
•	With respect to State Street Funds that invest in securities that trade on foreign markets, pursuant to the State Street Funds' fair valuation procedures, pricing adjustments may be made based on information received from a third-party, multi-factor fair valuation pricing service.

The State Street Funds' distributor has detailed procedures that document the transparency oversight and monitoring processes performed by the State Street Funds' transfer agent.

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Delivery of Documents to Accounts Sharing an Address

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a State Street Fund identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Fund (if you hold shares directly with the Fund) or to your financial intermediary (if you do not hold shares directly with the Fund).

Dividends, Distributions and Tax Considerations

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An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by the Fund, including any capital gain dividends, and net gains recognized on the redemption of shares of the Fund.

Financial Intermediary Arrangements

Distribution Arrangements and Rule 12b-1 Fees

The Fund has adopted a distribution plan pursuant to Rule 12b-1 under the 1940 Act under which the Fund may compensate SSGA FD (or others) for services in connection with the distribution of the Fund's Class R Shares and for services provided to Fund shareholders (the “Plan”). The Plan calls for payments at an annual rate (based on average daily net assets) of 0.60% of the Fund's net assets attributable to its Class R Shares. Because these fees are paid out of the assets of the Fund attributable to its Class R Shares on an ongoing basis, they will increase the cost of your investment and may cost you more over time than paying other types of sales charges.

The Fund may pay distribution fees and other amounts described in this Prospectus at a time when shares of the Fund are unavailable for purchase.

Other Payments to Financial Intermediaries

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The Financial Intermediary is often compensated by SSGA FD or its affiliates for the services it performs and in such cases is typically paid continually over time, during the period when the Financial Intermediary's clients hold investments in the Fund. The amount of continuing compensation paid by SSGA FD or its affiliates to different Financial Intermediaries for distribution and/or shareholder services varies. Any compensation is typically a percentage of the value of the Financial Intermediary's clients' investments in the Fund or a per account fee. The variation in compensation may, but will not necessarily, reflect enhanced or additional services provided by the Financial Intermediary.

If you invest through a Financial Intermediary and meet the eligibility criteria for more than one share class, you should discuss with your Financial Intermediary which share class is appropriate for you. Your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend one share class over another, when you are eligible to invest in more than one share class. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by the Fund or its affiliates with respect to the different share classes offered by the Fund.

SSGA FD and its affiliates (including SSGA FM), at their own expense and out of their own assets, may also provide other compensation to Financial Intermediaries in connection with sales of the Fund's shares or the servicing of shareholders or shareholder accounts. Such compensation may include, but is not limited to, financial assistance to Financial Intermediaries in connection with conferences, sales, or training programs for their employees; seminars for the public; advertising or sales campaigns; or other Financial Intermediary-sponsored special events. In some instances, this compensation may be made available only to certain Financial Intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the Fund's shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as Financial Industry Regulatory Authority, Inc.

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Financial Highlights

The financial highlight tables are intended to help you understand the Class R Shares financial performance for the past five fiscal years. Certain information reflects the performance results for a single Fund Share. The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in the Fund (assuming reinvestment of all dividends and distributions). This information has been audited by Ernst & Young LLP, the Trust's independent registered public accounting firm, whose report, along with the Fund's financial highlights and financial statements, is included in the annual report to shareholders, which is available upon request. Any references to Notes in these financial highlight tables refer to the “Notes to Financial Statements” section of the Fund's financial statements, and the financial information included in these tables should be read in conjunction with the financial statements incorporated by reference in the SAI.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET EQUITY 500 INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class R Shares
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	Year Ended 12/31/14
Net asset value, beginning of period	$ 21.61	$ 18.81	$ 17.15	$ 17.26	$ 15.49
Income (loss) from investment operations:
Net investment income (loss) (a)	0.24	0.29	0.18	0.19	0.22
Net realized and unrealized gain (loss)	(1.33)	3.66	1.76	(0.09)	1.78
Total from investment operations	(1.09)	3.95	1.94	0.10	2.00
Distributions to shareholders from:
Net investment income	(0.30)	(0.36)	(0.20)	(0.21)	(0.23)
Net realized gains	(0.60)	(0.79)	(0.08)	—	—
Total distributions	(0.90)	(1.15)	(0.28)	(0.21)	(0.23)
Net asset value, end of period	$ 19.62	$ 21.61	$ 18.81	$ 17.15	$ 17.26
Total return (b)	(5.04)%	20.96%	11.26%	0.58%	12.91%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$32,099	$42,249	$39,086	$37,845	$41,148
Ratios to Average Net Assets:(c)
Total expenses	0.72%(d)	0.71%(d)	0.72%(d)	0.76%(d)	0.75%(e)
Net expenses	0.62%(d)	0.63%(d)	0.63%(d)	0.63%(d)	0.68%(e)
Net investment income (loss)	1.06%	1.41%	0.99%	1.09%	1.37%
Portfolio turnover rate	8%(f)	30%(f)	5%(f)	5%(f)	4%(g)

(a)	Net investment income per share is calculated using the average shares method.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Prior to August 11, 2014, the per shares amounts and percentages included the Fund's proportionate share of income and expenses of the State Street Equity 500 Index Portfolio.
(d)	Ratio does not include the expenses of the State Street Equity 500 Index II Portfolio.
(e)	Ratio includes expenses allocated from the State Street Equity 500 Index Portfolio from 1/1/2014 through 8/10/2014, and does not include the expenses of the State Street Equity 500 Index II Portfolio from 8/11/2014 through 12/31/2014.
(f)	Portfolio turnover rate is from the State Street Equity 500 Index II Portfolio.
(g)	Portfolio turnover rate is calculated from the State Street Equity 500 Index Portfolio (from 1/1/2014 to 8/10/2014) and the State Street Equity 500 Index II Portfolio (from 8/11/2014 to 12/31/2014).

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Index/Trademark Licenses/Disclaimers

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Contacting the State Street Funds

Online:	www.ssgafunds.com	24 hours a day, 7 days a week
Phone:	(800) 647-7327	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Overnight/ Registered, Express, Certified Mail
State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737	State Street Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407

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For more information about the Fund:

The Fund's SAI includes additional information about the Fund and is incorporated by reference into this document. Additional information about the Fund's investments is available in the Fund's most recent annual and semi-annual reports to shareholders. In a Fund's annual report, you will find a discussion of the market conditions and investment strategies that significantly affected the Fund's performance during its last fiscal year. The Fund's SAI is available, without charge, upon request. The Fund's annual and semi-annual reports are available, without charge, upon request. Shareholders in the Fund may make inquiries to the Fund to receive such information by calling (800) 997-7327 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. The Fund's Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, free of charge, on the Funds' website at www.ssgafunds.com.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

SSITCLRSTATPRO

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Equity 500 Index Fund: Service Shares (STBIX)

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in the State Street Equity 500 Index Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

The Fund may offer multiple classes of shares. This Prospectus covers only the Service Shares.

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Fund Summary	1
State Street Equity 500 Index Fund	1
Additional Information About Investment Objective, Principal Strategies and Risks	7
Additional Information About Non-Principal Investment Strategies and Risks	12
Portfolio Holdings Disclosure	13
Management and Organization	14
Shareholder Information	16
Dividends, Distributions and Tax Considerations	19
Financial Intermediary Arrangements	20
Financial Highlights	22
Index/Trademark Licenses/Disclaimers	24

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State Street Equity 500 Index Fund

Investment Objective

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	0.02%
Distribution and/or Shareholder Service (12b-1) Fees	0.25%
Other Expenses	0.12%
Total Annual Fund Operating Expenses	0.39%
Less Fee Waivers and/or Expense Reimbursements ¹	(0.12)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.27%

Example:

1 year		3 years		5 years		10 years
$28		$113		$207		$481

Portfolio Turnover:

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Principal Investment Strategies

Principal Risks

In addition, the Fund is subject to the following risks:

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Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's' returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of the Index. The bar chart shows how the Service Shares' returns have varied for each full calendar year shown. The Fund's past performance does not necessarily indicate how the Fund will perform in the future.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 15.92% (Q2, 2009)
Lowest Quarterly Return: -14.03% (Q3, 2011)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Five Years	Ten Years	Inception Date
Service Shares				3/10/2003
Return Before Taxes	-4.66%	8.11%	12.74%
Return After Taxes on Distributions	-5.75%	7.25%	12.07%
Return After Taxes on Distributions and Sale of Fund Shares	-2.02%	6.28%	10.54%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	-4.38%	8.49%	13.12%

The Fund will make updated performance information, including its current net asset value, available at the Fund's website: www.ssgafunds.com.

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Investment Adviser

SSGA FM serves as the investment adviser to the Fund and the Portfolio.

Michael Feehily, CFA, is a Senior Managing Director of the Adviser and the Head of Global Equity Beta Solutions in the Americas. He worked at the Adviser from 1997 to 2006 and rejoined in 2010.

Karl Schneider, CAIA, is a Managing Director of the Adviser and Deputy Head of Global Equity Beta Solutions in the Americas. He joined the Adviser in 1997.

Amy Scofield is a Principal of the Adviser and a Portfolio Manager in the Global Equity Beta Solutions Group. She joined the Adviser in 2010.

Purchase and Sale of Fund Shares

Purchase Minimums

To establish an account	$25,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

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Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objective, Principal Strategies and Risks

State Street Equity 500 Index Fund Service Shares

Investment Objective

Principal Investment Strategies

The Fund generally intends to invest in all stocks comprising the S&P 500 in approximate proportion to their weightings in the Index. However, under various circumstances, it may not be possible or practicable to purchase all stocks in those weightings. In those circumstances, the Fund may purchase a sample of the stocks in the Index in proportions expected by SSGA FM to match generally the performance of the Index as a whole. In addition, from time to time stocks are added to or removed from the Index. The Fund may sell securities that are represented in the Index, or purchase securities that are not yet represented in the Index, in anticipation of their removal from or addition to the Index. Under normal market conditions, the Fund will not invest less than 80% of its total assets in stocks in the Index. Shareholders will receive sixty (60) days' notice prior to a change in the 80% investment policy. For this purpose, “total assets” means net assets plus borrowings, if any. The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. In addition, the Fund may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

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Additional Index Information . The Index's components are reconstituted and rebalanced quarterly.

Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure.

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Large-Capitalization Securities Risk. Securities issued by large-capitalization companies may present risks not present in smaller companies. For example, larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or other market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies, especially during strong economic periods. Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies.

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Leveraging Risk . Borrowing transactions, reverse repurchase agreements, certain derivatives transactions, securities lending transactions and other investment transactions such as when-issued, delayed-delivery, or forward commitment transactions may create investment leverage. If the Fund engages in transactions that have a leveraging effect on the Fund's investment portfolio, the value of the Fund will be potentially more volatile and all other risks will tend to be compounded. This is because leverage generally creates investment risk with respect to a larger base of assets than the Fund would otherwise have and so magnifies the effect of any increase or decrease in the value of the Fund's underlying assets. The use of leverage is considered to be a speculative investment practice and may result in losses to the Fund. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. The use of leverage may cause the Fund to liquidate positions when it may not be advantageous to do so to satisfy repayment, interest payment, or margin obligations or to meet asset segregation or coverage requirements.

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Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject the Fund to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and the Fund's investment program in particular can be uncertain. In recent periods, governmental and non-governmental issuers have defaulted on, or have been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including, without limitation, in Europe or Asia. Defaults or restructurings by governments or others of their debts could have substantial adverse effects on economies, financial markets, and asset valuations around the world. Further Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, or investor perception that these efforts are not succeeding, could negatively affect financial markets generally as well as the values and liquidity of certain securities.

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Unconstrained Sector Risk . The Fund may invest a substantial portion of its assets within one or more economic sectors or industries, which may change from time to time. When the Fund focuses its investments in a particular industry or sector, financial, economic, business, and other developments affecting issuers in that industry, market, or economic sector will have a greater effect on the Fund than if it had not focused its assets in that industry, market, or economic sector, which may increase the volatility of the Fund. Any such investment focus may also limit the liquidity of the Fund. In addition, investors may buy or sell substantial amounts of the Fund's shares in response to factors affecting or expected to affect an industry, market, or economic sector in which the Fund focuses its investments, resulting in extreme inflows or outflows of cash into and out of the Fund. Such extreme cash inflows or outflows might affect management of the Fund adversely.

Additional Information About Non-Principal Investment Strategies and Risks

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Fund. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for the Fund and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by the Fund. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Fund) or otherwise using such information for the benefit of its clients or itself.

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Portfolio Holdings Disclosure

The Fund's portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

Investment Adviser

Total Annual Fund Operating Expense Waiver . SSGA FM, as the investment adviser to the Fund, is contractually obligated, through April 30, 2020, (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing and sub-transfer agency fees) exceed 0.02% of average daily net assets on an annual basis. This waiver and/or reimbursement arrangement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

A discussion regarding the Board's consideration of the Fund's Investment Advisory Agreement is provided in the Fund's Semi-Annual Report to Shareholders for the period ended June 30, 2018.

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The professionals primarily responsible for the day-to-day management of the Equity 500 Index II Portfolio and the Equity 500 Index Fund include the following:

Additional information about the portfolio managers' compensation, other accounts managed by the portfolio managers, and the portfolio managers' ownership of the Fund is available in the SAI.

Other Fund Services

The Administrator, Sub-Administrator and Custodian

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Fund's transfer agent and dividend disbursing agent (the “Transfer Agent”).

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Fund's distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

Additional Information

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Shareholder Information

Determination of Net Asset Value

The Fund determines its net asset value (“NAV”) per share once each business day as of the close of regular trading on the New York Stock Exchange (the “NYSE”). Pricing does not occur on NYSE holidays. A business day is one on which the NYSE is open for regular trading. The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. In unusual circumstances, such as an emergency or an unscheduled close or halt of trading on the NYSE, the time at which share prices are determined may be changed. The NAV per share is based on the market value of the investments held in the Fund. The NAV of the Fund's Service Shares is calculated by dividing the value of the assets of the Fund attributable to its Service Shares less the liabilities of the Fund attributable to its Service Shares by the number of Service Shares outstanding. As noted in this Prospectus, the Fund may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when the Fund does not price its shares. Consequently, the NAV of the Fund's shares may change on days when shareholders are not able to purchase or redeem the Fund's shares. Purchase and redemption orders for Fund Shares are processed, respectively, at the NAV next determined after the Fund accepts a purchase order or receives a redemption request in good form. The Fund values each security or other investment pursuant to guidelines adopted by the Fund's Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Portfolio's Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii) a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by the Fund occurs after the close of a related exchange but before the determination of the Fund's NAV. Attempts to determine the fair value of securities or other investments introduce an element of subjectivity to the pricing of securities or other investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the price the Fund would have received had it sold the investment. To the extent that the Fund invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the funds. The prospectuses of these funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

Investing in State Street Institutional Investment Trust Shares

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Purchasing Shares

Investors pay no sales load to invest in the Service Shares of the Fund. The price for Fund shares is the NAV per share. Orders received in good form (a purchase order is in good form if it meets the requirements implemented from time to time by the Fund or its Transfer Agent, and for new accounts includes submission of a completed and signed application and all documentation necessary to open an account) will be priced at the NAV next calculated after the order is accepted by the Fund.

The minimum initial investment in the Service Shares is $25 million, although the Adviser may waive the minimum in its discretion. There is no minimum subsequent investment. The Fund intends to be as fully invested as is practicable; therefore, investments must be made either in Federal Funds ( i.e ., monies credited to the account of the Fund's custodian bank by a Federal Reserve Bank) or securities (“in-kind”) acceptable to the Adviser. (Please consult your tax adviser regarding in-kind transactions.) (If you purchase shares by check, your order will not be in good form until the Transfer Agent receives federal funds for the check.) The Fund reserves the right to cease accepting investments at any time or to reject any purchase order.

If you are purchasing through a Financial Intermediary, please contact your Financial Intermediary as their requirements may differ.

Redeeming Shares

If your account is held through an Intermediary, please contact them for additional assistance and advice on how to redeem your shares.

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About Mail Transactions

Frequent-Trading Limits

As a means to protect each State Street Fund and its shareholders from Excessive Trading:

•	The State Street Funds' transfer agent compiles, monitors and reports account-level information on omnibus and underlying shareholder/participant activity. Depending on the account type, monitoring will be performed on a daily, monthly, quarterly and/or annual basis;
•	The State Street Funds' distributor has obtained information from each Financial Intermediary holding shares in an omnibus account with the State Street Funds regarding whether the Financial Intermediary has adopted and maintains procedures that are reasonably designed to protect the Funds against harmful short-term trading; and
•	With respect to State Street Funds that invest in securities that trade on foreign markets, pursuant to the State Street Funds' fair valuation procedures, pricing adjustments may be made based on information received from a third-party, multi-factor fair valuation pricing service.

The State Street Funds' distributor has detailed procedures that document the transparency oversight and monitoring processes performed by the State Street Funds' transfer agent.

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Delivery of Documents to Accounts Sharing an Address

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a State Street Fund identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Fund (if you hold shares directly with the Fund) or to your financial intermediary (if you do not hold shares directly with the Fund).

Dividends, Distributions and Tax Considerations

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An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by the Fund, including any capital gain dividends, and net gains recognized on the redemption of shares of the Fund.

Financial Intermediary Arrangements

Distribution Arrangements and Rule 12b-1 Fees

The Fund has adopted a distribution plan pursuant to Rule 12b-1 under the 1940 Act under which the Fund may compensate SSGA FD (or others) for services in connection with the distribution of the Fund's Service Shares and for services provided to Fund shareholders (the “Plan”). The Plan calls for payments at an annual rate (based on average daily net assets) of 0.25% of the Fund's net assets attributable to its Service Shares. Because these fees are paid out of the assets of the Fund attributable to its Service Shares on an ongoing basis, they will increase the cost of your investment and may cost you more over time than paying other types of sales charges.

The Fund may pay distribution fees and other amounts described in this Prospectus at a time when shares of the Fund are unavailable for purchase.

Other Payments to Financial Intermediaries

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The Financial Intermediary is often compensated by SSGA FD or its affiliates for the services it performs and in such cases is typically paid continually over time, during the period when the Financial Intermediary's clients hold investments in the Fund. The amount of continuing compensation paid by SSGA FD or its affiliates to different Financial Intermediaries for distribution and/or shareholder services varies. Any compensation is typically a percentage of the value of the Financial Intermediary's clients' investments in the Fund or a per account fee. The variation in compensation may, but will not necessarily, reflect enhanced or additional services provided by the Financial Intermediary.

If you invest through a Financial Intermediary and meet the eligibility criteria for more than one share class, you should discuss with your Financial Intermediary which share class is appropriate for you. Your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend one share class over another, when you are eligible to invest in more than one share class. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by the Fund or its affiliates with respect to the different share classes offered by the Fund.

SSGA FD and its affiliates (including SSGA FM), at their own expense and out of their own assets, may also provide other compensation to Financial Intermediaries in connection with sales of the Fund's shares or the servicing of shareholders or shareholder accounts. Such compensation may include, but is not limited to, financial assistance to Financial Intermediaries in connection with conferences, sales, or training programs for their employees; seminars for the public; advertising or sales campaigns; or other Financial Intermediary-sponsored special events. In some instances, this compensation may be made available only to certain Financial Intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the Fund's shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as Financial Industry Regulatory Authority, Inc.

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Financial Highlights

The financial highlight tables are intended to help you understand the Fund's Service Shares financial performance for the past five fiscal years. Certain information reflects the performance results for a single Fund Share. The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in the Fund (assuming reinvestment of all dividends and distributions). This information has been audited by Ernst & Young LLP, the Trust's independent registered public accounting firm, whose report, along with the Fund's financial highlights and financial statements, is included in the annual report to shareholders, which is available upon request. Any references to Notes in these financial highlight tables refer to the “Notes to Financial Statements” section of the Fund's financial statements, and the financial information included in these tables should be read in conjunction with the financial statements incorporated by reference in the SAI.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET EQUITY 500 INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Service Shares
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	Year Ended 12/31/14
Net asset value, beginning of period	$ 21.60	$ 18.81	$ 17.15	$ 17.25	$ 15.49
Income (loss) from investment operations:
Net investment income (loss) (a)	0.32	0.15	0.26	0.22	0.28
Net realized and unrealized gain (loss)	(1.33)	3.87	1.74	(0.05)	1.77
Total from investment operations	(1.01)	4.02	2.00	0.17	2.05
Distributions to shareholders from:
Net investment income	(0.37)	(0.44)	(0.26)	(0.27)	(0.29)
Net realized gains	(0.60)	(0.79)	(0.08)	—	—
Total distributions	(0.97)	(1.23)	(0.34)	(0.27)	(0.29)
Net asset value, end of period	$ 19.62	$ 21.60	$ 18.81	$ 17.15	$ 17.25
Total return (b)	(4.66)%	21.33%	11.65%	0.98%	13.24%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$20,897	$27,876	$124,591	$104,730	$126,412
Ratios to Average Net Assets:(c)
Total expenses	0.37%(d)	0.36%(d)	0.37%(d)	0.41%(d)	0.40%(e)
Net expenses	0.27%(d)	0.28%(d)	0.27%(d)	0.28%(d)	0.33%(e)
Net investment income (loss)	1.44%	0.73%	1.46%	1.25%	1.73%
Portfolio turnover rate	8%(f)	30%(f)	5%(f)	5%(f)	4%(g)

(a)	Net investment income per share is calculated using the average shares method.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Prior to August 11, 2014, the per shares amounts and percentages included the Fund's proportionate share of income and expenses of the State Street Equity 500 Index Portfolio.
(d)	Ratio does not include the expenses of the State Street Equity 500 Index II Portfolio.
(e)	Ratio includes expenses allocated from the State Street Equity 500 Index Portfolio from 1/1/2014 through 8/10/2014, and does not include the expenses of the State Street Equity 500 Index II Portfolio from 8/11/2014 through 12/31/2014.
(f)	Portfolio turnover rate is from the State Street Equity 500 Index II Portfolio.
(g)	Portfolio turnover rate is calculated from the State Street Equity 500 Index Portfolio (from 1/1/2014 to 8/10/2014) and the State Street Equity 500 Index II Portfolio (from 8/11/2014 to 12/31/2014).

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Index/Trademark Licenses/Disclaimers

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Contacting the State Street Funds

Online:	www.ssgafunds.com	24 hours a day, 7 days a week
Phone:	(800) 647-7327	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Overnight/ Registered, Express, Certified Mail
State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737	State Street Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407

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For more information about the Fund:

The Fund's SAI includes additional information about the Fund and is incorporated by reference into this document. Additional information about the Fund's investments is available in the Fund's most recent annual and semi-annual reports to shareholders. In a Fund's annual report, you will find a discussion of the market conditions and investment strategies that significantly affected the Fund's performance during its last fiscal year. The Fund's SAI is available, without charge, upon request. The Fund's annual and semi-annual reports are available, without charge, upon request. Shareholders in the Fund may make inquiries to the Fund to receive such information by calling (800) 997-7327 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. The Fund's Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, free of charge, on the Funds' website at www.ssgafunds.com.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

SSITSERVSTATPRO

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Institutional Liquid Reserves Fund

Institutional Class (SSHXX) Administration Class (SSYXX) Investment Class (SSVXX) Investor Class (SSZXX) Premier Class (SSIXX)

State Street Institutional U.S. Government Money Market Fund

Institutional Class (SAHXX) Administration Class (SALXX) Investment Class (GVVXX) Investor Class (SAMXX) Premier Class (GVMXX)

State Street Institutional Treasury Money Market Fund

Institutional Class (SSJXX) Administration Class (SSKXX) Investment Class (TRVXX) Investor Class (SSNXX) Premier Class (TRIXX)

State Street Institutional Treasury Plus Money Market Fund

Institutional Class (SAJXX) Administration Class (SSQXX) Investment Class (TPVXX) Investor Class (SAEXX) Premier Class (TPIXX)

Beginning on January 1, 2021, as permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of a Fund's annual and semi- annual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Fund (or from your financial intermediary, such as a broker-dealer or bank). Instead, the reports will be made available on the Fund's website (www.ssga.com/cash), and you will be notified by mail each time a report is posted, and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Funds electronically by calling (866) 392-0869.

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with a Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling (866) 392-0869. Your election to receive reports in paper will apply to all funds held in your account, if you invest through your financial intermediary or all funds held with the fund complex if you invest directly with a Fund.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in any of the Funds offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Each Fund may offer multiple classes of shares. This Prospectus covers only the Institutional Class, Administration Class, Investment Class, Investor Class and Premier Class Shares of the applicable Funds.

State Street Institutional Liquid Reserves Fund is a “floating net asset value” money market fund. The share price of this Fund will fluctuate.

None of State Street Corporation, State Street Bank and Trust Company, State Street Global Advisors, SSGA Funds Management, Inc. or their affiliates (“State Street Entities”) guarantee the value of your investment at $1.00 per share or any other target share price. Investors should have no expectation of capital support to the Funds from State Street Entities.

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Fund Summaries	1
State Street Institutional Liquid Reserves Fund	1
State Street Institutional U.S. Government Money Market Fund	8
State Street Institutional Treasury Money Market Fund	14
State Street Institutional Treasury Plus Money Market Fund	19
Additional Information About Investment Objectives, Principal Strategies and Risks	24
Additional Information About Non-Principal Investment Strategies and Risks	32
Portfolio Holdings Disclosure	34
Management and Organization	35
Shareholder Information	36
Dividends, Distributions and Tax Considerations	43
Financial Intermediary Arrangements	45
Financial Highlights	47

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State Street Institutional Liquid Reserves Fund

Investment Objective

The investment objective of the State Street Institutional Liquid Reserves Fund (the “ILR Fund” or sometimes referred to in context as the “Fund”) is to seek to maximize current income, to the extent consistent with the preservation of capital and liquidity, by investing in U.S. dollar-denominated money market securities.

Fees and Expenses of the Fund

The table below describes the fees and expenses that you may pay if you buy and hold shares of the ILR Fund (“Fund Shares”). The expenses shown in the table and the Example reflect the expenses of the Fund and the Fund's proportionate share of the expenses of the State Street Money Market Portfolio (the “Money Market Portfolio” or sometimes referred to in context as the “Portfolio”).

Shareholder Fees (fees paid directly from your investment)

	Institutional	Administration	Investment	Investor	Premier
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None	None	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None	None	None	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Institutional	Administration	Investment	Investor	Premier
Management Fee	0.05%	0.05%	0.05%	0.05%	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%	0.05%	0.10%	0.00%	0.00%
Other Expenses ¹	0.10%	0.27%	0.32%	0.15%	0.07%
Total Annual Fund Operating Expenses	0.15%	0.37%	0.47%	0.20%	0.12%

¹	Other Expenses are based on estimates for the current fiscal year for the Institutional Class.

Example:

	1 year	3 years	5 years	10 years
Institutional	$15	$ 48	$ 85	$192
Administration	$38	$119	$208	$468
Investment	$48	$151	$263	$591
Investor	$20	$ 64	$113	$255
Premier	$12	$ 39	$ 68	$154

Principal Investment Strategies

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quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity.

Although the Fund is a money market fund, the net asset value (“NAV”) of the Fund's Shares “floats,” fluctuating with changes in the values of the Fund's portfolio securities. The Fund typically accepts purchase and redemption orders multiple times per day, and calculates its NAV at each such time.

The Fund attempts to meet its investment objective by investing in a broad range of money market instruments. These may include among other things: U.S. government securities, including U.S. Treasury bills, notes and bonds and other securities issued or guaranteed as to principal and/or interest, as applicable, by the U.S. government or its agencies or instrumentalities; certificates of deposits and time deposits of U.S. and foreign banks (including ECDs, ETDs and YCDs (as defined below), commercial paper and other high quality obligations of U.S. or foreign companies; asset-backed securities, including asset-backed commercial paper; mortgage-related securities; and repurchase agreements. These instruments may bear fixed, variable or floating rates of interest or may be zero-coupon securities. The Fund also may invest in shares of other money market funds, including funds advised by the Adviser. Under normal market conditions, the Fund intends to invest more than 25% of its total assets in bank obligations. A substantial portion of the Fund may be invested in securities that are issued or traded pursuant to exemptions from registration under the federal securities laws.

European Certificates of Deposit (“ECDs”) are U.S. dollar-denominated certificates of deposit issued by a bank outside of the United States. European Time Deposits (“ETDs”) are U.S. dollar-denominated deposits in foreign branches of U.S. banks and foreign banks. Yankee Certificates of Deposit (“YCDs”) are U.S. dollar-denominated certificates of deposit issued by U.S. branches of foreign banks. These instruments have different risks than those associated with the obligations of U.S. banks operating in the United States.

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the Money Market Portfolio, which has substantially identical investment policies to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio, and it participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Portfolio.

Principal Risks

You could lose money by investing in the Fund. Because the share price of the Fund will fluctuate, when you sell your shares they may be worth more or less than what you originally paid for them. The Fund may impose a fee upon the sale of your shares or may temporarily suspend your ability to sell shares if the Fund's liquidity falls below required minimums because of market conditions or other factors. An investment in the Fund is subject to investment risks, including possible loss of principal, is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (“FDIC”) or any other government agency. The Fund's sponsor has no legal obligation to provide financial support to the Fund, and you should not expect that the sponsor will provide financial support to the Fund at any time. The risks are described in alphabetical order and not in the order of importance or potential exposure.

In addition, the Fund is subject to the following principal risks:

Counterparty Risk: The Fund will be subject to credit risk with respect to the counterparties with which the Fund enters into repurchase agreements and other transactions. If a counterparty fails to meet its contractual obligations, the Fund may be unable to terminate the transaction, and it may be delayed or prevented from realizing on any collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty.

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effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

Large Shareholder Risk: To the extent a large proportion of the interests of the Portfolio are held by a small number of investors (or a single investor), including funds or accounts over which the Adviser has investment discretion, the Portfolio is subject to the risk that these investors will purchase or redeem Portfolio interests in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of the Portfolio to conduct its investment program.

Low Short-Term Interest Rates: During market conditions in which short-term interest rates are at low levels, the Fund's yield can be very low. During these conditions, it is possible that the Fund will generate an insufficient amount of income to pay its expenses, and that it will not be able to pay a daily dividend and may have a negative yield (i.e., it may lose money on an operating basis). It is possible that the Fund would, during these conditions, maintain a substantial portion of its assets in cash, on which it may earn little, if any, income.

Money Market Risk-Floating NAV: The Fund does not maintain a constant net asset value per share. The value of the Fund's shares is calculated to four decimal places and will vary reflecting the value of the portfolio of investments held by the Fund. It is possible to lose money by investing in the Fund.

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Non-U.S. Securities Risk: Non-U.S. securities (including depositary receipts) are subject to political, regulatory, and economic risks not present in domestic investments. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, legal and financial report standards comparable to those in the United States. Further, such entities and/or their securities may be subject to risks associated with currency controls; expropriation; changes in tax policy; greater market volatility; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. Securities traded on foreign markets may be less liquid (harder to sell) than securities traded domestically. Foreign governments may impose restrictions on the repatriation of capital to the U.S. In addition, to the extent investments are made in a limited number of countries, events in those countries will have a more significant impact on the Fund. Investments in depositary receipts may be less liquid and more volatile than the underlying shares in their primary trading market.

Rapid Changes in Interest Rates Risk: Rapid changes in interest rates may cause significant requests to redeem Fund Shares, and possibly cause the Fund to sell portfolio securities at a loss to satisfy those requests.

Repurchase Agreement Risk: Repurchase agreements may be viewed as loans made by the Fund which are collateralized by the securities subject to repurchase. If the Fund's counterparty should default on its obligations and the Fund is delayed or prevented from recovering the collateral, or if the value of the collateral is insufficient, the Fund may realize a loss.

Restricted Securities Risk: The Fund may hold securities that have not been registered for sale to the public under the U.S. federal securities laws. There can be no assurance that a trading market will exist at any time for any particular restricted security. Limitations on the resale of these securities may have an adverse effect on their marketability, and may prevent the Fund from disposing of them promptly at reasonable prices. The Fund may have to bear the expense of registering the securities for resale and the risk of substantial delays in effecting the registration. Also, restricted securities may be difficult to value because market quotations may not be readily available, and the securities may have significant volatility.

Variable and Floating Rate Securities Risk: During periods of increasing interest rates, changes in the coupon rates of variable or floating rate securities may lag behind the changes in market rates or may have limits on the maximum increases in coupon rates. Alternatively, during periods of declining interest rates, the coupon rates on such securities will typically readjust downward resulting in a lower yield. In addition, investment in derivative variable rate securities, such as inverse floaters, whose rates vary inversely with market rates of interest, or range floaters or capped floaters, whose rates are subject to periodic or lifetime caps, or in securities that pay a rate of interest determined by applying a multiple to the variable rate involves special risks as compared to investment in a fixed-rate security and may involve leverage.

Zero-Coupon Bond Risk: Zero-coupon bonds usually trade at a deep discount from their face or par values and are subject to greater market value fluctuations from changing interest rates than debt obligations of comparable maturities that make current distributions of interest.

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Performance

The bar chart and table below provide some indication of the risks of investing in the ILR Fund by illustrating the variability of the Fund's returns for Premier Class shares from year-to-year. Performance history will be available for the Institutional Class Shares of the Fund after they have been in operation for one calendar year. Returns of this share class could have been similar to the returns shown for Premier Class shares because the shares are invested in the same portfolio of securities. Returns would differ only to the extent that this share class does not have the same expenses as Premier Class shares. Institutional Class shares are generally expected to incur higher expenses, and so have generally lower returns, than Premier Class shares. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.57% (Q4, 2018)
Lowest Quarterly Return: 0.02% (Q1, 2014)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Five Years	10-Years or Since Inception	Inception Date
Premier Class	2.00%	0.74%	0.48%	8/12/2004
Investment Class	1.67%	0.49%	0.26%	10/15/2007
Administration Class	1.75%	-	1.12%	8/29/2016
Investor Class	1.92%	-	1.68%	7/13/2017

To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

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Purchase and Sale of Fund Shares

Purchase Minimums

Institutional Class
To establish an account	$25,000,000
To add to an existing account	No minimum
Administration Class
To establish an account	$1,000
To add to an existing account	No minimum
Investment Class
To establish an account	$25,000,000
To add to an existing account	No minimum
Investor Class
To establish an account	$10,000,000
To add to an existing account	No minimum
Premier Class
To establish an account	$250,000,000
To add to an existing account	No minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone:

For wire transfer instructions, please call (866) 392-0869 between 7:00 a.m. and 5:00 p.m. Eastern time. Redemptions by telephone are permitted only if you previously have been authorized for these transactions.

By Intermediary:

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Tax Information

For U.S. federal income tax purposes, the Fund's distributions are generally taxed as ordinary income unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or individual retirement account. Any withdrawals made from such tax-advantaged arrangement may be taxable to you.

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Payments to Broker-Dealers and Other Financial Intermediaries

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State Street Institutional U.S. Government Money Market Fund

Investment Objective

The investment objective of the State Street Institutional U.S. Government Money Market Fund (the “U.S. Government Fund” or sometimes referred to in context as the “Fund”) is to seek to maximize current income, to the extent consistent with the preservation of capital and liquidity and the maintenance of a stable $1.00 per share net asset value (“NAV”).

Fees and Expenses of the Fund

The table below describes the fees and expenses that you may pay if you buy and hold shares of the U.S. Government Fund (“Fund Shares”). The expenses shown in the table and the Example reflect the expenses of the Fund and the Fund's proportionate share of the expenses of the State Street U.S. Government Money Market Portfolio (the “U.S. Government Portfolio” or sometimes referred to in context as the “Portfolio”).

Shareholder Fees (fees paid directly from your investment)

	Institutional	Administration	Investment	Investor	Premier
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None	None	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None	None	None	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Institutional	Administration	Investment	Investor	Premier
Management Fee	0.05%	0.05%	0.05%	0.05%	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%	0.05%	0.10%	0.00%	0.00%
Other Expenses ¹	0.10%	0.27%	0.32%	0.15%	0.07%
Total Annual Fund Operating Expenses	0.15%	0.37%	0.47%	0.20%	0.12%

¹	Other Expenses are based on estimates for the current fiscal year for the Institutional Class.

Example:

	1 year	3 years	5 years	10 years
Institutional	$15	$ 48	$ 85	$192
Administration	$38	$119	$208	$468
Investment	$48	$151	$263	$591
Investor	$20	$ 64	$113	$255
Premier	$12	$ 39	$ 68	$154

Principal Investment Strategies

The U.S. Government Fund is a government money market fund and invests only in obligations issued or guaranteed as to principal and/or interest, as applicable, by the U.S. government or its agencies and instrumentalities, as well as repurchase agreements secured by such instruments. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

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The Fund follows a disciplined investment process that attempts to provide stability of principal, liquidity and current income, by investing in U.S. government securities. Among other things, SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, conducts its own credit analyses of potential investments and portfolio holdings, and relies substantially on a dedicated short-term credit research team. The Fund invests in accordance with regulatory requirements applicable to money market funds. Regulations require, among other things, a money market fund to invest only in short-term, high quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity. All securities held by the Fund are U.S. dollar-denominated, and they may have fixed, variable or floating interest rates.

The Fund attempts to meet its investment objective by investing in:

•

Obligations issued or guaranteed as to principal and/or interest, as applicable, by the U.S. government or its agencies and instrumentalities, such as U.S. Treasury securities and securities issued by the Government National Mortgage Association (“GNMA”), which are backed by the full faith and credit of the United States;

•	Obligations issued or guaranteed by the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association, and U.S. government-sponsored entities such as the Federal Home Loan Bank, and the Federal Farm Credit Banks Funding Corporation, which are not backed by the full faith and credit of the United States; and
•	Repurchase agreements collateralized by U.S. government securities.

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the U.S. Government Portfolio, which has substantially identical investment policies to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio, and it participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Portfolio.

Principal Risks

You could lose money by investing in the Fund. Although the Fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. An investment in the Fund is subject to investment risks, including possible loss of principal, is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Fund's sponsor has no legal obligation to provide financial support to the Fund, and you should not expect that the sponsor will provide financial support to the Fund at any time. The risks are described in alphabetical order and not in the order of importance or potential exposure.

In addition, the Fund is subject to the following principal risks:

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Money Market Risk: An investment in a money market fund is not a deposit of any bank and is not insured or guaranteed by the FDIC or any other government agency. Although a money market fund generally seeks to preserve the value of its shares at $1.00 per share, there can be no assurance that it will do so, and it is possible to lose money by investing in a money market fund. A major or unexpected increase in interest rates or a decline in the credit quality of an issuer or entity providing credit support, an inactive trading market for money market instruments, or adverse market, economic, industry, political, regulatory, geopolitical, and other conditions could cause a money market fund's share price to fall below $1.00.

Stable Share Price Risk: If the market value of one or more of the Fund's investments changes substantially, the Fund may not be able to maintain a stable share price of $1.00. This risk typically is higher during periods of rapidly changing interest rates or when issuer credit quality generally is falling, and is made worse when the Fund experiences significant redemption requests.

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Significant Exposure to U.S. Government Agencies or Instrumentalities Risk: To the extent the Fund focuses its investments in securities issued or guaranteed by U.S. government agencies or instrumentalities, any market movements, regulatory changes or changes in political or economic conditions that affect the U.S. government agencies or instrumentalities in which the Fund invests may have a significant impact on the Fund's performance. Events that would adversely affect the market prices of securities issued or guaranteed by one government agency or instrumentality may adversely affect the market price of securities issued or guaranteed by other government agencies or instrumentalities.

Performance

The bar chart and table below provide some indication of the risks of investing in the U.S. Government Fund by illustrating the variability of the Fund's returns for Premier Class shares from year-to-year. Performance history will be available for the Institutional Class shares of the Fund after the Institutional Class shares have been in operation for one calendar year. Returns of this share class could have been similar to the returns shown for Premier Class shares because the shares are invested in the same portfolio of securities. Returns would differ only to the extent that this share class does not have the same expenses as Premier Class shares. Institutional Class shares are generally expected to incur higher expenses, and so have generally lower returns, than Premier Class shares. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.54% (Q4, 2018)
Lowest Quarterly Return: 0.00% (Q4, 2011)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Five Years	10-Years or Since Inception	Inception Date
Premier Class	1.76%	0.56%	0.32%	10/25/2007
Investment Class	1.40%	0.37%	0.19%	10/17/2007
Administration Class	1.51%	-	0.42%	8/23/2016
Investor Class	1.68%	-	0.91%	3/21/2016

To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

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Purchase and Sale of Fund Shares

Purchase Minimums

Institutional Class
To establish an account	$25,000,000
To add to an existing account	No minimum
Administration Class
To establish an account	$1,000
To add to an existing account	No minimum
Investment Class
To establish an account	$25,000,000
To add to an existing account	No minimum
Investor Class
To establish an account	$10,000,000
To add to an existing account	No minimum
Premier Class
To establish an account	$250,000,000
To add to an existing account	No minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone:

By Intermediary:

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Tax Information

The Fund's distributions are expected to be taxed as ordinary income unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or individual retirement account. Any withdrawals made from such tax-advantaged arrangement may be taxable to you.

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Payments to Broker-Dealers and Other Financial Intermediaries

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State Street Institutional Treasury Money Market Fund

Investment Objective

The investment objective of State Street Institutional Treasury Money Market Fund (the “Treasury Fund” or sometimes referred to in context as the “Fund”) is to seek a high level of current income consistent with preserving principal and liquidity and the maintenance of a stable $1.00 per share net asset value (“NAV”).

Fees and Expenses of the Fund

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Treasury Fund (“Fund Shares”). The expenses shown in the table and the Example reflect the expenses of the Fund and the Fund's proportionate share of the expenses of the State Street Treasury Money Market Portfolio (the “Treasury Portfolio” or sometimes referred to in context as the “Portfolio”).

Shareholder Fees (fees paid directly from your investment)

	Institutional	Administration	Investment	Investor	Premier
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None	None	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None	None	None	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Institutional	Administration	Investment	Investor	Premier
Management Fee	0.05%	0.05%	0.05%	0.05%	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%	0.05%	0.10%	0.00%	0.00%
Other Expenses ¹	0.10%	0.27%	0.32%	0.15%	0.07%
Total Annual Fund Operating Expenses	0.15%	0.37%	0.47%	0.20%	0.12%

¹	Other expenses are based on estimates for the current fiscal year for the Institutional Class and Administration Class shares.

Example:

	1 year	3 years	5 years	10 years
Institutional	$15	$ 48	$ 85	$192
Administration	$38	$119	$208	$468
Investment	$48	$151	$263	$591
Investor	$20	$ 64	$113	$255
Premier	$12	$ 39	$ 68	$154

Principal Investment Strategies

The Treasury Fund is a government money market fund and attempts to meet its investment objective by investing only in U.S. Treasury bills, notes and bonds (which are direct obligations of the U.S. government). The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

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The Fund invests in accordance with regulatory requirements applicable to money market funds, which require, among other things, the Fund to invest only in short-term securities (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity.

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the Treasury Portfolio, which has substantially identical investment policies to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio, and it participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Portfolio.

Principal Risks

In addition, the Fund is subject to the following principal risks:

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tial conflicts of interest. The Fund will bear its pro rata portion of the expenses incurred by the master fund. Substantial redemptions by other investors in a master fund may affect the master fund's investment program adversely and limit the ability of the master fund to achieve its objective.

U.S. Treasury Obligations Risk: U.S. Treasury obligations may differ from other fixed income securities in their interest rates, maturities, times of issuance and other characteristics. Similar to other issuers, changes to the financial condition or credit rating of the U.S. government may cause the value of the Fund's U.S. Treasury obligations to decline.

Performance

The bar chart and table below provide some indication of the risks of investing in the Treasury Fund by illustrating the variability of the Fund's returns for Premier Class shares from year-to-year. Performance history will be available for the Institutional Class and Administration Class shares of the Fund after they have been in operation for one calendar year. Returns of these share classes could have been similar to the returns shown for Premier Class shares because the shares are invested in the same portfolio of securities. Returns would differ only to the extent that these share classes do not have the same expenses as Premier Class shares. Institutional Class and Administration Class shares are generally expected to incur higher expenses, and so have generally lower returns, than Premier Class shares. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.54% (Q4, 2018)
Lowest Quarterly Return: 0.00% (Q1, 2010)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Five Years	10-Years or Since Inception	Inception Date
Premier Class	1.74%	0.54%	0.27%	10/25/2007
Investment Class	1.39%	0.36%	0.18%	10/25/2007
Investor Class	1.66%	-	1.16%	12/22/2016

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To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Purchase and Sale of Fund Shares

Purchase Minimums

Institutional Class
To establish an account	$25,000,000
To add to an existing account	No minimum
Administration Class
To establish an account	$1,000
To add to an existing account	No minimum
Investment Class
To establish an account	$25,000,000
To add to an existing account	No minimum
Investor Class
To establish an account	$10,000,000
To add to an existing account	No minimum
Premier Class
To establish an account	$250,000,000
To add to an existing account	No minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone:

By Intermediary:

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

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Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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State Street Institutional Treasury Plus Money Market Fund

Investment Objective

The investment objective of State Street Institutional Treasury Plus Money Market Fund (the “Treasury Plus Fund” or sometimes referred to in context as the “Fund”) is to seek a high level of current income consistent with preserving principal and liquidity and the maintenance of a stable $1.00 per share net asset value (“NAV”).

Fees and Expenses of the Fund

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Treasury Plus Fund (“Fund Shares”). The expenses shown in the table and the Example reflect the expenses of the Fund and the Fund's proportionate share of the expenses of the State Street Treasury Plus Money Market Portfolio (the “Treasury Plus Portfolio” or sometimes referred to in context as the “Portfolio”).

Shareholder Fees (fees paid directly from your investment)

	Institutional	Administration	Investment	Investor	Premier
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None	None	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None	None	None	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Institutional	Administration	Investment	Investor	Premier
Management Fee	0.05%	0.05%	0.05%	0.05%	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%	0.05%	0.10%	0.00%	0.00%
Other Expenses ¹	0.10%	0.27%	0.32%	0.15%	0.07%
Total Annual Fund Operating Expenses	0.15%	0.37%	0.47%	0.20%	0.12%

¹	Other expenses are based on estimates for the current fiscal year for the Institutional Class and Administration Class shares.

Example:

	1 year	3 years	5 years	10 years
Institutional	$15	$ 48	$ 85	$192
Administration	$38	$119	$208	$468
Investment	$48	$151	$263	$591
Investor	$20	$ 64	$113	$255
Premier	$12	$ 39	$ 68	$154

Principal Investment Strategies

The Treasury Plus Fund is a government money market fund and attempts to meet its investment objective by investing only in U.S. Treasury bills, notes and bonds (which are direct obligations of the U.S. government) and repurchase agreements collateralized by these obligations. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

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The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the Treasury Plus Portfolio, which has substantially identical investment policies to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio, and it participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Portfolio.

Principal Risks

In addition, the Fund is subject to the following principal risks:

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Performance

The bar chart and table below provide some indication of the risks of investing in the Treasury Plus Fund by illustrating the variability of the Fund's returns for Premier Class shares from year-to-year. Performance history will be available for the Institutional Class and Administration Class shares of the Fund after they have been in operation for one calendar year. Returns of these share classes could have been similar to the returns shown for Premier Class shares because the shares are invested in the same portfolio of securities. Returns would differ only to the extent that these share classes do not have the same expenses as Premier Class shares. Institutional Class and Administration Class shares are generally expected to incur higher expenses, and so have generally lower returns, than Premier Class shares. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.54% (Q4, 2018)
Lowest Quarterly Return: 0.00% (Q4, 2011)

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Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Five Years	10-Years or Since Inception	Inception Date
Premier Class	1.75%	0.54%	0.28%	10/24/2007
Investment Class	1.40%	0.36%	0.18%	10/24/2007
Investor Class	1.67%	-	1.08%	10/14/2016

To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Purchase and Sale of Fund Shares

Purchase Minimums

Institutional Class
To establish an account	$25,000,000
To add to an existing account	No minimum
Administration Class
To establish an account	$1,000
To add to an existing account	No minimum
Investment Class
To establish an account	$25,000,000
To add to an existing account	No minimum
Investor Class
To establish an account	$10,000,000
To add to an existing account	No minimum
Premier Class
To establish an account	$250,000,000
To add to an existing account	No minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone:

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By Intermediary:

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objectives, Principal Strategies and Risks

Investment Objective

The investment objective of each of the ILR Fund, U.S. Government Fund, the Treasury Fund and the Treasury Plus Fund, as stated in each Fund's Summary, may be changed without shareholder approval.

ILR Fund

Principal Investment Strategies

The ILR Fund follows a disciplined investment process in which SSGA FM bases its decisions on the relative attractiveness of different money market instruments. In the Adviser's opinion, the attractiveness of an instrument may vary depending on the general level of interest rates, as well as imbalances of supply and demand in the market. Among other things, SSGA FM conducts its own credit analyses of potential investments and portfolio holdings, and relies substantially on a dedicated short-term credit research team. The Fund invests in accordance with regulatory requirements applicable to money market funds, which require, among other things, the Fund to invest only in short-term, high quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity.

U.S. Government Fund

Principal Investment Strategies

The U.S. Government Fund is a government money market fund and invests only in obligations issued or guaranteed as to principal and/or interest, as applicable, by the U.S. government or its agencies and instrumentalities, as well as repurchase agreements secured by such instruments. The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

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The Fund follows a disciplined investment process that attempts to provide stability of principal, liquidity and current income, by investing in U.S. government securities. Among other things, SSGA FM conducts its own credit analyses of potential investments and portfolio holdings, and relies substantially on a dedicated short-term credit research team. The Fund invests in accordance with regulatory requirements applicable to money market funds. Regulations require, among other things, a money market fund to invest only in short-term, high quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity. All securities held by the Fund are U.S. dollar-denominated, and they may have fixed, variable or floating interest rates.

The Fund attempts to meet its investment objective by investing in:

•

•	Obligations issued or guaranteed by the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association, and U.S. government-sponsored entities such as the Federal Home Loan Bank, and the Federal Farm Credit Banks Funding Corporation, which are not backed by the full faith and credit of the United States; and
•	Repurchase agreements collateralized by U.S. government securities.

Treasury Fund

Principal Investment Strategies

The Treasury Fund is a government money market fund and attempts to meet its investment objective by investing only in U.S. Treasury bills, notes and bonds (which are direct obligations of the U.S. government). The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

Treasury Plus Fund

Principal Investment Strategies

The Treasury Plus Fund is a government money market fund and attempts to meet its investment objective by investing only in U.S. Treasury bills, notes and bonds (which are direct obligations of the U.S. government) and repurchase agreements collateralized by these obligations. The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

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Additional Information About Risks

Risk information is applicable to all Funds unless otherwise noted. The risks are described in alphabetical order and not in the order of importance or potential exposure.

Call/Prepayment Risk (principal risk for the ILR Fund and U.S. Government Fund) . Call/prepayment risk is the risk that an issuer will exercise its right to pay principal on an obligation held by a Fund earlier than expected or required. This may occur, for example, when there is a decline in interest rates, and an issuer of bonds or preferred stock redeems the bonds or stock in order to replace them with obligations on which it is required to pay a lower interest or dividend rate. It may also occur when there is an unanticipated increase in the rate at which mortgages or other receivables underlying mortgage- or asset-backed securities held by a Fund are prepaid. In any such case, a Fund may be forced to invest the prepaid amounts in lower-yielding investments, resulting in a decline in the Fund's income.

Counterparty Risk (principal risk for the ILR Fund, U.S. Government Fund and Treasury Plus Fund) . A Fund will be subject to credit risk with respect to the counterparties with which a Fund enters into repurchase agreements and other transactions. If a counterparty fails to meet its contractual obligations, a Fund may be unable to terminate the transaction, and it may be delayed or prevented from realizing on any collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty.

Credit Risk (principal risk for the ILR Fund, U.S. Government Fund and Treasury Plus Fund) . Credit risk is the risk that an issuer, guarantor or liquidity provider of a fixed-income security held by a Fund may be unable or unwilling, or may be perceived (whether by market participants, ratings agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. It includes the risk that the security will be downgraded by a credit rating agency; generally, lower credit quality issuers present higher credit risks. An actual or perceived decline in creditworthiness of an issuer of a fixed-income security held by a Fund may result in a decrease in the value of the security. It is possible that the ability of an issuer to meet its obligations will decline substantially during the period when a Fund owns securities of the issuer or that the issuer will default on its obligations or that the obligations of the issuer will be limited or restructured.

Debt Securities Risk . The values of debt securities may increase or decrease as a result of the following: market fluctuations, increases in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments or illiquidity in debt securities markets; the risk of low rates of return due to reinvestment of securities during periods of falling interest rates or repayment by issuers with higher coupon or interest rates; and/or the risk of low income due to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of a Fund's fixed income securities to decrease, an adverse impact on the liquidity of a Fund's fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal

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may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by a Fund may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

Extension Risk (principal risk for the ILR Fund and U.S. Government Fund). During periods of rising interest rates, the average life of certain types of securities may be extended because of slower-than-expected principal payments. This may increase the period of time during which an investment earns a below-market interest rate, increase the security's duration and reduce the value of the security. Extension risk may be heightened during periods of adverse economic conditions generally, as payment rates decline due to higher unemployment levels and other factors.

Financial Institutions Risk (principal risk for the ILR Fund) . Some instruments are issued or guaranteed by financial institutions, such as banks and brokers, or are collateralized by securities issued or guaranteed by financial institutions. Changes in the creditworthiness of any of these institutions may adversely affect the values of instruments of issuers in financial industries. Financial institutions may be particularly sensitive to certain economic factors such as interest rate changes, adverse developments in the real estate market, fiscal and monetary policy and general economic cycles. Adverse developments in banking and other financial industries may cause a Fund to underperform relative to other funds that invest more broadly across different industries or have a smaller exposure to financial institutions. Changes in governmental regulation and oversight of financial institutions may have an adverse effect on the financial condition or the earnings or operations of a financial institution and on the types and amounts of businesses in which a financial institution may engage. An investor may be delayed or prevented from exercising certain remedies against a financial institution. The amount of a Fund's assets that may be invested in any financial institution, or financial institutions generally, may be limited by applicable law.

Income Risk (principal risk for the ILR Fund and U.S. Government Fund). A Fund's income may decline due to falling interest rates or other factors. Issuers of securities held by a Fund may call or redeem the securities during periods of falling interest rates, and the Fund would likely be required to reinvest in securities paying lower interest rates. If an obligation held by a Fund is prepaid, the Fund may have to reinvest the prepayment in other obligations paying income at lower rates. A reduction in the income earned by a Fund may limit the Fund's ability to achieve its objective.

Interest Rate Risk . Interest rate risk is the risk that the securities held by a Fund will decline in value because of increases in market interest rates. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. Debt securities with longer durations tend to be more sensitive to changes in interest rates, usually making them more volatile than debt securities with shorter durations. For example, the value of a security with a duration of five years would be expected to decrease by 5% for every 1% increase in interest rates. Falling interest rates also create the potential for a decline in a Fund's income and yield. Interest-only and principal-only securities are especially sensitive to interest rate changes, which can affect not only their prices but can also change the income flows and repayment assumptions about those investments. Variable and floating rate securities also generally increase or decrease in value in response to changes in interest rates, although generally to a lesser degree than fixed-rate securities. A substantial increase in interest rates may also have an adverse impact on the liquidity of a security, especially those with longer durations. Changes in governmental policy, including changes in central bank monetary policy, could cause interest rates to rise rapidly, or cause investors to expect a rapid rise in interest rates. This could lead to heightened levels of interest rate, volatility and liquidity risks for the fixed income markets generally and could have a substantial and immediate effect on the values of a Fund's investments.

Large Shareholder Risk . To the extent a large proportion of the interests of a Portfolio are highly concentrated or held by a small number of investors (or a single investor), including funds or accounts over which the Adviser has investment discretion, a Portfolio is subject to the risk that these investors will purchase or redeem Portfolio interests in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of a Portfolio to conduct its investment program. For example, they could require a Portfolio to sell portfolio securities or purchase portfolio securities unexpectedly and incur substantial transaction costs and/or accelerate the realization of taxable income and/or gains to investors, or a Portfolio may be required to sell its more liquid portfolio investments to meet a large redemption, in which case a Portfolio's remaining assets may be less liquid, more volatile, and more difficult to price. A Portfolio may hold a relatively large proportion of its assets in cash in anticipation of large redemptions, diluting its investment returns.

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wide fluctuations in market value. It may be difficult for a Fund to value illiquid securities accurately. The market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. Disposal of illiquid securities may entail registration expenses and other transaction costs that are higher than those for liquid securities. A Fund may seek to borrow money to meet its obligations (including among other things redemption obligations) if it is unable to dispose of illiquid investments, resulting in borrowing expenses and possible leveraging of the Fund. In some cases, due to unanticipated levels of illiquidity a Fund may choose to meet its redemption obligations wholly or in part by distributions of assets in-kind.

Low Short-Term Interest Rate Risk . During market conditions in which short-term interest rates are at low levels a Fund's yield can be very low. During these conditions, it is possible that a Fund will generate an insufficient amount of income to pay its expenses, and that it will not be able to pay a daily dividend and may have a negative yield (i.e., it may lose money on an operating basis). It is possible that a Fund would, during these conditions, maintain a substantial portion of its assets in cash, on which it may earn little, if any, income.

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ter fund. Investment by a Fund in the master fund may be beneficial in the management of the master fund, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest a Fund's assets in a master fund sponsored or managed by the Adviser or its affiliates in lieu of investments by a Fund directly in portfolio securities, or may have an incentive to invest in such master fund over a master fund sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by a Fund in a master fund sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a master fund sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Fund does so. A Fund will bear its pro rata portion of the expenses incurred by the master fund.

Money Market Risk-Floating NAV (principal risk for the ILR Fund) . The Fund does not maintain a constant net asset value per share. The value of the Fund's Shares is calculated to four decimal places and will vary reflecting the value of the portfolio of investments held by the Fund. It is possible to lose money by investing in the Fund.

Money Market Risk (principal risk for the U.S. Government Fund, Treasury Fund and Treasury Plus Fund) . An investment in a money market fund is not a deposit of any bank and is not insured or guaranteed by the FDIC or any other government agency. Although a money market fund generally seeks to preserve the value of its shares at $1.00 per share, there can be no assurance that it will do so, and it is possible to lose money by investing in a money market fund. A major or unexpected increase in interest rates or a decline in the credit quality of an issuer or entity providing credit support, an inactive trading market for money market instruments, or adverse market, economic, industry, political, regulatory, geopolitical, and other conditions could cause a money market fund's share price to fall below $1.00. It is possible that a money market fund will issue and redeem shares at $1.00 per share at times when the fair value of the money market fund's portfolio per share is more or less than $1.00. A money market fund may be permitted or required to impose redemption fees or to impose limitations on redemptions during periods of high illiquidity in the markets for the investments held by it. None of State Street Corporation, State Street, State Street Global Advisors, SSGA FM or their affiliates (collectively, the “State Street Entities”) guarantee the value of an investment in a money market fund at $1.00 per share. Investors should have no expectation of capital support to a money market fund from the State Street Entities.

Mortgage-Related and Other Asset-Backed Securities Risk (principal risk for the ILR Fund and U.S. Government Fund) . Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed income investments. The liquidity of mortgage-related and asset-backed securities may change over time. Mortgage-related securities represent a participation in, or are secured by, mortgage loans. Other asset-backed securities are typically structured like mortgage-related securities, but instead of mortgage loans or interests in mortgage loans, the underlying assets may include, for example, items such as motor vehicle installment sales or installment loan contracts, leases on various types of real and personal property, and receivables from credit card agreements. During periods of falling interest rates, mortgage-related and other asset-backed securities, which typically provide the issuer with the right to prepay the security prior to maturity, may be prepaid, which may result in a Fund having to reinvest the proceeds in other investments at lower interest rates. During periods of rising interest rates, the average life of mortgage-related and other asset-backed securities may extend because of slower-than expected principal payments. This may lock in a below market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. As a result, mortgage-related and other asset-backed securities may have less potential for capital appreciation during periods of declining interest rates than other debt securities of comparable maturities, although they may have a similar risk of decline in market values during periods of rising interest rates. Prepayment rates are difficult to predict and the potential impact of prepayments on the value of a mortgage-related or other asset-backed security depends on the terms of the instrument and can result in significant volatility. The price of a mortgage-related or other asset-backed security also depends on the credit quality and adequacy of the underlying assets or collateral. Mortgage-related or other asset-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) will generally entail greater credit risk than obligations guaranteed by the U.S. Government. Defaults on the underlying assets, if any, may impair the value of a mortgage-related or other asset-backed security. For some asset-backed securities in which a Fund invests, such as those backed by credit card receivables, the underlying cash flows may not be supported by a security interest in a related asset. Moreover, the values of mortgage-related and other asset-backed securities may be substantially dependent on the servicing of the underlying asset pools, and are therefore subject to risks associated with the negligence or malfeasance by their servicers and to the credit risk of their servicers. In certain situations, the mishandling of related documentation may also affect the rights of securities holders in and to the underlying collateral. There may be legal and practical limitations on the enforceability of any security interest granted with respect to underlying assets, or the value of the underlying assets, if any, may be insufficient if the issuer defaults.

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available to investors may be more limited than those available with regard to U.S. investments. Income and gains with respect to investments in certain countries may be subject to withholding and other taxes. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, and financial reporting standards, regulatory framework and practices comparable to those in the United States. The securities of some non-U.S. entities are less liquid and at times more volatile than securities of comparable U.S. entities, and could become subject to sanctions or embargoes that adversely affect a Fund's investment. Non-U.S. transaction costs, such as brokerage commissions and custody costs may be higher than in the U.S. In addition, there may be a possibility of nationalization or expropriation of assets, imposition of currency exchange controls, confiscatory taxation, and diplomatic developments that could adversely affect the values of a Fund's investments in certain non-U.S. countries. Investments in securities of non-U.S. issuers also are subject to foreign political and economic risk not associated with U.S. investments, meaning that political events (civil unrest, national elections, changes in political conditions and foreign relations, imposition of exchange controls and repatriation restrictions), social and economic events (labor strikes, rising inflation) and natural disasters occurring in a country where a Fund invests could cause the Fund's investments in that country to experience gains or losses.

Rapid Changes in Interest Rates . The values of most instruments held by a Fund are adversely affected by changes in interest rates generally, especially increases in interest rates. Rapid changes in interest rates may cause significant requests to redeem Fund Shares, and possibly cause a Fund to sell portfolio securities at a loss to satisfy those requests. Significant losses would negatively affect the NAV per share of the ILR Fund and, in the case of the U.S. Government Fund, Treasury Fund and Treasury Plus Fund, could impair the Fund's ability to maintain a stable share price of $1.00.

Reinvestment Risk (principal risk for the ILR Fund and U.S. Government Fund). Income from a Fund's portfolio may decline when the Fund invests the proceeds from investment income, sales of portfolio securities or matured, traded or called debt obligations. For instance, during periods of declining interest rates, an issuer of debt obligations may exercise an option to redeem securities prior to maturity, forcing a Fund to reinvest the proceeds in lower-yielding securities. A decline in income received by a Fund from its investments is likely to have a negative effect on the yield and total return of the Fund Shares.

Repurchase Agreement Risk (principal risk for the ILR Fund, U.S. Government Fund and Treasury Plus Fund) . A repurchase agreement is an agreement to buy a security from a seller at one price and a simultaneous agreement to sell it back to the original seller at an agreed-upon price, typically representing the purchase price plus interest. Repurchase agreements may be viewed as loans made by a Fund which are collateralized by the securities subject to repurchase. A Fund's investment return on such transactions will depend on the counterparty's willingness and ability to perform its obligations under a repurchase agreement. If a Fund's counterparty should default on its obligations and a Fund is delayed or prevented from recovering the collateral, or if the value of the collateral is insufficient, a Fund may realize a loss.

Restricted Securities Risk (principal risk for the ILR Fund) . A Fund may hold securities that have not been registered for sale to the public under the U.S. federal securities laws pursuant to an exemption from registration. These securities may be less liquid than securities registered for sale to the general public. The liquidity of a restricted security may be affected by a number of factors, including, among others: (i) the creditworthiness of the issuer; (ii) the frequency of trades and quotes for the security; (iii) the number of dealers willing to purchase or sell the security and the number of other potential purchasers; (iv) dealer undertakings to make a market in the security; (v) the nature of any legal restrictions governing trading in the security; and (vi) the nature of the security and the nature of marketplace trades. There can be no assurance that a liquid trading market will exist at any time for any particular restricted security. Also, restricted securities may be difficult to value because market quotations may not be readily available, and the securities may have significant volatility.

Risk of Investment in Other Pools (principal risk for the ILR Fund) . If a Fund invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected. A Fund is exposed indirectly to all of the risks applicable to an investment in such other pool. In addition, lack of liquidity in the underlying pool could result in its value being more volatile than the underlying portfolio of securities, and may limit the ability of a Fund to sell or redeem its interest in the pool at a time or at a price it might consider desirable. The investment policies and limitations of the other pool may not be the same as those of the Fund; as a result, the Fund may be subject to additional or different risks, or may achieve a reduced investment return, as a result of its investment in another pool. If a pool is an exchange-traded fund or other product traded on a securities exchange or otherwise actively traded, its shares may trade at a premium or discount to their NAV, an effect that might be more pronounced in less liquid markets. A Fund bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Fund may invest, leading to potential conflicts of interest. For example, the Adviser or its affiliates may receive fees based on the amount of assets invested in the pool. Investment by a Fund in the pool may be beneficial to the Adviser or an affiliate in the management of the pool, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest a Fund's assets in a pool sponsored or managed by the Adviser

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or its affiliates in lieu of investments by the Fund directly in portfolio securities, or may have an incentive to invest in the pool over a pool sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by a Fund in a pool sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Fund does so.

Section 4(a)(2) Commercial Paper and Rule 144A Securities Risk (principal risk for the ILR Fund) . A Fund may invest in commercial paper issued in reliance on the private placement exemption from registration afforded by Section 4(a)(2) of the Securities Act of 1933, as amended (the “1933 Act”). This commercial paper is commonly called “Section 4(a)(2) paper.” A Fund may also invest in securities that may be offered and sold only to “qualified institutional buyers” under Rule 144A of the 1933 Act (“Rule 144A securities”).

Section 4(a)(2) paper is sold to institutional investors who must agree to purchase the paper for investment and not with a view to public distribution. Any resale by the purchaser must be in a transaction exempt from the registration requirements of the 1933 Act. Section 4(a)(2) paper normally is resold to other institutional investors like a Fund through or with the assistance of the issuer or investment dealers that make a market in Section 4(a)(2) paper. As a result it suffers from liquidity risk, the risk that the securities may be difficult to value because of the absence of an active market and the risk that it may be sold only after considerable expense and delay, if at all. Rule 144A securities generally must be sold only to other qualified institutional buyers.

Section 4(a)(2) paper and Rule 144A securities will not be considered illiquid for purposes of a Fund's limitation on illiquid securities if the Adviser (pursuant to guidelines adopted by the Board) determines that a liquid trading market exists for the securities in question. There can be no assurance that a liquid trading market will exist at any time for any particular Section 4(a)(2) paper or Rule 144A securities.

Significant Exposure to U.S. Government Agencies or Instrumentalities Risk (principal risk for the U.S. Government Fund) . To the extent a Fund focuses its investments in securities issued or guaranteed by U.S. government agencies or instrumentalities, any market movements, regulatory changes or changes in political or economic conditions that affect the U.S. government agencies or instrumentalities in which the Fund invests may have a significant impact on a Fund's performance. Events that would adversely affect the market prices of securities issued or guaranteed by one government agency or instrumentality may adversely affect the market price of securities issued or guaranteed by other government agencies or instrumentalities.

Stable Share Price Risk (principal risk for the U.S. Government Fund, Treasury Fund and Treasury Plus Fund) . If the market value of one or more of the Fund's investments changes substantially, the Fund may not be able to maintain a stable share price of $1.00. This risk typically is higher during periods of rapidly changing interest rates or when issuer credit quality generally is falling, and is made worse when the Fund experiences significant redemption requests.

U.S. Government Securities Risk (principal risk for the ILR Fund and U.S. Government Fund) . U.S. government securities, such as Treasury bills, notes and bonds and mortgage-backed securities guaranteed by the Government National Mortgage Association (“Ginnie Mae”), are supported by the full faith and credit of the United States; others are supported by the right of the issuer to borrow from the U.S. Treasury; others are supported by the discretionary authority of the U.S. government to purchase the agency's obligations; and still others are supported only by the credit of the issuing agency, instrumentality, or enterprise. Although U.S. government-sponsored enterprises such as the Federal Home Loan Mortgage Corporation (“Freddie Mac”) and the Federal National Mortgage Association (“Fannie Mae”) may be chartered or sponsored by Congress, they are not funded by Congressional appropriations, and their securities are not issued by the U.S. Treasury nor supported by the full faith and credit of the U.S. government. There is no assurance that the U.S. government would provide financial support to its agencies and instrumentalities if not required to do so. In addition, certain governmental entities have been subject to regulatory scrutiny regarding their accounting policies and practices and other concerns that may result in legislation, changes in regulatory oversight and/or other consequences that could adversely affect the credit quality, availability, or investment character of securities issued by these entities. The value and liquidity of U.S. government securities may be affected adversely by changes in the ratings of those securities. Securities issued by the U.S. Treasury historically have been considered to present minimal credit risk. The downgrade in the long-term U.S. credit rating by at least one major rating agency has introduced greater uncertainty about the ability of the U.S. to repay its obligations. A further credit rating downgrade or a U.S. credit default could decrease the value and increase the volatility of a Fund's investments.

U.S. Treasury Obligations Risk (principal risk for the Treasury Fund and Treasury Plus Fund) . U.S. Treasury obligations may differ from other securities in their interest rates, maturities, times of issuance and other characteristics. Similar to other issuers, changes to the financial condition or credit rating of the U.S. government may cause the value of a Fund's U.S. Treasury obligations to decline. The total public debt of the United States as a percent of gross domestic product grew rapidly after the financial crisis of 2008 and

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has remained at a historically high level. Although high debt levels do not necessarily indicate or cause economic problems, they may create certain systemic risks if sound debt management practices are not implemented. A high national debt level may increase market pressures to meet government funding needs, which may drive debt cost higher and cause a country to sell additional debt, thereby increasing refinancing risk. A high national debt also raises concerns that a government will not be able to make principal or interest payments when they are due. In the worst case, unsustainable debt levels can cause a decline in the value of the dollar (which may lead to inflation), and can prevent the U.S. government from implementing effective counter-cyclical fiscal policy in economic downturns. On August 5, 2011, Standard & Poor's Ratings Services downgraded U.S. Treasury securities from AAA rating to AA+ rating. Standard & Poor's Ratings Services stated that its decision was prompted by its view on the rising public debt burden and its perception of greater policymaking uncertainty. A downgrade of the ratings of U.S. government debt obligations, which are often used as a benchmark for other borrowing arrangements, could result in higher interest rates for individual and corporate borrowers, cause disruptions in the international bond markets and have a substantial negative effect on the U.S. economy. A downgrade of U.S. Treasury securities from another ratings agency or a further downgrade below AA+ rating by Standard & Poor's Ratings Services may cause the value of the Fund's U.S. Treasury obligations to decline. In recent years, impasses in Congress regarding the federal budget have caused repeated temporary Federal government shutdowns. While Congress has temporarily suspended the debt limit from time to time, the risks that the U.S. government will not adopt a long-term budget or deficit reduction plan, of one or more additional Federal government shutdowns or of future failures to not increase the Federal government's debt limit, may affect investor and consumer confidence and may adversely impact financial markets and the broader economy, perhaps suddenly and to a significant degree.

Variable and Floating Rate Securities Risk . Variable or floating rate securities are debt securities with variable or floating interest rates payments. Variable or floating rate securities bear rates of interest that are adjusted periodically according to formulae intended generally to reflect market rates of interest and allow a Fund to participate (determined in accordance with the terms of the securities) in increases in interest rates through upward adjustments of the coupon rates on the securities. However, during periods of increasing interest rates, changes in the coupon rates may lag behind the changes in market rates or may have limits on the maximum increases in coupon rates. Alternatively, during periods of declining interest rates, the coupon rates on such securities will typically readjust downward resulting in a lower yield. A Fund may also invest in variable or floating rate equity securities, whose dividend payments vary based on changes in market rates of interest or other factors.

Zero-Coupon Bond Risk (principal risk for the ILR Fund) . Zero-coupon bonds are debt obligations that are generally issued at a discount and payable in full at maturity, and that do not provide for current payments of interest prior to maturity. Zero-coupon bonds usually trade at a deep discount from their face or par values and are subject to greater market value fluctuations from changing interest rates than debt obligations of comparable maturities that make current distributions of interest. When interest rates rise, the values of zero-coupon bonds fall more rapidly than securities paying interest on a current basis, because a Fund is unable to reinvest interest payments at the higher rates.

Additional Information About Non-Principal Investment Strategies and Risks

The investments described below reflect the Funds' and the Portfolios' current practices. In addition to the principal risks described above, other risks are described in some of the descriptions of the investments below:

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various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by a Fund. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Funds) or otherwise using such information for the benefit of its clients or itself.

Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Funds) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, a Fund, a Portfolio, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect a Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect a Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject a Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of a Fund inaccessible or inaccurate or incomplete. A Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. A Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. Each Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Funds. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which each Fund invests, which could result in material adverse consequences for such issuers, and may cause a Fund's investment in such securities to lose value.

Risk of Investment in Other Pools (risk for the U.S. Government Fund, Treasury Fund and Treasury Plus Fund) . If a Fund invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected. A Fund is exposed indirectly to all of the risks applicable to an investment in such other pool. In addition, lack of liquidity in the underlying pool could result in its value being more volatile than the underlying portfolio of securities, and may limit the ability of a Fund to sell or redeem its interest in the pool at a time or at a price it might consider desirable. The investment policies and limitations of the other pool may not be the same as those of the Fund; as a result, the Fund may be subject to additional or different risks, or may achieve a reduced investment return, as a result of its investment in another pool. If a pool is an exchange-traded fund or other product traded on a securities exchange or otherwise actively traded, its shares may trade at a premium or discount to their NAV, an effect that might be more pronounced in less liquid markets. A Fund bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Fund may invest, leading to potential conflicts of interest. For example, the Adviser or its affiliates may receive fees based on the amount of assets invested in the pool. Investment by a Fund in the pool may be beneficial to the Adviser or an affiliate in the management of the pool, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest a Fund's assets in a pool sponsored or managed by the Adviser or its affiliates in lieu of investments by the Fund directly in portfolio securities, or may have an incentive to invest in the pool over a pool sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by a Fund in a pool sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Fund does so.

Temporary Defensive Positions . In response to actual or perceived adverse market, economic, political, or other conditions, a Fund may (but will not necessarily), without notice, depart from its principal investment strategies by temporarily investing for defensive purposes. While investing defensively, the Fund may maintain a substantial portion of its assets in cash, on which the Fund may earn little if any income. If a Fund invests for defensive purposes, it may not achieve its investment objective. In addition, the defensive strategy may not work as intended.

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Portfolio Holdings Disclosure

The Funds' portfolio holdings disclosure policy is described in the SAI.

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Management and Organization

Investment Adviser

SSGA FM serves as the investment adviser to each Fund and corresponding Portfolio and, subject to the oversight of the Board, is responsible for the investment management of each Fund. The Adviser provides an investment management program for each Fund and manages the investment of each Fund's assets. The Adviser is a wholly-owned subsidiary of State Street Global Advisors, Inc., which itself is a wholly-owned subsidiary of State Street Corporation. The Adviser is registered with the U.S. Securities and Exchange Commission (“SEC”) under the Investment Advisers Act of 1940, as amended. The Adviser and certain other affiliates of State Street Corporation make up SSGA. SSGA is one of the world's largest institutional money managers and the investment management arm of State Street Corporation. As of December 31, 2018, the Adviser managed approximately $452.10 billion in assets and SSGA managed approximately $2.51 trillion in assets. The Adviser's principal business address is One Iron Street, Boston, Massachusetts 02210.

Each Fund has entered into an investment advisory agreement with the Adviser pursuant to which the Adviser will manage the Fund's assets directly, for compensation paid at an annual rate of 0.05% of the Fund's average daily net assets, in the event that the Fund were to cease investing substantially all of its assets in its corresponding Portfolio or another investment company with essentially the same investment objectives and policies as the Fund. The Adviser does not receive any management fees from a Fund under that agreement so long as the Fund continues to invest substantially all of its assets in the corresponding Portfolio or in another investment company with essentially the same investment objectives and policies as the Fund. The Adviser places all orders for purchases and sales of the Portfolios' investments. For the year ended December 31, 2018, the effective management fee paid, reflecting certain fee waivers and expense reimbursements of the Adviser, was 0.05% for Money Market Portfolio, 0.05% for U.S. Government Portfolio, 0.05% for Treasury Portfolio and 0.05% for Treasury Plus Portfolio.

Total Annual Fund Operating Expense Waivers . SSGA FM, as the investment adviser to each Fund, is contractually obligated, through April 30, 2020, for the ILR Fund, U.S. Government Fund, and Treasury Plus Fund (i) to waive up to the full amount of the advisory fee payable by each Fund, and/or (ii) to reimburse a Fund for expenses to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.07% of average daily net assets on an annual basis. These waiver and/or reimbursement arrangements may not be terminated prior to April 30, 2020 except with approval of the Funds' Board of Trustees.

Under an agreement with the Adviser relating to the Adviser's historical voluntary reduction of fees and reimbursement of expenses for the Treasury Plus Fund, the Treasury Plus Fund has agreed to reimburse the Adviser for the full dollar amount of any such voluntary fee waivers or expense reductions beginning on October 1, 2012, subject to certain limitations. The Fund is not obligated to reimburse the Adviser more than three years after the end of the fiscal year in which the Adviser provided a voluntary reduction. As of December 31, 2018, for the Premier Class of the Treasury Plus Fund, the Adviser had waived fees and/or reimbursed expenses in the aggregate amount of $6,580,096 since October 1, 2012, of which $0, is potentially recoverable under this agreement.

A reimbursement to the Adviser would increase the Treasury Plus Fund's expenses and negatively impact the Fund's future yield. Reimbursement payments by the Fund to the Adviser in connection with this agreement are considered “extraordinary expenses” and are not subject to any contractual expense limitation agreement in effect for the Fund at the time of such payment. The Adviser may, in its sole discretion, irrevocably waive receipt of any or all reimbursement amounts due from the Fund.

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A discussion regarding the Board's consideration of the Funds' Investment Advisory Agreement is provided in the Funds' Semi-Annual Report to Shareholders for the period ended June 30, 2018.

The Administrator, Sub-Administrator and Custodian

The Adviser serves as administrator of each Fund. The amount of the fee paid to the Adviser for administrative services may vary by share class. Each Fund currently pays the Adviser an administrative fee at the annual rate of 0.05% in respect of the class of shares in this Prospectus. State Street Bank and Trust Company (“State Street”), a subsidiary of State Street Corporation, serves as the sub-administrator for the Funds for a fee that is paid by the Adviser. State Street also serves as custodian of the Funds for a separate fee that is paid by the Funds. SSGA FM serves as administrator of the Portfolios and State Street serves as sub-administrator and custodian of the Portfolios.

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Funds' transfer agent and dividend disbursing agent (the “Transfer Agent”).

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Funds' distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

The Shareholder Servicing Agent

SSGA FD serves as the Funds' shareholder servicing agent pursuant to the Shareholder Servicing Agreement between SSGA FD and the Trust and receives fees from the Funds for the provision and procurement of applicable services. Please see the SAI for more information on SSGA FD's role as the Funds' shareholder servicing agent.

Additional Information

Shareholder Information

Determination of Net Asset Value

For the ILR Fund

The Fund determines its NAV per share three times each day on which the New York Stock Exchange (the “NYSE”), the Federal Reserve banks and State Street are open for business (a “Business Day”) at 8:00 a.m., 12:00 p.m. and 3:00 p.m. ET. The price for Fund shares is the NAV next calculated after the purchase order is accepted by a Fund. Orders accepted before 12:00 p.m. will receive the 12:00 p.m. NAV, orders accepted before 3:00 p.m. will receive the 3:00 p.m. NAV, and orders accepted after 3:00 p.m. will receive 8:00 a.m. NAV calculated on the following Business Day. The Fund calculates its NAV to four decimal places.

The NAV of each class of the ILR Fund's shares is calculated by dividing the value of the assets of the ILR Fund attributable to that class less the liabilities of the ILR Fund attributable to that class by the number of shares in the class outstanding. The ILR Fund values each security or other investment pursuant to guidelines adopted by the Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Portfolio's Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii) a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by the Fund occurs after the close of a related exchange but before the determination of the ILR Fund's NAV. Attempts to determine the fair value of securities or other investments introduce an element of subjectivity to the pricing of securities or other investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the

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price a Fund would have received had it sold the investment. To the extent that the ILR Fund invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the funds. The prospectuses of these funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

For the U.S. Government Fund, Treasury Plus Fund and Treasury Fund

The Treasury Plus Fund and the U.S. Government Fund each determines its NAV per share once each Business Day at 5:00 p.m. ET except for days when the NYSE closes earlier than its regular closing time, in which event those Funds will determines their NAVs at the earlier closing time. The Treasury Fund determines its NAV per share once each Business Day at 2:30 p.m. ET, or the close of the NYSE, whichever is earlier (the time when a Fund determines its NAV per share is referred to herein as the “Valuation Time”). Each Fund seeks to maintain a $1.00 per share NAV and, accordingly, uses the amortized cost valuation method, in compliance with the risk limiting conditions of Rule 2a-7 under the Investment Company Act of 1940, as amended (the “1940 Act”), to value its portfolio instruments. The amortized cost valuation method initially prices an instrument at its cost and thereafter assumes a constant amortization to maturity of any discount or premium, regardless of the impact of fluctuating interest rates on the market value of the instrument.

For all Funds

Pricing does not occur on NYSE holidays. The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. The Funds reserve the right to accept orders to purchase or redeem shares, or to continue to accept such orders following the close of the NYSE, on any day that is not a Business Day or any day on which the NYSE closes early, provided the Federal Reserve remains open. As noted in this Prospectus, certain Funds may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when a Fund does not price its shares. Consequently, the NAV of a Fund's shares may change on days when shareholders are not able to purchase or redeem the Fund's shares. The Funds also may establish special hours on those days to determine each Fund's NAV. In the event that the Funds invoke the right to accept orders to purchase or redeem shares on any day that is not a Business Day or adopt special hours of operation, the Fund will post advance notice of these events at:www.ssga.com/cash.

If you hold shares of a Fund through a broker-dealer or other financial intermediary, your intermediary may offer additional services and account features that are not described in this Prospectus. Please contact your intermediary directly for an explanation of these services.

Investing in State Street Institutional Investment Trust Shares

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Purchasing Shares

The Funds offer five classes of shares through this Prospectus: Institutional Class, Administration Class, Investment Class, Investor Class and Premier Class available to you subject to the eligibility requirements set forth below. All classes of a Fund share the same investment objective and investments, but the different share classes have different expense structures and eligibility requirements. You should choose the class with the expense structure that best meets your needs for which you are eligible. In choosing a share class, you should consider the amount you plan to invest. Your investment professional can help you choose the share class that best suits your investment needs.

The minimum purchase amount may be waived for specific investors or types of investors, including, without limitation, retirement plans, employees of State Street Corporation and its affiliates and their family. In the case of shareholders purchasing shares through a Financial Intermediary, the minimum purchase amount may be applied at the level of the Financial Intermediary.

	Institutional Class	Administration Class	Investment Class	Investor Class	Premier Class
Minimum Initial Investment	$25,000,000	$1,000	$25,000,000	$10,000,000	$250,000,000
Maximum Investment	None.	None.	None.	None.	None.
Initial Sales Charge	No. Entire purchase price is invested in shares of a Fund.	No. Entire purchase price is invested in shares of a Fund.	No. Entire purchase price is invested in shares of a Fund.	No. Entire purchase price is invested in shares of a Fund.	No. Entire purchase price is invested in shares of a Fund.
Deferred (CDSC) Sales Charge	No.	No.	No.	No.	No.
Distribution and/or Service (12b-1) Fees	No.	0.05% annual fee.	0.10% annual fee.	No.	No.
Redemption Fees	No.	No.	No.	No.	No.

Investors pay no sales load to invest in the shares of the Funds. The price for Fund Shares is the NAV per share.

Purchase requests received by a Fund in good order (a purchase request is in good order if it meets the requirements implemented from time to time by the Transfer Agent or authorized agent of the Fund, and for new accounts includes submission of a completed and signed application and all documentation necessary to open an account) on a Business Day will, if payment is received by FedWire, be priced at the NAV next determined after the order is accepted by the Fund. Payments received by FedWire prior to the last Valuation Times (for the ILR Fund generally, 3:00 p.m. ET, unless the Fund closes earlier) will earn dividend accrual for that purchase.

All purchases that are made by check will be priced with the last valuation price and begin earning dividends the following Business Day after the day the order is accepted. (If you purchase shares by check, your order will not be in good form until the Transfer Agent receives federal funds for the check.) All purchase orders are subject to acceptance by the Funds. The Funds intend to be as fully invested as is practicable; therefore, investments must be made in Federal Funds ( i.e ., monies credited to the account of the Funds' custodian bank by a Federal Reserve Bank).

The minimum initial investment in Institutional Class, Administration, Investment, Investor and Premier shares of the Funds is $25 million, $1 thousand, $25 million, $10 million and $250 million, respectively, although the Adviser may waive the minimum in its discretion. Holdings of related customer accounts may be aggregated for purposes of determining the minimum investment amount. “Related customer accounts” may include but are not limited to accounts held by the same investment or retirement plan, financial institution, broker, dealer or intermediary. The Funds and the Adviser reserve the right to increase or decrease the minimum amount

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required to open or maintain an account. There is no minimum subsequent investment, except in relation to maintaining certain minimum account balances (See “Redeeming Shares” below). The Funds require prior notification of subsequent investments in excess of $10 million for the Treasury Fund and $50 million for the U.S. Government Fund and Treasury Plus Fund.

The Funds reserve the right to cease accepting investments at any time or to reject any investment order. In addition, the U.S. Government Fund and the Treasury Plus Fund may limit the amount of a purchase order received after 3:00 p.m. ET. The Treasury Fund may limit the amount of a purchase order received after 12:00 p.m. (noon) ET. The ILR Fund determines its NAV at 8:00 a.m., 12:00 p.m. and 3:00 p.m. ET. The 8:00 a.m., 12:00 p.m. and 3:00 p.m. NAV calculation times are intended to facilitate same day settlement.

How to Purchase Shares

By Mail:

An initial investment in the Funds must be preceded or accompanied by a completed, signed Institutional Account Application Form, sent to:
State Street Funds
P.O. Box 219737
Kansas City, MO 64121‐9737

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone/Fax:

An initial investment in the Funds must be preceded or accompanied by a completed, signed Institutional Account Application Form, faxed to (816) 218-0400. Call the Fund at (866) 392-0869 between the hours of 7:00 a.m. ET and 5:00 p.m. ET to:

➣ confirm receipt of the faxed Institutional Account Application Form (initial purchases only),
➣ request your new account number (initial purchases only),
➣ confirm the amount being wired and wiring bank, and
➣ receive a confirmation number for your purchase order (your trade is not effective until you have received a confirmation number from the Fund).

For your initial investment, send the original, signed Institutional Account Application Form to the address above.

Wire Instructions:

Instruct your bank to transfer money by Federal Funds wire to:
State Street Bank and Trust Company
1 Iron Street
Boston, MA 02110

ABA# 011000028
DDA# 9904-631-0
State Street Institutional Investment Trust
Fund Name
Class Name
Account Number
Account Registration

On Columbus Day and Veterans Day, you will not be able to purchase shares by wiring Federal Funds because the Federal Funds wiring does not occur on those days. Payment for Fund Shares must be in Federal Funds (or converted to Federal Funds by the Transfer Agent) by the close of the Federal Reserve.

You will not be able to redeem shares from the account until the original Application has been received. The Funds and the Funds' agents are not responsible for transfer errors by the sending or receiving bank and will not be liable for any loss incurred due to a wire transfer not having been received.

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Automatic Investment Plan . An Automatic Investment Plan is available for all operational State Street Funds that offer the Administration Class shares. Once an initial investment has been accepted, you may elect to make automatic subsequent investments of $100 or more on a periodic basis (i.e., monthly, quarterly, semi-annually, or annually) by authorizing the Fund to debit your bank checking or savings account through Automated Clearing House (ACH). For the ILR Fund Administration Class shares, purchases made through the Automated Investment Plan will be priced at the last valuation price on the day of the transaction. Once this option has been established, you may call the State Street Funds to make additional automatic purchases, to change the amount of the existing automatic purchase, or to discontinue the service. The Fund reserves the right to cancel your Automatic Investment Plan if any correspondence sent by the Fund to your address of record is returned by the postal service or other delivery service as “undeliverable.” Ask your financial adviser or financial intermediary for details.

Redeeming Shares

An investor may redeem all or any portion of its investment. Redemption orders are processed at the NAV next determined after a Fund receives a redemption order in good form.

For the ILR Fund

If the Fund receives a redemption order in good form prior to its last valuation time (generally, 3:00 p.m. ET, unless the Fund closes earlier) on a Business Day, the Fund typically sends payment for redeemed shares on that day, but no later than the next Business Day if redemption proceeds are sent by wire or ACH. If redemption proceeds are sent by check, the Fund typically expects to pay out redemption proceeds on the next Business Day. If a full redemption order is requested, no dividends will accrue with respect to shares on the day the redemption proceeds are sent. If a redemption order is placed after the last valuation time (generally, 3:00 p.m. ET, unless the Fund closes earlier) the Fund typically expects to pay out redemption proceeds on the next Business Day (and dividends will accrue up to, but not including, the day that redemption proceeds are sent). The Fund reserves the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Fund.

Certain special limitations affecting redemptions . The SEC has implemented a number of requirements, including liquidity fees and redemption gates, for money market funds based on the amount of fund assets in “weekly liquid assets,” which generally includes cash, direct obligations of the U.S. government, certain other U.S. government or agency securities, and securities that will mature or are subject to a demand feature that is exercisable and payable within five Business Days. The ILR Fund will pass through to its investors any liquidity fee or suspension of redemptions imposed by the Money Market Portfolio on the same terms and conditions as imposed by the Money Market Portfolio on the ILR Fund.

If the Money Market Portfolio's weekly liquid assets fall below 30% of its total assets and the Portfolio's Board of Trustees determines it is in the best interests of the Portfolio, the Portfolio may immediately impose a liquidity fee of no more than 2% and/or temporarily suspend redemptions for up to 10 Business Days in any 90 day period. If the Portfolio's weekly liquid assets fall below 10% of its total assets at the end of any Business Day, the Portfolio will impose a liquidity fee of 1% on all redemptions beginning on the next Business Day, unless the Portfolio's Board determines that imposing such a fee would not be in the best interests of the Portfolio or determines that a lower or higher fee (not to exceed 2%) would be in the best interests of the Portfolio, which would remain in effect until weekly liquid assets return to 30% or the Portfolio's Board determines that the fee is no longer in the best interests of the Portfolio. All liquidity fees payable by the ILR Fund would be passed through to its shareholders, would be payable to the Portfolio and could offset any losses realized by the Portfolio when seeking to honor redemption requests. If liquidity fees are imposed or redemptions are suspended by the Portfolio, the ILR Fund will notify shareholders on the ILR Fund's website. The ILR Fund expects to treat such liquidity fees paid to the Portfolio as reducing proceeds paid to shareholders in redemption of ILR Fund shares, and not constituting income to the Portfolio or the Fund. There may be circumstances under which the ILR Fund may impose its own liquidity fees and/or suspend redemptions based on the level of the ILR Fund's own weekly liquid assets, in which case the ILR Fund will also provide notice to shareholders.

If the Money Market Portfolio's weekly liquid assets fall below 10% of its assets on a Business Day, the Portfolio may cease honoring redemptions and liquidate in the discretion of the Portfolio's Board. If the ILR Fund is notified that its Portfolio's weekly liquid assets fall below 10% of the Portfolio's assets and the Portfolio has suspended redemptions and intends to liquidate, the ILR Fund may also do so in the discretion of the ILR Fund's Board. There may be circumstances under which the ILR Fund may cease honoring redemptions and liquidate in the discretion of its Board based on the level of the ILR Fund's own weekly liquid assets. If the ILR Fund ceases honoring redemptions and determines to liquidate, the ILR Fund expects that it would notify shareholders on the ILR Fund's website. Distributions to shareholders of liquidation proceeds may occur in one or more disbursements.

For the Treasury Fund and the Treasury Plus Fund

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If the Treasury Fund or the Treasury Plus Fund receives a redemption order in good form prior to 2:30 p.m. ET for the Treasury Fund and 5:00 p.m. ET for the Treasury Plus Fund on a Business Day, the Fund typically expects to pay out redemption proceeds on that day, but no later than the next Business Day if redemption proceeds are sent by wire or ACH. If redemption proceeds are sent by check, the Fund typically expects to pay out redemption proceeds on the next Business Day. No dividends will be paid on shares that are redeemed and wired the same day. If a redemption order is placed after 2:30 p.m. ET for the Treasury Fund and 5:00 p.m. for the Treasury Plus Fund, the Treasury Fund and the Treasury Plus Fund typically expect to pay out redemption proceeds on the next Business Day (and dividends will accrue up to, but not including, the day that redemption proceeds are sent). Each of the Treasury Fund and the Treasury Plus Fund reserves the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Fund.

For the U.S. Government Fund

If the U.S. Government Fund receives a redemption order in good form prior to 5:00 p.m. ET on a Business Day, shares are redeemed and the Fund typically sends payment for redeemed shares on that day, but no later than the next Business Day if redemption proceeds are sent by wire or ACH. If redemption proceeds are sent by check, the Fund typically expects to pay out redemption proceeds on the next Business Day. If a full redemption order is requested, no dividends will accrue with respect to shares on the day the redemption proceeds are sent. If a redemption order is placed after 5:00 p.m. ET, the Fund typically expects to pay out redemption proceeds on the next Business Day (and dividends will accrue up to, but not including, the day that redemption proceeds are sent). The Fund reserves the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Fund.

For All Funds

Each of the Treasury Fund, Treasury Plus Fund and U.S. Government Fund is a government money market fund that has not elected to be subject to the fees and gates provisions of Rule 2a-7. The right of any investor to receive payment with respect to any redemption may be suspended or the payment of the redemption proceeds postponed beyond 7 days in accordance with Section 22(e) of the 1940 Act and the rules thereunder, including during any period in which the NYSE is closed (other than weekends or holidays) or trading on the NYSE is restricted or if an emergency exists as a result of which disposal by the Fund of securities owned by it is not reasonably practicable or it is not reasonably practicable for the Fund fairly to determine the value of its net assets. In addition, the SEC may by order permit suspension of redemptions for the protection of shareholders of the Funds. Although each of the Treasury Fund, Treasury Plus Fund and U.S. Government Fund attempts to maintain its NAV at $1.00 per share, there can be no assurance that it will be successful, and there can be no assurance that a shareholder will receive $1.00 per share upon any redemption.

Under normal circumstances, the Funds expect to meet redemption requests by using cash or cash equivalents in its portfolio and/or selling portfolio assets to generate cash. The Funds also may pay redemption proceeds using cash obtained through borrowing arrangements that may be available from time to time.

During periods of deteriorating or stressed market conditions or during extraordinary or emergency circumstances, a Fund may be more likely to pay redemption proceeds with cash obtained through short-term borrowing arrangements (if available) or by giving you securities.

A request for a partial redemption by an investor whose account balance is below the minimum amount or a request for partial redemption by an investor that would bring the account below the minimum amount may be treated as a request for a complete redemption of the account. These minimums may be different for investments made through certain financial intermediaries as determined by their policies and may be waived in the Adviser's discretion. The Funds reserve the right to modify minimum account requirements at any time with or without prior notice. The Funds also reserve the right to involuntarily redeem an investor's account if the investor's account balance falls below the applicable minimum amount due to transaction activity.

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How to Redeem Shares


By Mail:	Send a signed letter to: State Street Institutional Investment Trust Funds P.O. Box 219737 Kansas City, MO 64121-9737
	The letter should include information necessary to process your request as described below. The Fund may require a medallion guarantee in certain circumstances. See “Medallion Guarantees” below.
By Overnight:	State Street Institutional Investment Trust Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407
By Telephone:	Please call (866) 392-0869 between the hours of 7:00 a.m. and 5:00 p.m. ET.
The Funds will need the following information to process your redemption request:
➣ name(s) of account owners; ➣ account number(s); ➣ the name of the Fund; ➣ your daytime telephone number; and ➣ the dollar amount or number of shares being redeemed.

On any day that the Funds calculate their NAVs earlier than normal, the Funds reserve the right to adjust the times noted above for purchasing and redeeming shares.

Medallion Guarantees . Certain redemption requests must include a medallion guarantee for each registered account owner if any of the following apply:

•	Your account address has changed within the last 10 Business Days.

•	Redemption proceeds are being transferred to an account with a different registration.
•	A wire is being sent to a financial institution other than the one that has been established on your Fund account.
•	Other unusual situations as determined by the Transfer Agent.

The Funds reserve the right to waive medallion guarantee requirements, require a medallion guarantee under other circumstances or reject or delay redemption if the medallion guarantee is not in good form. Medallion guarantees may be provided by an eligible financial institution such as a commercial bank, a Financial Industry Regulatory Authority, Inc. (“FINRA”) member firm such as a stock broker, a savings association or a national securities exchange. A notary public cannot provide a medallion guarantee. The Funds reserve the right to reject a medallion guarantee if it is not provided by a STAMP Medallion guarantor.

About Telephone Transactions . Telephone transactions are convenient but are not free from risk. Neither the Funds nor the Funds' agents will be responsible for any losses resulting from unauthorized telephone transactions if reasonable security procedures are followed. In addition, you are responsible for: (i) verifying the accuracy of all data and information transmitted by telephone, (ii) verifying the accuracy of your account statements immediately upon receipt, and (iii) promptly notifying the Funds of any errors or inaccuracies including, without limitation, any errors or inaccuracies relating to shareholder data or information transmitted by telephone. During periods of heavy market activity or other times, it may be difficult to reach the Funds by telephone. If you are unable to reach us by telephone, consider sending written instructions.

The Funds may terminate the receipt of redemption orders by telephone at any time, in which case you may redeem shares by other means.

If you choose to purchase or redeem shares by sending instructions by regular mail, they will not be deemed received in good order until they are released by the post office and redelivered to the Transfer Agent's physical location at 430 W 7th Street Suite 219737 in Kansas City, MO 64105-1407. There will be a time lag, which may be one or more days, between regular mail receipt at the post office box and redelivery to such physical location in Kansas City, and a Fund's NAV may change over those days. You might consider using express rather than regular mail if you believe the time of receipt of your transaction request to be sensitive.

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Automatic Withdrawal Plan . An Automatic Withdrawal Plan is available for all operational State Street Funds that offer the Administration Class shares, except for the State Street Institutional Liquid Reserves Fund. If your account balance is over $10,000, you may request periodic (i.e., monthly, quarterly, semi-annually, or annually) automatic cash withdrawals on any Business Day of $100 or more, which can be mailed to you, or any person or entity, you designate or sent through Automated Clearing House (ACH) to your designated bank account. Proceeds from such withdrawals will be transmitted to your designated bank account two Business Days after the redemption of shares occurs. No interest will accrue on the amounts represented by the uncashed redemption check(s). Ask your financial adviser or financial intermediary for details.

Exchanging Shares

An exchange occurs when you use the proceeds from the redemption of shares of a Fund in the State Street Institutional Investment Trust to simultaneously purchase shares of a different Fund in the State Street Institutional Investment Trust. Currently, exchanging shares is allowed from/to the Treasury Plus Fund, U.S. Government Fund, and Treasury Fund. Exchanges may be made within the same class ( i.e . Institutional Class shares for Institutional Class shares; Investor Class shares for Investor Class shares). The account holding the original shares must be registered in the same name as the account holding the new shares received in the exchange. You may make exchange requests by telephone, or by mail. See Purchasing Shares and Redeeming Shares. Exchanges are subject to the terms applicable to the purchases of the fund into which you are exchanging. Exchange privileges may not be available for mutual funds advised by SSGA FM (the “State Street Funds”) and may be suspended or rejected.

Excessive Trading

Because the Funds are money market funds, the Funds' Board of Trustees has not adopted policies and procedures with respect to frequent purchases and redemptions of Fund shares by Fund shareholders. Nonetheless, the Funds may take any reasonable action that they deem necessary or appropriate to prevent excessive trading in Fund shares without providing prior notification to the account holder. Such action may include rejecting any purchase, in whole or part, including, without limitation, by a person whose trading activity in Fund shares may be deemed harmful to the Fund. While the Funds attempt to discourage such excessive trading, there can be no guarantee that they will be able to identify investors who are engaging in excessive trading or limit their trading practices. Additionally, frequent trades of small amounts may not be detected. The Funds recognize that they may not always be able to detect or prevent excessive trading or other activity that may disadvantage the Funds or their shareholders.

Delivery of Documents to Accounts Sharing an Address

To reduce expenses, we may mail only one copy of the Funds' Prospectus and each annual and semi-annual report to those addresses shared by two or more accounts. If you wish to receive individual copies of these documents, please call us at (877) 521-4083, or contact your financial institution. We will begin sending you individual copies thirty (30) days after receiving your request.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a State Street Fund identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Fund (if you hold shares directly with the Fund) or to your financial intermediary (if you do not hold shares directly with the Fund).

Dividends, Distributions and Tax Considerations

The Funds intend to declare dividends on shares from net investment income daily and pay them as of the last business day of each month. Distributions from capital gains, if any, will be made annually in December. Income dividends and capital gains distributions will be paid in additional shares on the reinvestment date unless you have elected to receive them in cash. No interest will accrue on the amounts represented by uncashed distribution checks. If you have elected to receive distributions by check, and the postal or other delivery service is unable to deliver the checks because of an incorrect mailing address, or if a distribution check remains uncashed for six months, the uncashed distribution and all future distributions will be reinvested at the then-current NAV of the Fund.

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Each Fund has elected to be treated as a regulated investment company and intends each year to qualify and to be eligible to be treated as such. A regulated investment company generally is not subject to tax at the corporate level on income and gains that are timely distributed to shareholders. In order to qualify and be eligible for treatment as a regulated investment company, a Fund must, among other things, satisfy diversification, 90% gross income and distribution requirements. A Fund's failure to qualify as a regulated investment company would result in corporate level taxation, and consequently, a reduction in income available for distribution to shareholders.

Each Fund invests substantially all of its investible assets in a corresponding Portfolio that is treated as a partnership for U.S. federal income tax purposes. Therefore, the nature and character of each Fund's income, gains, losses and deductions generally will be determined at the Portfolio level, and each Fund will be allocated its share of the corresponding Portfolio's income, gains, losses and deductions. As applicable, references in this discussion to income, gains and losses of a Fund will be to income, gains and losses recognized and deductions accruing at the Portfolio level and allocated to or otherwise taken into account by the Fund, and references to assets of a Fund will be to the Fund's allocable share of the assets of the corresponding Portfolio.

Distributions are taxable to you even if they are paid from income or gains earned by a Fund before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares.

When the NAV of Fund Shares varies from a shareholder's tax basis in such shares, including when the NAV of such Fund Shares varies from $1.0000 per share, the shareholder generally will realize a gain or loss upon the redemption or other taxable disposition of such Fund Shares. Any such gain generally would be taxable to you as either short-term or long-term capital gain, depending upon how long you held the Fund Shares. The IRS permits a simplified method of accounting for gains and losses realized upon the disposition of shares of a regulated investment company that is a money market fund. If you elect to adopt this simplified method of accounting, rather than compute gain or loss on every taxable disposition of Fund Shares, you will determine your gain or loss based on the change in the aggregate value of your Fund Shares during a computation period (such as your taxable year), reduced by your net investment (purchase minus sales) in those shares during that period. Under this simplified method, any resulting net capital gain or loss would be treated as short-term capital gain or loss. Shareholders should see the SAI for further information.

A Fund's income from or proceeds of investments in non-U.S. assets may be subject to non-U.S. withholding and other taxes. This will decrease the Fund's return on securities subject to such taxes. Tax treaties between certain countries and the U.S. may reduce or eliminate such taxes. Although such taxes will reduce a Fund's taxable income, shareholders generally will not be entitled separately to claim a credit or deduction with respect to foreign taxes incurred by the Fund.

An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by a Fund and net gains recognized on the redemption of shares of a Fund.

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Financial Intermediary Arrangements

Distribution Arrangements and Rule 12b-1 Fees

The Funds have adopted a distribution plan pursuant to Rule 12b-1 under the 1940 Act under which a Fund may compensate SSGA FD (or others) for services in connection with the distribution of a Fund's shares and for services provided to Fund shareholders (the “Plan”). The Plan calls for payments at an annual rate (based on average daily net assets) of 0.05% and 0.10% of each Fund's net assets attributable to its Administration Class shares and Investment Class shares, respectively. Because these fees are paid out of the assets of a Fund attributable to its shares on an ongoing basis, they will increase the cost of your investment and may cost you more over time than paying other types of sales charges. Long-term shareholders of the Fund may pay more in Rule 12b-1 fees than the economic equivalent of the maximum front-end sales charge permitted by the FINRA.

Because a Fund pays distribution and other fees for the sale of their shares and for services provided to shareholders out of the Funds' assets on an ongoing basis, over time those fees will increase the cost of your investment and may cost you more than paying other types of sales loads.

A Fund may pay distribution fees and other amounts described in this Prospectus at a time when shares of that Fund are unavailable for purchase.

Other Payments to Financial Intermediaries

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cial Intermediary-sponsored special events. In some instances, this compensation may be made available only to certain Financial Intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the Funds' shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as FINRA.

Third-Party Transactions . The State Street Funds have authorized certain Financial Intermediaries to accept purchase, redemption and exchange orders on the State Street Funds' behalf. Orders received for a State Street Fund by a Financial Intermediary that has been authorized to accept orders on the Fund's behalf (or other Financial Intermediaries designated by the Financial Intermediary) will be deemed accepted by the Fund at the time they are received by the Financial Intermediary and will be priced based on the Fund's next NAV determination as long as the Financial Intermediary transmits the order in good form and in a timely manner to the applicable State Street Fund(s). For the ILR Fund, the State Street Funds will be the sole party to determine if a trade is received in good order. The Financial Intermediary is responsible for transmitting your orders and associated funds in good form and in a timely manner to the applicable State Street Fund(s). The State Street Funds will not be responsible for delays by the Financial Intermediary in transmitting your orders, including timely transfer of payment, to a Fund.

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Financial Highlights

The financial highlight tables are intended to help you understand each Fund's financial performance for the past five fiscal years. Certain information reflects the performance results for a single Fund Share. The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in each Fund (assuming reinvestment of all dividends and distributions). This information has been audited by Ernst & Young LLP, the Trust's independent registered public accounting firm, whose report, along with each Fund's financial highlights and financial statements, is included in the annual report to shareholders, which is available upon request. Any references to Notes in these financial highlight tables refer to the “Notes to Financial Statements” section of each Fund's financial statements, and the financial information included in these tables should be read in conjunction with the financial statements incorporated by reference in the SAI.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL LIQUID RESERVES FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Institutional Class(a)
	For the Period 7/6/18* 12/31/18
Net asset value, beginning of period	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0108
Net realized and unrealized gain (loss)	0.0001
Total from investment operations	0.0109
Distributions to shareholders from:
Net investment income	(0.0108)
Net asset value, end of period	$ 1.0001
Total return (b)	1.08%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 55
Ratios to Average Net Assets:
Total expenses	0.15%(c)
Net expenses	0.15%(c)
Net investment income (loss)	2.21%(c)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL LIQUID RESERVES FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Administration Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	For the Period 8/29/16* - 12/31/16
Net asset value, beginning of period	$ 1.0000	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0174	0.0080	0.0008
Net realized and unrealized gain (loss)	(0.0001)	0.0000(b)	0.0000(b)
Total from investment operations	0.0173	0.0080	0.0008
Distributions to shareholders from:
Net investment income	(0.0174)	(0.0080)	(0.0008)
Net realized gains	—	(0.0000)(b)	—
Total distributions	(0.0174)	(0.0080)	(0.0008)
Net asset value, end of period	$ 0.9999	$ 1.0000	$ 1.0000
Total return (c)	1.75%	0.80%	0.08%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$956,750	$831,606	$798,447
Ratios to Average Net Assets:
Total expenses	0.37%	0.37%	0.38%(d)
Net expenses	0.37%	0.37%	0.38%(d)
Net investment income (loss)	1.74%	0.80%	0.22%(d)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL LIQUID RESERVES FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Investment Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	Year Ended 12/31/14
Net asset value, beginning of period	$ 0.9999	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0164	0.0070	0.0010	0.0000(b)(c)	0.0000(b)(c)
Net realized and unrealized gain (loss)	0.0001	(0.0001)	0.0000(b)	0.0000(b)	0.0000(b)
Total from investment operations	0.0165	0.0069	0.0010	0.0000(b)	0.0000(b)
Distributions to shareholders from:
Net investment income	(0.0164)	(0.0070)	(0.0010)	—	—
Net realized gains	—	(0.0000)(b)	—	—	—
Total distributions	(0.0164)	(0.0070)	(0.0010)	—	—
Net asset value, end of period	$ 1.0000	$ 0.9999	$ 1.0000	$ 1.0000	$ 1.0000
Total return (d)	1.67%	0.69%	0.10%	0.00%(e)	0.00%(e)
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 23	$ 5,547	$ 5,582	$485,292	$726,910
Ratios to Average Net Assets:
Total expenses	0.47%	0.47%	0.47%	0.47%	0.47%
Net expenses	0.47%	0.47%	0.46%	0.24%	0.19%
Net investment income (loss)	1.18%	0.70%	0.08%	0.00%(e)	0.00%(e)

(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Per share numbers have been calculated using average shares outstanding, which more appropriately presents the per share data for the period.
(d)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(e)	Amount is less than 0.005%.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL LIQUID RESERVES FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Investor Class(a)
	Year Ended 12/31/18	For the Period 7/13/17* - 12/31/17
Net asset value, beginning of period	$ 0.9999	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0191	0.0055
Net realized and unrealized gain (loss)	—	(0.0001)
Total from investment operations	0.0191	0.0054
Voluntary expense reimbursement from Affiliate	—	0.0000(b)
Distributions to shareholders from:
Net investment income	(0.0191)	(0.0055)
Net realized gains	—	(0.0000)(b)
Total distributions	(0.0191)	(0.0055)
Net asset value, end of period	$ 0.9999	$ 0.9999
Total return (c)	1.92%	0.54%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 40,881	$ 34,361
Ratios to Average Net Assets:
Total expenses	0.20%	0.20%(d)
Net expenses	0.20%	0.20%(d)
Net investment income (loss)	1.95%	1.19%(d)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL LIQUID RESERVES FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Premier Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	Year Ended 12/31/14
Net asset value, beginning of period	$ 0.9999	$ 1.0001	$ 1.0000	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0199	0.0105	0.0045	0.0012(b)	0.0008(b)
Net realized and unrealized gain (loss)	—	(0.0002)	0.0001	0.0000(c)	(0.0001)
Total from investment operations	0.0199	0.0103	0.0046	0.0012	0.0007
Distributions to shareholders from:
Net investment income	(0.0199)	(0.0105)	(0.0045)	(0.0012)	(0.0007)
Net realized gains	—	(0.0000)(c)	—	—	—
Total distributions	(0.0199)	(0.0105)	(0.0045)	(0.0012)	(0.0007)
Net asset value, end of period	$ 0.9999	$ 0.9999	$ 1.0001	$ 1.0000	$ 1.0000
Total return (d)	2.00%	1.05%	0.45%	0.12%	0.07%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$9,489,591	$8,303,222	$6,255,384	$45,207,442	$37,932,781
Ratios to Average Net Assets:
Total expenses	0.12%	0.12%	0.12%	0.12%	0.12%
Net expenses	0.12%	0.12%	0.12%	0.12%	0.12%
Net investment income (loss)	2.00%	1.06%	0.43%	0.12%	0.07%

(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Per share numbers have been calculated using average shares outstanding, which more appropriately presents the per share data for the period.
(c)	Amount is less than $0.00005 per share.
(d)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL TREASURY MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Institutional Class(a)
	For the Period 7/31/18* 12/31/18
Net asset value, beginning of period	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0085
Net realized gain (loss)	(0.0000)(b)
Total from investment operations	0.0085
Distributions to shareholders from:
Net investment income	(0.0085)
Net asset value, end of period	$ 1.0000
Total return (c)	0.85%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 50
Ratios to Average Net Assets:
Total expenses	0.15%(d)
Net investment income (loss)	2.01%(d)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL TREASURY MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Administration Class(a)
	For the Period 07/31/18*- 12/31/18
Net asset value, beginning of period	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0076
Net realized gain (loss)	(0.0000)(b)
Total from investment operations	0.0076
Distributions to shareholders from:
Net investment income	(0.0076)
Total distributions	(0.0076)
Net asset value, end of period	$ 1.0000
Total return (c)	0.76%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 50
Ratios to Average Net Assets:
Total expenses	0.37%(d)
Net investment income (loss)	1.79%(d)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL TREASURY MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Investment Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	Year Ended 12/31/14
Net asset value, beginning of period	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0138	0.0041	0.0000(b)	0.0000(b)(c)	(0.0010)(c)
Net realized gain (loss)	(0.0000)(b)	0.0000(b)	0.0000(b)	0.0000(b)	0.0010
Total from investment operations	0.0138	0.0041	0.0000(b)	0.0000(b)	0.0000(b)
Distributions to shareholders from:
Net investment income	(0.0138)	(0.0041)	(0.0000)(b)	—	—
Net realized gains	—	(0.0000)(b)	—	—	(0.0000)(b)
Total distributions	(0.0138)	(0.0041)	(0.0000)(b)	—	(0.0000)(b)
Net asset value, end of period	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Total return (d)	1.39%	0.41%	0.00%(e)	0.00%(e)	0.00%(e)
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$390,735	$366,364	$609,545	$724,683	$741,248
Ratios to Average Net Assets:
Total expenses	0.47%	0.47%	0.47%	0.47%	0.47%
Net expenses	0.47%	0.47%	0.31%	0.04%	0.05%
Net investment income (loss)	1.37%	0.38%	0.00%(e)	0.00%(e)	0.00%(e)

(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Per share numbers have been calculated using average shares outstanding, which more appropriately presents the per share data for the period.
(d)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(e)	Amount is less than 0.005%.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL TREASURY MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Investor Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	For the Period 12/22/16* - 12/31/16
Net asset value, beginning of period	$ 1.0000	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0165	0.0068	0.0001
Net realized gain (loss)	(0.0000)(b)	0.0000(b)	(0.0000)(b)
Total from investment operations	0.0165	0.0068	0.0001
Distributions to shareholders from:
Net investment income	(0.0165)	(0.0068)	(0.0001)
Net realized gains	—	(0.0000)	—
Total distributions	(0.0165)	(0.0068)	(0.0001)
Net asset value, end of period	$ 1.0000	$ 1.0000	$ 1.0000
Total return (c)	1.66%	0.68%	0.00%(d)
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 97,241	$ 29,583	$ 27,402
Ratios to Average Net Assets:
Total expenses	0.20%	0.20%	0.18%(e)
Net investment income (loss)	1.70%	0.71%	0.31%(e)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Amount is less than 0.005%.
(e)	Annualized.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL TREASURY MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Premier Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	Year Ended 12/31/14
Net asset value, beginning of period	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0173	0.0076	0.0019	0.0000(b)(c)	—(c)
Net realized gain (loss)	(0.0000)(b)	0.0000(b)	0.0000(b)	0.0000(b)	0.0000(b)
Total from investment operations	0.0173	0.0076	0.0019	0.0000(b)	0.0000(b)
Distributions to shareholders from:
Net investment income	(0.0173)	(0.0076)	(0.0019)	(0.0000)(b)	—
Net realized gains	—	(0.0000)(b)	—	—	(0.0000)(b)
Total distributions	(0.0173)	(0.0076)	(0.0019)	(0.0000)(b)	(0.0000)(b)
Net asset value, end of period	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Total return (d)	1.74%	0.76%	0.19%	0.00%(e)	0.00%(e)
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$9,424,507	$12,123,627	$12,651,785	$10,412,966	$8,338,818
Ratios to Average Net Assets:
Total expenses	0.12%	0.12%	0.12%	0.12%	0.12%
Net expenses	0.12%	0.12%	0.12%	0.04%	0.04%
Net investment income (loss)	1.71%	0.76%	0.19%	0.00%(e)	0.00%(e)

(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Per share numbers have been calculated using average shares outstanding, which more appropriately presents the per share data for the period.
(d)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(e)	Amount is less than 0.005%.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL TREASURY PLUS MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Institutional Class(a)
	For the Period 7/31/18* 12/31/18
Net asset value, beginning of period	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0085
Net realized gain (loss)	—
Total from investment operations	0.0085
Distributions to shareholders from:
Net investment income	(0.0085)
Total distributions	(0.0085)
Net asset value, end of period	$ 1.0000
Total return (b)	0.85%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 94,554
Ratios to Average Net Assets:
Total expenses	0.15%(c)
Net expenses	0.15%(c)
Net investment income (loss)	2.04%(c)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Annualized.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL TREASURY PLUS MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Administration Class(a)
	For the Period 07/31/18*- 12/31/18
Net asset value, beginning of period	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0076
Net realized gain (loss)	—
Total from investment operations	0.0076
Distributions to shareholders from:
Net investment income	(0.0076)
Total distributions	(0.0076)
Net asset value, end of period	$ 1.0000
Total return (b)	0.76%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 50
Ratios to Average Net Assets:
Total expenses	0.37%(c)
Net expenses	0.37%(c)
Net investment income (loss)	1.78%(c)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Annualized.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL TREASURY PLUS MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Investment Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	Year Ended 12/31/14
Net asset value, beginning of period	$ 1.0000	$ 1.0000	$ 1.0000	$1.0000	$1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0139	0.0042	0.0000(b)	0.0000(b)(c)	0.0000(b)(c)
Net realized gain (loss)	—	0.0000(b)	0.0000(b)	0.0000(b)	0.0000(b)
Total from investment operations	0.0139	0.0042	0.0000(b)	0.0000(b)	0.0000(b)
Distributions to shareholders from:
Net investment income	(0.0139)	(0.0042)	(0.0000)(b)	—	—
Net realized gains	—	(0.0000)(b)	—	—	—
Total distributions	(0.0139)	(0.0042)	(0.0000)(b)	—	—
Net asset value, end of period	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Total return (d)	1.40%	0.42%	0.00%(e)	0.00%(e)	0.00%(e)
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 69,812	$ 19,242	$ 48,170	$60,041	$74,781
Ratios to Average Net Assets:
Total expenses	0.47%	0.47%	0.49%	0.49%	0.48%
Net expenses	0.47%	0.47%	0.31%	0.06%	0.05%
Net investment income (loss)	1.54%	0.36%	0.00%(e)	0.00%(e)	0.00%(e)

(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Per share numbers have been calculated using average shares outstanding, which more appropriately presents the per share data for the period.
(d)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(e)	Amount is less than 0.005%.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL TREASURY PLUS MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Investor Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	For the Period 10/14/16* - 12/31/16
Net asset value, beginning of period	$ 1.0000	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0166	0.0069	0.0004
Net realized gain (loss)	—	0.0000(b)	0.0000(b)
Total from investment operations	0.0166	0.0069	0.0004
Distributions to shareholders from:
Net investment income	(0.0166)	(0.0069)	(0.0004)
Net realized gains	—	(0.0000)(b)	—
Total distributions	(0.0166)	(0.0069)	(0.0004)
Net asset value, end of period	$ 1.0000	$ 1.0000	$ 1.0000
Total return (c)	1.67%	0.69%	0.04%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$774,885	$328,764	$101,461
Ratios to Average Net Assets:
Total expenses	0.20%	0.20%	0.20%(d)
Net expenses	0.20%	0.20%	0.20%(d)
Net investment income (loss)	1.67%	0.70%	0.19%(d)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Annualized.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL TREASURY PLUS MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Premier Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	Year Ended 12/31/14
Net asset value, beginning of period	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0174	0.0077	0.0019	0.0000(b)(c)	0.0000(b)(c)
Net realized gain (loss)	—	0.0000(b)	0.0000(b)	0.0000(b)	0.0000(b)
Total from investment operations	0.0174	0.0077	0.0019	0.0000(b)	0.0000(b)
Distributions to shareholders from:
Net investment income	(0.0174)	(0.0077)	(0.0019)	(0.0000)(b)	—
Net realized gains	—	(0.0000)(b)	—	—	—
Total distributions	(0.0174)	(0.0077)	(0.0019)	(0.0000)(b)	—
Net asset value, end of period	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Total return (d)	1.75%	0.77%	0.19%	0.00%(e)	0.00%(e)
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$8,402,049	$4,000,478	$2,515,246	$1,684,652	$2,690,959
Ratios to Average Net Assets:
Total expenses	0.12%	0.12%	0.14%	0.14%	0.13%
Net expenses	0.12%	0.12%	0.12%	0.06%	0.05%
Net investment income (loss)	1.80%	0.81%	0.20%	0.00%(e)	0.00%(e)

(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Per share numbers have been calculated using average shares outstanding, which more appropriately presents the per share data for the period.
(d)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(e)	Amount is less than 0.005%.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL U.S. GOVERNMENT MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Institutional Class(a)
	For the Period 1/18/18* 12/31/18
Net asset value, beginning of period	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0170
Net realized gain (loss)	—
Total from investment operations	0.0170
Distributions to shareholders from:
Net investment income	(0.0170)
Net asset value, end of period	$ 1.0000
Total return (b)	1.67%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$639,733
Ratios to Average Net Assets:
Total expenses	0.15%(c)
Net investment income (loss)	1.71%(c)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Annualized.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL U.S. GOVERNMENT MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Administration Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	For the Period 8/23/16* - 12/31/16
Net asset value, beginning of period	$ 1.0000	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0150	0.0054	0.0001
Net realized gain (loss)	—	0.0000(b)	(0.0000)(b)
Total from investment operations	0.0150	0.0054	0.0001
Distributions to shareholders from:
Net investment income	(0.0150)	(0.0054)	(0.0001)
Net realized gains	—	(0.0000)(b)	—
Total distributions	(0.0150)	(0.0054)	(0.0001)
Net asset value, end of period	$ 1.0000	$ 1.0000	$ 1.0000
Total return (c)	1.51%	0.54%	0.01%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$1,686,105	$1,909,670	$3,423,655
Ratios to Average Net Assets:
Total expenses	0.37%	0.37%	0.37%(d)
Net investment income (loss)	1.47%	0.50%	0.04%(d)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Annualized.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL U.S. GOVERNMENT MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Investment Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	Year Ended 12/31/14
Net asset value, beginning of period	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0140	0.0044	0.0000(b)	0.0000(b)(c)	(0.0000)(b)(c)
Net realized gain (loss)	—	0.0000(b)	0.0000(b)	—	—
Total from investment operations	0.0140	0.0044	0.0000(b)	0.0000(b)	(0.0000)(b)
Distributions to shareholders from:
Net investment income	(0.0140)	(0.0044)	(0.0000)(b)	—	—
Net realized gains	—	(0.0000)(b)	—	—	—
Total distributions	(0.0140)	(0.0044)	(0.0000)(b)	—	—
Net asset value, end of period	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Total return (d)	1.40%	0.44%	0.00%(e)	0.00%(e)	0.00%(e)
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$380,085	$432,488	$903,050	$971,551	$615,706
Ratios to Average Net Assets:
Total expenses	0.47%	0.47%	0.47%	0.47%	0.47%
Net expenses	0.47%	0.47%	0.37%	0.10%	0.07%
Net investment income (loss)	1.42%	0.40%	0.00%(e)	0.00%(e)	0.00%(e)

(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Per share numbers have been calculated using average shares outstanding, which more appropriately presents the per share data for the period.
(d)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(e)	Amount is less than 0.005%.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL U.S. GOVERNMENT MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Investor Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	For the Period 3/21/16* - 12/31/16
Net asset value, beginning of period	$ 1.0000	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0170	0.0071	0.0014
Net realized gain (loss)	—	0.0000(b)	(0.0000)(b)
Total from investment operations	0.0170	0.0071	0.0014
Distributions to shareholders from:
Net investment income	(0.0170)	(0.0071)	(0.0014)
Net realized gains	—	(0.0000)(b)	—
Total distributions	(0.0170)	(0.0071)	(0.0014)
Net asset value, end of period	$ 1.0000	$ 1.0000	$ 1.0000
Total return (c)	1.68%	0.71%	0.14%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$1,875,096	$1,245,204	$230,156
Ratios to Average Net Assets:
Total expenses	0.20%	0.20%	0.20%(d)
Net investment income (loss)	1.68%	0.83%	0.21%(d)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Annualized.

Table of Contents

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL U.S. GOVERNMENT MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Premier Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	Year Ended 12/31/14
Net asset value, beginning of period	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0170	0.0079	0.0025	0.0000(b)(c)	(0.0000)(b)(c)
Net realized gain (loss)	—	0.0000(b)	(0.0000)(b)	0.0000(b)	—
Total from investment operations	0.0170	0.0079	0.0025	0.0000(b)	(0.0000)(b)
Distributions to shareholders from:
Net investment income	(0.0170)	(0.0079)	(0.0025)	(0.0000)(b)	—
Net realized gains	—	(0.0000)(b)	—	—	—
Total distributions	(0.0170)	(0.0079)	(0.0025)	(0.0000)(b)	—
Net asset value, end of period	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Total return (d)	1.76%	0.79%	0.25%	0.00%(e)	0.00%(e)
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$32,939,927	$38,921,503	$43,302,733	$13,516,264	$10,962,800
Ratios to Average Net Assets:
Total expenses	0.12%	0.12%	0.12%	0.12%	0.12%
Net expenses	0.12%	0.12%	0.12%	0.09%	0.07%
Net investment income (loss)	1.74%	0.78%	0.27%	0.00%(e)	0.00%(e)

(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Per share numbers have been calculated using average shares outstanding, which more appropriately presents the per share data for the period.
(d)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(e)	Amount is less than 0.005%.

Table of Contents

Contacting the State Street Funds

Online:	www.ssga.com/cash	24 hours a day, 7 days a week
Phone:	(877) 521-4083	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Overnight/ Registered, Express, Certified Mail
State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737	State Street Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407

Table of Contents

For more information about the Funds:

The Funds' SAI includes additional information about the Funds and is incorporated by reference into this document. Additional information about the Funds' investments is available in the Funds' most recent annual and semi-annual reports to shareholders. The Funds' SAI is available, without charge, upon request. The Funds' annual and semi-annual reports are available, without charge, upon request. Shareholders in the Funds may make inquiries to the Funds to receive such information by calling (877) 521-4083 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. Each Fund's Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, free of charge, on the Funds' website at www.ssga.com/cash.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

MULTICLSTATPRO

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Institutional Liquid Reserves Fund: Service Class (LRSXX)

State Street Institutional U.S. Government Money Market Fund: Service Class (GVSXX)

State Street Institutional Treasury Money Market Fund: Service Class (TYSXX)

State Street Institutional Treasury Plus Money Market Fund: Service Class (TPSXX)

Beginning on January 1, 2021, as permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of a Fund's annual and semi- annual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Fund (or from your financial intermediary, such as a broker-dealer or bank). Instead, the reports will be made available on the Fund's website (www.ssga.com/cash), and you will be notified by mail each time a report is posted, and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Funds electronically by calling (866) 392-0869.

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with a Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling (866) 392-0869. Your election to receive reports in paper will apply to all funds held in your account, if you invest through your financial intermediary or all funds held with the fund complex if you invest directly with a Fund.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in any of the Funds offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Each Fund may offer multiple classes of shares. This Prospectus covers only the Service Class Shares of the applicable Funds.

State Street Institutional Liquid Reserves Fund is a “floating net asset value” money market fund. The share price of this Fund will fluctuate.

TABLE OF CONTENTS

Fund Summaries	1
State Street Institutional Liquid Reserves Fund	1
State Street Institutional U.S. Government Money Market Fund	7
State Street Institutional Treasury Money Market Fund	12
State Street Institutional Treasury Plus Money Market Fund	16
Additional Information About Investment Objectives, Principal Strategies and Risks	20
Additional Information About Non-Principal Investment Strategies and Risks	28
Portfolio Holdings Disclosure	30
Management and Organization	31
Shareholder Information	32
Dividends, Distributions and Tax Considerations	38
Financial Intermediary Arrangements	40
Financial Highlights	41

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State Street Institutional Liquid Reserves Fund

Investment Objective

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%
Other Expenses ¹	0.12%
Total Annual Fund Operating Expenses	0.17%

¹	Other expenses are based on estimates for the current fiscal year.

Example:

1 year		3 years		5 years		10 years
$17		$55		$96		$217

Principal Investment Strategies

The ILR Fund follows a disciplined investment process in which SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, bases its decisions on the relative attractiveness of different money market instruments. In the Adviser's opinion, the attractiveness of an instrument may vary depending on the general level of interest rates, as well as imbalances of supply and demand in the market. Among other things, SSGA FM conducts its own credit analyses of potential investments and portfolio holdings, and relies substantially on a dedicated short-term credit research team. The Fund invests in accordance with regulatory requirements applicable to money market funds, which require, among other things, the Fund to invest only in short-term, high quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity.

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its and time deposits of U.S. and foreign banks (including ECDs, ETDs and YCDs (as defined below), commercial paper and other high quality obligations of U.S. or foreign companies; asset-backed securities, including asset-backed commercial paper; mortgage-related securities; and repurchase agreements. These instruments may bear fixed, variable or floating rates of interest or may be zero-coupon securities. The Fund also may invest in shares of other money market funds, including funds advised by the Adviser. Under normal market conditions, the Fund intends to invest more than 25% of its total assets in bank obligations. A substantial portion of the Fund may be invested in securities that are issued or traded pursuant to exemptions from registration under the federal securities laws.

Principal Risks

In addition, the Fund is subject to the following principal risks:

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made in a limited number of countries, events in those countries will have a more significant impact on the Fund. Investments in depositary receipts may be less liquid and more volatile than the underlying shares in their primary trading market.

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Performance

The bar chart and table below provide some indication of the risks of investing in the ILR Fund by illustrating the variability of the Fund's returns for Premier Class shares from year-to-year. Performance history will be available for the Service Class shares of the Fund after they have been in operation for one calendar year. Returns of Service Class shares could have been similar to the returns shown for Premier Class shares because the shares are invested in the same portfolio of securities. Returns would differ only to the extent that Service Class shares do not have the same expenses as Premier Class shares. Service Class shares are generally expected to incur higher expenses, and so generally lower returns, than Premier Class shares. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.57% (Q4, 2018)
Lowest Quarterly Return: 0.02% (Q1, 2014)

Average Annual Total Returns (for periods ended 12/31/18)

		One Year		Five Years		Ten Years		Inception Date
Premier Class		2.00%		0.74%		0.48%		8/12/2004

To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Purchase and Sale of Fund Shares

Purchase Minimums

Service Class
To establish an account	$10,000,000
To add to an existing account	No minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone:

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By Intermediary:

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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State Street Institutional U.S. Government Money Market Fund

Investment Objective

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%
Other Expenses ¹	0.12%
Total Annual Fund Operating Expenses	0.17%

¹	Other expenses are based on estimates for the current fiscal year.

Example:

1 year		3 years		5 years		10 years
$17		$55		$96		$217

Principal Investment Strategies

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The Fund attempts to meet its investment objective by investing in:

•

•	Obligations issued or guaranteed by the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association, and U.S. government-sponsored entities such as the Federal Home Loan Bank, and the Federal Farm Credit Banks Funding Corporation, which are not backed by the full faith and credit of the United States; and
•	Repurchase agreements collateralized by U.S. government securities.

Principal Risks

In addition, the Fund is subject to the following principal risks:

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by Congress, they are not funded by Congressional appropriations, and their securities are not issued by the U.S. Treasury, are not supported by the full faith and credit of the U.S. government, and involve increased credit risks.

Performance

The bar chart and table below provide some indication of the risks of investing in the U.S. Government Fund by illustrating the variability of the Fund's returns for Premier Class shares from year-to-year. Performance history will be available for the Service Class shares of the Fund after they have been in operation for one calendar year. Returns of Service Class shares could have been similar to the returns shown for Premier Class shares because the shares are invested in the same portfolio of securities. Returns would differ only to the extent that Service Class shares do not have the same expenses as Premier Class shares. Service Class shares are generally expected to incur higher expenses, and so generally lower returns, than Premier Class shares. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.54% (Q4, 2018)
Lowest Quarterly Return: 0.00% (Q4, 2011)

Average Annual Total Returns (for periods ended 12/31/18)

		One Year		Five Years		Ten Years		Inception Date
Premier Class		1.76%		0.56%		0.32%		10/25/2007

To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Purchase and Sale of Fund Shares

Purchase Minimums

Service Class
To establish an account	$10,000,000
To add to an existing account	No minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

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By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone:

By Intermediary:

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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State Street Institutional Treasury Money Market Fund

Investment Objective

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%
Other Expenses ¹	0.12%
Total Annual Fund Operating Expenses	0.17%

¹	Other expenses are based on estimates for the current fiscal year.

Example:

1 year		3 years		5 years		10 years
$17		$55		$96		$217

Principal Investment Strategies

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Principal Risks

In addition, the Fund is subject to the following principal risks:

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Performance

The bar chart and table below provide some indication of the risks of investing in the Treasury Fund by illustrating the variability of the Fund's returns for Premier Class shares from year-to-year. Performance history will be available for the Service Class shares of the Fund after they have been in operation for one calendar year. Returns of Service Class shares could have been similar to the returns shown for Premier Class shares because the shares are invested in the same portfolio of securities. Returns would differ only to the extent that Service Class shares do not have the same expenses as Premier Class shares. Service Class shares are generally expected to incur higher expenses, and so generally lower returns, than Premier Class shares. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.54% (Q4, 2018)
Lowest Quarterly Return: 0.00% (Q1, 2010)

Average Annual Total Returns (for periods ended 12/31/18)

		One Year		Five Years		Ten Years		Inception Date
Premier Class		1.74%		0.54%		0.27%		10/25/2007

To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Purchase and Sale of Fund Shares

Purchase Minimums

Service Class
To establish an account	$10,000,000
To add to an existing account	No minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

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You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone:

By Intermediary:

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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State Street Institutional Treasury Plus Money Market Fund

Investment Objective

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%
Other Expenses ¹	0.12%
Total Annual Fund Operating Expenses	0.17%

¹	Other expenses are based on estimates for the current fiscal year.

Example:

1 year		3 years		5 years		10 years
$17		$55		$96		$217

Principal Investment Strategies

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Principal Risks

In addition, the Fund is subject to the following principal risks:

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an inactive trading market for money market instruments, or adverse market, economic, industry, political, regulatory, geopolitical, and other conditions could cause a money market fund's share price to fall below $1.00.

Performance

The bar chart and table below provide some indication of the risks of investing in the Treasury Plus Fund by illustrating the variability of the Fund's returns for Premier Class shares from year-to-year. Performance history will be available for the Service Class shares of the Fund after they have been in operation for one calendar year. Returns of Service Class shares could have been similar to the returns shown for Premier Class shares because the shares are invested in the same portfolio of securities. Returns would differ only to the extent that Service Class shares do not have the same expenses as Premier Class shares. Service Class shares are generally expected to incur higher expenses, and so generally lower returns, than Premier Class shares. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.54% (Q4, 2018)
Lowest Quarterly Return: 0.00% (Q4, 2011)

Average Annual Total Returns (for periods ended 12/31/18)

		One Year		Five Years		Ten Years		Inception Date
Premier Class		1.75%		0.54%		0.28%		10/24/2007

To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

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Purchase and Sale of Fund Shares

Purchase Minimums

Service Class
To establish an account	$10,000,000
To add to an existing account	No minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone:

By Intermediary:

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objectives, Principal Strategies and Risks

Investment Objective

The investment objective of each of the ILR Fund, U.S. Government Fund, the Treasury Fund and the Treasury Plus Fund, as stated in each Fund's Summary, may be changed without shareholder approval.

ILR Fund

Principal Investment Strategies

U.S. Government Fund

Principal Investment Strategies

The U.S. Government Fund is a government money market fund and invests only in obligations issued or guaranteed as to principal and/or interest, as applicable, by the U.S. government or its agencies and instrumentalities, as well as repurchase agreements secured by such instruments. The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

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The Fund follows a disciplined investment process that attempts to provide stability of principal, liquidity and current income, by investing in U.S. government securities. Among other things, SSGA FM conducts its own credit analyses of potential investments and portfolio holdings, and relies substantially on a dedicated short-term credit research team. The Fund invests in accordance with regulatory requirements applicable to money market funds. Regulations require, among other things, a money market fund to invest only in short-term, high quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity. All securities held by the Fund are U.S. dollar-denominated, and they may have fixed, variable or floating interest rates.

The Fund attempts to meet its investment objective by investing in:

•

•	Obligations issued or guaranteed by the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association, and U.S. government-sponsored entities such as the Federal Home Loan Bank, and the Federal Farm Credit Banks Funding Corporation, which are not backed by the full faith and credit of the United States; and
•	Repurchase agreements collateralized by U.S. government securities.

Treasury Fund

Principal Investment Strategies

The Treasury Fund is a government money market fund and attempts to meet its investment objective by investing only in U.S. Treasury bills, notes and bonds (which are direct obligations of the U.S. government). The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

Treasury Plus Fund

Principal Investment Strategies

The Treasury Plus Fund is a government money market fund and attempts to meet its investment objective by investing only in U.S. Treasury bills, notes and bonds (which are direct obligations of the U.S. government) and repurchase agreements collateralized by these obligations. The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

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Additional Information About Risks

Risk information is applicable to all Funds unless otherwise noted. The risks are described in alphabetical order and not in the order of importance or potential exposure.

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Additional Information About Non-Principal Investment Strategies and Risks

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Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Funds) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, a Fund, a Portfolio, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect a Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect a Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject a Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of a Fund inaccessible or inaccurate or incomplete. A Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. A Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. Each Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Funds. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which each Fund invests, which could result in material adverse consequences for such issuers, and may cause a Fund's investment in such securities to lose value.

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Portfolio Holdings Disclosure

The Funds' portfolio holdings disclosure policy is described in the SAI.

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Management and Organization

Investment Adviser

SSGA FM serves as the investment adviser to each Fund and corresponding Portfolio and, subject to the oversight of the Board, is responsible for the investment management of each Fund. The Adviser provides an investment management program for each Fund and manages the investment of each Fund's assets. The Adviser is a wholly-owned subsidiary of State Street Global Advisors, Inc., which itself is a wholly-owned subsidiary of State Street Corporation. The Adviser is registered with the SEC under the Investment Advisers Act of 1940, as amended. The Adviser and certain other affiliates of State Street Corporation make up SSGA. SSGA is one of the world's largest institutional money managers and the investment management arm of State Street Corporation. As of December 31, 2018, the Adviser managed approximately $452.10 billion in assets and SSGA managed approximately $2.51 trillion in assets. The Adviser's principal business address is One Iron Street, Boston, Massachusetts 02210.

Total Annual Fund Operating Expense Waivers . SSGA FM, as the investment adviser to each Fund, is contractually obligated, through April 30, 2020, for the ILR Fund, the U.S. Government Fund, and Treasury Plus Fund (i) to waive up to the full amount of the advisory fee payable by each Fund, and/or (ii) to reimburse a Fund for expenses to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.07% of average daily net assets on an annual basis. These waiver and/or reimbursement arrangements may not be terminated prior to April 30, 2020 except with approval of the Funds' Board of Trustees.

A discussion regarding the Board's consideration of the Funds' Investment Advisory Agreement is provided in the Funds' Semi-Annual Report to Shareholders for the period ended June 30, 2018.

The Administrator, Sub-Administrator and Custodian

The Adviser serves as administrator of each Fund. The amount of the fee paid to the Adviser for administrative services may vary by share class. Each Fund currently pays the Adviser an administrative fee at the annual rate of 0.05% in respect of the class of shares in this Prospectus. State Street Bank and Trust Company (“State Street”), a subsidiary of State Street Corporation, serves as the sub-administrator for the Funds for a fee that is paid by the Adviser. State Street also serves as custodian of the Funds for a separate fee that is paid by the Funds. SSGA FM serves as administrator of the Portfolios and State Street serves as sub-administrator and custodian of the Portfolios.

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Funds' transfer agent and dividend disbursing agent (the “Transfer Agent”).

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The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Funds' distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

The Shareholder Servicing Agent

Additional Information

Shareholder Information

Determination of Net Asset Value

For the ILR Fund

For the U.S. Government Fund, Treasury Plus Fund and Treasury Fund

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the risk limiting conditions of Rule 2a-7 under the Investment Company Act of 1940, as amended (the “1940 Act”), to value its portfolio instruments. The amortized cost valuation method initially prices an instrument at its cost and thereafter assumes a constant amortization to maturity of any discount or premium, regardless of the impact of fluctuating interest rates on the market value of the instrument.

For all Funds

Investing in State Street Institutional Investment Trust Shares

Purchasing Shares

Investors pay no sales load to invest in the Service Class Shares of the Funds. Purchase requests received by a Fund in good order (a purchase request is in good order if it meets the requirements implemented from time to time by the Transfer Agent or authorized agent of the Fund, and for new accounts includes submission of a completed and signed application and all documentation necessary to open an account) on a Business Day will, if payment is received by FedWire, be priced at the NAV next determined after the order is accepted by the Fund. Payments received by FedWire prior to the last Valuation Times (for the ILR Fund generally, 3:00 p.m. ET, unless the Fund closes earlier) will earn dividend accrual for that purchase.

The minimum initial investment in Service Class of the Funds is $10 million, although the Adviser may waive the minimum in its discretion. Holdings of related customer accounts may be aggregated for purposes of determining the minimum investment amount. “Related customer accounts” may include, but are not limited to, accounts held by the same investment or retirement plan, financial institution, broker, dealer or intermediary. The Funds and the Adviser reserve the right to increase or decrease the minimum amount required to open or maintain an account. There is no minimum subsequent investment, except in relation to maintaining certain minimum account balances (See “Redeeming Shares” below).The Funds require prior notification of subsequent investments in excess of $10 million for the Treasury Fund and $50 million for the U.S. Government Fund and Treasury Plus Fund.

All purchases that are made by check will be priced with the last valuation price and begin earning dividends the following Business

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Day after the day the order is accepted. (If you purchase shares by check, your order will not be in good form until the Transfer Agent receives federal funds for the check.) All purchase orders are subject to acceptance by the Funds. The Funds intend to be as fully invested as is practicable; therefore, investments must be made in Federal Funds (i.e., monies credited to the account of the Funds' custodian bank by a Federal Reserve Bank).

How to Purchase Shares

By Mail:

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone/Fax:

For your initial investment, send the original, signed Institutional Account Application Form to the address above.

Wire Instructions:

Instruct your bank to transfer money by Federal Funds wire to:
State Street Bank and Trust Company
1 Iron Street
Boston, MA 02110

ABA# 011000028
DDA# 9904-631-0
State Street Institutional Investment Trust
Fund Name
Class Name
Account Number
Account Registration

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Redeeming Shares

An investor may redeem all or any portion of its investment. Redemption orders are processed at the NAV next determined after a Fund receives a redemption order in good form.

For the ILR Fund

For the Treasury Fund and the Treasury Plus Fund

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For the U.S. Government Fund

For All Funds

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How to Redeem Shares


By Mail:	Send a signed letter to: State Street Institutional Investment Trust Funds P.O. Box 219737 Kansas City, MO 64121-9737
	The letter should include information necessary to process your request as described below. The Fund may require a medallion guarantee in certain circumstances. See “Medallion Guarantees” below.
By Overnight:	State Street Institutional Investment Trust Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407
By Telephone:	Please call (866) 392-0869 between the hours of 7:00 a.m. and 5:00 p.m. ET.
The Funds will need the following information to process your redemption request:
➣ name(s) of account owners; ➣ account number(s); ➣ the name of the Fund; ➣ your daytime telephone number; and ➣ the dollar amount or number of shares being redeemed.

On any day that the Funds calculate their NAVs earlier than normal, the Funds reserve the right to adjust the times noted above for purchasing and redeeming shares.

Medallion Guarantees . Certain redemption requests must include a medallion guarantee for each registered account owner if any of the following apply:

•	Your account address has changed within the last 10 Business Days.

•	Redemption proceeds are being transferred to an account with a different registration.
•	A wire is being sent to a financial institution other than the one that has been established on your Fund account.
•	Other unusual situations as determined by the Transfer Agent.

The Funds may terminate the receipt of redemption orders by telephone at any time, in which case you may redeem shares by other means.

If you choose to purchase or redeem shares by sending instructions by regular mail, they will not be deemed received in good order until they are released by the post office and redelivered to the Transfer Agent's physical location at 430 W 7th Street Suite 219737 in Kansas City, MO 64105-1407. There will be a time lag, which may be one or more days, between regular mail receipt at the post office box and redelivery to such physical location in Kansas City, and a Fund's NAV may change over those days. You might consider using express rather than regular mail if you believe the time of receipt of your transaction request to be sensitive.

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Exchanging Shares

An exchange occurs when you use the proceeds from the redemption of shares of a Fund in the State Street Institutional Investment Trust to simultaneously purchase shares of a different Fund in the State Street Institutional Investment Trust. Currently, exchanging shares is allowed from/to the Treasury Plus Fund, U.S. Government Fund, and Treasury Fund. Exchanges may be made within the same class ( i.e . Service Class shares for Service Class shares). The account holding the original shares must be registered in the same name as the account holding the new shares received in the exchange. You may make exchange requests by telephone, or by mail. See Purchasing Shares and Redeeming Shares. Exchanges are subject to the terms applicable to the purchases of the fund into which you are exchanging. Exchange privileges may not be available for mutual funds advised by SSGA FM (the “State Street Funds”) and may be suspended or rejected.

Excessive Trading

Delivery of Documents to Accounts Sharing an Address

To reduce expenses, we may mail only one copy of the Funds' Prospectus and each annual and semi-annual report to those addresses shared by two or more accounts. If you wish to receive individual copies of these documents, please call us at (877) 521-4083, or contact your financial institution. We will begin sending you individual copies thirty (30) days after receiving your request.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a State Street Fund identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Fund (if you hold shares directly with the Fund) or to your financial intermediary (if you do not hold shares directly with the Fund).

Dividends, Distributions and Tax Considerations

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An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by a Fund and net gains recognized on the redemption of shares of a Fund.

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Financial Intermediary Arrangements

Payments to Financial Intermediaries

Third-Party Transactions . The State Street Funds have authorized certain Financial Intermediaries to accept purchase, redemption and exchange orders on the State Street Funds' behalf. Orders received for a State Street Fund by a Financial Intermediary that has been authorized to accept orders on the Fund's behalf (or other Financial Intermediaries designated by the Financial Intermediary) will be deemed accepted by the Fund at the time they are received by the Financial Intermediary and will be priced based on the Fund's next NAV determination as long as the Financial Intermediary transmits the order in good form and in a timely manner to the applicable State Street Fund(s). For the ILR Fund, the State Street Funds will be the sole party to determine if a trade is received in good order. The Financial Intermediary is responsible for transmitting your orders and associated funds in good form and in a timely manner to the applicable State Street Fund(s). The State Street Funds will not be responsible for delays by the Financial Intermediary in transmitting your orders, including timely transfer of payment, to a Fund.

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Financial Highlights

The Service Class shares of the Funds had not commenced operations prior to the date of this Prospectus and therefore do not have financial information.

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For more information about the Funds:

The Funds' SAI includes additional information about the Funds and is incorporated by reference into this document. Additional information about the Funds' investments is available in the Funds' most recent annual and semi-annual reports to shareholders. The Funds' SAI is available, without charge, upon request. The Funds' annual and semi-annual reports are available, without charge, upon request. Shareholders in the Funds may make inquiries to the Funds to receive such information by calling (877) 521-4083 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. Each Fund's Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, or will be available, free of charge, on the Funds' website at www.ssga.com/cash.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

MULTISVSTATPRO

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Equity 500 Index II Portfolio (SSEYX)

State Street Aggregate Bond Index Portfolio (SSAFX)

State Street Global Equity ex-U.S. Index Portfolio (SSGVX)

State Street Small/Mid Cap Equity Index Portfolio (SSMHX)

Beginning on January 1, 2021, as permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of a Portfolio's annual and semi- annual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Portfolio (or from your financial intermediary, such as a broker-dealer or bank). Instead, the reports will be made available on the Portfolio's website (www.ssgafunds.com), and you will be notified by mail each time a report is posted, and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Portfolios electronically by calling (800) 647-7327.

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with a Portfolio, you can inform the Portfolio that you wish to continue receiving paper copies of your shareholder reports by calling (800) 647-7327. Your election to receive reports in paper will apply to all funds held in your account.

An investment in any of the Portfolios offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

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Fund Summaries	1
State Street Equity 500 Index II Portfolio	1
State Street Aggregate Bond Index Portfolio	6
State Street Global Equity ex-U.S. Index Portfolio	13
State Street Small/Mid Cap Equity Index Portfolio	21
Additional Information About Investment Objectives, Principal Strategies and Risks	27
Additional Information About Non-Principal Investment Strategies and Risks	41
Portfolio Holdings Disclosure	43
Management and Organization	44
Shareholder Information	46
Dividends, Distributions and Tax Considerations	48
Financial Highlights	51
Index/Trademark Licenses/Disclaimers	56

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State Street Equity 500 Index II Portfolio

Investment Objective

The State Street Equity 500 Index II Portfolio (the “Equity 500 Index II Portfolio” or the “Portfolio”) seeks to provide investment results that, before expenses, correspond generally to the total return of the S&P 500 ^® Index (the “S&P 500” or sometimes referred to in context as the “Index”).

Fees and Expenses of the Portfolio

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Equity 500 Index II Portfolio (“Portfolio Shares”). The Portfolio's shares are offered exclusively to investors that pay fees to SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the Portfolio's investment adviser, or its affiliates; the Portfolio pays no management fee to SSGA FM, as shown in the table below.

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Portfolio Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	N/A
Distribution and/or Shareholder Service (12b-1) Fees	N/A
Other Expenses ¹	0.03%
Total Annual Fund Operating Expenses	0.03%
Less Fee Waivers and/or Expense Reimbursements ²	(0.01%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.02%

Other Expenses have been restated to reflect current fees.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Portfolio, and/or (ii) to reimburse the Portfolio to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.02% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Portfolio's Board of Trustees.

Example:

This Example is intended to help you compare the cost of investing in the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated, and then sell all of your Portfolio Shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Portfolio's operating expenses remain the same. The calculation of costs for the one-year period takes into account the effect of any current contractual fee waivers and/or reimbursements; and the calculation of costs for the remaining periods takes such fee waivers and/or reimbursements into account only for the first year of each such period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

1 year		3 years		5 years		10 years
$2		$9		$16		$38

Portfolio Turnover:

The Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Portfolio Shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Portfolio's performance. During the most recent fiscal year, the Portfolio's portfolio turnover rate was 8% of the average value of its portfolio.

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Principal Investment Strategies

The Portfolio uses a passive management strategy designed to track the performance of the S&P 500. The Index is a well-known stock market index that includes common stocks of 500 companies from a number of sectors and that measures the performance of the large-cap sector of the U.S. equities market. As of February 28, 2019, a significant portion of the Index comprised companies in the information technology sector, although this may change from time to time.

The Portfolio is not managed according to traditional methods of “active” investment management, which involve the buying and selling of securities based upon economic, financial and market analysis and investment judgment. Instead, the Portfolio, using a “passive” or “indexing” investment approach, seeks to provide investment results that, before expenses, correspond generally to the total return of the S&P 500.

The Portfolio generally intends to invest in all stocks comprising the S&P 500 in approximate proportion to their weightings in the Index. However, under various circumstances, it may not be possible or practicable to purchase all stocks in those weightings. In those circumstances, the Portfolio may purchase a sample of the stocks in the Index in proportions expected by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Portfolio, to match generally the performance of the Index as a whole. In addition, from time to time stocks are added to or removed from the Index. The Portfolio may sell securities that are represented in the Index, or purchase securities that are not yet represented in the Index, in anticipation of their removal from or addition to the Index. Under normal circumstances, the Portfolio generally invests substantially all, but at least 80%, of its net assets (plus borrowings, if any) in securities comprising the Index or in securities that the Adviser determines have economic characteristics that are comparable to the economic characteristics of securities that comprise the Index. The notional value of the Portfolio's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. Shareholders will receive sixty (60) days' notice prior to a change in the 80% investment policy. In addition, the Portfolio may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

The Portfolio may at times purchase or sell futures contracts, or options on those futures, in lieu of investing directly in the stocks making up the Index. The Portfolio might do so, for example, in order to increase its investment exposure pending investment of cash in the stocks comprising the Index. Alternatively, the Portfolio might use futures or options on futures to reduce its investment exposure in situations where it intends to sell a portion of the stocks in its portfolio but the sale has not yet been completed. The Portfolio may also enter into other derivatives transactions, including the use of options or swap transactions, in lieu of investing directly in the stocks making up the Index. The Portfolio may also, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Portfolio (including funds advised by the Adviser).

Principal Risks of investing in the Portfolio

You could lose money by investing in the Portfolio. An investment in the Portfolio is subject to investment risks, including possible loss of principal, is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Portfolio may not achieve its investment objective. The Portfolio is subject to the following principal risks. The Portfolio is not intended to be a complete investment program, but rather is intended for investment as part of a diversified investment portfolio. Investors should consult their own advisers as to the role of the Portfolio in their overall investment programs. The risks are described in alphabetical order and not in the order of importance or potential exposure.

In addition, the Portfolio is subject to the following risks:

Counterparty Risk: The Portfolio will be subject to credit risk with respect to the counterparties with which the Portfolio enters into derivatives contracts, repurchase agreements, reverse repurchase agreements, and other transactions. If a counterparty fails to meet its contractual obligations, the Portfolio may be unable to terminate or realize any gain on the investment or transaction, or to recover collateral posted to the counterparty, resulting in a loss to the Portfolio. If the Portfolio holds collateral posted by its counterparty, it may be delayed or prevented from realizing on the collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty.

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unwilling to make timely settlement payments, return the Portfolio's margin, or otherwise honor its obligations. A derivatives transaction may not behave in the manner anticipated by the Adviser or may not have the effect on the Portfolio anticipated by the Adviser.

Equity Investing Risk: The market prices of equity securities owned by the Portfolio may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer and also may decline due to general industry or market conditions that are not specifically related to a particular company. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Indexing Strategy/Index Tracking Risk: The Portfolio is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Portfolio's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Portfolio. While the Adviser seeks to track the performance of the Index ( i.e. , achieve a high degree of correlation with the Index), the Portfolio's return may not match the return of the Index. The Portfolio incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Portfolio may not be fully invested at times, generally as a result of cash flows into or out of the Portfolio or reserves of cash held by the Portfolio to meet redemptions. The Adviser may attempt to replicate the Index return by investing in fewer than all of the securities in the Index, or in some securities not included in the Index, potentially increasing the risk of divergence between the Portfolio's return and that of the Index.

Large Shareholder Risk: To the extent a large proportion of the shares of the Portfolio are held by a small number of shareholders (or a single shareholder), including funds or accounts over which the Adviser has investment discretion, the Portfolio is subject to the risk that these shareholders will purchase or redeem Portfolio Shares in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of the Portfolio to conduct its investment program.

Liquidity Risk: Lack of a ready market or restrictions on resale may limit the ability of the Portfolio to sell a security at an advantageous time or price or at all. Illiquid securities may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value. Illiquidity of the Portfolio's holdings may limit the ability of the Portfolio to obtain cash to meet redemptions on a timely basis. In addition, the Portfolio, due to limitations on investments in any illiquid securities and/or the difficulty in purchasing and selling such investments, may be unable to achieve its desired level of exposure to a certain market or sector.

Market Risk: The Portfolio's investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Portfolio is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.

Risk of Investment in Other Pools: If the Portfolio invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected and is exposed indirectly to all of the risks applicable to an investment in such other pool. The investment policies of the other pool may not be the same as those of the Portfolio; as a result, an investment in the other pool may be subject to additional or different risks than those to which the Portfolio is typically subject. The Portfolio bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Portfolio may invest, leading to potential conflicts of interest. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which the Portfolio does so.

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Technology Sector Risk: Market or economic factors impacting technology companies and companies that rely heavily on technological advances could have a major effect on the value of the Portfolio's investments. The value of stocks of technology companies and companies that rely heavily on technology is particularly vulnerable to rapid changes in technology product cycles, rapid product obsolescence, government regulation and competition, both domestically and internationally, including competition from foreign competitors with lower production costs. Stocks of technology companies and companies that rely heavily on technology, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market. Technology companies are heavily dependent on patent and intellectual property rights, the loss or impairment of which may adversely affect profitability. Additionally, companies in the technology sector may face dramatic and often unpredictable changes in growth rates and competition for the services of qualified personnel.

Unconstrained Sector Risk: The Portfolio may invest a substantial portion of its assets within one or more economic sectors or industries, which may change from time to time. Greater investment focus on one or more sectors or industries increases the potential for volatility and the risk that events negatively affecting such sectors or industries could reduce returns, potentially causing the value of the Portfolio's Shares to decrease, perhaps significantly.

Performance

The bar chart and table below provide some indication of the risks of investing in the Portfolio by illustrating the variability of the Portfolio's returns from year-to-year and by showing how the Portfolio's average annual returns for the periods indicated compared with those of the Index. The Portfolio's past performance does not necessarily indicate how the Portfolio will perform in the future. Current performance information for the Portfolio is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 7.68% (Q3, 2018)
Lowest Quarterly Return: -13.55% (Q4, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
			8/11/2014
Return Before Taxes	-4.42%	8.23%
Return After Taxes on Distributions	-6.10%	6.76%
Return After Taxes on Distributions and Sale of Fund Shares	-2.10%	5.97%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	-4.38%	8.26%

The Portfolio will make updated performance information, including its current net asset value, available at the Portfolio's website: www.ssgafunds.com.

Investment Adviser

SSGA FM serves as the investment adviser to the Portfolio.

The professionals primarily responsible for the day-to-day management of the Portfolio are Michael Feehily, Karl Schneider and Amy Scofield each of which has served as a portfolio manager of the Portfolio since inception in 2014.

Michael Feehily, CFA, is a Senior Managing Director of the Adviser and the Head of Global Equity Beta Solutions in the Americas. He worked at the Adviser from 1997 to 2006 and rejoined in 2010.

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Karl Schneider, CAIA, is a Managing Director of the Adviser and Deputy Head of Global Equity Beta Solutions in the Americas. He joined the Adviser in 1997.

Amy Scofield is a Principal of the Adviser and a Portfolio Manager in the Global Equity Beta Solutions Group. She joined the Adviser in 2010.

Purchase and Sale of Portfolio Shares

Generally, shares of the Portfolio may be purchased only by or on behalf of other registered investment companies or private clients that compensate the Adviser or its affiliates directly.

Purchase Minimums

To establish an account	None
To add to an existing account	None

You may purchase or redeem Portfolio Shares on any day the Portfolio is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Portfolio Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Corporation
Attention: Transfer Agent
Box 5493
Mail Code: OHD0100
North Quincy, MA 02171

By Overnight:

State Street Corporation
Attention: Transfer Agent
1 Heritage Drive
North Quincy, MA 02171

By Intermediary:

If you wish to purchase or redeem Portfolio Shares through a broker, bank or other financial intermediary (“Financial Intermediary”), please contact that Financial Intermediary directly. Your Financial Intermediary may have different or additional requirements for opening an account and/or for the processing of purchase and redemption orders, or may be closed at times when the Portfolio is open.

Financial Intermediaries may contact State Street Dealer Services Group at 617-662-7300 or email them at broker-dealerservices@statestreet.com with questions.

Tax Information

The Portfolio's distributions are expected to be taxed as ordinary income, qualified dividend income and/or capital gains, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or individual retirement account. Any withdrawals made from such tax-advantaged arrangement may be taxable to you.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase Portfolio Shares through a broker-dealer or other Financial Intermediary (such as a bank), the Adviser or its affiliates may pay the Financial Intermediary for certain activities related to the Portfolio, including educational training programs, conferences, the development of technology platforms and reporting systems, or other services related to the sale or promotion of the Portfolio. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Portfolio over another investment. Ask your salesperson or visit your Financial Intermediary's website for more information.

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State Street Aggregate Bond Index Portfolio

Investment Objective

The State Street Aggregate Bond Index Portfolio (the “Aggregate Bond Index Portfolio” or the “Portfolio”) seeks to provide investment results that, before fees and expenses, correspond generally to the price and yield performance of an index that tracks the U.S. dollar denominated investment grade bond market over the long term.

Fees and Expenses of the Portfolio

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Aggregate Bond Index Portfolio (“Portfolio Shares”). The Portfolio's shares are offered exclusively to investors that pay fees to SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the Portfolio's investment adviser, or its affiliates; the Portfolio pays no management fee to SSGA FM, as shown in the table below.

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Portfolio Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	N/A
Distribution and/or Shareholder Service (12b-1) Fees	N/A
Other Expenses ¹	0.040%
Total Annual Fund Operating Expenses	0.040%
Less Fee Waivers and/or Expense Reimbursements ^2,3	(0.015)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.025%

¹	Other Expenses have been restated to reflect current fees.
²	The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Portfolio, and/or (ii) to reimburse the Portfolio to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.025% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Portfolio's Board of Trustees.
³	SSGA FM is contractually obligated to waive up to the portion of the management fee and/or expenses attributable to acquired fund fees and expenses in connection with the Portfolio's investments in To Be Announced (“TBA”) securities. This fee waiver and/or expense reimbursement may only be terminated with approval of the Portfolio's Board of Trustees.

Example:

1 year		3 years		5 years		10 years
$3		$11		$21		$50

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Portfolio Turnover:

Principal Investment Strategies

The Portfolio is an “index” fund that seeks to track, before fees and expenses, the total return performance of the Bloomberg Barclays U.S. Aggregate Bond Index (the “U.S. Aggregate Bond Index” or sometimes referred to in context as the “Index”) over the long term. As an “index” fund, the Portfolio is not managed according to traditional methods of “active” investment management, which involve the buying and selling of securities based upon economic, financial and market analysis and investment judgment.

Under normal circumstances, the Portfolio generally invests substantially all, but at least 80%, of its net assets (plus borrowings, if any) in securities comprising the Index or in securities that the Adviser determines have economic characteristics that are comparable to the economic characteristics of securities that comprise the Index. The notional value of the Portfolio's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. The Portfolio will provide shareholders with at least sixty (60) days' notice prior to any change in this 80% investment policy. The Portfolio may also invest in other debt securities, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

The Portfolio may at times purchase or sell futures contracts on fixed-income securities, or options on those futures, in lieu of investing directly in fixed-income securities themselves. The Portfolio may also purchase or sell futures contracts and related options on the Index (or other fixed-income securities indices). The Portfolio might do so, for example, in order to adjust the interest-rate sensitivity of the Portfolio to bring the characteristics of the Portfolio more closely in line with those of the Index. It might also do so to increase its investment exposure pending investment of cash in bonds or other investments or to reduce its investment exposure in situations where it intends to sell a portion of the securities in its portfolio but the sale has not yet been completed. The Portfolio may also enter into other derivatives transactions, including the use of options or swap transactions, in lieu of investing directly in the stocks making up the Index. The Portfolio may, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Portfolio (including funds advised by the Adviser).

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general trade parameters such as agency, settlement date, par amount and price. The actual pools delivered generally are determined two days prior to the settlement date; however, it is not anticipated that the Portfolio will receive pools, but instead will participate in rolling TBA Transactions. The Portfolio expects to enter into such contracts on a regular basis.

The Index is sponsored by Bloomberg Index Services Limited (the “Index Provider”) which is not affiliated with the Portfolio or the Adviser. The Index Provider determines the composition of the Index, relative weightings of the securities in the Index and publishes information regarding the market value of the Index.

Principal Risks of investing in the Portfolio

In addition, the Portfolio is subject to the following risks:

Debt Securities Risk: The values of debt securities may increase or decrease as a result of the following: market fluctuations, increases in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments or illiquidity in debt securities markets; the risk of low rates of return due to reinvestment of securities during periods of falling interest rates or repayment by issuers with higher coupon or interest rates; and/or the risk of low income due to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of the Portfolio's fixed income securities to decrease, an adverse impact on the liquidity of the Portfolio's fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Portfolio may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

Derivatives Risk: Derivative transactions can create investment leverage and may have significant volatility. It is possible that a derivative transaction will result in a much greater loss than the principal amount invested, and the Portfolio may not be able to close out a derivative transaction at a favorable time or price. The counterparty to a derivatives contract may be unable or unwilling to make timely settlement payments, return the Portfolio's margin, or otherwise honor its obligations. A derivatives transaction may not behave in the manner anticipated by the Adviser or may not have the effect on the Portfolio anticipated by the Adviser.

Income Risk: The Portfolio's income may decline due to falling interest rates or other factors. Issuers of securities held by the Portfolio may call or redeem the securities during periods of falling interest rates, and the Portfolio would likely be required to reinvest in securities paying lower interest rates. If an obligation held by the Portfolio is prepaid, the Portfolio may have to reinvest the prepayment in other obligations paying income at lower rates.

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folio incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Portfolio may not be fully invested at times, generally as a result of cash flows into or out of the Portfolio or reserves of cash held by the Portfolio to meet redemptions. The Adviser may attempt to replicate the Index return by investing in fewer than all of the securities in the Index, or in some securities not included in the Index, potentially increasing the risk of divergence between the Portfolio's return and that of the Index.

Large Shareholder Risk: To the extent a large proportion of the shares of the Portfolio are held by a small number of shareholders (or a single shareholder), including funds or accounts over which the Adviser has investment discretion, the Portfolio is subject to the risk that these shareholders will purchase or redeem Portfolio Shares in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of the Portfolio to conduct its investment program.

Mortgage-Related and Other Asset-Backed Securities Risk: Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed-income investments. The liquidity of mortgage-related and asset-backed securities may change over time. During periods of falling interest rates, mortgage- and asset-backed securities may be called or prepaid, which may result in the Portfolio having to reinvest proceeds in other investments at a lower interest rate. During periods of rising interest rates, the average life of mortgage- and asset-backed securities may extend, which may lock in a below-market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. Enforcing rights against the underlying assets or collateral may be difficult, and the underlying assets or collateral may be insufficient if the issuer defaults.

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Valuation Risk: Some portfolio holdings, potentially a large portion of the Portfolio's investment portfolio, may be valued on the basis of factors other than market quotations. This may occur more often in times of market turmoil or reduced liquidity. There are multiple methods that can be used to value a portfolio holding when market quotations are not readily available. The value established for any portfolio holding at a point in time might differ from what would be produced using a different methodology or if it had been priced using market quotations. Portfolio holdings that are valued using techniques other than market quotations, including “fair valued” securities, may be subject to greater fluctuation in their valuations from one day to the next than if market quotations were used. In addition, there is no assurance that the Portfolio could sell or close out a portfolio position for the value established for it at any time, and it is possible that the Portfolio would incur a loss because a portfolio position is sold or closed out at a discount to the valuation established by the Portfolio at that time. Investors who purchase or redeem Portfolio Shares on days when the Portfolio is holding fair-valued investments may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the Portfolio had not fair-valued the holding(s) or had used a different valuation methodology.

When-Issued, TBA and Delayed Delivery Securities Risk: The Portfolio may purchase securities on a when-issued, to-be-announced (“TBA”) or delayed delivery basis and may purchase securities on a forward commitment basis. The purchase price of the securities is typically fixed at the time of the commitment, but delivery and payment can take place a month or more after the date of the commitment. At the time of delivery of the securities, the value may be more or less than the purchase or sale price. Purchase of securities on a when-issued, TBA, delayed delivery, or forward commitment basis may give rise to investment leverage, and may result in increased volatility of the Portfolio's net asset value. Default by, or bankruptcy of, a counterparty to a when-issued, TBA or delayed delivery transaction would expose the Portfolio to possible losses because of an adverse market action, expenses or delays in connection with the purchase or sale of the pools specified in such transaction. Recently finalized rules of the Financial Industry Regulatory Authority, Inc. would impose mandatory margin requirements for certain types of when-issued, TBA delayed delivery or forward commitment transactions, with limited exceptions. Such transactions historically have not been required to be collateralized, and, if those rules are implemented, mandatory collateralization could increase the cost of such transactions and impose added operational complexity.

Performance

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 3.06% (Q1, 2016)
Lowest Quarterly Return: -3.03% (Q4, 2016)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
			9/18/2014
Return Before Taxes	-0.12%	1.93%
Return After Taxes on Distributions	-1.26%	0.81%
Return After Taxes on Distributions and Sale of Fund Shares	-0.08%	0.97%
Bloomberg Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)	0.01%	2.05%

The Portfolio will make updated performance information, including its current net asset value, available at the Portfolio's website: www.ssgafunds.com.

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Investment Adviser

SSGA FM serves as the investment adviser to the Portfolio.

The professionals primarily responsible for the day-to-day management of the Portfolio are Marc DiCosimo and Joanna Madden. They have served as portfolio managers of the Portfolio since 2014 and 2016, respectively.

Marc DiCosimo, CFA, is a Vice President of the Adviser and a Senior Portfolio Manager in the Fixed Income Beta Solutions Group. He joined the Adviser in 2013.

Joanna Madden is a Vice President of the Adviser and a Portfolio Manager in the Fixed Income Beta Solutions Group. She joined the Adviser in 2003.

Purchase and Sale of Portfolio Shares

Generally, shares of the Portfolio may be purchased only by or on behalf of other registered investment companies or private clients that compensate the Adviser or its affiliates directly.

Purchase Minimums

To establish an account	None
To add to an existing account	None

You may purchase or redeem Portfolio Shares on any day the Portfolio is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Portfolio Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Corporation
Attention: Transfer Agent
Box 5493
Mail Code: OHD0100
North Quincy, MA 02171

By Overnight:

State Street Corporation
Attention: Transfer Agent
1 Heritage Drive
North Quincy, MA 02171

By Intermediary:

Financial Intermediaries may contact State Street Dealer Services Group at 617-662-7300 or email them at broker-dealerservices@statestreet.com with questions.

Tax Information

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Payments to Broker-Dealers and Other Financial Intermediaries

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State Street Global Equity ex-U.S. Index Portfolio

Investment Objective

The State Street Global Equity ex-U.S. Index Portfolio (the “Global Equity ex-U.S. Index Portfolio” or the “Portfolio”) seeks to provide investment results that, before fees and expenses, correspond generally to the total return performance of a broad-based index of world (ex-U.S.) equity markets over the long term.

Fees and Expenses of the Portfolio

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Global Equity ex-U.S. Index Portfolio (“Portfolio Shares”). The Portfolio's shares are offered exclusively to investors that pay fees to SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the Portfolio's investment adviser, or its affiliates; the Portfolio pays no management fee to SSGA FM, as shown in the table below.

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Portfolio Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	N/A
Distribution and/or Shareholder Service (12b-1) Fees	N/A
Other Expenses	0.06%
Total Annual Fund Operating Expenses	0.06%

Example:

1 year		3 years		5 years		10 years
$6		$19		$34		$77

Portfolio Turnover:

Principal Investment Strategies

The Portfolio is an “index” fund that seeks to track, before fees and expenses, the total return performance of the MSCI ACWI ex USA Index (the “MSCI ACWI ex USA Index” or sometimes referred to in context as the “Index”) over the long term. As an “index” fund, the Portfolio is not managed according to traditional methods of “active” investment management, which involve the buying and selling of securities based upon economic, financial and market analysis and investment judgment. As of February 28, 2019, a significant portion of the Index comprised companies in the financial sector, although this may change from time to time. As of February 28, 2019, a significant portion of the Index comprised companies located in Japan and the United Kingdom and a significant portion of the Index constituents are denominated in the Yen and the Great Britain Pound although this may change from time to time.

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Under normal circumstances, the Portfolio generally invests substantially all, but at least 80%, of its net assets (plus borrowings, if any) in securities comprising the Index or in American Depositary Receipts (“ADRs”) or Global Depositary Receipts (“GDRs”) providing exposure to securities comprising the Index. The notional value of the Portfolio's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. The Portfolio will provide shareholders with at least sixty (60) days' notice prior to any change in this 80% investment policy. In addition, the Portfolio may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

The Portfolio may also purchase or sell futures contracts, or options on those futures, in lieu of investing directly in the stocks making up the Index. The Portfolio might do so, for example, in order to increase its investment exposure pending investment of cash in stocks or other investments. Alternatively, the Portfolio might use futures or options on futures to reduce its investment exposure in situations where it intends to sell a portion of the stocks in its portfolio but the sale has not yet been completed. The Portfolio may also enter into other derivatives transactions, including the use of options, forwards or swap transactions, in lieu of investing directly in the stocks making up the Index. The Portfolio may also, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Portfolio (including funds advised by the Adviser).

The Index is sponsored by Morgan Stanley Capital International Inc. (the “Index Provider”), which is not affiliated with the Portfolio or the Adviser. The Index Provider determines the composition of the Index, relative weightings of the securities in the Index and publishes information regarding the market value of the Index.

Principal Risks of investing in the Portfolio

In addition, the Portfolio is subject to the following risks:

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Currency Risk: The value of the Portfolio's assets may be affected favorably or unfavorably by currency exchange rates, currency exchange control regulations, and delays, restrictions or prohibitions on the repatriation of foreign currencies. Foreign currency exchange rates may have significant volatility, and changes in the values of foreign currencies against the U.S. dollar may result in substantial declines in the values of the Portfolio's assets denominated in foreign currencies.

Depositary Receipts Risk: Investments in depositary receipts may be less liquid and more volatile than the underlying securities in their primary trading market. If a depositary receipt is denominated in a different currency than its underlying securities, the Portfolio will be subject to the currency risk of both the investment in the depositary receipt and the underlying security. Holders of depositary receipts may have limited or no rights to take action with respect to the underlying securities or to compel the issuer of the receipts to take action. The prices of depositary receipts may differ from the prices of securities upon which they are based. To the extent the Portfolio invests in depositary receipts based on securities included in the Index, such differences in prices may increase index tracking risk.

Derivatives Risk: Derivative transactions can create investment leverage and may have significant volatility. It is possible that a derivative transaction will result in a much greater loss than the principal amount invested, and the Portfolio may not be able to close out a derivative transaction at a favorable time or price. The counterparty to a derivatives contract may be unable or unwilling to make timely settlement payments, return the Portfolio's margin, or otherwise honor its obligations. A derivatives transaction may not behave in the manner anticipated by the Adviser or may not have the effect on the Portfolio anticipated by the Adviser.

Emerging Markets Risk: Risks of investing in emerging markets include, among others, greater political and economic instability, greater volatility in currency exchange rates, less developed securities markets, possible trade barriers, currency transfer restrictions, a more limited number of potential buyers and issuers, an emerging market country's dependence on revenue from particular commodities or international aid, less governmental supervision and regulation, unavailability of currency hedging techniques, differences in auditing and financial reporting standards, and less developed legal systems. There is also the potential for unfavorable action such as expropriation, nationalization, embargo, and acts of war. The securities of emerging market companies may trade less frequently and in smaller volumes than more widely held securities. Market disruptions or substantial market corrections may limit very significantly the liquidity of securities of certain companies in a particular country or geographic region, or of all companies in the country or region. The Portfolio may be unable to liquidate its positions in such securities at any time, or at a favorable price, in order to meet the Portfolio's obligations. These risks are generally greater for investments in frontier market countries, which typically have smaller economies or less developed capital markets than traditional emerging market countries.

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Europe: Developed and emerging market countries in Europe will be significantly affected by the fiscal and monetary controls of the Economic and Monetary Union of the European Union (“EU”). Changes in regulations on trade, decreasing imports or exports, changes in the exchange rate of the euro and recessions among European countries may have a significant adverse effect on the economies of other European countries. In addition, one or more countries may abandon the euro and/or withdraw from the EU. For example, in June 2016, citizens of the United Kingdom voted in a referendum to leave the EU (known as “Brexit”), creating economic and political uncertainty in its wake. In March 2017, the United Kingdom formally notified the European Council of the United Kingdom's intention to withdraw from the EU pursuant to Article 50 of the Treaty on European Union. This formal notification began a two-year period of negotiations regarding the terms of the United Kingdom's exit from the EU. It is unclear how withdrawal negotiations will be conducted and what the potential consequences may be. Any exits from the EU, or the possibility of such exits, may have a significant impact on the United Kingdom, Europe, and global economies, which may result in increased volatility and illiquidity, new legal and regulatory uncertainties and potentially lower economic growth for such economies that could potentially have an adverse effect on the value of the Portfolio's investments. In addition, a number of countries in Europe have suffered terrorist attacks and additional attacks may occur in the future. Such attacks may cause uncertainty in financial markets and may adversely affect the performance of the issuers to which the Portfolio has exposure.

Japan: The growth of Japan's economy has historically lagged that of its Asian neighbors and other major developed economies. The Japanese economy is heavily dependent on international trade and has been adversely affected by trade tariffs, other protectionist measures, competition from emerging economies and the economic conditions of its trading partners. China has become an important trading partner with Japan, yet the countries' political relationship has become strained. Should political tension increase, it could adversely affect the economy, especially the export sector, and destabilize the region as a whole. Japan also remains heavily dependent on oil imports, and higher commodity prices could therefore have a negative impact on the economy. The Japanese yen has fluctuated widely at times and any increase in its value may cause a decline in exports that could weaken the Japanese economy. Japan has, in the past, intervened in the currency markets to attempt to maintain or reduce the value of the yen. Japanese intervention in the currency markets could cause the value of the yen to fluctuate sharply and unpredictably and could cause losses to investors. Japan has an aging workforce and has experienced a significant population decline in recent years. Japan's labor market appears to be undergoing fundamental structural changes, as a labor market traditionally accustomed to lifetime employment adjusts to meet the need for increased labor mobility, which may adversely affect Japan's economic competitiveness. Natural disasters, such as earthquakes, volcanoes, typhoons or tsunamis, could occur in Japan or surrounding areas and could negatively affect the Japanese economy and, in turn, the Portfolio.

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Large Shareholder Risk: To the extent a large proportion of the shares of the Portfolio are held by a small number of shareholders (or a single shareholder), including funds or accounts over which the Adviser has investment discretion, the Portfolio is subject to the risk that these shareholders will purchase or redeem Portfolio Shares in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of the Portfolio to conduct its investment program.

Non-U.S. Securities Risk: Non-U.S. securities (including depositary receipts) are subject to political, regulatory, and economic risks not present in domestic investments. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, legal and financial report standards comparable to those in the United States. Further, such entities and/or their securities may be subject to risks associated with currency controls; expropriation; changes in tax policy; greater market volatility; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. Securities traded on foreign markets may be less liquid (harder to sell) than securities traded domestically. Foreign governments may impose restrictions on the repatriation of capital to the U.S. In addition, to the extent the Portfolio buys securities denominated in a foreign currency, there are special risks such as changes in currency exchange rates and the risk that a foreign government could regulate foreign exchange transactions. In addition, to the extent investments are made in a limited number of countries, events in those countries will have a more significant impact on the Portfolio. Investments in depositary receipts may be less liquid and more volatile than the underlying shares in their primary trading market.

Small-, Mid-, and Micro-Capitalization Securities Risk: The securities of small-, mid-, and micro-capitalization companies may be more volatile and may involve more risk than the securities of larger companies. These companies may have limited product lines, markets or financial resources, may lack the competitive strength of larger companies, and may depend on a few key employees. In addition, these companies may have been recently organized and may have little or no track record of success. The securities of smaller companies may trade less frequently and in smaller volumes than more widely held securities. Some securities of smaller issuers may be illiquid or may be restricted as to resale, and their values may have significant volatility. The Portfolio may be unable to liquidate its positions in such securities at any time, or at a favorable price, in order to meet the Portfolio's obligations. Returns on investments in securities of small-, mid-, and micro-capitalization companies could trail the returns on investments in securities of larger companies.

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Performance

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 7.78% (Q1, 2017)
Lowest Quarterly Return: -11.90% (Q3, 2015)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
			9/16/2014
Return Before Taxes	-13.99%	-0.03%
Return After Taxes on Distributions	-15.04%	-1.02%
Return After Taxes on Distributions and Sale of Fund Shares	-8.29%	-0.45%
MSCI ACWI ex USA Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-14.20%	0.00%

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The Portfolio will make updated performance information, including its current net asset value, available at the Portfolio's website: www.ssgafunds.com.

Investment Adviser

SSGA FM serves as the investment adviser to the Portfolio.

The professionals primarily responsible for the day-to-day management of the Portfolio are Michael Feehily, Karl Schneider, and Olga Winner. They have served on the Portfolio since inception in 2014.

Michael Feehily, CFA, is a Senior Managing Director of the Adviser and the Head of Global Equity Beta Solutions in the Americas. He worked at the Adviser from 1997 to 2006 and rejoined in 2010.

Karl Schneider, CAIA, is a Managing Director of the Adviser and Deputy Head of Global Equity Beta Solutions in the Americas. He joined the Adviser in 1997.

Olga Winner, CFA, is a Vice President of the Adviser and a Senior Portfolio Manager in the Global Equity Beta Solutions Group. She joined the Adviser in 2007.

Purchase and Sale of Portfolio Shares

Generally, shares of the Portfolio may be purchased only by or on behalf of other registered investment companies or private clients that compensate the Adviser or its affiliates directly.

Purchase Minimums

To establish an account	None
To add to an existing account	None

You may purchase or redeem Portfolio Shares on any day the Portfolio is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Portfolio Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Corporation
Attention: Transfer Agent
Box 5493
Mail Code: OHD0100
North Quincy, MA 02171

By Overnight:

State Street Corporation
Attention: Transfer Agent
1 Heritage Drive
North Quincy, MA 02171

By Intermediary:

Financial Intermediaries may contact State Street Dealer Services Group at 617-662-7300 or email them at broker-dealerservices@statestreet.com with questions.

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Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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State Street Small/Mid Cap Equity Index Portfolio

Investment Objective

The State Street Small/Mid Cap Equity Index Portfolio (the “Small/Mid Cap Equity Index Portfolio” or the “Portfolio”) seeks to provide investment results that, before expenses, correspond generally to the total return of an index that tracks the performance of mid-to small- capitalization exchange traded U.S. equity securities.

Fees and Expenses of the Portfolio

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Small/Mid Cap Equity Index Portfolio (“Portfolio Shares”). The Portfolio's shares are offered exclusively to investors that pay fees to SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the Portfolio's investment adviser, or its affiliates; the Portfolio pays no management fee to SSGA FM, as shown in the table below.

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Portfolio Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	N/A
Distribution and/or Shareholder Service (12b-1) Fees	N/A
Other Expenses	0.05%
Total Annual Fund Operating Expenses	0.05%
Less Fee Waivers and/or Expense Reimbursements ¹	(0.02%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.03%

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Portfolio, and/or (ii) to reimburse the Portfolio to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.03% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Portfolio's Board of Trustees.

Example:

1 year		3 years		5 years		10 years
$3		$14		$26		$62

Portfolio Turnover:

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Principal Investment Strategies

The Portfolio uses a passive management strategy designed to track the performance of the Russell Small Cap Completeness Index (the “Index”). The Index is a float-adjusted, market capitalization index which measures the performance of the Russell 3000 ^® Index companies excluding S&P 500 ^® constituents. The Index is constructed to provide a comprehensive and unbiased barometer of the extended broad market beyond the S&P 500 exposure. As of February 28, 2019, the market capitalization of the companies included in the Index ranged from $5.04 million to $43.74 billion. As of February 28, 2019, the Index comprised 2,480 securities. As of February 28, 2019, a significant portion of the Index comprised companies in the financial services and technology sectors, although this may change from time to time.

The Portfolio generally intends to invest in all stocks comprising the Index in approximate proportion to their weightings in the Index. However, under various circumstances, it may not be possible or practicable to purchase all stocks in those weightings. In those circumstances, the Portfolio may purchase a sample of the stocks in the Index in proportions expected by SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Portfolio, to match generally the performance of the Index as a whole. In addition, from time to time stocks are added to or removed from the Index. The Portfolio may sell securities that are represented in the Index, or purchase securities that are not yet represented in the Index, in anticipation of their removal from or addition to the Index. Under normal market conditions, the Portfolio invests at least 80% of its net assets (plus borrowings, if any) in stocks in the Index. The Portfolio will provide shareholders with at least sixty (60) days' notice prior to any change in this 80% investment policy. The notional value of the Portfolio's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. In addition, the Fund may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

The Portfolio may purchase or sell futures contracts on the Index, or options on those futures, in lieu of investing directly in the stocks making up the Index. The Portfolio might do so, for example, in order to increase its investment exposure pending investment of cash in the stocks comprising the Index. Alternatively, the Portfolio might use futures or options on futures to reduce its investment exposure in situations where it intends to sell a portion of the stocks in its portfolio but the sale has not yet been completed. The Portfolio may also enter into other derivatives transactions, including the use of options or swap transactions relating to the Index or any securities comprising the Index, in lieu of investing directly in the stocks making up the Index. The Portfolio may, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Portfolio (including funds advised by the Adviser).

The Index is sponsored by Frank Russell Company (the “Index Provider”), which is not affiliated with the Portfolio or the Adviser. The Index Provider determines the composition of the Index, relative weightings of the securities in the Index and publishes information regarding the market value of the Index.

Principal Risks of investing in the Portfolio

In addition, the Portfolio is subject to the following risks:

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Derivatives Risk: Derivative transactions can create investment leverage and may have significant volatility. It is possible that a derivative transaction will result in a much greater loss than the principal amount invested, and the Portfolio may not be able to close out a derivative transaction at a favorable time or price. The counterparty to a derivatives contract may be unable or unwilling to make timely settlement payments, return the Portfolio's margin, or otherwise honor its obligations. A derivatives transaction may not behave in the manner anticipated by the Adviser or may not have the effect on the Portfolio anticipated by the Adviser.

Large Shareholder Risk: To the extent a large proportion of the shares of the Portfolio are held by a small number of shareholders (or a single shareholder), including funds or accounts over which the Adviser has investment discretion, the Portfolio is subject to the risk that these shareholders will purchase or redeem Portfolio Shares in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of the Portfolio to conduct its investment program.

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its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Portfolio may invest, leading to potential conflicts of interest. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which the Portfolio does so.

Technology Sector Risk: Market or economic factors impacting technology companies and companies that rely heavily on technological advances could have a major effect on the value of the Portfolio's investments. The value of stocks of technology companies and companies that rely heavily on technology is particularly vulnerable to rapid changes in technology product cycles, rapid product obsolescence, government regulation and competition, both domestically and internationally, including competition from foreign competitors with lower production costs. Stocks of technology companies and companies that rely heavily on technology, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market. Technology companies are heavily dependent on patent and intellectual property rights, the loss or impairment of which may adversely affect profitability. Additionally, companies in the technology sector may face dramatic and often unpredictable changes in growth rates and competition for the services of qualified personnel.

Performance

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 7.11% (Q3, 2016)
Lowest Quarterly Return: -17.83% (Q4, 2018)

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Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
			8/11/2015
Return Before Taxes	-9.07%	4.81%
Return After Taxes on Distributions	-10.85%	3.48%
Return After Taxes on Distributions and Sale of Fund Shares	-4.89%	3.28%
Russell Small Cap Completeness Index (reflects no deduction for fees, expenses or taxes)	-9.21%	4.77%

The Portfolio will make updated performance information, including its current net asset value, available at the Portfolio's website: www.ssgafunds.com.

Investment Adviser

SSGA FM serves as the investment adviser to the Portfolio.

The professionals primarily responsible for the day-to-day management of the Portfolio are Michael Feehily, Karl Schneider and Ted Janowsky each of which has served as a portfolio manager of the Portfolio since inception in 2015.

Michael Feehily, CFA, is a Senior Managing Director of the Adviser and the Head of Global Equity Beta Solutions in the Americas. He worked at the Adviser from 1997 to 2006 and rejoined in 2010.

Karl Schneider, CAIA, is a Managing Director of the Adviser and Deputy Head of Global Equity Beta Solutions in the Americas. He joined the Adviser in 1997.

Ted Janowsky, CFA, is a Vice President of the Adviser and a Senior Portfolio Manager in the Global Equity Beta Solutions Group. He joined the Adviser in 2005.

Purchase and Sale of Portfolio Shares

Generally, shares of the Portfolio may be purchased only by or on behalf of other registered investment companies or private clients that compensate the Adviser or its affiliates directly.

Purchase Minimums

To establish an account	None
To add to an existing account	None

You may purchase or redeem Portfolio Shares on any day the Portfolio is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Portfolio Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Corporation
Attention: Transfer Agent
Box 5493
Mail Code: OHD0100
North Quincy, MA 02171

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By Overnight:

State Street Corporation
Attention: Transfer Agent
1 Heritage Drive
North Quincy, MA 02171

By Intermediary:

Financial Intermediaries may contact State Street Dealer Services Group at 617-662-7300 or email them at broker-dealerservices@statestreet.com with questions.

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objectives, Principal Strategies and Risks

Investment Objective

The Trust's Board of Trustees may change each Portfolio's investment strategies and other policies without shareholder approval, except as otherwise indicated. The Board of Trustees may change each Portfolio's investment objective without shareholder approval.

State Street Equity 500 Index II Portfolio

Principal Investment Strategies

The Portfolio generally intends to invest in all stocks comprising the S&P 500 in approximate proportion to their weightings in the Index. However, under various circumstances, it may not be possible or practicable to purchase all stocks in those weightings. In those circumstances, the Portfolio may purchase a sample of the stocks in the Index in proportions expected by SSGA FM to match generally the performance of the Index as a whole. In addition, from time to time stocks are added to or removed from the Index. The Portfolio may sell securities that are represented in the Index, or purchase securities that are not yet represented in the Index, in anticipation of their removal from or addition to the Index. Under normal circumstances, the Portfolio generally invests substantially all, but at least 80%, of its net assets (plus borrowings, if any) in securities comprising the Index or in securities that the Adviser determines have economic characteristics that are comparable to the economic characteristics of securities that comprise the Index. The notional value of the Portfolio's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. Shareholders will receive sixty (60) days' notice prior to a change in the 80% investment policy. In addition, the Portfolio may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

The S&P 500 . Stocks in the S&P 500 are weighted according to their float adjusted market capitalizations ( i.e ., the number of float shares outstanding multiplied by the stock's current price). The companies selected for inclusion in the S&P 500 are those of large publicly held companies which generally have large market values within their respective industries. The composition of the S&P 500 is determined by S&P Dow Jones Indices and is based on such factors as the domicile, market capitalization, liquidity, financial viability and investable weight factor of each stock and its adequacy as a representation of stocks in a particular industry group, and may be changed from time to time. “S&P” and “S&P 500” are registered trademarks of Standard & Poor's Financial Services, LLC (“S&P”), a division of S&P Global, and have been licensed for use by the Portfolio. The Portfolio is not sponsored, endorsed, sold or marketed by S&P, and S&P makes no representation regarding the advisability of investing in the Portfolio. It is not possible to invest directly in the S&P 500.

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Index Futures Contracts and Related Options . The Portfolio may buy and sell futures contracts and options on those futures contracts. An “index futures” contract is a contract to buy or sell units of an index at an agreed price on a specified future date. Depending on the change in value of the Index between the time when the Portfolio enters into and closes out an index future or option transaction, the Portfolio realizes a gain or loss. Options and futures transactions involve risks. For example, it is possible that changes in the prices of futures contracts will not correlate precisely with changes in the value of the Index. In those cases, use of futures contracts and related options might decrease the correlation between the return of the Portfolio and the return of the Index. In addition, the Portfolio incurs transaction costs in entering into, and closing out, positions in futures contracts and related options. Funds that enter into contracts with counterparties run the risk that the counterparty will be unwilling or unable to make timely settlement payments or otherwise honor its obligations. This risk is typically less for exchange-traded derivatives, such as those the Portfolio may invest in.

These costs typically have the effect of reducing the correlation between the return of the Portfolio and the return of the Index. Because the secondary market for futures contracts and options may be illiquid, the Portfolio may have to hold a contract or option when the Adviser would otherwise have sold it, or it may only be able to sell at a price lower than what the Adviser believes is the fair value of the contract or option, thereby potentially reducing the return of the Portfolio.

Other Derivative Transactions . The Portfolio may enter into derivatives transactions involving options and swaps. These transactions involve many of the same risks as those described above under “Index Futures Contracts and Related Options.” In addition, since many of such transactions are conducted directly with counterparties, and not on an exchange or board of trade, the Portfolio's ability to realize any investment return on such transactions may depend on the counterparty's ability or willingness to meet its obligations.

Additional Index Information . The Index's components are reconstituted and rebalanced quarterly.

State Street Aggregate Bond Index Portfolio

Principal Investment Strategies

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The Portfolio expects typically to invest a significant portion of its assets in U.S. agency mortgage pass-through securities up to a total weight that is comparable to that of the Index. Most transactions in mortgage pass-through securities occur through standardized contracts for future delivery in which the exact mortgage pools to be delivered are not specified until a few days prior to settlement, referred to as a “to-be-announced transaction” or “TBA Transaction.” In a TBA Transaction, the buyer and seller agree upon general trade parameters such as agency, settlement date, par amount and price. The actual pools delivered generally are determined two days prior to the settlement date; however, it is not anticipated that the Portfolio will receive pools, but instead will participate in rolling TBA Transactions. The Portfolio expects to enter into such contracts on a regular basis.

Additional Index Information . The components of the Index are reconstituted and rebalanced monthly.

State Street Global Equity ex-U.S. Index Portfolio

Principal Investment Strategies

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nificant portion of the Index comprised companies in the financial sector, although this may change from time to time. As of February 28, 2019, a significant portion of the Index comprised companies located in Japan and the United Kingdom and a significant portion of the Index constituents are denominated in the Yen and the Great Britain Pound although this may change from time to time.

Under normal circumstances, the Portfolio generally invests substantially all, but at least 80%, of its net assets (plus borrowings, if any) in securities comprising the Index or in American Depositary Receipts (“ADRs”) or Global Depositary Receipts (“GDRs”) providing exposure to securities comprising the Index. The notional value of the Portfolio's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. The Portfolio will provide shareholders with at least sixty (60) days' notice prior to any change in this 80% investment policy. In addition, the Portfolio may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

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State Street Small/Mid Cap Equity Index Portfolio

Principal Investment Strategies

The Portfolio generally intends to invest in all stocks comprising the Index in approximate proportion to their weightings in the Index. However, under various circumstances, it may not be possible or practicable to purchase all stocks in those weightings. In those circumstances, the Portfolio may purchase a sample of the stocks in the Index in proportions expected by SSGA FM to match generally the performance of the Index as a whole. In addition, from time to time stocks are added to or removed from the Index. The Portfolio may sell securities that are represented in the Index, or purchase securities that are not yet represented in the Index, in anticipation of their removal from or addition to the Index. Under normal market conditions, the Portfolio invests at least 80% of its net assets (plus borrowings, if any) in stocks in the Index. The Portfolio will provide shareholders with at least sixty (60) days' notice prior to any change in this 80% investment policy. The notional value of the Portfolio's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. In addition, the Fund may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

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Additional Index Information . The Index's components are reconstituted annually and rebalanced monthly.

Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure.

Call/Prepayment Risk (principal risk for the Aggregate Bond Index Portfolio) . Call/prepayment risk is the risk that an issuer will exercise its right to pay principal on an obligation held by a Portfolio earlier than expected or required. This may occur, for example, when there is a decline in interest rates, and an issuer of bonds or preferred stock redeems the bonds or stock in order to replace them with obligations on which it is required to pay a lower interest or dividend rate. It may also occur when there is an unanticipated increase in the rate at which mortgages or other receivables underlying mortgage- or asset-backed securities held by a Portfolio are prepaid. In any such case, a Portfolio may be forced to invest the prepaid amounts in lower-yielding investments, resulting in a decline in the Portfolio's income.

Counterparty Risk . A Portfolio will be subject to credit risk with respect to the counterparties with which the Portfolio enters into derivatives contracts and other transactions such as repurchase agreements or reverse repurchase agreements. A Portfolio's ability to profit from these types of investments and transactions will depend on the willingness and ability of its counterparty to perform its obligations. If a counterparty fails to meet its contractual obligations, a Portfolio may be unable to terminate or realize any gain on the investment or transaction, resulting in a loss to the Portfolio. A Portfolio may experience significant delays in obtaining any recovery in an insolvency, bankruptcy, or other reorganization proceeding involving its counterparty (including recovery of any collateral posted by it) and may obtain only a limited recovery or may obtain no recovery in such circumstances. If a Portfolio holds collateral posted by its counterparty, it may be delayed or prevented from realizing on the collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty. Under applicable law or contractual provisions, including if a Portfolio enters into an investment or transaction with a financial institution and such financial institution (or an affiliate of the financial institution) experiences financial difficulties, then the Portfolio may in certain situations be prevented or delayed from exercising its rights to terminate the investment or transaction, or to realize on any collateral and may result in the suspension of payment and delivery obligations of the parties under such investment or transactions or in another institution being substituted for that financial institution without the consent of the Portfolio. Further, a Portfolio may be subject to “bail-in” risk under applicable law whereby, if required by the financial institution's authority, the financial institution's liabilities could be written down, eliminated or converted into equity or an alternative instrument of ownership. A bail-in of a financial institution may result in a reduction in value of some or all of its securities and, if a Portfolio holds such securities or has entered into a transaction with such a financial security when a bail-in occurs, such Portfolio may also be similarly impacted.

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Credit Risk (principal risk for the Aggregate Bond Index Portfolio) . Credit risk is the risk that an issuer, guarantor or liquidity provider of a fixed-income security held by a Portfolio may be unable or unwilling, or may be perceived (whether by market participants, ratings agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. It includes the risk that the security will be downgraded by a credit rating agency; generally, lower credit quality issuers present higher credit risks. An actual or perceived decline in creditworthiness of an issuer of a fixed-income security held by a Portfolio may result in a decrease in the value of the security. It is possible that the ability of an issuer to meet its obligations will decline substantially during the period when a Portfolio owns securities of the issuer or that the issuer will default on its obligations or that the obligations of the issuer will be limited or restructured.

The credit rating assigned to any particular investment does not necessarily reflect the issuer's current financial condition and does not reflect an assessment of an investment's volatility or liquidity. Securities rated in the lowest category of investment-grade are considered to have speculative characteristics. If a security held by a Portfolio loses its rating or its rating is downgraded, the Portfolio may nonetheless continue to hold the security in the discretion of the Adviser. In the case of asset-backed or mortgage-related securities, changes in the actual or perceived ability of the obligors on the underlying assets or mortgages to make payments of interest and/or principal may affect the values of those securities.

Currency Risk (principal risk for the Global Equity ex-U.S. Index Portfolio). Investments in issuers in different countries are often denominated in currencies other than the U.S. dollar. Changes in the values of those currencies relative to the U.S. dollar may have a positive or negative effect on the values of a Portfolio's investments denominated in those currencies. The values of other currencies relative to the U.S. dollar may fluctuate in response to, among other factors, interest rate changes, intervention (or failure to intervene) by national governments, central banks, or supranational entities such as the International Monetary Fund, the imposition of currency controls, and other political or regulatory developments. Currency values can decrease significantly both in the short term and over the long term in response to these and other developments. Continuing uncertainty as to the status of the Euro and the Economic and Monetary Union of the European Union (the “EMU”) has created significant volatility in currency and financial markets generally. Any partial or complete dissolution of the EMU, or any continued uncertainty as to its status, could have significant adverse effects on currency and financial markets, and on the values of a Portfolio's portfolio investments.

Debt Securities Risk (principal risk for the Aggregate Bond Index Portfolio) . The values of debt securities may increase or decrease as a result of the following: market fluctuations, increases in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments or illiquidity in debt securities markets; the risk of low rates of return due to reinvestment of securities during periods of falling interest rates or repayment by issuers with higher coupon or interest rates; and/or the risk of low income due to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of a Portfolio's fixed income securities to decrease, an adverse impact on the liquidity of a Portfolio's fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by a Portfolio may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

Depositary Receipts Risk (principal risk for the Global Equity ex-U.S. Index Portfolio) . American Depositary Receipts (“ADRs”) are typically trust receipts issued by a U.S. bank or trust company that evidence an indirect interest in underlying securities issued by a foreign entity. Global Depositary Receipts (“GDRs”), European Depositary Receipts (“EDRs”), and other types of depositary receipts are typically issued by non-U.S. banks or financial institutions to evidence an interest in underlying securities issued by either a U.S. or a non-U.S. entity. Investments in non-U.S. issuers through ADRs, GDRs, EDRs, and other types of depositary receipts generally involve risks applicable to other types of investments in non-U.S. issuers. Investments in depositary receipts may be less liquid and more volatile than the underlying securities in their primary trading market. If a depositary receipt is denominated in a different currency than its underlying securities, a Portfolio will be subject to the currency risk of both the investment in the depositary receipt and the underlying security. There may be less publicly available information regarding the issuer of the securities underlying a depositary receipt than if those securities were traded directly in U.S. securities markets. Depositary receipts may or may not be sponsored by the issuers of the underlying securities, and information regarding issuers of securities underlying unsponsored depositary receipts may be more limited than for sponsored depositary receipts. The values of depositary receipts may decline for a number of reasons relating to the issuers or sponsors of the depositary receipts, including, but not limited to, insolvency of the issuer or sponsor. Holders of depositary receipts may have limited or no rights to take action with respect to the underlying securities or to compel the issuer of the receipts to take action. The prices of depositary receipts may differ from the prices of securities upon which they are based. To the extent the Portfolio invests in depositary receipts based on securities included in the Index, such differences in prices may increase index tracking risk.

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Derivatives Risk. A derivative is a financial contract the value of which depends on, or is derived from, the value of an underlying asset, interest rate, or index. Derivative transactions typically involve leverage and may have significant volatility. It is possible that a derivative transaction will result in a loss greater than the principal amount invested, and a Portfolio may not be able to close out a derivative transaction at a favorable time or price. Risks associated with derivative instruments include potential changes in value in response to interest rate changes or other market developments or as a result of the counterparty's credit quality; the potential for the derivative transaction not to have the effect the Adviser anticipated or a different or less favorable effect than the Adviser anticipated; the failure of the counterparty to the derivative transaction to perform its obligations under the transaction or to settle a trade; possible mispricing or improper valuation of the derivative instrument; imperfect correlation in the value of a derivative with the asset, rate, or index underlying the derivative; the risk that a Portfolio may be required to post collateral or margin with its counterparty, and will not be able to recover the collateral or margin in the event of the counterparty's insolvency or bankruptcy; the risk that a Portfolio will experience losses on its derivatives investments and on its other portfolio investments, even when the derivatives investments may be intended in part or entirely to hedge those portfolio investments; the risks specific to the asset underlying the derivative instrument; lack of liquidity for the derivative instrument, including without limitation absence of a secondary trading market; the potential for reduced returns to a Portfolio due to losses on the transaction and an increase in volatility; the potential for the derivative transaction to have the effect of accelerating the recognition of gain; and legal risks arising from the documentation relating to the derivative transaction.

Emerging Markets Risk (principal risk for the Global Equity ex-U.S. Index Portfolio) . Investments in emerging markets are generally subject to a greater risk of loss than investments in developed markets. This may be due to, among other things, the possibility of greater market volatility, lower trading volume and liquidity, greater risk of expropriation, nationalization, and social, political and economic instability, greater reliance on a few industries, international trade or revenue from particular commodities, less developed accounting, legal and regulatory systems, higher levels of inflation, deflation or currency devaluation, greater risk of market shut down, and more significant governmental limitations on investment policy as compared to those typically found in a developed market. In addition, issuers (including governments) in emerging market countries may have less financial stability than in other countries. The securities of emerging market companies may trade less frequently and in smaller volumes than more widely held securities. Market disruptions or substantial market corrections may limit very significantly the liquidity of securities of certain companies in a particular country or geographic region, or of all companies in the country or region. A Portfolio may be unable to liquidate its positions in such securities at any time, or at a favorable price, in order to meet the Portfolio's obligations. There is also the potential for unfavorable action such as embargo and acts of war. As a result, there will tend to be an increased risk of price volatility in investments in emerging market countries, which may be magnified by currency fluctuations relative to the U.S. dollar. Settlement and asset custody practices for transactions in emerging markets may differ from those in developed markets. Such differences may include possible delays in settlement and certain settlement practices, such as delivery of securities prior to receipt of payment, which increase the likelihood of a “failed settlement.” Failed settlements can result in losses. For these and other reasons, investments in emerging markets are often considered speculative.

Equity Investing Risk (principal risk for the Equity 500 Index II Portfolio, Global Equity ex-U.S. Index Portfolio and Small/Mid Cap Equity Index Portfolio) . The market prices of equity securities owned by a Portfolio may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer, such as management performance, financial leverage, non-compliance with regulatory requirements, and reduced demand for the issuer's goods or services. The values of equity securities also may decline due to general industry or market conditions that are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates, or adverse investor sentiment generally. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Extension Risk (principal risk for the Aggregate Bond Index Portfolio). During periods of rising interest rates, the average life of certain types of securities may be extended because of slower-than-expected principal payments. This may increase the period of time during which an investment earns a below-market interest rate, increase the security's duration and reduce the value of the security. Extension risk may be heightened during periods of adverse economic conditions generally, as payment rates decline due to higher unemployment levels and other factors.

Financial Sector Risk (principal risk for the Global Equity ex-U.S. Index Portfolio and Small/Mid Cap Equity Index Portfolio). Financial services companies are subject to extensive governmental regulation which may limit both the amounts and types of loans and other financial commitments they can make, the interest rates and fees they can charge, the scope of their activities, the prices they can charge and the amount of capital they must maintain. Profitability is largely dependent on the availability and cost of capital funds and can fluctuate significantly when interest rates change or due to increased competition. In addition, deterioration of the credit markets generally may cause an adverse impact in a broad range of markets, including U.S. and international credit and interbank money markets generally, thereby affecting a wide range of financial institutions and markets. Certain events in the financial

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sector may cause an unusually high degree of volatility in the financial markets, both domestic and foreign, and cause certain financial services companies to incur large losses. Securities of financial services companies may experience a dramatic decline in value when such companies experience substantial declines in the valuations of their assets, take action to raise capital (such as the issuance of debt or equity securities), or cease operations. Credit losses resulting from financial difficulties of borrowers and financial losses associated with investment activities can negatively impact the sector. Insurance companies may be subject to severe price competition. Adverse economic, business or political developments could adversely affect financial institutions engaged in mortgage finance or other lending or investing activities directly or indirectly connected to the value of real estate.

Geographic Focus Risk (principal risk for the Global Equity ex-U.S. Index Portfolio) . The performance of a fund that is less diversified across countries or geographic regions will be closely tied to market, currency, economic, political, environmental, or regulatory conditions and developments in the countries or regions in which the fund invests, and may be more volatile than the performance of a more geographically-diversified fund.

Responses to the financial problems by European governments, central banks and others, including austerity measures and reforms, may not produce the desired results, may result in social unrest and may limit future growth and economic recovery or have other unintended consequences. Further defaults or restructurings by governments and other entities of their debt could have additional adverse effects on economies, financial markets and asset valuations around the world. In addition, one or more countries may abandon the euro and/or withdraw from the EU. For example, in June 2016, citizens of the United Kingdom voted in a referendum to leave the EU (known as “Brexit”), creating economic and political uncertainty in its wake and resulting in S&P downgrading the EU's credit rating from “AA+” to “AA” in the days following the vote. The country's referendum vote sparked depreciation in the value of the British pound, short-term declines in the stock markets and heightened risk of continued economic volatility worldwide. In March 2017, the United Kingdom formally notified the European Council of the United Kingdom's intention to withdraw from the EU pursuant to Article 50 of the Treaty on European Union. This formal notification began a two-year period of negotiations regarding the terms of the United Kingdom's exit from the EU. It is unclear how withdrawal negotiations will be conducted and what the potential consequences may be. Any exits from the EU, or the possibility of such exits, may have a significant impact on the United Kingdom, Europe, and global economies, which may result in increased volatility and illiquidity, new legal and regulatory uncertainties and potentially lower economic growth for such economies that could potentially have an adverse effect on the value of the Portfolio's investments. In addition, a number of countries in Europe have suffered terrorist attacks and additional attacks may occur in the future. Such attacks may cause uncertainty in financial markets and may adversely affect the performance of the issuers to which the Portfolio has exposure.

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Income Risk (principal risk for the Aggregate Bond Index Portfolio). A Portfolio's income may decline due to falling interest rates or other factors. Issuers of securities held by a Portfolio may call or redeem the securities during periods of falling interest rates, and the Portfolio would likely be required to reinvest in securities paying lower interest rates. If an obligation held by a Portfolio is prepaid, the Portfolio may have to reinvest the prepayment in other obligations paying income at lower rates. A reduction in the income earned by a Portfolio may limit the Portfolio's ability to achieve its objective.

Indexing Strategy/Index Tracking Risk . Each Portfolio is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities. Each Portfolio will seek to replicate Index returns, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. Each Portfolio generally will buy and will not sell a security included in the Index as long as the security is part of the Index regardless of any sudden or material decline in value or foreseeable material decline in value of the security, even though the Adviser may make a different investment decision for other actively managed accounts or portfolios that hold the security. As a result, a Portfolio's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index (in absolute terms and by comparison with other indices) and, consequently, the performance, volatility, and risk of a Portfolio. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), a Portfolio's return may not match the return of the Index for a number of reasons. For example, the return on the sample of securities purchased by a Portfolio (or the return on securities not included in the Index) to replicate the performance of the Index may not correlate precisely with the return of the Index. Each Portfolio incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, a Portfolio may not be fully invested at times, either as a result of cash flows into or out of the Portfolio or reserves of cash held by the Portfolio to meet redemptions. The Adviser may attempt to replicate the Index return by investing in fewer than all of the securities in the Index, or in some securities not included in the Index, potentially increasing the risk of divergence between a Portfolio's return and that of the Index. Changes in the composition of the Index and regulatory requirements also may impact a Portfolio's ability to match the return of the Index. The Adviser may apply one or more “screens” or investment techniques to refine or limit the number or types of issuers included in the Index in which a Portfolio may invest. Application of such screens or techniques may result in investment performance below that of the Index and may not produce results expected by the Adviser. Index tracking risk may be heightened during times of increased market volatility or other unusual market conditions.

Inflation Risk (principal risk for the Aggregate Bond Index Portfolio) . Inflation risk is the risk that the value of assets or income from investments will be less in the future as inflation decreases the value of money. As inflation increases, the values of a Portfolio's assets can decline.

Interest Rate Risk (principal risk for Aggregate Bond Index Portfolio) . Interest rate risk is the risk that the securities held by a Portfolio will decline in value because of increases in market interest rates. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. Debt securities with longer durations tend to be more sensitive to changes in interest rates, usually making them more volatile than debt securities with shorter durations. For example, the value of a security with a duration of five years would be expected to decrease by 5% for every 1% increase in interest rates. Falling interest rates also create the potential for a decline in a Portfolio's income and yield. Interest-only and principal-only securities are especially sensitive to interest rate changes, which can affect not only their prices but can also change the income flows and repayment assumptions about those investments. Variable and floating rate securities also generally increase or decrease in value in response to changes in interest rates, although generally to a lesser degree than fixed-rate securities. A substantial increase in interest rates may also have an adverse

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impact on the liquidity of a security, especially those with longer durations. Changes in governmental policy, including changes in central bank monetary policy, could cause interest rates to rise rapidly, or cause investors to expect a rapid rise in interest rates. This could lead to heightened levels of interest rate, volatility and liquidity risks for the fixed income markets generally and could have a substantial and immediate effect on the values of a Portfolio's investments.

Large-Capitalization Securities Risk (principal risk for the Equity 500 Index II Portfolio and Global Equity ex-U.S. Portfolio) . Securities issued by large-capitalization companies may present risks not present in smaller companies. For example, larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or other market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies, especially during strong economic periods. Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies.

Large Shareholder Risk . To the extent a large proportion of the shares of a Portfolio are highly concentrated or held by a small number of shareholders (or a single shareholder), including funds or accounts over which the Adviser has investment discretion, a Portfolio is subject to the risk that these shareholders will purchase or redeem Portfolio Shares in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of a Portfolio to conduct its investment program. For example, they could require a Portfolio to sell portfolio securities or purchase portfolio securities unexpectedly and incur substantial transaction costs and/or accelerate the realization of taxable income and/or gains to shareholders, or a Portfolio may be required to sell its more liquid portfolio investments to meet a large redemption, in which case a Portfolio's remaining assets may be less liquid, more volatile, and more difficult to price. A Portfolio may hold a relatively large proportion of its assets in cash in anticipation of large redemptions, diluting its investment returns.

Leveraging Risk . Borrowing transactions, reverse repurchase agreements, certain derivatives transactions, securities lending transactions and other investment transactions such as when-issued, delayed-delivery, or forward commitment transactions may create investment leverage. If a Portfolio engages in transactions that have a leveraging effect on the Portfolio's investment portfolio, the value of the Portfolio will be potentially more volatile and all other risks will tend to be compounded. This is because leverage generally creates investment risk with respect to a larger base of assets than a Portfolio would otherwise have and so magnifies the effect of any increase or decrease in the value of the Portfolio's underlying assets. The use of leverage is considered to be a speculative investment practice and may result in losses to a Portfolio. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. The use of leverage may cause a Portfolio to liquidate positions when it may not be advantageous to do so to satisfy repayment, interest payment, or margin obligations or to meet asset segregation or coverage requirements.

Liquidity Risk . Liquidity risk is the risk that a Portfolio may not be able to dispose of securities or close out derivatives transactions readily at a favorable time or prices (or at all) or at prices approximating those at which a Portfolio currently values them. For example, certain investments may be subject to restrictions on resale, may trade in the over-the-counter market or in limited volume, or may not have an active trading market. Illiquid securities may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value. It may be difficult for a Portfolio to value illiquid securities accurately. The market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. Disposal of illiquid securities may entail registration expenses and other transaction costs that are higher than those for liquid securities. A Portfolio may seek to borrow money to meet its obligations (including among other things redemption obligations) if it is unable to dispose of illiquid investments, resulting in borrowing expenses and possible leveraging of the Portfolio. In some cases, due to unanticipated levels of illiquidity a Portfolio may choose to meet its redemption obligations wholly or in part by distributions of assets in-kind.

The term “illiquid securities” for this purpose means securities that a Portfolio reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the securities. If any Portfolio determines at any time that it owns illiquid securities in excess of 15% of its net assets, it will cease to undertake new commitments to acquire illiquid securities until its holdings are no longer in excess of 15% of its NAV, report the occurrence in compliance with Rule 30b1-10 under the 1940 Act and, depending on circumstances, may take additional steps to reduce its holdings of illiquid securities.

In compliance with the SEC's new liquidity risk management rule applicable to open-end mutual funds, the Portfolios recently established a liquidity risk management program. The rule's impact on the Portfolios, and on the open-end fund industry in general, is not yet fully known, but the rule could affect a Portfolio's performance and its ability to achieve its investment objectives. While the liquidity risk management program attempts to assess and manage liquidity risk, there is no guarantee it will be effective in its operations and may not reduce the liquidity risk inherent in a Portfolio's investments.

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Market Disruption and Geopolitical Risk. A Portfolio is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets. War, terrorism, and related geopolitical events have led, and in the future may lead, to increased short-term market volatility and may have adverse long-term effects on U.S. and world economies and markets generally. Likewise, natural and environmental disasters and systemic market dislocations may be highly disruptive to economies and markets. Those events as well as other changes in foreign and domestic economic and political conditions also could adversely affect individual issuers or related groups of issuers, securities markets, interest rates, credit ratings, inflation, investor sentiment, and other factors affecting the value of a Portfolio's investments. Given the increasing interdependence among global economies and markets, conditions in one country, market, or region might adversely affect markets, issuers, and/or foreign exchange rates in other countries, including the U.S. Any partial or complete dissolution of the Economic and Monetary Union of the European Union, or any increased uncertainty as to its status, could have significant adverse effects on currency and financial markets, and on the values of a Portfolio's investments. Securities and financial markets may be susceptible to market manipulation or other fraudulent trade practices, which could disrupt the orderly functioning of these markets or adversely affect the values of investments traded in these markets, including investments held by a Portfolio. To the extent a Portfolio has focused its investments in the market or index of a particular region, adverse geopolitical and other events could have a disproportionate impact on the Portfolio.

Market Risk . Market prices of investments held by a Portfolio will go up or down, sometimes rapidly or unpredictably. A Portfolio's investments are subject to changes in general economic conditions, general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in actual or perceived creditworthiness of issuers and general market liquidity. Even if general economic conditions do not change, the value of an investment in a Portfolio could decline if the particular industries, sectors or companies in which the Portfolio invests do not perform well or are adversely affected by events. Further, legal, political, regulatory and tax changes also may cause fluctuations in markets and securities prices.

Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject a Portfolio to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and a Portfolio's investment program in particular can be uncertain. In recent periods, governmental and non-governmental issuers have defaulted on, or have been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including, without limitation, in Europe or Asia. Defaults or restructurings by governments or others of their debts could have substantial adverse effects on economies, financial markets, and asset valuations around the world. Further Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, or investor perception that these efforts are not succeeding, could negatively affect financial markets generally as well as the values and liquidity of certain securities.

Mortgage-Related and Other Asset-Backed Securities Risk (principal risk for the Aggregate Bond Index Portfolio) . Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed income investments. The liquidity of mortgage-related and asset-backed securities may change over time. Mortgage-related securities represent a participation in, or are secured by, mortgage loans. Other asset-backed securities are typically structured like mortgage-related securities, but instead of mortgage loans or interests in mortgage loans, the underlying assets may include, for example, items such as motor vehicle installment sales or installment loan contracts, leases on various types of real and personal property, and receivables from credit card agreements. During periods of falling interest rates, mortgage-related and other asset-backed securities, which typically provide the issuer with the right to prepay the security prior to maturity, may be prepaid, which may result in a Portfolio having to reinvest the proceeds in other investments at lower interest rates. During periods of rising interest rates, the average life of mortgage-related and other asset-backed securities may extend because of slower-than expected principal payments. This may lock in a below market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. As a result, mortgage-related and other asset-backed securities may have less potential for capital appreciation during periods of declining interest rates than other debt securities of comparable maturities, although they may have a similar risk of decline in market values during periods of rising interest rates. Prepayment rates are difficult to predict and the potential impact of prepayments on the value of a mortgage-related or other asset-backed security depends on the terms of the instrument and can result in significant volatility. The price of a mortgage-related or other asset-backed security also depends on the credit quality and adequacy of the underlying assets or collateral. Mortgage-related or other asset-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) will generally entail greater credit risk than obligations guaranteed by the U.S. Government. Defaults on the underlying assets, if any, may impair the value of a mortgage-related or other asset-backed security. For

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some asset-backed securities in which a Portfolio invests, such as those backed by credit card receivables, the underlying cash flows may not be supported by a security interest in a related asset. Moreover, the values of mortgage-related and other asset-backed securities may be substantially dependent on the servicing of the underlying asset pools, and are therefore subject to risks associated with the negligence or malfeasance by their servicers and to the credit risk of their servicers. In certain situations, the mishandling of related documentation may also affect the rights of securities holders in and to the underlying collateral. There may be legal and practical limitations on the enforceability of any security interest granted with respect to underlying assets, or the value of the underlying assets, if any, may be insufficient if the issuer defaults.

In a “forward roll” transaction, a Portfolio will sell a mortgage-related security to a bank or other permitted entity and simultaneously agree to purchase a similar security from the institution at a later date at an agreed upon price. The mortgage securities that are purchased will bear the same interest rate as those sold, but generally will be collateralized by different pools of mortgages with different prepayment histories than those sold. The values of such transactions will be affected by many of the same factors that affect the values of mortgage-related securities generally. In addition, forward roll transactions may have the effect of creating investment leverage in a Portfolio.

Non-U.S. Securities Risk (principal risk for the Global Equity ex-U.S. Index Portfolio) . Investments in securities of non-U.S. issuers (including depositary receipts) entail risks not typically associated with investing in securities of U.S. issuers. Similar risks may apply to securities traded on a U.S. securities exchange that are issued by entities with significant exposure to non-U.S. countries. In certain countries, legal remedies available to investors may be more limited than those available with regard to U.S. investments. Because non-U.S. securities are typically denominated and traded in currencies other than the U.S. dollar, the value of the Portfolio's assets, to the extent they are non-U.S. dollar denominated, may be affected favorably or unfavorably by currency exchange rates, exchange control regulations, and restrictions or prohibitions on the repatriation of non-U.S. currencies. Income and gains with respect to investments in certain countries may be subject to withholding and other taxes. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, and financial reporting standards, regulatory framework and practices comparable to those in the United States. The securities of some non-U.S. entities are less liquid and at times more volatile than securities of comparable U.S. entities, and could become subject to sanctions or embargoes that adversely affect a Portfolio's investment. Non-U.S. transaction costs, such as brokerage commissions and custody costs may be higher than in the U.S. In addition, there may be a possibility of nationalization or expropriation of assets, imposition of currency exchange controls, confiscatory taxation, and diplomatic developments that could adversely affect the values of a Portfolio's investments in certain non-U.S. countries. Investments in securities of non-U.S. issuers also are subject to foreign political and economic risk not associated with U.S. investments, meaning that political events (civil unrest, national elections, changes in political conditions and foreign relations, imposition of exchange controls and repatriation restrictions), social and economic events (labor strikes, rising inflation) and natural disasters occurring in a country where a Portfolio invests could cause the Portfolio's investments in that country to experience gains or losses.

Reinvestment Risk (principal risk for the Aggregate Bond Index Portfolio). Income from a Portfolio may decline when the Portfolio invests the proceeds from investment income, sales of portfolio securities or matured, traded or called debt obligations. For instance, during periods of declining interest rates, an issuer of debt obligations may exercise an option to redeem securities prior to maturity, forcing a Portfolio to reinvest the proceeds in lower-yielding securities. A decline in income received by a Portfolio from its investments is likely to have a negative effect on the yield and total return of the Portfolio Shares.

Risk of Investment in Other Pools . If a Portfolio invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected. A Portfolio is exposed indirectly to all of the risks applicable to an investment in such other pool. In addition, lack of liquidity in the underlying pool could result in its value being more volatile than the underlying portfolio of securities, and may limit the ability of a Portfolio to sell or redeem its interest in the pool at a time or at a price it might consider desirable. The investment policies and limitations of the other pool may not be the same as those of the Portfolio; as a result, the Portfolio may be subject to additional or different risks, or may achieve a reduced investment return, as a result of its investment in another pool. If a pool is an exchange-traded fund or other product traded on a securities exchange or otherwise actively traded, its shares may trade at a premium or discount to their NAV, an effect that might be more pronounced in less liquid markets. A Portfolio bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Portfolio may invest, leading to potential conflicts of interest. For example, the Adviser or its affiliates may receive fees based on the amount of assets invested in the pool. Investment by a Portfolio in the pool may be beneficial to the Adviser or an affiliate in the management of the pool, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest a Portfolio's assets in a pool sponsored or managed by the Adviser or its affiliates in lieu of investments by the Portfolio directly in portfolio securities, or may have an incentive to invest in the pool over

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a pool sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by a Portfolio in a pool sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Portfolio does so.

Settlement Risk (principal risk for the Global Equity ex-U.S. Index Portfolio) . Markets in different countries have different clearance and settlement procedures and in certain markets there have been times when settlements have been unable to keep pace with the volume of transactions. Delays in settlement may increase credit risk to a Portfolio, limit the ability of a Portfolio to reinvest the proceeds of a sale of securities, hinder the ability of a Portfolio to lend its portfolio securities, and potentially subject a Portfolio to penalties for its failure to deliver to on-purchasers of securities whose delivery to a Portfolio was delayed. Delays in the settlement of securities purchased by a Portfolio may limit the ability of a Portfolio to sell those securities at times and prices it considers desirable, and may subject a Portfolio to losses and costs due to its own inability to settle with subsequent purchasers of the securities from it. A Portfolio may be required to borrow monies it had otherwise expected to receive in connection with the settlement of securities sold by it, in order to meet its obligations to others. Limits on the ability of a Portfolio to purchase or sell securities due to settlement delays could increase any variance between a Portfolio's performance and that of its benchmark index.

Small-, Mid- and Micro-Capitalization Securities Risk (principal risk for the Global Equity ex-U.S. Index Portfolio and Small/Mid Cap Equity Index Portfolio) . The securities of small-, mid- and micro-capitalization companies may be more volatile and may involve more risk than the securities of larger companies. These companies may have limited product lines, markets or financial resources, may lack the competitive strength of larger companies, and may depend on a few key employees. In addition, these companies may have been recently organized and may have little or no track record of success. The securities of smaller companies may trade less frequently and in smaller volumes than more widely held securities. The prices of these securities may fluctuate more sharply than those of other securities, and a Portfolio may experience some difficulty in establishing or closing out positions in these securities at prevailing market prices. There may be less publicly available information about the issuers of these securities or less market interest in these securities than in the case of larger companies, both of which can cause significant price volatility. Some securities of smaller issuers may be illiquid or may be restricted as to resale. A Portfolio may be unable to liquidate its positions in such securities at any time, or at a favorable price, in order to meet a Portfolio's obligations. Returns on investments in securities of small-, mid- and micro-capitalization companies could trail the returns on investments in securities of larger companies.

Special Risk Considerations of Investing in China (principal risk for the Global Equity ex-U.S. Index Portfolio) . Investing in securities of Chinese issuers, including by investing in A Shares, involves certain risks and considerations not typically associated with investing in securities of U.S. issuers, including, among others, (i) more frequent (and potentially widespread) trading suspensions and government interventions with respect to Chinese issuers, resulting in a lack of liquidity and in price volatility, (ii) currency revaluations and other currency exchange rate fluctuations or blockage, (iii) the nature and extent of intervention by the Chinese government in the Chinese securities markets, whether such intervention will continue and the impact of such intervention or its discontinuation, (iv) the risk of nationalization or expropriation of assets, (v) the risk that the Chinese government may decide not to continue to support economic reform programs, (vi) limitations on the use of brokers, (vii) potentially higher rates of inflation, (viii) the unavailability of consistently-reliable economic data, (ix) the relatively small size and absence of operating history of many Chinese companies, (x) accounting, auditing and financial reporting standards in China are different from U.S. standards and, therefore, disclosure of certain material information may not be available, (xi) greater political, economic, social, legal and tax-related uncertainty, (xii) higher market volatility caused by any potential regional territorial conflicts or natural disasters, (xiii) higher dependence on exports and international trade, (xiv) the risk of increased trade tariffs, embargoes and other trade limitations, (xv) restrictions on foreign ownership, and (xvi) custody risks associated with investing through programs to access Chinese securities. Significant portions of the Chinese securities markets may become rapidly illiquid, as Chinese issuers have the ability to suspend the trading of their equity securities, and have shown a willingness to exercise that option in response to market volatility and other events. The liquidity of Chinese securities may shrink or disappear suddenly and without warning as a result of adverse economic, market or political events, or adverse investor perceptions, whether or not accurate.

Technology Sector Risk (principal risk for the Equity 500 Index II Portfolio and Small/Mid Cap Equity Index Portfolio). Market or economic factors impacting technology companies and companies that rely heavily on technological advances could have a major effect on the value of the Portfolio's investments. The value of stocks of technology companies and companies that rely heavily on technology is particularly vulnerable to rapid changes in technology product cycles, rapid product obsolescence, government regulation and competition, both domestically and internationally, including competition from foreign competitors with lower production costs. Stocks of technology companies and companies that rely heavily on technology, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market. Technology companies are heavily dependent on patent and intellectual property rights, the loss or impairment of which may adversely affect profitability. Additionally, companies in the technology sector may face dramatic and often unpredictable changes in growth rates and competition for the services of qualified personnel.

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Unconstrained Sector Risk . A Portfolio may invest a substantial portion of its assets within one or more economic sectors or industries, which may change from time to time. When a Portfolio focuses its investments in a particular industry or sector, financial, economic, business, and other developments affecting issuers in that industry, market, or economic sector will have a greater effect on the Portfolio than if it had not focused its assets in that industry, market, or economic sector, which may increase the volatility of the Portfolio. Any such investment focus may also limit the liquidity of the Portfolio. In addition, investors may buy or sell substantial amounts of the Portfolio's shares in response to factors affecting or expected to affect an industry, market, or economic sector in which the Portfolio focuses its investments, resulting in extreme inflows or outflows of cash into and out of the Portfolio. Such extreme cash inflows and outflows might affect the management of the Portfolio adversely.

U.S. Government Securities Risk (principal risk for the Aggregate Bond Index Portfolio) . U.S. government securities, such as Treasury bills, notes and bonds and mortgage-backed securities guaranteed by the Government National Mortgage Association (“Ginnie Mae”), are supported by the full faith and credit of the United States; others are supported by the right of the issuer to borrow from the U.S. Treasury; others are supported by the discretionary authority of the U.S. government to purchase the agency's obligations; and still others are supported only by the credit of the issuing agency, instrumentality, or enterprise. Although U.S. government-sponsored enterprises such as the Federal Home Loan Mortgage Corporation (“Freddie Mac”) and the Federal National Mortgage Association (“Fannie Mae”) may be chartered or sponsored by Congress, they are not funded by Congressional appropriations, and their securities are not issued by the U.S. Treasury nor supported by the full faith and credit of the U.S. government. There is no assurance that the U.S. government would provide financial support to its agencies and instrumentalities if not required to do so. In addition, certain governmental entities have been subject to regulatory scrutiny regarding their accounting policies and practices and other concerns that may result in legislation, changes in regulatory oversight and/or other consequences that could adversely affect the credit quality, availability, or investment character of securities issued by these entities. The value and liquidity of U.S. government securities may be affected adversely by changes in the ratings of those securities. Securities issued by the U.S. Treasury historically have been considered to present minimal credit risk. The downgrade in the long-term U.S. credit rating by at least one major rating agency has introduced greater uncertainty about the ability of the U.S. to repay its obligations. A further credit rating downgrade or a U.S. credit default could decrease the value and increase the volatility of a Portfolio's investments.

Valuation Risk (principal risk for the Global Equity ex-U.S. Index Portfolio, Small/Mid Cap Equity Index Portfolio and Aggregate Bond Index Portfolio) . Some portfolio holdings, potentially a large portion of a Portfolio's investment portfolio, may be valued on the basis of factors other than market quotations. This may occur more often in times of market turmoil or reduced liquidity. There are multiple methods that can be used to value a portfolio holding when market quotations are not readily available. The value established for any portfolio holding at a point in time might differ from what would be produced using a different methodology or if it had been priced using market quotations. Portfolio holdings that are valued using techniques other than market quotations, including “fair valued” securities, may be subject to greater fluctuation in their valuations from one day to the next than if market quotations were used. Technological issues or other service disruption issues involving third-party service providers may cause a Portfolio to value its investments incorrectly. In addition, there is no assurance that a Portfolio could sell or close out a portfolio position for the value established for it at any time, and it is possible that a Portfolio would incur a loss because a portfolio position is sold or closed out at a discount to the valuation established by a Portfolio at that time. Investors who purchase or redeem Portfolio Shares on days when a Portfolio is holding fair-valued investments may receive fewer or more shares or lower or higher redemption proceeds than they would have received if a Portfolio had not fair-valued the holding(s) or had used a different valuation methodology.

When-Issued, TBA and Delayed Delivery Securities Risk (principal risk for the Aggregate Bond Index Portfolio). A Portfolio may purchase securities on a when-issued, TBA or delayed delivery basis and may purchase securities on a forward commitment basis. The purchase price of the securities is typically fixed at the time of the commitment, but delivery and payment can take place a month or more after the date of the commitment. The prices of the securities so purchased or sold are subject to market fluctuations. At the time of delivery of the securities, the value may be more or less than the purchase or sale price. Purchase of securities on a when-issued, TBA, delayed delivery, or forward commitment basis may give rise to investment leverage, and may result in increased volatility of a Portfolio's net asset value. Default by, or bankruptcy of, a counterparty to a when-issued, TBA or delayed delivery transaction would expose a Portfolio to possible losses because of an adverse market action, expenses or delays in connection with the purchase or sale of the pools specified in such transaction. Recently finalized rules of the Financial Industry Regulatory Authority, Inc. would impose mandatory margin requirements for certain types of when-issued, TBA delayed delivery or forward commitment transactions, with limited exceptions. Such transactions historically have not been required to be collateralized, and, if those rules are implemented, mandatory collateralization could increase the cost of such transactions and impose added operational complexity.

Additional Information About Non-Principal Investment Strategies and Risks

Conflicts of Interest Risk. An investment in a Portfolio will be subject to a number of actual or potential conflicts of interest. For example, the Adviser or its affiliates may provide services to a Portfolio, such as securities lending agency services, custodial, admin-

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istrative, bookkeeping, and accounting services, transfer agency and shareholder servicing, securities brokerage services, and other services for which the Portfolio would compensate the Adviser and/or such affiliates. The Portfolios may invest in other pooled investment vehicles sponsored, managed, or otherwise affiliated with the Adviser. There is no assurance that the rates at which a Portfolio pays fees or expenses to the Adviser or its affiliates, or the terms on which it enters into transactions with the Adviser or its affiliates will be the most favorable available in the market generally or as favorable as the rates the Adviser makes available to other clients. Because of its financial interest, the Adviser will have an incentive to enter into transactions or arrangements on behalf of a Portfolio with itself or its affiliates in circumstances where it might not have done so in the absence of that interest, provided that the Adviser will comply with applicable regulatory requirements.

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Portfolios. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for a Portfolio and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by a Portfolio. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Portfolios) or otherwise using such information for the benefit of its clients or itself.

The foregoing does not purport to be a comprehensive list or complete explanation of all potential conflicts of interests which may affect a Portfolio. A Portfolio may encounter circumstances, or enter into transactions, in which conflicts of interest that are not listed or discussed above may arise.

Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Portfolios) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, a Portfolio, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect a Portfolio or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect a Portfolio's ability to calculate its NAV, cause the release of private shareholder information or confidential Portfolio information, impede trading, cause reputational damage, and subject a Portfolio to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Portfolio assets and transactions, shareholder ownership of Portfolio Shares, and other data integral to the functioning of a Portfolio inaccessible or inaccurate or incomplete. A Portfolio may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. A Portfolio and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. Each Portfolio relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Portfolio from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Portfolios. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which each Portfolio invests, which could result in material adverse consequences for such issuers, and may cause a Portfolio's investment in such securities to lose value.

Index Construction Risk . A security included in an Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Portfolio's holdings may not exhibit returns consistent with that characteristic or exposure.

Index Licensing Risk . It is possible that the license under which the Adviser or a Portfolio is permitted to replicate or otherwise use an Index will be terminated or may be disputed, impaired or cease to remain in effect. In such a case, the Adviser may be required to replace the Index with another index which it considers to be appropriate in light of the investment strategy of a Portfolio. The use of any such substitute index may have an adverse impact on a Portfolio's performance. In the event that the Adviser is unable to identify a suitable replacement for the Index, it may determine to terminate a Portfolio.

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Portfolio Turnover Risk (principal risk for the Aggregate Bond Index Portfolio) . A Portfolio may engage in frequent trading of its portfolio securities. Portfolio turnover generally involves a number of direct and indirect costs and expenses to a Portfolio, including, for example, brokerage commissions, dealer mark-ups and bid/asked spreads, and transaction costs on the sale of securities and reinvestment in other securities. The costs related to increased portfolio turnover have the effect of reducing a Portfolio's investment return, and the sale of securities by a Portfolio may result in the realization of taxable capital gains, including short-term capital gains, which are taxed to individuals as ordinary income.

Securities Lending Risk . Each Portfolio may lend portfolio securities in an amount not to exceed 40% of the value of its net assets. For these purposes, net assets shall exclude the value of all assets received as collateral for the loan. Such loans may be terminated at any time. Any such loans must be continuously secured by collateral maintained on a current basis in an amount at least equal to the market value of the securities loaned by a Portfolio, marked to market each trading day. In a loan transaction, as compensation for lending its securities, a Portfolio will receive a portion of the dividends or interest accrued on the securities held as collateral or, in the case of cash collateral, a portion of the income from the investment of such cash. In addition, a Portfolio will receive the amount of all dividends, interest and other distributions on the loaned securities. However, the borrower has the right to vote the loaned securities. A Portfolio will call loans to vote proxies if a material issue affecting the investment is to be voted upon. Efforts to recall such securities promptly may be unsuccessful, especially for foreign securities or thinly traded securities, and may involve expenses to a Portfolio. Securities lending involves the risk that the Portfolio may lose money because the borrower of the loaned securities fails to return the securities in a timely manner or at all. Should the borrower of the securities fail financially, a Portfolio may experience delays in recovering the securities or exercising its rights in the collateral. Loans are made only to borrowers that are deemed by the securities lending agent to be of good financial standing. In a loan transaction, a Portfolio will also bear the risk of any decline in value of securities acquired with cash collateral. Each Portfolio expects to invest cash collateral in a pooled investment vehicle advised by the Adviser. With respect to index funds, to the extent the collateral provided or investments made with cash collateral differ from securities included in the relevant Index, such collateral or investments may have a greater risk of loss than the securities included in the Index. In addition, a Portfolio will be subject to the risk that any income generated by reinvesting cash collateral is lower than any fees the Portfolio has agreed to pay a borrower.

Portfolio Holdings Disclosure

The Portfolios' portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

Each Portfolio is a separate, diversified series of the State Street Institutional Investment Trust (the “Trust”), which is an open-end management investment company organized as a business trust under the laws of The Commonwealth of Massachusetts.

Investment Adviser

SSGA FM serves as the investment adviser to each Portfolio and, subject to the oversight of the Board, is responsible for the investment management of each Portfolio. The Adviser provides an investment management program for each Portfolio and manages the investment of each Portfolio's assets. The Adviser is a wholly-owned subsidiary of State Street Global Advisors, Inc., which itself is a wholly-owned subsidiary of State Street Corporation. The Adviser is registered with the U.S. Securities and Exchange Commission (“SEC”) under the Investment Advisers Act of 1940, as amended. The Adviser and certain other affiliates of State Street Corporation make up SSGA. SSGA is one of the world's largest institutional money managers and the investment management arm of State Street Corporation. As of December 31, 2018, the Adviser managed approximately $452.10 billion in assets and SSGA managed approximately $2.51 trillion in assets. The Adviser's principal business address is One Iron Street, Boston, Massachusetts 02210.

The Portfolios' shares are offered exclusively to other investors (including without limitation, registered investment companies, private investment pools, bank collective funds, and investment separate accounts) that pay fees to SSGA FM or its affiliates. The Portfolios pay no investment advisory fees to SSGA FM. The fees paid by those investment vehicles to SSGA FM (or its affiliates) vary depending on a number of factors, including by way of example, the services provided, the risks borne by SSGA FM (or its affiliates), fee rates paid by competitive investment vehicles, and in some cases direct negotiation with investors.

Total Annual Fund Operating Expense Waiver . SSGA FM, as the investment adviser to each of the Small/Mid Cap Equity Index Portfolio and the Global Equity ex-U.S. Index Portfolio, is contractually obligated, through April 30, 2020, (i) to waive up to the full amount of the advisory fee payable by the Portfolio, and/or (ii) to reimburse the Portfolio for expenses to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, extraordinary expenses, acquired fund fees and Distribution, Shareholder Servicing and Sub-Transfer Agency Fees) exceed average daily net assets on an annual basis of 0.08% for the Global Equity ex-U.S. Index Portfolio and 0.03% for the Small/Mid Cap Equity Index Portfolio. These waiver and/or reimbursement arrangements may not be terminated prior to April 30, 2020 except with approval of the Portfolios' Board of Trustees. SSGA FM, as the investment adviser to the Equity 500 Index II Portfolio and the Aggregate Bond Index Portfolio, is contractually obligated, through April 30, 2020, (i) to waive up to the full amount of the advisory fee payable by the Portfolio and/or (ii) to reimburse the Portfolio to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, any class-specific expenses such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed average daily net assets on an annual basis of 0.02% for the Equity 500 Index II Portfolio and 0.025% for Aggregate Bond Index Portfolio.

A discussion regarding the Board's consideration of the Portfolio's Investment Advisory Agreement for each of the Aggregate Bond Index Portfolio, the Equity 500 Index II Portfolio, the Global Equity ex-U.S. Index Portfolio and the Small/Mid Cap Equity Index Portfolio is provided in the Trust's Semi-Annual Report to Shareholders for the period ended June 30, 2018.

Portfolio Management

The Adviser manages the Portfolios using a team of investment professionals. The team approach is used to create an environment that encourages the flow of investment ideas. The portfolio managers within the team work together in a cohesive manner to develop and enhance techniques that drive the investment process for the respective investment strategy. This approach requires portfolio managers to share a variety of responsibilities including investment strategy and analysis while retaining responsibility for the implementation of the strategy within any particular portfolio. The approach also enables the team to draw upon the resources of other groups within SSGA. Each portfolio management team is overseen by the SSGA Investment Committee.

The table below identifies the professionals primarily responsible for the day-to-day management of each Portfolio:

Portfolio Managers		Portfolios
Michael Feehily, Karl Schneider and Amy Scofield		Equity 500 Index II Portfolio
Marc DiCosimo and Joanna Madden		Aggregate Bond Index Portfolio
Michael Feehily, Olga Winner and Karl Schneider		Global Equity ex-U.S. Index Portfolio
Michael Feehily, Ted Janowsky and Karl Schneider		Small/Mid Cap Equity Index Portfolio

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Additional information about the portfolio managers' compensation, other accounts managed by the portfolio managers, and the portfolio managers' ownership of the Portfolios is available in the SAI.

Other Fund Services

The Administrator, Sub-Administrator, Custodian, Transfer Agent and Dividend Disbursing Agent

The Adviser serves as administrator of each Portfolio. State Street, a subsidiary of State Street Corporation, serves as sub-administrator, custodian, transfer agent and dividend disbursing agent (the “Transfer Agent”) for each Portfolio. Each Portfolio pays an annual fee that is accrued daily and payable monthly for the administration, sub-administration, custody and transfer agency services SSGA FM and State Street provide.

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Portfolios' distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

Additional Information

The Trustees of the Trust oversee generally the operations of the Portfolios and the Trust. The Trust enters into contractual arrangements with various parties, including among others the Portfolios' investment adviser, custodian, transfer agent, and accountants, who provide services to the Portfolios. Shareholders are not parties to any such contractual arrangements or intended beneficiaries of those contractual arrangements, and those contractual arrangements are not intended to create in any shareholder any right to enforce them directly against the service providers or to seek any remedy under them directly against the service providers.

This Prospectus provides information concerning the Trust and the Portfolios that you should consider in determining whether to purchase shares of the Portfolios. Neither this Prospectus, nor the related SAI, is intended, or should be read, to be or to give rise to an agreement or contract between the Trust or the Portfolios and any investor, or to give rise to any rights in any shareholder or other person other than any rights under federal or state law that may not be waived.

Shareholder Information

Determination of Net Asset Value

Each Portfolio determines its net asset value (“NAV”) per share once each business day as of the scheduled close of regular trading on the New York Stock Exchange (the “NYSE”). Pricing does not occur on NYSE holidays. A business day is one on which the NYSE is open for regular trading. The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. In unusual circumstances, such as an emergency or an unscheduled close or halt of trading on the NYSE, the time at which share prices are determined may be changed. The NAV per share is based on the market value of the investments held in a Portfolio. The NAV of each class of a Portfolio's Shares is calculated by dividing the value of the assets of the Portfolio attributable to that class less the liabilities of the Portfolio attributable to that class by the number of shares in the class outstanding. As noted in this Prospectus, each Portfolio may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when each Portfolio does not price its shares. Consequently, the NAV of each Portfolio's shares may change on days when shareholders are not able to purchase or redeem the Portfolio's shares. Purchase and redemption orders for Portfolio Shares are processed, respectively, at the NAV next determined after the Portfolio accepts a purchase order or receives a redemption request in good form . Each Portfolio values each security or other investment pursuant to guidelines adopted by the Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Portfolios' Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii) a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by a Portfolio occurs after the close of a related exchange but before the determination of a Portfolio's NAV. Attempts to determine the fair value of securities or other investments introduce an element of

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subjectivity to the pricing of securities or other investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the price a Portfolio would have received had it sold the investment. To the extent that a Portfolio invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the funds. The prospectuses of these funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

Purchasing Shares

Generally, shares of a Portfolio may be purchased only by or on behalf of other registered investment companies or private clients for which the Adviser or an affiliate serves as investment adviser (or in a similar capacity). The price for Portfolio Shares is the NAV per share. Orders received in good form (a purchase order is in good form if it meets the requirements implemented from time to time by a Portfolio or its Transfer Agent, and for new accounts includes submission of a completed and signed application and all documentation necessary to open an account) will be priced at the NAV next calculated after the order is accepted by the Portfolios.

There is no minimal initial investment in a Portfolio and there is no minimum subsequent investment. (If you purchase shares by check, your order will not be in good form until the Portfolio's transfer agent receives federal funds for the check.) The Portfolios reserve the right to cease accepting investments at any time or to reject any purchase order.

In accordance with certain federal regulations, the Trust is required to obtain, verify and record information that identifies each entity that applies to open an account. For this reason, when you open (or change ownership of) an account, the Trust will request certain information, including your name, residential/business address, date of birth (for individuals) and taxpayer identification number or other government identification number and other information that will allow us to identify you which will be used to verify your identity. The Trust may also request to review other identification documents such as driver license, passport or documents showing the existence of the business entity. If you do not provide sufficient information to verify your identity, the Trust will not open an account for you. As required by law, the Trust may employ various procedures, such as comparing your information to fraud databases or requesting additional information and documentation from you, to ensure that the information supplied by you is correct. The Trust reserves the right to reject any purchase order for any reason, including failure to provide the Trust with information necessary to confirm your identity as required by law.

If you are purchasing through a Financial Intermediary, please contact your intermediary as their requirements may differ.

Redeeming Shares

An investor may redeem all or any portion of its investment at the NAV next determined after it submits a redemption request, in proper form, to a Portfolio. A Portfolio will typically pay the proceeds of the redemption on the next business day after the redemption, but in any event no more than seven days after the redemption. A Portfolio may delay paying redemption proceeds if the request is made within 15 days of the purchase of such Portfolio Shares and the payment or customer verification process is not complete. There will be no such delay for redemptions following purchases paid by federal funds wire or by bank cashier's check, certified check or treasurer's check. The right of any investor to receive payment with respect to any redemption may be suspended or the payment of the redemption proceeds postponed beyond seven days during any period in which the NYSE is closed (other than weekends or holidays) or trading on the NYSE is restricted or, to the extent otherwise permitted by the 1940 Act, as amended, if an emergency exists as a result of which disposal by a Portfolio of securities owned by it is not reasonably practicable or it is not reasonably practicable for a Portfolio fairly to determine the value of its net assets. In addition, the SEC may by order permit suspension of redemptions for the protection of investors of the Portfolios.

Under normal circumstances, each Portfolio expects to meet redemption requests by using cash or cash equivalents in its portfolio and/or selling portfolio assets to generate cash. The Portfolios also may pay redemption proceeds using cash obtained through borrowing arrangements (including under the Portfolios' line of credit, which is shared across all registered funds advised by SSGA FM (other than money market funds)) that may be available from time to time.

A Portfolio may pay all or a portion of your redemption proceeds by giving you securities (for example, if the Portfolio reasonably believes that a cash redemption may have a substantial impact on the Portfolio and its remaining shareholders). You may pay transaction costs to dispose of the securities, and you may receive less for them than the price at which they were valued for purposes of the redemption. In addition, you will be subject to the market risks associated with such securities until such time as you choose to dispose of the security.

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During periods of deteriorating or stressed market conditions, when an increased portion of a Portfolio's portfolio may be comprised of less liquid investments, or during extraordinary or emergency circumstances, a Portfolio may be more likely to pay redemption proceeds with cash obtained through short-term borrowing arrangements (if available) or by giving you securities.

If your account is held through an Intermediary, please contact them for additional assistance and advice on how to redeem your shares.

About Mail Transactions

If you choose to purchase or redeem shares by sending instructions by regular mail, they will not be deemed received in good order until they are released by the post office and redelivered to the Transfer Agent's physical location at 430 W 7th Street Suite 219737 in Kansas City, MO 64105-1407. There will be a time lag, which may be one or more days, between regular mail receipt at the post office box and redelivery to such physical location and a Portfolio's net asset value may change over those days. You might consider using express rather than regular mail if you believe time of receipt of your transaction request to be sensitive.

Policies to Prevent Market Timing

Frequent purchases and redemptions of Portfolio Shares may present risks for other shareholders of the Portfolios, which may include, among other things, interference in the efficient management of a Portfolio's portfolio, dilution in the value of Portfolio Shares held by long-term shareholders, increased brokerage and administrative costs and forcing the Portfolios to hold excess levels of cash.

Therefore, the Trust's Board of Trustees has adopted policies and procedures designed to detect and prevent inappropriate short-term trading activity that is harmful to the Portfolios. Because most of the interests in the Portfolios are held by investors indirectly through one or more financial intermediaries, the Portfolios do not generally have information about the identity of those investors or about transactions effected by those investors. Rather, the Portfolios and their service providers periodically review cash inflows and outflows from and to those intermediaries in an attempt to detect inappropriate trading activity by investors holding shares through those intermediaries. The Portfolios may seek to obtain underlying account trading activity information from financial intermediaries when, in the Adviser's judgment, the trading activity suggests possible market timing. There is no assurance that the Portfolios or the Adviser will be able to determine whether trading by an investor holding shares through a financial intermediary is engaged in trading activity that may be harmful to the Portfolios or their shareholders.

The Portfolios reserve the right in their discretion to reject any purchase, in whole or in part including, without limitation, by a person whose trading activity in Portfolio Shares the Adviser believes could be harmful to the Portfolios. The Portfolios may decide to restrict purchase activity in their shares based on various factors, including, without limitation, whether frequent purchase and sale activity will disrupt portfolio management strategies and adversely affect performance. There can be no assurance that the Portfolios, the Adviser or State Street will identify all frequent purchase and sale activity affecting the Portfolios.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a Portfolio identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to a Portfolio (if you hold shares directly with a Portfolio) or to your financial intermediary (if you do not hold shares directly with a Portfolio).

Dividends, Distributions and Tax Considerations

Income and capital gains dividends of the Portfolios will be declared and paid at least annually. Any income and capital gains that have not been distributed by December of each calendar year are generally distributed at such time. When a Portfolio distributes income or capital gains, the NAV per share is reduced by the amount of the distribution. Income and capital gains dividends will be paid in additional shares on the record date unless you have elected to receive them in cash.

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Delivery of Documents to Accounts Sharing an Address

To reduce expenses, we may mail only one copy of the Portfolios' Prospectus and each annual and semi-annual report to those addresses shared by two or more accounts. If you wish to receive individual copies of these documents, please call us at (800) 997-7327, or contact your financial institution. We will begin sending you individual copies thirty (30) days after receiving your request.

Tax Considerations

The following discussion is a summary of some important U.S. federal income tax considerations generally applicable to an investment in a Portfolio. Your investment in a Portfolio may have other tax implications. Please consult your tax advisor about federal, state, local, foreign or other tax laws applicable to you. Investors, including non-U.S. investors, may wish to consult the SAI tax section for additional disclosure.

Each Portfolio has elected to be treated as a regulated investment company and intends each year to qualify and to be eligible to be treated as such. A regulated investment company generally is not subject to tax at the corporate level on income and gains that are timely distributed to shareholders. In order to qualify and be eligible for treatment as a regulated investment company, a Portfolio must, among other things, satisfy diversification, 90% gross income and distribution requirements. A Portfolio's failure to qualify as a regulated investment company would result in corporate level taxation, and consequently, a reduction in income available for distribution to shareholders.

For U.S. federal income tax purposes, distributions of investment income generally are taxable to you as ordinary income. Taxes on distributions of capital gains generally are determined by how long a Portfolio owned (or is deemed to have owned) the investments that generated them, rather than how long you have owned your Portfolio Shares. Distributions of net capital gains (that is, the excess of net long-term capital gains over net short-term capital losses) from the sale of investments that a Portfolio owned (or is deemed to have owned) for more than one year that are properly reported by a Portfolio as capital gain dividends generally will be treated as long-term capital gain includible in your net capital gain and taxed to individuals at reduced rates. Distributions of gains from investments that a Portfolio owned (or is deemed to have owned) for one year or less generally will be taxable to you as ordinary income. Distributions of investment income properly reported by a Portfolio as derived from “qualified dividend income,” which will not include income from the Portfolio's portfolio securities on loan, are taxed to individuals at the rates applicable to net capital gain, provided holding period and other requirements are met by both the shareholder and the Portfolio when distributed to you by the Portfolio. Distributions are taxable to you even if they are paid from income or gains earned by a Portfolio before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares.

Any gain resulting from the redemption or other taxable disposition of Portfolio Shares generally will also be taxable to you as either short-term or long-term capital gain, depending upon how long you held such Portfolio Shares.

An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by a Portfolio, including any capital gain dividends, and net gains recognized on the redemption of shares of a Portfolio.

A Portfolio's income from or proceeds of dispositions of its investments in non-U.S. assets may be subject to non-U.S. withholding or other taxes, which will reduce the yield on those investments. In certain instances, a Portfolio may be entitled to elect to pass through to its shareholders a credit (or deduction, for a shareholder that itemizes deductions and so chooses) for foreign taxes (if any) borne with respect to foreign securities income earned by the Portfolio. If the Portfolio so elects, shareholders will include in gross income from foreign sources their pro rata shares of such taxes, if any, treated as paid by the Portfolio. There can be no assurance that a Portfolio will make such election, even if it is eligible to do so. If the Portfolio does not qualify for or does not make such election, shareholders will not be entitled separately to claim a credit or deduction with respect to foreign taxes paid by the Portfolio; in that case the foreign tax will nonetheless reduce the Portfolio's taxable income. Shareholders that are not subject to U.S. federal income tax, and those who invest in a Portfolio through tax-advantaged accounts (including those who invest through individual retirement accounts or other tax-advantaged retirement plans), generally will receive no benefit from any tax credit or deduction passed through by the Portfolio.

Certain of a Portfolio's investment practices, including derivative transactions and investments in debt obligations issued or purchased at a discount, will be subject to special and complex U.S. federal income tax provisions. These special rules may affect the timing, character, and/or amount of a Portfolio's distributions, and may require the Portfolio to sell its investments at a time when it is not advantageous to do so.

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If you are not a U.S. person, dividends paid by a Portfolio that the Portfolio properly reports as capital gain dividends, short-term capital gain dividends, or interest-related dividends, each as further defined in the SAI, are not subject to withholding of U.S. federal income tax, provided that certain other requirements are met. A Portfolio is permitted, but is not required, to report any part of its dividends as are eligible for such treatment. A Portfolio's dividends other than those the Portfolio so reports as capital gain dividends, short-term capital gain dividends, or interest-related dividends generally will be subject to U.S. withholding tax at a 30% rate (or lower applicable treaty rate). See each Portfolio's SAI for further information.

The U.S. Treasury and IRS generally require a Portfolio to obtain information sufficient to identify the status of each shareholder under sections 1471-1474 of the Internal Revenue Code of 1986, as amended, and the U.S. Treasury and IRS guidance issued thereunder (collectively, the “Foreign Account Tax Compliance Act” or “FATCA”) or under an applicable intergovernmental agreement between the United States and a foreign government. Please see the SAI for more information on FATCA reporting requirements.

Cost Basis Reporting . Department of the Treasury regulations mandate cost basis reporting to shareholders and the IRS for redemptions of Portfolio Shares acquired on or after January 1, 2012 (“Post Effective Date Shares”). If you acquire and hold shares directly through the Portfolios and not through a Financial Intermediary, DST Asset Manager Solutions, Inc. will use a default average cost basis methodology for tracking and reporting your cost basis on Post Effective Date Shares, unless you request, in writing, another cost basis reporting methodology.

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Financial Highlights

The financial highlight tables are intended to help you understand each Portfolio's financial performance since each Portfolio's inception. Certain information reflects the performance results for a single Portfolio Share. The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in each Portfolio (assuming reinvestment of all dividends and distributions). This information has been audited by Ernst & Young LLP, the Trust's independent registered public accounting firm, whose report, along with each Portfolio's financial highlights and financial statements, is included in the annual report to shareholders, which is available upon request. Any references to Notes in these financial highlight tables refer to the “Notes to Financial Statements” section of each Portfolio's financial statements, and the financial information included in these tables should be read in conjunction with the financial statements incorporated by reference in the SAI.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET EQUITY 500 INDEX II PORTFOLIO

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period


	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 8/11/14* - 12/31/14
Net asset value, beginning of period	$ 13.07	$ 11.31	$ 10.32	$ 10.55	$ 10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.26	0.25	0.23	0.22	0.08
Net realized and unrealized gain (loss)	(0.86)	2.21	1.02	(0.09)	0.63
Total from investment operations	(0.60)	2.46	1.25	0.13	0.71
Distributions to shareholders from:
Net investment income	(0.26)	(0.27)	(0.18)	(0.20)	(0.08)
Net realized gains	(0.44)	(0.43)	(0.08)	(0.16)	(0.08)
Total distributions	(0.70)	(0.70)	(0.26)	(0.36)	(0.16)
Net asset value, end of period	$ 11.77	$ 13.07	$ 11.31	$ 10.32	$ 10.55
Total return (b)	(4.42)%	21.66%	12.18%	1.29%	7.12%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$2,634,533	$2,199,181	$1,227,444	$541,335	$426,710
Ratios to average net assets:
Total expenses	0.03%	0.03%	0.04%	0.04%	0.04%(c)
Net expenses	0.02%	0.03%	0.03%	0.03%	0.03%(c)
Net investment income (loss)	1.93%	1.98%	2.15%	2.05%	2.06%(c)
Portfolio turnover rate	8%	30%	5%	5%	4%(d)(e)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Annualized.
(d)	Not annualized.
(e)	Portfolio turnover rate excludes in-kind security transactions.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET AGGREGATE BOND INDEX PORTFOLIO

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period


	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/19/14* - 12/31/14
Net asset value, beginning of period	$ 10.00	$ 9.91	$ 9.89	$ 10.14	$ 10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.26	0.23	0.23	0.20	0.04
Net realized and unrealized gain (loss)	(0.28)	0.10	0.01	(0.13)	0.16
Total from investment operations	(0.02)	0.33	0.24	0.07	0.20
Voluntary contribution from Adviser	—	—	—	0.00(b)	0.00(b)
Distributions to shareholders from:
Net investment income	(0.27)	(0.24)	(0.21)	(0.19)	(0.04)
Net realized gains	—	—	(0.01)	(0.11)	(0.02)
Return of Capital	—	—	—	(0.02)	—
Total distributions	(0.27)	(0.24)	(0.22)	(0.32)	(0.06)
Net asset value, end of period	$ 9.71	$ 10.00	$ 9.91	$ 9.89	$ 10.14
Total return (c)	(0.12)%	3.38%	2.39%	0.65%(d)	2.00%(e)
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$846,759	$687,541	$249,906	$83,842	$80,044
Ratios to average net assets:
Total expenses	0.04%	0.06%	0.14%	0.17%	0.25%(f)
Net expenses	0.03%	0.03%	0.01%	0.03%	0.04%(f)
Net investment income (loss)	2.73%	2.31%	2.24%	2.00%	1.52%(f)
Portfolio turnover rate	90%	99%	194%	62%(g)	16%(g)(h)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Adviser had not made a voluntary contribution during the year ended 12/31/15, the total return would have decreased by less than 0.005%.
(e)	If the Adviser had not made a voluntary contribution during the period ended 12/31/14, the total return would have decreased by less than 0.005%.
(f)	Annualized.
(g)	Portfolio turnover rate excludes to-be-announced (“TBA”) transactions.
(h)	Not annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET GLOBAL EQUITY EX-U.S. INDEX PORTFOLIO

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period


	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/17/14* - 12/31/14
Net asset value, beginning of period	$ 10.81	$ 8.73	$ 8.45	$ 9.17	$ 10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.30	0.26	0.22	0.25	0.05
Net realized and unrealized gain (loss)	(1.82)	2.12	0.20	(0.79)	(0.82)
Total from investment operations	(1.52)	2.38	0.42	(0.54)	(0.77)
Voluntary contribution from Adviser	—	—	—	0.00(b)	0.00(b)
Distributions to shareholders from:
Net investment income	(0.27)	(0.25)	(0.14)	(0.18)	(0.06)
Net realized gains	((0.00))(b)	(0.05)	—	—	—
Total distributions	(0.27)	(0.30)	(0.14)	(0.18)	(0.06)
Net asset value, end of period	$ 9.02	$ 10.81	$ 8.73	$ 8.45	$ 9.17
Total return (c)	(13.99)%	27.20%	5.06%	(5.84)%(d)	(7.72)%(e)
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$1,907,599	$1,655,261	$552,700	$117,461	$49,460
Ratios to average net assets:
Total expenses	0.06%	0.06%	0.23%	0.48%	0.73%(f)
Net expenses	0.06%	0.06%	0.08%	0.08%	0.31%(f)
Net investment income (loss)	2.89%	2.59%	2.51%	2.73%	1.77%(f)
Portfolio turnover rate	4%	2%	8%	3%	0%(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Adviser had not made a voluntary contribution during the year ended 12/31/15, the total return would have decreased by less than 0.005%.
(e)	If the Adviser had not made a voluntary contribution during the period ended 12/31/14, the total return would have decreased by less than 0.005%.
(f)	Annualized.
(g)	Not annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET SMALL/MID CAP EQUITY INDEX PORTFOLIO

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period


	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	For the Period 8/12/15* - 12/31/15
Net asset value, beginning of period	$ 12.10	$ 10.65	$ 9.30	$ 10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.19	0.17	0.15	0.06
Net realized and unrealized gain (loss)	(1.31)	1.76	1.38	(0.69)
Total from investment operations	(1.12)	1.93	1.53	(0.63)
Distributions to shareholders from:
Net investment income	(0.19)	(0.15)	(0.09)	(0.06)
Net realized gains	(0.48)	(0.33)	(0.09)	(0.01)
Total distributions	(0.67)	(0.48)	(0.18)	(0.07)
Net asset value, end of period	$ 10.31	$ 12.10	$ 10.65	$ 9.30
Total return (b)	(9.07)%	18.20%	16.46%	6.30%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$628,732	$464,870	$142,269	$28,151
Ratios to average net assets:
Total expenses	0.05%	0.07%	0.22%	0.41%(c)
Net expenses	0.03%	0.03%	0.03%	0.03%(c)
Net investment income (loss)	1.52%	1.46%	1.55%	1.61%(c)
Portfolio turnover rate	22%	21%	21%	8%(d)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Annualized.
(d)	Not annualized.

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Index/Trademark Licenses/Disclaimers

The State Street Equity 500 Index II Portfolio is not sponsored, endorsed, sold or marketed by S&P Dow Jones Indices LLC, Dow Jones, S&P, any of their respective affiliates (collectively, “S&P Dow Jones Indices”). S&P Dow Jones Indices does not make any representation or warranty, express or implied, to the owners of the State Street Equity 500 Index II Portfolio or any member of the public regarding the advisability of investing in securities generally or in the State Street Equity 500 Index II Portfolio particularly or the ability of the Indices to track general market performance. S&P Dow Jones Indices licenses to Licensee the Index and certain trademarks, service marks and/or trade names of S&P Dow Jones Indices and/or its licensors. The Indices are determined, composed and calculated by S&P Dow Jones Indices without regard to Licensee or the State Street Equity 500 Index II Portfolio. S&P Dow Jones Indices have no obligation to take the needs of Licensee or the owners of the State Street Equity 500 Index II Portfolio into consideration in determining, composing or calculating the Indices. S&P Dow Jones Indices is not responsible for and has not participated in the determination of the prices, and amount of the State Street Equity 500 Index II Portfolio or the timing of the issuance or sale of the State Street Equity 500 Index II Portfolio or in the determination or calculation of the equation by which the State Street Equity 500 Index II Portfolio are to be converted into cash, surrendered or redeemed, as the case may be. S&P Dow Jones Indices has no obligation or liability in connection with the administration, marketing or trading of the State Street Equity 500 Index II Portfolio. S&P Dow Jones Indices LLC is not an investment or tax advisor. Inclusion of a security within an index is not a recommendation by S&P Dow Jones Indices to buy, sell, or hold such security, nor is it considered to be investment advice.

NEITHER S&P DOW JONES INDICES NOR THIRD PARTY LICENSOR GUARANTEES THE ADEQUACY, ACCURACY, TIMELINESS AND/OR THE COMPLETENESS OF THE INDICES OR ANY DATA RELATED THERETO OR ANY COMMUNICATION, INCLUDING BUT NOT LIMITED TO, ORAL OR WRITTEN COMMUNICATION (INCLUDING ELECTRONIC COMMUNICATIONS) WITH RESPECT THERETO. S&P DOW JONES INDICES AND THIRD PARTY LICENSOR SHALL NOT BE SUBJECT TO ANY DAMAGES OR LIABILITY FOR ANY ERRORS, OMISSIONS, OR DELAYS THEREIN. S&P DOW JONES INDICES AND THIRD PARTY LICENSOR MAKES NO EXPRESS OR IMPLIED WARRANTIES, AND EXPRESSLY DISCLAIMS ALL WARRANTIES, OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE OR AS TO RESULTS TO BE OBTAINED BY LICENSEE, OWNERS OF THE STATE STREET EQUITY 500 INDEX II PORTFOLIO, OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE INDICES OR WITH RESPECT TO ANY DATA RELATED THERETO. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT WHATSOEVER SHALL S&P DOW JONES INDICES OR THIRD PARTY LICENSOR BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES INCLUDING BUT NOT LIMITED TO, LOSS OF PROFITS, TRADING LOSSES, LOST TIME OR GOODWILL, EVEN IF THEY HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, WHETHER IN CONTRACT, TORT, STRICT LIABILITY, OR OTHERWISE. THERE ARE NO THIRD PARTY BENEFICIARIES OF ANY AGREEMENTS OR ARRANGEMENTS BETWEEN S&P DOW JONES INDICES AND LICENSEE, OTHER THAN THE LICENSORS OF S&P DOW JONES INDICES.

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any representation or warranty, express or implied, regarding the advisability of investing in the State Street Aggregate Bond Index Portfolio or the advisability of investing in securities generally or the ability of the Bloomberg Barclays U.S. Aggregate Bond Index to track corresponding or relative market performance. Neither Bloomberg nor Barclays has passed on the legality or suitability of the State Street Aggregate Bond Index Portfolio with respect to any person or entity. Neither Bloomberg nor Barclays is responsible for or has participated in the determination of the timing of, prices at, or quantities of the State Street Aggregate Bond Index Portfolio to be issued. Neither Bloomberg nor Barclays has any obligation to take the needs of the Issuer or the owners of the State Street Aggregate Bond Index Portfolio or any other third party into consideration in determining, composing or calculating the Bloomberg Barclays U.S. Aggregate Bond Index. Neither Bloomberg nor Barclays has any obligation or liability in connection with administration, marketing or trading of the State Street Aggregate Bond Index Portfolio.

THE STATE STREET GLOBAL EQUITY EX-U.S. INDEX PORTFOLIO IS NOT SPONSORED, ENDORSED, SOLD OR PROMOTED BY MSCI INC. (“MSCI”), MSCI'S PARENT COMPANY, ANY OF MSCI'S OR MSCI'S PARENT COMPANY'S DIRECTLY OR INDIRECTLY HELD SUBSIDIARIES, ANY OF MSCI'S OR MSCI'S PARENT COMPANY'S INFORMATION PROVIDERS OR ANY THIRD PARTY INVOLVED IN, OR RELATED TO, COMPILING, COMPUTING OR CREATING ANY MSCI INDEX (COLLECTIVELY, THE “MSCI PARTIES”).THE MSCI INDICES ARE THE EXCLUSIVE PROPERTY OF MSCI. MSCI AND THE MSCI INDEX NAMES ARE SERVICE MARK(S) OF MSCI OR ITS AFFILIATES AND HAVE BEEN LICENSED FOR USE FOR CERTAIN PURPOSES BY THE LICENSEE. NONE OF THE MSCI PARTIES MAKES ANY REPRESENTATION OR WARRANTY, EXPRESS OR IMPLIED, TO THE ISSUER OR OWNERS OF THE MSCI FUNDS OR ANY OTHER PERSON OR ENTITY REGARDING THE ADVISABILITY OF INVESTING IN FUNDS GENERALLY OR IN THE MSCI FUNDS PARTICULARLY OR THE ABILITY OF ANY MSCI INDEX TO TRACK CORRESPONDING STOCK MARKET PERFORMANCE. MSCI OR ITS AFFILIATES ARE THE LICENSORS OF CERTAIN TRADEMARKS, SERVICE MARKS AND TRADE NAMES AND OF THE MSCI INDICES WHICH ARE DETERMINED, COMPOSED AND CALCULATED BY MSCI WITHOUT REGARD TO THE MSCI FUNDS OR THE ISSUER OR OWNERS OF THE MSCI FUNDS OR ANY OTHER PERSON OR ENTITY. NONE OF THE MSCI PARTIES HAS ANY OBLIGATION TO TAKE THE NEEDS OF THE ISSUER OR OWNERS OF THE MSCI FUNDS OR ANY OTHER PERSON OR ENTITY INTO CONSIDERATION IN DETERMINING, COMPOSING OR CALCULATING THE MSCI INDICES. NONE OF THE MSCI PARTIES IS RESPONSIBLE FOR OR HAS PARTICIPATED IN THE DETERMINATION OF THE TIMING OF, PRICES AT, OR QUANTITIES OF THE MSCI FUNDS TO BE ISSUED OR IN THE DETERMINATION OR CALCULATION OF THE EQUATION BY OR THE CONSIDERATION INTO WHICH THE MSCI

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FUNDS ARE REDEEMABLE. FURTHER, NONE OF THE MSCI PARTIES HAS ANY OBLIGATION OR LIABILITY TO THE ISSUER OR OWNERS OF THE MSCI FUNDS OR ANY OTHER PERSON OR ENTITY IN CONNECTION WITH THE ADMINISTRATION, MARKETING OR OFFERING OF THE MSCI FUNDS.

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For more information about the Portfolios:

The Portfolios' SAI includes additional information about the Portfolios and is incorporated by reference into this document. Additional information about the Portfolios' investments is available in the Portfolios' most recent annual and semi-annual reports to shareholders. In a Portfolio's annual report, you will find a discussion of the market conditions and investment strategies that significantly affected the Portfolio's performance during its last fiscal year. The Portfolios' SAI is available, without charge, upon request. The Portfolios' annual and semi-annual reports are available, without charge, upon request. Shareholders in the Portfolios may make inquiries to the Portfolios to receive such information by calling (877) 521-4083 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. The Portfolio's annual and semi-annual reports to shareholders are available, free of charge, on the Portfolios' website at www.ssgafunds.com.

Reports and other information about the Portfolios are available free of charge on the EDGAR Database on the SEC's Internet site at http://www.sec.gov. Copies of this information also may be obtained, after paying a duplicating fee, by electronic request at the following E-mail address: publicinfo@sec.gov.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

SSITCFSTATPRO

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Target Retirement 2015 Fund
Class I (SSBFX) Class K (SSBHX)

State Street Target Retirement 2020 Fund
Class I (SSBNX) Class K (SSBOX)

State Street Target Retirement 2025 Fund
Class I (SSBRX) Class K (SSBSX)

State Street Target Retirement 2030 Fund
Class I (SSBWX) Class K (SSBYX)

State Street Target Retirement 2035 Fund
Class I (SSCJX) Class K (SSCKX)

State Street Target Retirement 2040 Fund
Class I (SSCNX) Class K (SSCQX)

State Street Target Retirement 2045 Fund
Class I (SSDDX) Class K (SSDEX)

State Street Target Retirement 2050 Fund
Class I (SSDJX) Class K (SSDLX)

State Street Target Retirement 2055 Fund
Class I (SSDOX) Class K (SSDQX)

State Street Target Retirement 2060 Fund
Class I (SSDWX) Class K (SSDYX)

State Street Target Retirement Fund
Class I (SSFNX) Class K (SSFOX)

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in any of the Funds offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Each Fund may offer multiple classes of shares. This Prospectus covers only the Class I and Class K Shares of the applicable Funds.

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Fund Summaries	1
State Street Target Retirement 2015 Fund	1
State Street Target Retirement 2020 Fund	11
State Street Target Retirement 2025 Fund	21
State Street Target Retirement 2030 Fund	31
State Street Target Retirement 2035 Fund	41
State Street Target Retirement 2040 Fund	51
State Street Target Retirement 2045 Fund	61
State Street Target Retirement 2050 Fund	71
State Street Target Retirement 2055 Fund	81
State Street Target Retirement 2060 Fund	91
State Street Target Retirement Fund	101
Additional Information About Investment Objectives, Principal Strategies and Risks	110
Additional Information About Non-Principal Investment Strategies and Risks	122
Portfolio Holdings Disclosure	123
Management and Organization	124
Shareholder Information	125
Dividends, Distributions and Tax Considerations	134
Financial Intermediary Arrangements	136
Financial Highlights	137
Appendix A – Underlying Funds	160
Index/Trademark Licenses/Disclaimers	164

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State Street Target Retirement 2015 Fund

Investment Objective

The investment objective of the State Street Target Retirement 2015 Fund (the “Target Retirement 2015 Fund” or the “Fund”) is to seek capital growth and income over the long term.

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”).

Shareholder Fees (fees paid directly from your investment)

	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class I	Class K
Management Fee	0.05%	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%	0.00%
Other Expenses ¹	0.36%	0.16%
Acquired Fund Fees and Expenses	0.12%	0.12%
Total Annual Fund Operating Expenses	0.53%	0.33%
Less Fee Waivers and/or Expense Reimbursements ²	(0.24%)	(0.24%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.29%	0.09%

Other Expenses have been restated to reflect current fees for Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.09% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

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	1 year	3 years	5 years	10 years
Class I	$30	$146	$272	$642
Class K	$ 9	$ 82	$161	$395

Portfolio Turnover:

Principal Investment Strategies

SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, manages the Target Retirement 2015 Fund using a proprietary asset allocation strategy. The Fund is a “fund of funds” that invests in a combination of mutual funds and ETFs sponsored by the Adviser or its affiliates (the “Underlying Funds”). The Underlying Funds may invest in a wide variety of asset classes, including equity and fixed-income securities of issuers anywhere in the world, including emerging markets investments, and including, among others, high yield, commodity, and real estate investments. The Underlying Funds may invest in obligations of domestic U.S. issuers, non-U.S. issuers, or both.

The Fund is intended for investors who have retired or who expected to retire around the year 2015 and who were likely to stop making new investments in the Fund around that time. The Fund is designed for an investor who plans to withdraw the value of the investor's account gradually following that date. The Adviser seeks to optimize the Fund's “glide path” for the wealth accumulation, wealth preservation, and income generation phases of retirement planning and includes adjustments in the critical years immediately preceding and following the retirement date. For example, a Fund with a target retirement date far into the future will typically invest a greater portion of its assets in asset classes with higher risk profiles and the potential for higher returns. As the target date for a Fund approaches, the Adviser will adjust the asset allocation and risk profile of the Fund – its glide path – to what is generally seen to be a more conservative approach to reduce (but not to eliminate) risk by increasing the allocation to asset classes that have historically been subject to lower levels of volatility. A fund intended for investors who have already achieved retirement age would typically invest a greater portion of its assets in bonds and cash items, with a relatively smaller allocation to equity securities.

The Underlying Funds employ a wide array of investment styles. For example, the Underlying Funds can buy and sell common stocks of companies of any size, corporate bonds of varying credit quality, U.S. government and agency bonds, mortgage- and asset-backed securities, commodities, real estate and money market instruments. They may hold U.S. or non-U.S. investments. The Underlying Funds may use derivative instruments of any kind, including futures contracts, forward currency contracts, credit default swaps, interest rate swaps and commodities-related derivatives. Derivatives may be used by an Underlying Fund for hedging or risk management purposes, as a substitute for direct investment, or otherwise to seek to enhance the Underlying Fund's total return.

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The glide path depicted in the chart below shows how the Fund's strategic target allocations among asset classes are expected generally to place more emphasis on fixed income investments and less on equity investments as the target retirement date approaches.

The glide path shows the Fund's long term strategic target allocations. The Fund's actual allocations may differ. The Adviser periodically reviews the Fund's target asset allocations and may, at any time, in its discretion, change the target asset allocations or deviate from the target asset allocations. The glide path is presented only as an illustration of how the process of re-allocation occurs as the Fund approaches its target date.

The following table shows the Fund's strategic target allocations to the Underlying Funds as of the date of this Prospectus.

Underlying Funds		Target Retirement 2015 Fund
State Street Equity 500 Index II Portfolio		18.172%
State Street Small/Mid Cap Equity Index Portfolio		3.228%
State Street Global Equity ex-U.S. Index Portfolio		11.100%
State Street Aggregate Bond Index Portfolio		21.000%
SPDR Bloomberg Barclays TIPS ETF		0.000%
SPDR Bloomberg Barclays 1-10 Year TIPS ETF		19.500%
SPDR Bloomberg Barclays High Yield Bond ETF		7.000%
SPDR Dow Jones Global Real Estate ETF		5.000%
SPDR Portfolio Long Term Treasury ETF		0.000%
SPDR Portfolio Short Term Treasury ETF		12.000%
SPDR Portfolio Short Term Corporate Bond ETF		3.000%

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The Fund's actual allocations are expected to differ over time. The Adviser periodically reviews the Fund's target allocations to underlying investment options and may, at any time, in its discretion, change the target allocations or deviate from the target allocations. The Adviser may modify the selection of Underlying Funds from time to time, and may invest in other Underlying Funds, including any Underlying Funds that may be created in the future. The table is presented for illustrative purposes only. More current information regarding the Fund's allocations may be available on its website: www.ssgafunds.com.

Principal Risks

You could lose money by investing in the Fund. An investment in the Fund is subject to investment risks, including possible loss of principal, is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Fund may not achieve its investment objective. An investment in the Fund is not guaranteed, and you may experience losses, including losses near, at, or after the target date. There is no guarantee that the Fund will provide adequate portfolio growth or income at and through your retirement. The Fund is not intended to be a complete investment program, but rather is intended for investment as part of a diversified investment portfolio. Investors should consult their own advisers as to the role of the Fund in their overall investment programs. Except as otherwise stated, references in this section to “the Fund” or “a Fund” may relate to the Fund, one or more Underlying Funds, or both. The risks described below may arise out of the Fund's direct investments or the Fund's investments in one or more of the Underlying Funds. All or a portion of the Underlying Funds are managed pursuant to a passive investment strategy, while the Fund is managed pursuant to an active investment strategy. You will find additional information about each Underlying Fund's risks in its prospectus and SAI. The risks are described in alphabetical order and not in the order of importance or potential exposure.

In addition, the Fund is subject to the following principal risks:

Asset Allocation Risk: The Fund's investment performance depends upon the successful allocation by the Adviser of the Fund's assets among asset classes, geographical regions, industry sectors, and specific issuers and investments. There is no guarantee that the Adviser's allocation techniques and decisions will produce the desired results.

Below Investment-Grade Securities Risk: Lower-quality debt securities (“high yield” or “junk” bonds) are considered predominantly speculative, and can involve a substantially greater risk of default than higher quality debt securities. Issuers of lower-quality debt securities may have substantially greater risk of insolvency or bankruptcy than issuers of higher-quality debt securities. They can be illiquid, and their values can have significant volatility and may decline significantly over short periods of time. Lower-quality debt securities tend to be more sensitive to adverse news about the issuer, or the market or economy in general.

Commodities Risk: Commodity prices can have significant volatility, and exposure to commodities can cause the net asset value of Fund Shares to decline or fluctuate in a rapid and unpredictable manner. A liquid secondary market may not exist for certain commodity investments, which may make it difficult for the Fund to sell them at a desirable price or at the price at which it is carrying them.

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fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Fund may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

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Fund to meet redemptions. The Adviser may attempt to replicate the Index return by investing in fewer than all of the securities in the Index, or in some securities not included in the Index, potentially increasing the risk of divergence between the Fund's return and that of the Index.

Inflation Risk: Inflation risk is the risk that the value of assets or income from investments will be less in the future as inflation decreases the value of money. As inflation increases, the values of a fund's assets can decline.

Inflation-Indexed Securities Risk: The principal amount of an inflation-indexed security typically increases with inflation and decreases with deflation, as measured by a specified index. It is possible that, in a period of declining inflation rates, the Fund could receive at maturity less than the initial principal amount of an inflation-indexed security. Changes in the values of inflation-indexed securities may be difficult to predict, and it is possible that an investment in such securities will have an effect different from that anticipated by the Adviser.

IPO Risk: The Fund may at times have the opportunity to invest in securities offered in initial public offerings (“IPOs”). IPOs involve companies that have no public operating history and therefore entail more risk than established public companies. The prices of securities offered in IPOs can have significant volatility and the Fund may lose money on an investment in such securities. IPO investments in which other clients of the Adviser invest may not be made available to the Fund.

Large Shareholder Risk: To the extent a large proportion of the shares of the Fund are held by a small number of shareholders (or a single shareholder), including funds or accounts over which the Adviser has investment discretion, the Fund is subject to the risk that these shareholders will purchase or redeem Fund Shares in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of the Fund to conduct its investment program.

Longevity Risk: This is the risk that you will outlive your retirement assets.

Management Risk: The Fund is actively managed. The Adviser's judgments about the attractiveness, relative value, or potential appreciation of a particular sector, security, commodity or investment strategy may prove to be incorrect, and may cause the Fund to incur losses. There can be no assurance that the Adviser's investment techniques and decisions will produce the desired results.

Modeling Risk: The Adviser uses quantitative models in an effort to enhance returns and manage risk. Any imperfections, errors or limitations in these models could limit any benefit to the Fund from the use of the models, or could result in incorrect outputs or in investment outcomes different from or opposite to those expected or desired by the Adviser. There can be no assurance that the models will behave as expected in all market conditions. In addition, computer programming used to create quantitative models, or the data on which such models operate, might contain one or more errors.

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Real Estate Sector Risk: An investment in a real property company may be subject to risks similar to those associated with direct ownership of real estate, including, by way of example, the possibility of declines in the value of real estate, losses from casualty or condemnation, and changes in local and general economic conditions, supply and demand, interest rates, environmental liability, zoning laws, regulatory limitations on rents, property taxes, and operating expenses. Some real property companies have limited diversification because they invest in a limited number of properties, a narrow geographic area, or a single type of property.

REIT Risk: REITs are subject to the risks associated with investing in the securities of real property companies. In particular, REITs may be affected by changes in the values of the underlying properties that they own or operate. Further, REITs are dependent upon specialized management skills, and their investments may be concentrated in relatively few properties, or in a small geographic area or a single property type. REITs are also subject to heavy cash flow dependency and, as a result, are particularly reliant on the proper functioning of capital markets. A variety of economic and other factors may adversely affect a lessee's ability to meet its obligations to a REIT. In the event of a default by a lessee, the REIT may experience delays in enforcing its rights as a lessor and may incur substantial costs associated in protecting its investments. In addition, a REIT could fail to qualify for favorable regulatory treatment.

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key employees. In addition, these companies may have been recently organized and may have little or no track record of success. The securities of smaller companies may trade less frequently and in smaller volumes than more widely held securities. Some securities of smaller issuers may be illiquid or may be restricted as to resale, and their values may have significant volatility. The Fund may be unable to liquidate its positions in such securities at any time, or at a favorable price, in order to meet the Fund's obligations. Returns on investments in securities of small-, mid- and micro-capitalization companies could trail the returns on investments in securities of larger companies.

Target Date Assumptions Risk: This is the risk that assumptions and forecasts used by the Adviser in developing the Fund's asset allocation glide path are not in line with actual future investment returns and participant savings activities, which could result in losses near, at, or after the target date year or could result in the Fund not providing adequate income at and through retirement.

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Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of a broad measure of market performance and those of a composite of accounts with similar investment objectives (the “Composite Index”). The Composite Index is a custom composite which comprises each index tracked by the Underlying Funds of the Fund. The S&P 500 Index is a well-known stock market index that includes common stocks of 500 companies from a number of sectors and that measures the performance of the large-cap sector of the market. The bar chart shows how the Class I shares' returns have varied for each full calendar year shown. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 3.17% (Q1, 2017)
Lowest Quarterly Return: -4.56% (Q4, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
Class I			9/30/2014
Return Before Taxes	-2.89%	3.12%
Return After Taxes on Distributions	-4.37%	2.05%
Return After Taxes on Distributions and Sale of Fund Shares	-1.22%	2.05%
Class K	-2.86%	3.14%	9/30/2014
State Street Target Retirement 2015 Composite Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-2.91%	3.34%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	-4.38%	8.01%

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

The professionals primarily responsible for the day-to-day management of the Fund are Charles McGinn and Michael Narkiewicz. Mr. McGinn has served as a portfolio manager of the Fund since inception in 2014 and Mr. Narkiewicz has served as a portfolio manager of the Fund since 2018.

Charles McGinn is a Vice President of the Adviser and a Senior Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 1998.

Michael Narkiewicz is a Vice President of the Adviser and a Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 2013.

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Purchase and Sale of Fund Shares

Purchase Minimums

Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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State Street Target Retirement 2020 Fund

Investment Objective

The investment objective of the State Street Target Retirement 2020 Fund (the “Target Retirement 2020 Fund” or the “Fund”) is to seek capital growth and income over the long term.

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”).

Shareholder Fees (fees paid directly from your investment)

	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class I	Class K
Management Fee	0.05%	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%	0.00%
Other Expenses ¹	0.30%	0.10%
Acquired Fund Fees and Expenses	0.11%	0.11%
Total Annual Fund Operating Expenses	0.46%	0.26%
Less Fee Waivers and/or Expense Reimbursements ²	(0.17%)	(0.17%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.29%	0.09%

Other Expenses have been restated to reflect current fees for Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.09% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

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	1 year	3 years	5 years	10 years
Class I	$30	$130	$241	$563
Class K	$ 9	$ 66	$129	$314

Portfolio Turnover:

Principal Investment Strategies

SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, manages the Target Retirement 2020 Fund using a proprietary asset allocation strategy. The Fund is a “fund of funds” that invests in a combination of mutual funds and ETFs sponsored by the Adviser or its affiliates (the “Underlying Funds”). The Underlying Funds may invest in a wide variety of asset classes, including equity and fixed-income securities of issuers anywhere in the world, including emerging markets investments, and including, among others, high yield, commodity, and real estate investments. The Underlying Funds may invest in obligations of domestic U.S. issuers, non-U.S. issuers, or both.

The Fund is intended for investors expecting to retire around the year 2020 and who are likely to stop making new investments in the Fund at that time. The Fund is designed for an investor who plans to withdraw the value of the investor's account gradually following that date. The Adviser seeks to optimize the Fund's “glide path” for the wealth accumulation, wealth preservation, and income generation phases of retirement planning and includes adjustments in the critical years immediately preceding and following the retirement date. For example, a Fund with a target retirement date far into the future will typically invest a greater portion of its assets in asset classes with higher risk profiles and the potential for higher returns. As the target date for a Fund approaches, the Adviser will adjust the asset allocation and risk profile of the Fund – its glide path – to what is generally seen to be a more conservative approach to reduce (but not to eliminate) risk by increasing the allocation to asset classes that have historically been subject to lower levels of volatility. A fund intended for investors who have already achieved retirement age would typically invest a greater portion of its assets in bonds and cash items, with a relatively smaller allocation to equity securities.

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The following table shows the Fund's strategic target allocations to the Underlying Funds as of the date of this Prospectus.

Underlying Funds		Target Retirement 2020 Fund
State Street Equity 500 Index II Portfolio		24.195%
State Street Small/Mid Cap Equity Index Portfolio		4.955%
State Street Global Equity ex-U.S. Index Portfolio		16.350%
State Street Aggregate Bond Index Portfolio		25.000%
SPDR Bloomberg Barclays TIPS ETF		0.000%
SPDR Bloomberg Barclays 1-10 Year TIPS ETF		17.500%
SPDR Bloomberg Barclays High Yield Bond ETF		6.500%
SPDR Dow Jones Global Real Estate ETF		4.500%
SPDR Portfolio Long Term Treasury ETF		1.000%
SPDR Portfolio Short Term Treasury ETF		0.000%
SPDR Portfolio Short Term Corporate Bond ETF		0.000%

Table of Contents

Principal Risks

In addition, the Fund is subject to the following principal risks:

Table of Contents

Longevity Risk: This is the risk that you will outlive your retirement assets.

Table of Contents

Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of a broad measure of market performance and those of a composite of accounts with similar investment objectives (the “Composite Index”). The Composite Index is a custom composite which comprises each index tracked by the Underlying Funds of the Fund. The S&P 500 Index is a well-known stock market index that includes common stocks of 500 companies from a number of sectors and that measures the performance of the large-cap sector of the market. The bar chart shows how the Class I shares' returns have varied for each full calendar year shown. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 3.79% (Q1, 2017)
Lowest Quarterly Return: -6.16% (Q4, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
Class I			9/30/2014
Return Before Taxes	-4.17%	3.71%
Return After Taxes on Distributions	-5.66%	2.75%
Return After Taxes on Distributions and Sale of Fund Shares	-1.89%	2.60%
Class K	-4.16%	3.73%	9/30/2014
State Street Target Retirement 2020 Composite Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-4.23%	3.93%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	-4.38%	8.01%

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Charles McGinn is a Vice President of the Adviser and a Senior Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 1998.

Michael Narkiewicz is a Vice President of the Adviser and a Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 2013.

Table of Contents

Purchase and Sale of Fund Shares

Purchase Minimums

Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

Table of Contents

State Street Target Retirement 2025 Fund

Investment Objective

The investment objective of the State Street Target Retirement 2025 Fund (the “Target Retirement 2025 Fund” or the “Fund”) is to seek capital growth and income over the long term.

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”).

Shareholder Fees (fees paid directly from your investment)

	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class I	Class K
Management Fee	0.05%	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%	0.00%
Other Expenses ¹	0.29%	0.09%
Acquired Fund Fees and Expenses	0.08%	0.08%
Total Annual Fund Operating Expenses	0.42%	0.22%
Less Fee Waivers and/or Expense Reimbursements ²	(0.13%)	(0.13%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.29%	0.09%

Other Expenses have been restated to reflect current fees for Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.09% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

Table of Contents

	1 year	3 years	5 years	10 years
Class I	$30	$122	$222	$517
Class K	$ 9	$ 58	$111	$267

Portfolio Turnover:

Principal Investment Strategies

SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, manages the Target Retirement 2025 Fund using a proprietary asset allocation strategy. The Fund is a “fund of funds” that invests in a combination of mutual funds and ETFs sponsored by the Adviser or its affiliates (the “Underlying Funds”). The Underlying Funds may invest in a wide variety of asset classes, including equity and fixed-income securities of issuers anywhere in the world, including emerging markets investments, and including, among others, high yield, commodity, and real estate investments. The Underlying Funds may invest in obligations of domestic U.S. issuers, non-U.S. issuers, or both.

The Fund is intended for investors expecting to retire around the year 2025 and who are likely to stop making new investments in the Fund at that time. The Fund is designed for an investor who plans to withdraw the value of the investor's account gradually following that date. The Adviser seeks to optimize the Fund's “glide path” for the wealth accumulation, wealth preservation, and income generation phases of retirement planning and includes adjustments in the critical years immediately preceding and following the retirement date. For example, a Fund with a target retirement date far into the future will typically invest a greater portion of its assets in asset classes with higher risk profiles and the potential for higher returns. As the target date for a Fund approaches, the Adviser will adjust the asset allocation and risk profile of the Fund – its glide path – to what is generally seen to be a more conservative approach to reduce (but not to eliminate) risk by increasing the allocation to asset classes that have historically been subject to lower levels of volatility. A fund intended for investors who have already achieved retirement age would typically invest a greater portion of its assets in bonds and cash items, with a relatively smaller allocation to equity securities.

Table of Contents

The following table shows the Fund's strategic target allocations to the Underlying Funds as of the date of this Prospectus.

Underlying Funds		Target Retirement 2025 Fund
State Street Equity 500 Index II Portfolio		30.518%
State Street Small/Mid Cap Equity Index Portfolio		7.382%
State Street Global Equity ex-U.S. Index Portfolio		22.600%
State Street Aggregate Bond Index Portfolio		17.000%
SPDR Bloomberg Barclays TIPS ETF		8.500%
SPDR Bloomberg Barclays 1-10 Year TIPS ETF		0.000%
SPDR Bloomberg Barclays High Yield Bond ETF		6.000%
SPDR Dow Jones Global Real Estate ETF		2.000%
SPDR Portfolio Long Term Treasury ETF		6.000%
SPDR Portfolio Short Term Treasury ETF		0.000%
SPDR Portfolio Short Term Corporate Bond ETF		0.000%

Table of Contents

Principal Risks

In addition, the Fund is subject to the following principal risks:

Table of Contents

Longevity Risk: This is the risk that you will outlive your retirement assets.

Table of Contents

Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of a broad measure of market performance and those of a composite of accounts with similar investment objectives (the “Composite Index”). The Composite Index is a custom composite which comprises each index tracked by the Underlying Funds of the Fund. The S&P 500 Index is a well-known stock market index that includes common stocks of 500 companies from a number of sectors and that measures the performance of the large-cap sector of the market. The bar chart shows how the Class I shares' returns have varied for each full calendar year shown. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 4.65% (Q1, 2017)
Lowest Quarterly Return: -7.99% (Q4, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
Class I			9/30/2014
Return Before Taxes	-5.48%	4.19%
Return After Taxes on Distributions	-6.84%	3.19%
Return After Taxes on Distributions and Sale of Fund Shares	-2.65%	2.92%
Class K	-5.38%	4.25%	9/30/2014
State Street Target Retirement 2025 Composite Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-5.55%	4.43%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	-4.38%	8.01%

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Charles McGinn is a Vice President of the Adviser and a Senior Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 1998.

Michael Narkiewicz is a Vice President of the Adviser and a Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 2013.

Table of Contents

Purchase and Sale of Fund Shares

Purchase Minimums

Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

Table of Contents

State Street Target Retirement 2030 Fund

Investment Objective

The investment objective of the State Street Target Retirement 2030 Fund (the “Target Retirement 2030 Fund” or the “Fund”) is to seek capital growth and income over the long term.

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”).

Shareholder Fees (fees paid directly from your investment)

	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class I	Class K
Management Fee	0.05%	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%	0.00%
Other Expenses ¹	0.29%	0.09%
Acquired Fund Fees and Expenses	0.06%	0.06%
Total Annual Fund Operating Expenses	0.40%	0.20%
Less Fee Waivers and/or Expense Reimbursements ²	(0.11%)	(0.11%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.29%	0.09%

Other Expenses have been restated to reflect current fees for Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.09% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

Table of Contents

	1 year	3 years	5 years	10 years
Class I	$30	$117	$213	$494
Class K	$ 9	$ 53	$102	$244

Portfolio Turnover:

Principal Investment Strategies

SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, manages the Target Retirement 2030 Fund using a proprietary asset allocation strategy. The Fund is a “fund of funds” that invests in a combination of mutual funds and ETFs sponsored by the Adviser or its affiliates (the “Underlying Funds”). The Underlying Funds may invest in a wide variety of asset classes, including equity and fixed-income securities of issuers anywhere in the world, including emerging markets investments, and including, among others, high yield, commodity, and real estate investments. The Underlying Funds may invest in obligations of domestic U.S. issuers, non-U.S. issuers, or both.

The Fund is intended for investors expecting to retire around the year 2030 and who are likely to stop making new investments in the Fund at that time. The Fund is designed for an investor who plans to withdraw the value of the investor's account gradually following that date. The Adviser seeks to optimize the Fund's “glide path” for the wealth accumulation, wealth preservation, and income generation phases of retirement planning and includes adjustments in the critical years immediately preceding and following the retirement date. For example, a Fund with a target retirement date far into the future will typically invest a greater portion of its assets in asset classes with higher risk profiles and the potential for higher returns. As the target date for a Fund approaches, the Adviser will adjust the asset allocation and risk profile of the Fund – its glide path – to what is generally seen to be a more conservative approach to reduce (but not to eliminate) risk by increasing the allocation to asset classes that have historically been subject to lower levels of volatility. A fund intended for investors who have already achieved retirement age would typically invest a greater portion of its assets in bonds and cash items, with a relatively smaller allocation to equity securities.

Table of Contents

The following table shows the Fund's strategic target allocations to the Underlying Funds as of the date of this Prospectus.

Underlying Funds		Target Retirement 2030 Fund
State Street Equity 500 Index II Portfolio		34.222%
State Street Small/Mid Cap Equity Index Portfolio		9.778%
State Street Global Equity ex-U.S. Index Portfolio		27.000%
State Street Aggregate Bond Index Portfolio		13.000%
SPDR Bloomberg Barclays TIPS ETF		2.500%
SPDR Bloomberg Barclays 1-10 Year TIPS ETF		0.000%
SPDR Bloomberg Barclays High Yield Bond ETF		3.500%
SPDR Dow Jones Global Real Estate ETF		0.000%
SPDR Portfolio Long Term Treasury ETF		10.000%
SPDR Portfolio Short Term Treasury ETF		0.000%
SPDR Portfolio Short Term Corporate Bond ETF		0.000%

Table of Contents

Principal Risks

In addition, the Fund is subject to the following principal risks:

Table of Contents

Longevity Risk: This is the risk that you will outlive your retirement assets.

Table of Contents

Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of a broad measure of market performance and those of a composite of accounts with similar investment objectives (the “Composite Index”). The Composite Index is a custom composite which comprises each index tracked by the Underlying Funds of the Fund. The S&P 500 Index is a well-known stock market index that includes common stocks of 500 companies from a number of sectors and that measures the performance of the large-cap sector of the market. The bar chart shows how the Class I shares' returns have varied for each full calendar year shown. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 5.11% (Q1, 2017)
Lowest Quarterly Return: -9.05% (Q4, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
Class I			9/30/2014
Return Before Taxes	-6.24%	4.43%
Return After Taxes on Distributions	-7.51%	3.58%
Return After Taxes on Distributions and Sale of Fund Shares	-3.06%	3.25%
Class K	-6.22%	4.49%	9/30/2014
State Street Target Retirement 2030 Composite Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-6.32%	4.63%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	-4.38%	8.01%

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Charles McGinn is a Vice President of the Adviser and a Senior Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 1998.

Michael Narkiewicz is a Vice President of the Adviser and a Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 2013.

Table of Contents

Purchase and Sale of Fund Shares

Purchase Minimums

Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

Table of Contents

State Street Target Retirement 2035 Fund

Investment Objective

The investment objective of the State Street Target Retirement 2035 Fund (the “Target Retirement 2035 Fund” or the “Fund”) is to seek capital growth and income over the long term.

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”).

Shareholder Fees (fees paid directly from your investment)

	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class I	Class K
Management Fee	0.05%	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%	0.00%
Other Expenses ¹	0.30%	0.10%
Acquired Fund Fees and Expenses	0.05%	0.05%
Total Annual Fund Operating Expenses	0.40%	0.20%
Less Fee Waivers and/or Expense Reimbursements ²	(0.11%)	(0.11%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.29%	0.09%

Other Expenses have been restated to reflect current fees for Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.09% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

Table of Contents

	1 year	3 years	5 years	10 years
Class I	$30	$117	$213	$494
Class K	$ 9	$ 53	$102	$244

Portfolio Turnover:

Principal Investment Strategies

SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, manages the Target Retirement 2035 Fund using a proprietary asset allocation strategy. The Fund is a “fund of funds” that invests in a combination of mutual funds and ETFs sponsored by the Adviser or its affiliates (the “Underlying Funds”). The Underlying Funds may invest in a wide variety of asset classes, including equity and fixed-income securities of issuers anywhere in the world, including emerging markets investments, and including, among others, high yield, commodity, and real estate investments. The Underlying Funds may invest in obligations of domestic U.S. issuers, non-U.S. issuers, or both.

The Fund is intended for investors expecting to retire around the year 2035 and who are likely to stop making new investments in the Fund at that time. The Fund is designed for an investor who plans to withdraw the value of the investor's account gradually following that date. The Adviser seeks to optimize the Fund's “glide path” for the wealth accumulation, wealth preservation, and income generation phases of retirement planning and includes adjustments in the critical years immediately preceding and following the retirement date. For example, a Fund with a target retirement date far into the future will typically invest a greater portion of its assets in asset classes with higher risk profiles and the potential for higher returns. As the target date for a Fund approaches, the Adviser will adjust the asset allocation and risk profile of the Fund – its glide path – to what is generally seen to be a more conservative approach to reduce (but not to eliminate) risk by increasing the allocation to asset classes that have historically been subject to lower levels of volatility. A fund intended for investors who have already achieved retirement age would typically invest a greater portion of its assets in bonds and cash items, with a relatively smaller allocation to equity securities.

Table of Contents

The following table shows the Fund's strategic target allocations to the Underlying Funds as of the date of this Prospectus.

Underlying Funds		Target Retirement 2035 Fund
State Street Equity 500 Index II Portfolio		36.537%
State Street Small/Mid Cap Equity Index Portfolio		11.963%
State Street Global Equity ex-U.S. Index Portfolio		30.000%
State Street Aggregate Bond Index Portfolio		11.000%
SPDR Bloomberg Barclays TIPS ETF		0.000%
SPDR Bloomberg Barclays 1-10 Year TIPS ETF		0.000%
SPDR Bloomberg Barclays High Yield Bond ETF		0.500%
SPDR Dow Jones Global Real Estate ETF		0.000%
SPDR Portfolio Long Term Treasury ETF		10.000%
SPDR Portfolio Short Term Treasury ETF		0.000%
SPDR Portfolio Short Term Corporate Bond ETF		0.000%

Table of Contents

Principal Risks

In addition, the Fund is subject to the following principal risks:

Table of Contents

Longevity Risk: This is the risk that you will outlive your retirement assets.

Table of Contents

Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of a broad measure of market performance and those of a composite of accounts with similar investment objectives (the “Composite Index”). The Composite Index is a custom composite which comprises each index tracked by the Underlying Funds of the Fund. The S&P 500 Index is a well-known stock market index that includes common stocks of 500 companies from a number of sectors and that measures the performance of the large-cap sector of the market. The bar chart shows how the Class I shares' returns have varied for each full calendar year shown. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 5.37% (Q1, 2017)
Lowest Quarterly Return: -9.98% (Q4, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
Class I			9/30/2014
Return Before Taxes	-6.88%	4.60%
Return After Taxes on Distributions	-8.04%	3.82%
Return After Taxes on Distributions and Sale of Fund Shares	-3.43%	3.42%
Class K	-6.85%	4.68%	9/30/2014
State Street Target Retirement 2035 Composite Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-6.94%	4.78%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	-4.38%	8.01%

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Charles McGinn is a Vice President of the Adviser and a Senior Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 1998.

Michael Narkiewicz is a Vice President of the Adviser and a Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 2013.

Table of Contents

Purchase and Sale of Fund Shares

Purchase Minimums

Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

Table of Contents

State Street Target Retirement 2040 Fund

Investment Objective

The investment objective of the State Street Target Retirement 2040 Fund (the “Target Retirement 2040 Fund” or the “Fund”) is to seek capital growth and income over the long term.

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”).

Shareholder Fees (fees paid directly from your investment)

	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class I	Class K
Management Fee	0.05%	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%	0.00%
Other Expenses ¹	0.31%	0.11%
Acquired Fund Fees and Expenses	0.05%	0.05%
Total Annual Fund Operating Expenses	0.41%	0.21%
Less Fee Waivers and/or Expense Reimbursements ²	(0.12%)	(0.12%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.29%	0.09%

Other Expenses have been restated to reflect current fees for Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.09% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

Table of Contents

	1 year	3 years	5 years	10 years
Class I	$30	$120	$218	$506
Class K	$ 9	$ 55	$106	$256

Portfolio Turnover:

Principal Investment Strategies

SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, manages the Target Retirement 2040 Fund using a proprietary asset allocation strategy. The Fund is a “fund of funds” that invests in a combination of mutual funds and ETFs sponsored by the Adviser or its affiliates (the “Underlying Funds”). The Underlying Funds may invest in a wide variety of asset classes, including equity and fixed-income securities of issuers anywhere in the world, including emerging markets investments, and including, among others, high yield, commodity, and real estate investments. The Underlying Funds may invest in obligations of domestic U.S. issuers, non-U.S. issuers, or both.

The Fund is intended for investors expecting to retire around the year 2040 and who are likely to stop making new investments in the Fund at that time. The Fund is designed for an investor who plans to withdraw the value of the investor's account gradually following that date. The Adviser seeks to optimize the Fund's “glide path” for the wealth accumulation, wealth preservation, and income generation phases of retirement planning and includes adjustments in the critical years immediately preceding and following the retirement date. For example, a Fund with a target retirement date far into the future will typically invest a greater portion of its assets in asset classes with higher risk profiles and the potential for higher returns. As the target date for a Fund approaches, the Adviser will adjust the asset allocation and risk profile of the Fund – its glide path – to what is generally seen to be a more conservative approach to reduce (but not to eliminate) risk by increasing the allocation to asset classes that have historically been subject to lower levels of volatility. A fund intended for investors who have already achieved retirement age would typically invest a greater portion of its assets in bonds and cash items, with a relatively smaller allocation to equity securities.

Table of Contents

The following table shows the Fund's strategic target allocations to the Underlying Funds as of the date of this Prospectus.

Underlying Funds		Target Retirement 2040 Fund
State Street Equity 500 Index II Portfolio		37.643%
State Street Small/Mid Cap Equity Index Portfolio		14.157%
State Street Global Equity ex-U.S. Index Portfolio		32.200%
State Street Aggregate Bond Index Portfolio		6.000%
SPDR Bloomberg Barclays TIPS ETF		0.000%
SPDR Bloomberg Barclays 1-10 Year TIPS ETF		0.000%
SPDR Bloomberg Barclays High Yield Bond ETF		0.000%
SPDR Dow Jones Global Real Estate ETF		0.000%
SPDR Portfolio Long Term Treasury ETF		10.000%
SPDR Portfolio Short Term Treasury ETF		0.000%
SPDR Portfolio Short Term Corporate Bond ETF		0.000%

Table of Contents

Principal Risks

In addition, the Fund is subject to the following principal risks:

Table of Contents

Longevity Risk: This is the risk that you will outlive your retirement assets.

Table of Contents

Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of a broad measure of market performance and those of a composite of accounts with similar investment objectives (the “Composite Index”). The Composite Index is a custom composite which comprises each index tracked by the Underlying Funds of the Fund. The S&P 500 Index is a well-known stock market index that includes common stocks of 500 companies from a number of sectors and that measures the performance of the large-cap sector of the market. The bar chart shows how the Class I shares' returns have varied for each full calendar year shown. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 5.58% (Q1, 2017)
Lowest Quarterly Return: -10.74% (Q4, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
Class I			9/30/2014
Return Before Taxes	-7.46%	4.69%
Return After Taxes on Distributions	-8.63%	3.88%
Return After Taxes on Distributions and Sale of Fund Shares	-3.74%	3.49%
Class K	-7.52%	4.70%	9/30/2014
State Street Target Retirement 2040 Composite Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-7.51%	4.87%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	-4.38%	8.01%

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Charles McGinn is a Vice President of the Adviser and a Senior Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 1998.

Michael Narkiewicz is a Vice President of the Adviser and a Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 2013.

Table of Contents

Purchase and Sale of Fund Shares

Purchase Minimums

Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

Table of Contents

State Street Target Retirement 2045 Fund

Investment Objective

The investment objective of the State Street Target Retirement 2045 Fund (the “Target Retirement 2045 Fund” or the “Fund”) is to seek capital growth and income over the long term.

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”).

Shareholder Fees (fees paid directly from your investment)

	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class I	Class K
Management Fee	0.05%	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%	0.00%
Other Expenses ¹	0.34%	0.14%
Acquired Fund Fees and Expenses	0.05%	0.05%
Total Annual Fund Operating Expenses	0.44%	0.24%
Less Fee Waivers and/or Expense Reimbursements ²	(0.15%)	(0.15%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.29%	0.09%

Other Expenses have been restated to reflect current fees for Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.09% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

Table of Contents

	1 year	3 years	5 years	10 years
Class I	$30	$126	$231	$540
Class K	$ 9	$ 62	$120	$291

Portfolio Turnover:

Principal Investment Strategies

SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, manages the Target Retirement 2045 Fund using a proprietary asset allocation strategy. The Fund is a “fund of funds” that invests in a combination of mutual funds and ETFs sponsored by the Adviser or its affiliates (the “Underlying Funds”). The Underlying Funds may invest in a wide variety of asset classes, including equity and fixed-income securities of issuers anywhere in the world, including emerging markets investments, and including, among others, high yield, commodity, and real estate investments. The Underlying Funds may invest in obligations of domestic U.S. issuers, non-U.S. issuers, or both.

The Fund is intended for investors expecting to retire around the year 2045 and who are likely to stop making new investments in the Fund at that time. The Fund is designed for an investor who plans to withdraw the value of the investor's account gradually following that date. The Adviser seeks to optimize the Fund's “glide path” for the wealth accumulation, wealth preservation, and income generation phases of retirement planning and includes adjustments in the critical years immediately preceding and following the retirement date. For example, a Fund with a target retirement date far into the future will typically invest a greater portion of its assets in asset classes with higher risk profiles and the potential for higher returns. As the target date for a Fund approaches, the Adviser will adjust the asset allocation and risk profile of the Fund – its glide path – to what is generally seen to be a more conservative approach to reduce (but not to eliminate) risk by increasing the allocation to asset classes that have historically been subject to lower levels of volatility. A fund intended for investors who have already achieved retirement age would typically invest a greater portion of its assets in bonds and cash items, with a relatively smaller allocation to equity securities.

Table of Contents

The following table shows the Fund's strategic target allocations to the Underlying Funds as of the date of this Prospectus.

Underlying Funds		Target Retirement 2045 Fund
State Street Equity 500 Index II Portfolio		38.242%
State Street Small/Mid Cap Equity Index Portfolio		16.558%
State Street Global Equity ex-U.S. Index Portfolio		34.200%
State Street Aggregate Bond Index Portfolio		1.000%
SPDR Bloomberg Barclays TIPS ETF		0.000%
SPDR Bloomberg Barclays 1-10 Year TIPS ETF		0.000%
SPDR Bloomberg Barclays High Yield Bond ETF		0.000%
SPDR Dow Jones Global Real Estate ETF		0.000%
SPDR Portfolio Long Term Treasury ETF		10.000%
SPDR Portfolio Short Term Treasury ETF		0.000%
SPDR Portfolio Short Term Corporate Bond ETF		0.000%

Table of Contents

Principal Risks

In addition, the Fund is subject to the following principal risks:

Table of Contents

Longevity Risk: This is the risk that you will outlive your retirement assets.

Table of Contents

Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of a broad measure of market performance and those of a composite of accounts with similar investment objectives (the “Composite Index”). The Composite Index is a custom composite which comprises each index tracked by the Underlying Funds of the Fund. The S&P 500 Index is a well-known stock market index that includes common stocks of 500 companies from a number of sectors and that measures the performance of the large-cap sector of the market. The bar chart shows how the Class I shares' returns have varied for each full calendar year shown. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 5.89% (Q1, 2017)
Lowest Quarterly Return: -11.63% (Q4, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
Class I			9/30/2014
Return Before Taxes	-7.96%	4.76%
Return After Taxes on Distributions	-9.08%	3.90%
Return After Taxes on Distributions and Sale of Fund Shares	-4.04%	3.52%
Class K	-7.94%	4.78%	9/30/2014
State Street Target Retirement 2045 Composite Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-8.07%	4.94%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	-4.38%	8.01%

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Charles McGinn is a Vice President of the Adviser and a Senior Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 1998.

Michael Narkiewicz is a Vice President of the Adviser and a Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 2013.

Table of Contents

Purchase and Sale of Fund Shares

Purchase Minimums

Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

Table of Contents

State Street Target Retirement 2050 Fund

Investment Objective

The investment objective of the State Street Target Retirement 2050 Fund (the “Target Retirement 2050 Fund” or the “Fund”) is to seek capital growth and income over the long term.

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”).

Shareholder Fees (fees paid directly from your investment)

	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class I	Class K
Management Fee	0.05%	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%	0.00%
Other Expenses ¹	0.38%	0.18%
Acquired Fund Fees and Expenses	0.05%	0.05%
Total Annual Fund Operating Expenses	0.48%	0.28%
Less Fee Waivers and/or Expense Reimbursements ²	(0.19%)	(0.19%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.29%	0.09%

Other Expenses have been restated to reflect current fees for Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.09% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

Table of Contents

	1 year	3 years	5 years	10 years
Class I	$30	$135	$250	$585
Class K	$ 9	$ 71	$138	$337

Portfolio Turnover:

Principal Investment Strategies

SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, manages the Target Retirement 2050 Fund using a proprietary asset allocation strategy. The Fund is a “fund of funds” that invests in a combination of mutual funds and ETFs sponsored by the Adviser or its affiliates (the “Underlying Funds”). The Underlying Funds may invest in a wide variety of asset classes, including equity and fixed-income securities of issuers anywhere in the world, including emerging markets investments, and including, among others, high yield, commodity, and real estate investments. The Underlying Funds may invest in obligations of domestic U.S. issuers, non-U.S. issuers, or both.

The Fund is intended for investors expecting to retire around the year 2050 and who are likely to stop making new investments in the Fund at that time. The Fund is designed for an investor who plans to withdraw the value of the investor's account gradually following that date. The Adviser seeks to optimize the Fund's “glide path” for the wealth accumulation, wealth preservation, and income generation phases of retirement planning and includes adjustments in the critical years immediately preceding and following the retirement date. For example, a Fund with a target retirement date far into the future will typically invest a greater portion of its assets in asset classes with higher risk profiles and the potential for higher returns. As the target date for a Fund approaches, the Adviser will adjust the asset allocation and risk profile of the Fund – its glide path – to what is generally seen to be a more conservative approach to reduce (but not to eliminate) risk by increasing the allocation to asset classes that have historically been subject to lower levels of volatility. A fund intended for investors who have already achieved retirement age would typically invest a greater portion of its assets in bonds and cash items, with a relatively smaller allocation to equity securities.

Table of Contents

The following table shows the Fund's strategic target allocations to the Underlying Funds as of the date of this Prospectus.

Underlying Funds		Target Retirement 2050 Fund
State Street Equity 500 Index II Portfolio		38.321%
State Street Small/Mid Cap Equity Index Portfolio		17.079%
State Street Global Equity ex-U.S. Index Portfolio		34.600%
State Street Aggregate Bond Index Portfolio		0.000%
SPDR Bloomberg Barclays TIPS ETF		0.000%
SPDR Bloomberg Barclays 1-10 Year TIPS ETF		0.000%
SPDR Bloomberg Barclays High Yield Bond ETF		0.000%
SPDR Dow Jones Global Real Estate ETF		0.000%
SPDR Portfolio Long Term Treasury ETF		10.000%
SPDR Portfolio Short Term Treasury ETF		0.000%
SPDR Portfolio Short Term Corporate Bond ETF		0.000%

Table of Contents

Principal Risks

In addition, the Fund is subject to the following principal risks:

Table of Contents

Longevity Risk: This is the risk that you will outlive your retirement assets.

Table of Contents

Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of a broad measure of market performance and those of a composite of accounts with similar investment objectives (the “Composite Index”). The Composite Index is a custom composite which comprises each index tracked by the Underlying Funds of the Fund. The S&P 500 Index is a well-known stock market index that includes common stocks of 500 companies from a number of sectors and that measures the performance of the large-cap sector of the market. The bar chart shows how the Class I shares' returns have varied for each full calendar year shown. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 5.71% (Q1, 2017)
Lowest Quarterly Return: -11.82% (Q4, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
Class I			9/30/2014
Return Before Taxes	-8.14%	4.63%
Return After Taxes on Distributions	-9.27%	3.77%
Return After Taxes on Distributions and Sale of Fund Shares	-4.14%	3.42%
Class K	-8.13%	4.65%	9/30/2014
State Street Target Retirement 2050 Composite Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-8.18%	4.91%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	-4.38%	8.01%

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Charles McGinn is a Vice President of the Adviser and a Senior Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 1998.

Michael Narkiewicz is a Vice President of the Adviser and a Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 2013.

Table of Contents

Purchase and Sale of Fund Shares

Purchase Minimums

Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

Table of Contents

State Street Target Retirement 2055 Fund

Investment Objective

The investment objective of the State Street Target Retirement 2055 Fund (the “Target Retirement 2055 Fund” or the “Fund”) is to seek capital growth and income over the long term.

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”).

Shareholder Fees (fees paid directly from your investment)

	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class I	Class K
Management Fee	0.05%	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%	0.00%
Other Expenses ¹	0.55%	0.35%
Acquired Fund Fees and Expenses	0.05%	0.05%
Total Annual Fund Operating Expenses	0.65%	0.45%
Less Fee Waivers and/or Expense Reimbursements ²	(0.36%)	(0.36%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.29%	0.09%

Other Expenses have been restated to reflect current fees for Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.09% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

Table of Contents

	1 year	3 years	5 years	10 years
Class I	$30	$172	$327	$776
Class K	$ 9	$108	$216	$532

Portfolio Turnover:

Principal Investment Strategies

SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, manages the Target Retirement 2055 Fund using a proprietary asset allocation strategy. The Fund is a “fund of funds” that invests in a combination of mutual funds and ETFs sponsored by the Adviser or its affiliates (the “Underlying Funds”). The Underlying Funds may invest in a wide variety of asset classes, including equity and fixed-income securities of issuers anywhere in the world, including emerging markets investments, and including, among others, high yield, commodity, and real estate investments. The Underlying Funds may invest in obligations of domestic U.S. issuers, non-U.S. issuers, or both.

The Fund is intended for investors expecting to retire around the year 2055 and who are likely to stop making new investments in the Fund at that time. The Fund is designed for an investor who plans to withdraw the value of the investor's account gradually following that date. The Adviser seeks to optimize the Fund's “glide path” for the wealth accumulation, wealth preservation, and income generation phases of retirement planning and includes adjustments in the critical years immediately preceding and following the retirement date. For example, a Fund with a target retirement date far into the future will typically invest a greater portion of its assets in asset classes with higher risk profiles and the potential for higher returns. As the target date for a Fund approaches, the Adviser will adjust the asset allocation and risk profile of the Fund – its glide path – to what is generally seen to be a more conservative approach to reduce (but not to eliminate) risk by increasing the allocation to asset classes that have historically been subject to lower levels of volatility. A fund intended for investors who have already achieved retirement age would typically invest a greater portion of its assets in bonds and cash items, with a relatively smaller allocation to equity securities.

Table of Contents

The following table shows the Fund's strategic target allocations to the Underlying Funds as of the date of this Prospectus.

Underlying Funds		Target Retirement 2055 Fund
State Street Equity 500 Index II Portfolio		38.321%
State Street Small/Mid Cap Equity Index Portfolio		17.079%
State Street Global Equity ex-U.S. Index Portfolio		34.600%
State Street Aggregate Bond Index Portfolio		0.000%
SPDR Bloomberg Barclays TIPS ETF		0.000%
SPDR Bloomberg Barclays 1-10 Year TIPS ETF		0.000%
SPDR Bloomberg Barclays High Yield Bond ETF		0.000%
SPDR Dow Jones Global Real Estate ETF		0.000%
SPDR Portfolio Long Term Treasury ETF		10.000%
SPDR Portfolio Short Term Treasury ETF		0.000%
SPDR Portfolio Short Term Corporate Bond ETF		0.000%

Table of Contents

Principal Risks

In addition, the Fund is subject to the following principal risks:

Table of Contents

Longevity Risk: This is the risk that you will outlive your retirement assets.

Table of Contents

Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of a broad measure of market performance and those of a composite of accounts with similar investment objectives (the “Composite Index”). The Composite Index is a custom composite which comprises each index tracked by the Underlying Funds of the Fund. The S&P 500 Index is a well-known stock market index that includes common stocks of 500 companies from a number of sectors and that measures the performance of the large-cap sector of the market. The bar chart shows how the Class I shares' returns have varied for each full calendar year shown. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 5.91% (Q1, 2017)
Lowest Quarterly Return: -11.75% (Q4, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
Class I			9/30/2014
Return Before Taxes	-7.93%	4.74%
Return After Taxes on Distributions	-9.12%	3.85%
Return After Taxes on Distributions and Sale of Fund Shares	-3.96%	3.50%
Class K	-7.94%	4.71%	9/30/2014
State Street Target Retirement 2055 Composite Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-8.18%	4.91%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	-4.38%	8.01%

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Charles McGinn is a Vice President of the Adviser and a Senior Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 1998.

Michael Narkiewicz is a Vice President of the Adviser and a Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 2013.

Table of Contents

Purchase and Sale of Fund Shares

Purchase Minimums

Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

Table of Contents

State Street Target Retirement 2060 Fund

Investment Objective

The investment objective of the State Street Target Retirement 2060 Fund (the “Target Retirement 2060 Fund” or the “Fund”) is to seek capital growth and income over the long term.

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”).

Shareholder Fees (fees paid directly from your investment)

	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class I	Class K
Management Fee	0.05%	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%	0.00%
Other Expenses ¹	1.71%	1.51%
Acquired Fund Fees and Expenses	0.06%	0.06%
Total Annual Fund Operating Expenses	1.82%	1.62%
Less Fee Waivers and/or Expense Reimbursements ²	(1.53)%	(1.53)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.29%	0.09%

Other Expenses have been restated to reflect current fees for Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.09% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

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	1 year	3 years	5 years	10 years
Class I	$30	$423	$842	$2,011
Class K	$ 9	$361	$736	$1,792

Portfolio Turnover:

Principal Investment Strategies

SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, manages the Target Retirement 2060 Fund using a proprietary asset allocation strategy. The Fund is a “fund of funds” that invests in a combination of mutual funds and ETFs sponsored by the Adviser or its affiliates (the “Underlying Funds”). The Underlying Funds may invest in a wide variety of asset classes, including equity and fixed-income securities of issuers anywhere in the world, including emerging markets investments, and including, among others, high yield, commodity, and real estate investments. The Underlying Funds may invest in obligations of domestic U.S. issuers, non-U.S. issuers, or both.

The Fund is intended for investors expecting to retire around the year 2060 and who are likely to stop making new investments in the Fund at that time. The Fund is designed for an investor who plans to withdraw the value of the investor's account gradually following that date. The Adviser seeks to optimize the Fund's “glide path” for the wealth accumulation, wealth preservation, and income generation phases of retirement planning and includes adjustments in the critical years immediately preceding and following the retirement date. For example, a Fund with a target retirement date far into the future will typically invest a greater portion of its assets in asset classes with higher risk profiles and the potential for higher returns. As the target date for a Fund approaches, the Adviser will adjust the asset allocation and risk profile of the Fund – its glide path – to what is generally seen to be a more conservative approach to reduce (but not to eliminate) risk by increasing the allocation to asset classes that have historically been subject to lower levels of volatility. A fund intended for investors who have already achieved retirement age would typically invest a greater portion of its assets in bonds and cash items, with a relatively smaller allocation to equity securities.

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The following table shows the Fund's strategic target allocations to the Underlying Funds as of the date of this Prospectus.

Underlying Funds		Target Retirement 2060 Fund
State Street Equity 500 Index II Portfolio		38.321%
State Street Small/Mid Cap Equity Index Portfolio		17.079%
State Street Global Equity ex-U.S. Index Portfolio		34.600%
State Street Aggregate Bond Index Portfolio		0.000%
SPDR Bloomberg Barclays TIPS ETF		0.000%
SPDR Bloomberg Barclays 1-10 Year TIPS ETF		0.000%
SPDR Bloomberg Barclays High Yield Bond ETF		0.000%
SPDR Dow Jones Global Real Estate ETF		0.000%
SPDR Portfolio Long Term Treasury ETF		10.000%
SPDR Portfolio Short Term Treasury ETF		0.000%
SPDR Portfolio Short Term Corporate Bond ETF		0.000%

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Principal Risks

In addition, the Fund is subject to the following principal risks:

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Longevity Risk: This is the risk that you will outlive your retirement assets.

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Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of a broad measure of market performance and those of a composite of accounts with similar investment objectives (the “Composite Index”). The Composite Index is a custom composite which comprises each index tracked by the Underlying Funds of the Fund. The S&P 500 Index is a well-known stock market index that includes common stocks of 500 companies from a number of sectors and that measures the performance of the large-cap sector of the market. The bar chart shows how the Class I shares' returns have varied for each full calendar year shown. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 5.85% (Q1, 2017)
Lowest Quarterly Return: -11.76% (Q4, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
Class I			9/30/2014
Return Before Taxes	-8.13%	4.63%
Return After Taxes on Distributions	-9.52%	3.44%
Return After Taxes on Distributions and Sale of Fund Shares	-3.94%	3.30%
Class K	-8.13%	4.64%	9/30/2014
State Street Target Retirement 2060 Composite Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-8.18%	4.91%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	-4.38%	8.01%

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Charles McGinn is a Vice President of the Adviser and a Senior Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 1998.

Michael Narkiewicz is a Vice President of the Adviser and a Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 2013.

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Purchase and Sale of Fund Shares

Purchase Minimums

Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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State Street Target Retirement Fund

Investment Objective

The investment objective of the State Street Target Retirement Fund (the “Target Retirement Fund” or the “Fund”) is to seek current income and, secondarily, capital growth.

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”).

Shareholder Fees (fees paid directly from your investment)

	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class I	Class K
Management Fee	0.05%	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%	0.00%
Other Expenses ¹	0.39%	0.19%
Acquired Fund Fees and Expenses	0.15%	0.15%
Total Annual Fund Operating Expenses	0.59%	0.39%
Less Fee Waivers and/or Expense Reimbursements ²	(0.30%)	(0.30%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.29%	0.09%

Other Expenses have been restated to reflect current fees for Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.09% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

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	1 year	3 years	5 years	10 years
Class I	$30	$159	$299	$709
Class K	$ 9	$ 95	$189	$463

Portfolio Turnover:

Principal Investment Strategies

SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, manages the Target Retirement Fund using a proprietary asset allocation strategy. The Fund is a “fund of funds” that invests in a combination of mutual funds and ETFs sponsored by the Adviser or its affiliates (the “Underlying Funds”). The Underlying Funds may invest in a wide variety of asset classes, including equity and fixed-income securities of issuers anywhere in the world, including emerging markets investments, and including, among others, high yield, commodity, and real estate investments. The Underlying Funds may invest in obligations of domestic U.S. issuers, non-U.S. issuers, or both.

The Fund's assets are allocated among the Underlying Funds according to a target asset allocation strategy that emphasizes fixed income, but also includes a smaller allocation to equity and certain other asset classes. The Fund is intended for use as part of an overall investment strategy by an investor who is already in retirement.

The following table shows the Fund's strategic target allocations to the Underlying Funds as of the date of this Prospectus.

Underlying Funds		Target Retirement Fund
State Street Equity 500 Index II Portfolio		16.745%
State Street Small/Mid Cap Equity Index Portfolio		3.155%
State Street Global Equity ex-U.S. Index Portfolio		10.100%
State Street Aggregate Bond Index Portfolio		20.000%
SPDR Bloomberg Barclays TIPS ETF		0.000%
SPDR Bloomberg Barclays 1-10 Year TIPS ETF		18.000%
SPDR Bloomberg Barclays High Yield Bond ETF		7.000%
SPDR Dow Jones Global Real Estate ETF		5.000%
SPDR Portfolio Long Term Treasury ETF		0.000%
SPDR Portfolio Short Term Treasury ETF		16.000%
SPDR Portfolio Short Term Corporate Bond ETF		4.000%

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Principal Risks

In addition, the Fund is subject to the following principal risks:

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104

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Longevity Risk: This is the risk that you will outlive your retirement assets.

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Small-, Mid- and Micro-Capitalization Securities Risk: The securities of small-, mid- and micro-capitalization companies may be more volatile and may involve more risk than the securities of larger companies. These companies may have limited product lines, markets or financial resources, may lack the competitive strength of larger companies, and may depend on a few key employees. In addition, these companies may have been recently organized and may have little or no track record of success. The securities of smaller companies may trade less frequently and in smaller volumes than more widely held securities. Some securities of smaller issuers may be illiquid or may be restricted as to resale, and their values may have significant volatility. The Fund may be unable to liquidate its positions in such securities at any time, or at a favorable price, in order to meet the Fund's obligations. Returns on investments in securities of small-, mid- and micro-capitalization companies could trail the returns on investments in securities of larger companies.

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Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of a broad measure of market performance and those of a composite of accounts with similar investment objectives (the “Composite Index”). The Composite Index is a custom composite which comprises each index tracked by the Underlying Funds of the Fund. The S&P 500 Index is a well-known stock market index that includes common stocks of 500 companies from a number of sectors and that measures the performance of the large-cap sector of the market. The bar chart shows how the Class I shares' returns have varied for each full calendar year shown. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 2.67% (Q1, 2017)
Lowest Quarterly Return: -4.02% (Q4, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

	One Year	Since Inception	Inception Date
Class I			9/30/2014
Return Before Taxes	-2.50%	2.73%
Return After Taxes on Distributions	-3.83%	1.80%
Return After Taxes on Distributions and Sale of Fund Shares	-1.13%	1.80%
Class K	-2.50%	2.70%	9/30/2014
State Street Target Retirement Composite Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-2.59%	2.92%
Bloomberg Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)	0.01%	2.00%

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Charles McGinn is a Vice President of the Adviser and a Senior Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 1998.

Michael Narkiewicz is a Vice President of the Adviser and a Portfolio Manager in the Investment Solutions Group. He joined the Adviser in 2013.

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Purchase and Sale of Fund Shares

Purchase Minimums

Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objectives, Principal Strategies and Risks

Investment Objective

State Street Target Retirement Funds

The Target Retirement Fund, Target Retirement 2015 Fund, Target Retirement 2020 Fund, Target Retirement 2025 Fund, Target Retirement 2030 Fund, Target Retirement 2035 Fund, Target Retirement 2040 Fund, Target Retirement 2045 Fund, Target Retirement 2050 Fund, Target Retirement 2055 Fund and Target Retirement 2060 Fund are referred to collectively in this Prospectus as the “Target Retirement Funds” or the “Funds.”

Principal Investment Strategies

The Adviser invests each Target Retirement Fund among Underlying Funds according to a proprietary asset allocation. Each Fund's (except for the Retirement Fund) name refers to the approximate retirement year of the investors for whom the Fund's asset allocation strategy is intended. As the target date for a Fund approaches, the Adviser will adjust the asset allocation and risk profile of the Fund (except for the Retirement Fund) – its glide path – to a what is generally seen to be a more conservative approach to reduce (but not eliminate) risk by increasing the allocation to asset classes that have historically been subject to lower levels of volatility. For example, a Fund with a target retirement date far into the future will typically invest a greater portion of its assets in asset classes with higher risk profiles and the potential for higher returns. By contrast, the Retirement Fund is intended for investors in their retirement years. The Adviser allocates the Fund's assets according to a target asset allocation that emphasizes fixed income funds but also includes an allocation to equity and certain other funds.

When the target asset allocation of another Target Retirement Fund matches the Retirement Fund's target asset allocation, it is expected that the Fund will be combined with the Retirement Fund, and the Fund's shareholders will become shareholders of the Retirement Fund. This may be done without a vote of shareholders if the Trustees determine at the time of the proposed combination that combining the Funds is in the best interests of the Funds and their shareholders.

The Adviser intends to manage each Target Retirement Fund according to the Fund's target asset allocation strategy, and does not intend to trade actively among Underlying Funds or to attempt to capture short-term market opportunities as primary activities. The Adviser may modify the target asset allocation strategy or the selection of Underlying Funds for any Target Retirement Fund from time to time, and may invest in other Underlying Funds, including any Underlying Funds that may be created in the future.

Each Target Retirement Fund will bear a pro rata share of its Underlying Funds' expenses. Each Target Retirement Fund also bears all of the risks associated with the investment strategies used by its Underlying Funds.

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The tables below set forth each Target Retirement Fund's current strategic target allocations to the Underlying Funds as of the date of this Prospectus and show how each Fund's allocations among asset classes are expected generally to become more conservative as the target retirement date approaches ( i.e ., more emphasis on fixed income and less on equity).

Underlying Funds	Retirement	2015	2020	2025	2030	2035
State Street Equity 500 Index II Portfolio	16.745%	18.172%	24.195%	30.518%	34.222%	36.537%
State Street Small/Mid Cap Equity Index Portfolio	3.155%	3.228%	4.955%	7.382%	9.778%	11.963%
State Street Global Equity ex-U.S. Index Portfolio	10.100%	11.100%	16.350%	22.600%	27.000%	30.000%
State Street Aggregate Bond Index Portfolio	20.000%	21.000%	25.000%	17.000%	13.000%	11.000%
SPDR Bloomberg Barclays TIPS ETF	0.000%	0.000%	0.000%	8.500%	2.500%	0.000%
SPDR Bloomberg Barclays 1-10 Year TIPS ETF	18.000%	19.500%	17.500%	0.000%	0.000%	0.000%
SPDR Bloomberg Barclays High Yield Bond ETF	7.000%	7.000%	6.500%	6.000%	3.500%	0.500%
SPDR Dow Jones Global Real Estate ETF	5.000%	5.000%	4.500%	2.000%	0.000%	0.000%
SPDR Portfolio Long Term Treasury ETF	0.000%	0.000%	1.000%	6.000%	10.000%	10.000%
SPDR Portfolio Short Term Treasury ETF	16.000%	12.000%	0.000%	0.000%	0.000%	0.000%
SPDR Portfolio Short Term Corporate Bond ETF	4.000%	3.000%	0.000%	0.000%	0.000%	0.000%

Underlying Funds	2040	2045	2050	2055	2060
State Street Equity 500 Index II Portfolio	37.643%	38.242%	38.321%	38.321%	38.321%
State Street Small/Mid Cap Equity Index Portfolio	14.157%	16.558%	17.079%	17.079%	17.079%
State Street Global Equity ex-U.S. Index Portfolio	32.200%	34.200%	34.600%	34.600%	34.600%
State Street Aggregate Bond Index Portfolio	6.000%	1.000%	0.000%	0.000%	0.000%
SPDR Bloomberg Barclays TIPS ETF	0.000%	0.000%	0.000%	0.000%	0.000%
SPDR Bloomberg Barclays 1-10 Year TIPS ETF	0.000%	0.000%	0.000%	0.000%	0.000%
SPDR Bloomberg Barclays High Yield Bond ETF	0.000%	0.000%	0.000%	0.000%	0.000%
SPDR Dow Jones Global Real Estate ETF	0.000%	0.000%	0.000%	0.000%	0.000%
SPDR Portfolio Long Term Treasury ETF	10.000%	10.000%	10.000%	10.000%	10.000%
SPDR Portfolio Short Term Treasury ETF	0.000%	0.000%	0.000%	0.000%	0.000%
SPDR Portfolio Short Term Corporate Bond ETF	0.000%	0.000%	0.000%	0.000%	0.000%

The Funds' actual allocations are expected to differ over time. The Adviser periodically reviews each Fund's target allocations to underlying investment options and may, at any time, in its discretion, change the target allocations or deviate from the target allocations. The Adviser may modify the selection of Underlying Funds from time to time, and may invest in other Underlying Funds, including any Underlying Funds that may be created in the future. The tables are presented for illustrative purposes only.

A brief description of the Underlying Funds can be found in Appendix A. Appendix A lists the Underlying Funds that each Fund may utilize as of the date of this Prospectus.

Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure. Except as otherwise stated, references in this section to “the Fund” or “a Fund” may relate to the Fund, one or more Underlying Funds, or both. The risks described below may arise out of the Fund's direct investments or the Fund's investments in one or more of the Underlying Funds.

Asset Allocation Risk . A Fund's investment performance depends upon the successful allocation of the Fund's assets among asset classes, geographical regions, industry sectors, and specific issuers and investments. There is no guarantee that a Fund's allocation techniques and decisions will produce the desired results. It is possible to lose money on an investment in a Fund as a result of these allocation decisions.

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Below Investment-Grade Securities Risk . Securities rated below investment-grade and unrated securities of comparable credit quality (commonly known as “high-yield bonds” or “junk bonds”) lack strong investment-grade characteristics, are considered predominantly speculative with respect to the issuer's continuing ability to make principal and interest payments, and are subject to greater levels of credit, liquidity and market risk than higher-rated securities. They can involve a substantially greater risk of default than higher-rated securities, and their values can decline significantly over short periods of time. Issuers of lower-quality debt securities may have substantially greater risk of insolvency or bankruptcy than issuers of higher-quality debt securities. In the event the issuer of a debt security held by a Fund defaults on its payments or becomes insolvent or bankrupt, the Fund may not receive the return it was promised on the investment and could lose its entire investment. The lower ratings of junk bonds reflect a greater possibility that actual or perceived adverse changes in the financial condition of the issuer or in general economic conditions, or an unanticipated rise in interest rates, may impair the ability of the issuer to make payments of interest and principal. If this were to occur, the values of such securities held by a Fund may fall substantially and a Fund could lose some or all of the value of its investment. Lower-quality debt securities tend to be more sensitive to adverse news about the issuer, or the market or economy in general, than higher quality debt securities. The market for lower quality debt securities can be less liquid than for higher quality debt securities, especially during periods of recession or general market decline, which could make it difficult at times for a Fund to sell certain securities at prices used in calculating a Fund's net asset value. These securities may have significant volatility.

Call/Prepayment Risk . Call/prepayment risk is the risk that an issuer will exercise its right to pay principal on an obligation held by a Fund earlier than expected or required. This may occur, for example, when there is a decline in interest rates, and an issuer of bonds or preferred stock redeems the bonds or stock in order to replace them with obligations on which it is required to pay a lower interest or dividend rate. It may also occur when there is an unanticipated increase in the rate at which mortgages or other receivables underlying mortgage- or asset-backed securities held by a Fund are prepaid. In any such case, a Fund may be forced to invest the prepaid amounts in lower-yielding investments, resulting in a decline in the Fund's income.

Commodities Risk . Commodity prices can have significant volatility, and exposure to commodities can cause the net asset value of Fund Shares to decline or fluctuate in a rapid and unpredictable manner. The values of physical commodities may be affected by changes in overall market movements, real or perceived inflationary trends, commodity index volatility, changes in interest rates or currency exchange rates, population growth and changing demographics, international economic, political and regulatory developments, and factors affecting a particular region, industry or commodity, such as drought, floods, or other weather conditions, livestock disease, changes in storage costs, trade embargoes, competition from substitute products, transportation bottlenecks or shortages, fluctuations in supply and demand, and tariffs. Also, a liquid secondary market may not exist for certain commodity investments, which may make it difficult for the Fund to sell them at a desirable price or at the price at which it is carrying them. The commodity markets are subject to temporary distortions or other disruptions due to, among other factors, lack of liquidity, the participation of speculators, and government regulation and other actions.

Counterparty Risk . A Fund will be subject to credit risk with respect to the counterparties with which the Fund enters into derivatives contracts and other transactions such as repurchase agreements or reverse repurchase agreements. A Fund's ability to profit from these types of investments and transactions will depend on the willingness and ability of its counterparty to perform its obligations. If a counterparty fails to meet its contractual obligations, a Fund may be unable to terminate or realize any gain on the investment or transaction, resulting in a loss to the Fund. A Fund may experience significant delays in obtaining any recovery in an insolvency, bankruptcy, or other reorganization proceeding involving its counterparty (including recovery of any collateral posted by it) and may obtain only a limited recovery or may obtain no recovery in such circumstances. If a Fund holds collateral posted by its counterparty, it may be delayed or prevented from realizing on the collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty. Under applicable law or contractual provisions, including if a Fund enters into an investment or transaction with a financial institution and such financial institution (or an affiliate of the financial institution) experiences financial difficulties, then the Fund may in certain situations be prevented or delayed from exercising its rights to terminate the investment or transaction, or to realize on any collateral and may result in the suspension of payment and delivery obligations of the parties under such investment or transactions or in another institution being substituted for that financial institution without the consent of the Fund. Further, a Fund may be subject to “bail-in” risk under applicable law whereby, if required by the financial institution's authority, the financial institution's liabilities could be written down, eliminated or converted into equity or an alternative instrument of ownership. A bail-in of a financial institution may result in a reduction in value of some or all of its securities and, if a Fund holds such securities or has entered into a transaction with such a financial security when a bail-in occurs, such Fund may also be similarly impacted.

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perceived decline in creditworthiness of an issuer of a fixed-income security held by a Fund may result in a decrease in the value of the security. It is possible that the ability of an issuer to meet its obligations will decline substantially during the period when a Fund owns securities of the issuer or that the issuer will default on its obligations or that the obligations of the issuer will be limited or restructured.

Currency Risk. Investments in issuers in different countries are often denominated in currencies other than the U.S. dollar. Changes in the values of those currencies relative to the U.S. dollar may have a positive or negative effect on the values of a Fund's investments denominated in those currencies. The values of other currencies relative to the U.S. dollar may fluctuate in response to, among other factors, interest rate changes, intervention (or failure to intervene) by national governments, central banks, or supranational entities such as the International Monetary Fund, the imposition of currency controls, and other political or regulatory developments. Currency values can decrease significantly both in the short term and over the long term in response to these and other developments. Continuing uncertainty as to the status of the Euro and the Economic and Monetary Union of the European Union (the “EMU”) has created significant volatility in currency and financial markets generally. Any partial or complete dissolution of the EMU, or any continued uncertainty as to its status, could have significant adverse effects on currency and financial markets, and on the values of a Fund's portfolio investments.

Depositary Receipts Risk . American Depositary Receipts (“ADRs”) are typically trust receipts issued by a U.S. bank or trust company that evidence an indirect interest in underlying securities issued by a foreign entity. Global Depositary Receipts (“GDRs”), European Depositary Receipts (“EDRs”), and other types of depositary receipts are typically issued by non-U.S. banks or financial institutions to evidence an interest in underlying securities issued by either a U.S. or a non-U.S. entity. Investments in non-U.S. issuers through ADRs, GDRs, EDRs, and other types of depositary receipts generally involve risks applicable to other types of investments in non-U.S. issuers. Investments in depositary receipts may be less liquid and more volatile than the underlying securities in their primary trading market. If a depositary receipt is denominated in a different currency than its underlying securities, a Fund will be subject to the currency risk of both the investment in the depositary receipt and the underlying security. There may be less publicly available information regarding the issuer of the securities underlying a depositary receipt than if those securities were traded directly in U.S. securities markets. Depositary receipts may or may not be sponsored by the issuers of the underlying securities, and information regarding issuers of securities underlying unsponsored depositary receipts may be more limited than for sponsored depositary receipts. The values of depositary receipts may decline for a number of reasons relating to the issuers or sponsors of the depositary receipts, including, but not limited to, insolvency of the issuer or sponsor. Holders of depositary receipts may have limited or no rights to take action with respect to the underlying securities or to compel the issuer of the receipts to take action. The prices of depositary receipts may differ from the prices of securities upon which they are based. To the extent the Fund invests in depositary receipts based on securities included in the Index, such differences in prices may increase index tracking risk.

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response to interest rate changes or other market developments or as a result of the counterparty's credit quality; the potential for the derivative transaction not to have the effect the Adviser anticipated or a different or less favorable effect than the Adviser anticipated; the failure of the counterparty to the derivative transaction to perform its obligations under the transaction or to settle a trade; possible mispricing or improper valuation of the derivative instrument; imperfect correlation in the value of a derivative with the asset, rate, or index underlying the derivative; the risk that a Fund may be required to post collateral or margin with its counterparty, and will not be able to recover the collateral or margin in the event of the counterparty's insolvency or bankruptcy; the risk that a Fund will experience losses on its derivatives investments and on its other portfolio investments, even when the derivatives investments may be intended in part or entirely to hedge those portfolio investments; the risks specific to the asset underlying the derivative instrument; lack of liquidity for the derivative instrument, including without limitation absence of a secondary trading market; the potential for reduced returns to a Fund due to losses on the transaction and an increase in volatility; the potential for the derivative transaction to have the effect of accelerating the recognition of gain; and legal risks arising from the documentation relating to the derivative transaction.

Emerging Markets Risk . Investments in emerging markets are generally subject to a greater risk of loss than investments in developed markets. This may be due to, among other things, the possibility of greater market volatility, lower trading volume and liquidity, greater risk of expropriation, nationalization, and social, political and economic instability, greater reliance on a few industries, international trade or revenue from particular commodities, less developed accounting, legal and regulatory systems, higher levels of inflation, deflation or currency devaluation, greater risk of market shut down, and more significant governmental limitations on investment policy as compared to those typically found in a developed market. In addition, issuers (including governments) in emerging market countries may have less financial stability than in other countries. The securities of emerging market companies may trade less frequently and in smaller volumes than more widely held securities. Market disruptions or substantial market corrections may limit very significantly the liquidity of securities of certain companies in a particular country or geographic region, or of all companies in the country or region. A Fund may be unable to liquidate its positions in such securities at any time, or at a favorable price, in order to meet the Fund's obligations. There is also the potential for unfavorable action such as embargo and acts of war. As a result, there will tend to be an increased risk of price volatility in investments in emerging market countries, which may be magnified by currency fluctuations relative to the U.S. dollar. Settlement and asset custody practices for transactions in emerging markets may differ from those in developed markets. Such differences may include possible delays in settlement and certain settlement practices, such as delivery of securities prior to receipt of payment, which increase the likelihood of a “failed settlement.” Failed settlements can result in losses. For these and other reasons, investments in emerging markets are often considered speculative.

Equity Investing Risk . The market prices of equity securities owned by a Fund may go up or down, sometimes rapidly or unpredictably. The value of a security may decline for a number of reasons that may directly relate to the issuer, such as management performance, financial leverage, non-compliance with regulatory requirements, and reduced demand for the issuer's goods or services. The values of equity securities also may decline due to general industry or market conditions that are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates, or adverse investor sentiment generally. In addition, equity markets tend to move in cycles, which may cause stock prices to fall over short or extended periods of time.

Extension Risk. During periods of rising interest rates, the average life of certain types of securities may be extended because of slower-than-expected principal payments. This may increase the period of time during which an investment earns a below-market interest rate, increase the security's duration and reduce the value of the security. Extension risk may be heightened during periods of adverse economic conditions generally, as payment rates decline due to higher unemployment levels and other factors.

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Income Risk. A Fund's income may decline due to falling interest rates or other factors. Issuers of securities held by a Fund may call or redeem the securities during periods of falling interest rates, and the Fund would likely be required to reinvest in securities paying lower interest rates. If an obligation held by a Fund is prepaid, the Fund may have to reinvest the prepayment in other obligations paying income at lower rates. A reduction in the income earned by a Fund may limit the Fund's ability to achieve its objective.

Inflation Risk . Inflation risk is the risk that the value of assets or income from investments will be less in the future as inflation decreases the value of money. As inflation increases, the values of a Fund's assets can decline.

Inflation-Indexed Securities Risk . The principal amount of an inflation-indexed security typically increases with inflation and decreases with deflation, as measured by a specified index. It is possible that, in a period of declining inflation rates, a Fund could receive at maturity less than the initial principal amount of an inflation-indexed security. Although the holders of U.S. TIPS receive no less than the par value of the security at maturity, if a Fund purchases U.S. TIPS in the secondary market whose principal values have previously been adjusted upward and there is a period of subsequent declining inflation rates, a Fund may receive at maturity less than it invested. Depending on the changes in inflation rates during the period a Fund holds an inflation-indexed security, a Fund may earn less on the security than on a conventional bond. Changes in the values of inflation-indexed securities may be difficult to predict, and it is possible that an investment in such securities will have an effect different from that anticipated by the Adviser. The principal amounts of inflation-indexed securities are typically only adjusted periodically, and changes in the values of the securities may only approximately reflect changes in inflation rates and may occur substantially after the changes in inflation rates in question occur.

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ger durations. Changes in governmental policy, including changes in central bank monetary policy, could cause interest rates to rise rapidly, or cause investors to expect a rapid rise in interest rates. This could lead to heightened levels of interest rate, volatility and liquidity risks for the fixed income markets generally and could have a substantial and immediate effect on the values of a Fund's investments.

IPO Risk . Each Fund may at times have the opportunity to invest in securities offered in initial public offerings (“IPOs”). IPOs involve companies that have no public operating history and therefore entail more risk than established public companies. The prices of securities offered in IPOs can have significant volatility and a Fund may lose money on an investment in such securities. IPOs may not be available to a Funds at all times, and a Funds may not always invest in IPOs offered to it. Investments in IPOs may have a substantial beneficial effect on a Fund's investment performance. A Fund's investment return earned during a period of substantial investment in IPOs may not be sustained during other periods when a Fund makes more limited, or no, investments in IPOs. There can be no assurance that the Funds will have the opportunity to invest in IPOs that are made available to other clients of the Adviser.

Large Shareholder Risk . To the extent a large proportion of the shares of a Fund are highly concentrated or held by a small number of shareholders (or a single shareholder), including funds or accounts over which the Adviser has investment discretion, a Fund is subject to the risk that these shareholders will purchase or redeem Fund shares in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of a Fund to conduct its investment program. For example, they could require a Fund to sell portfolio securities or purchase portfolio securities unexpectedly and incur substantial transaction costs and/or accelerate the realization of taxable income and/or gains to shareholders, or a Fund may be required to sell its more liquid portfolio investments to meet a large redemption, in which case a Fund's remaining assets may be less liquid, more volatile, and more difficult to price. A Fund may hold a relatively large proportion of its assets in cash in anticipation of large redemptions, diluting its investment returns.

Liquidity Risk . Liquidity risk is the risk that a Fund may not be able to dispose of securities or close out derivatives transactions readily at a favorable time or prices (or at all) or at prices approximating those at which a Fund currently values them. For example, certain investments may be subject to restrictions on resale, may trade in the over-the-counter market or in limited volume, or may not have an active trading market. Illiquid securities may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value. It may be difficult for a Fund to value illiquid securities accurately. The market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. Disposal of illiquid securities may entail registration expenses and other transaction costs that are higher than those for liquid securities. A Fund may seek to borrow money to meet its obligations (including among other things redemption obligations) if it is unable to dispose of illiquid investments, resulting in borrowing expenses and possible leveraging of the Fund. In some cases, due to unanticipated levels of illiquidity a Fund may choose to meet its redemption obligations wholly or in part by distributions of assets in-kind.

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In compliance with the SEC's new liquidity risk management rule applicable to open-end mutual funds, the Funds recently established a liquidity risk management program. The rule's impact on the Funds, and on the open-end fund industry in general, is not yet fully known, but the rule could affect a Fund's performance and its ability to achieve its investment objectives. While the liquidity risk management program attempts to assess and manage liquidity risk, there is no guarantee it will be effective in its operations and may not reduce the liquidity risk inherent in the Fund's investments.

Longevity Risk. This is the risk that you will outlive your retirement assets.

Management Risk . Each Fund is actively managed. The Adviser's judgments about the attractiveness, relative value, or potential appreciation of a particular sector, security, commodity or investment strategy may prove to be incorrect, and may cause a Fund to incur losses. There can be no assurance that the Adviser's investment techniques and decisions will produce the desired results.

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Modeling Risk . The Adviser uses quantitative models in an effort to enhance returns and manage risk. Any imperfections, errors or limitations in these models could limit any benefit to a Fund from the use of the models, or could result in incorrect outputs or in investment outcomes different from or opposite to those expected or desired by the Adviser. These models may make simplifying assumptions that limit their effectiveness and may draw from historical data that does not adequately identify or reflect factors necessary to an appropriate or useful output. There can be no assurance that the models will behave as expected in all market conditions. In addition, computer programming used to create quantitative models, or the data on which such models operate, might contain one or more errors. Such errors might never be detected, or might be detected only after a Fund has sustained a loss (or reduced performance) related to such errors.

Mortgage-Related and Other Asset-Backed Securities Risk . Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed income investments. The liquidity of mortgage-related and asset-backed securities may change over time. Mortgage-related securities represent a participation in, or are secured by, mortgage loans. Other asset-backed securities are typically structured like mortgage-related securities, but instead of mortgage loans or interests in mortgage loans, the underlying assets may include, for example, items such as motor vehicle installment sales or installment loan contracts, leases on various types of real and personal property, and receivables from credit card agreements. During periods of falling interest rates, mortgage-related and other asset-backed securities, which typically provide the issuer with the right to prepay the security prior to maturity, may be prepaid, which may result in a Fund having to reinvest the proceeds in other investments at lower interest rates. During periods of rising interest rates, the average life of mortgage-related and other asset-backed securities may extend because of slower-than expected principal payments. This may lock in a below market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. As a result, mortgage-related and other asset-backed securities may have less potential for capital appreciation during periods of declining interest rates than other debt securities of comparable maturities, although they may have a similar risk of decline in market values during periods of rising interest rates. Prepayment rates are difficult to predict and the potential impact of prepayments on the value of a mortgage-related or other asset-backed security depends on the terms of the instrument and can result in significant volatility. The price of a mortgage-related or other asset-backed security also depends on the credit quality and adequacy of the underlying assets or collateral. Mortgage-related or other asset-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) will generally entail greater credit risk than obligations guaranteed by the U.S. Government. Defaults on the underlying assets, if any, may impair the value of a mortgage-related or other asset-backed security. For some asset-backed securities in which a Fund invest, such as those backed by credit card receivables, the underlying cash flows may not be supported by a security interest in a related asset. Moreover, the values of mortgage-related and other asset-backed securities may be substantially dependent on the servicing of the underlying asset pools, and are therefore subject to risks associated with the negligence or malfeasance by their servicers and to the credit risk of their servicers. In certain situations, the mishandling of related documentation may also affect the rights of securities holders in and to the underlying collateral. There may be legal and practical limitations on the enforceability of any security interest granted with respect to underlying assets, or the value of the underlying assets, if any, may be insufficient if the issuer defaults.

Non-U.S. Securities Risk . Investments in securities of non-U.S. issuers (including depositary receipts) entail risks not typically associated with investing in securities of U.S. issuers. Similar risks may apply to securities traded on a U.S. securities exchange that are issued by entities with significant exposure to non-U.S. countries. In certain countries, legal remedies available to investors may be more limited than those available with regard to U.S. investments. Because non-U.S. securities are typically denominated and traded in currencies other than the U.S. dollar, the value of the Fund's assets, to the extent they are non-U.S. dollar denominated, may be affected favorably or unfavorably by currency exchange rates, exchange control regulations, and restrictions or prohibitions on the repatriation of non-U.S. currencies. Income and gains with respect to investments in certain countries may be subject to withholding and other taxes. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, and financial reporting standards, regulatory framework and practices comparable to those in the United States. The securities of some non-U.S. entities are less liquid and at times more volatile than securities of comparable U.S. entities, and could become subject to sanctions or embargoes that adversely affect a Fund's investment. Non-U.S. transaction costs, such as brokerage commissions and custody costs may be higher than in the U.S. In addition, there may be a possibility of nationalization or expropriation of assets, imposition of currency exchange controls, confiscatory taxation, and diplomatic developments that could adversely affect the values of a Fund's investments in certain non-U.S. countries. Investments in securities

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of non-U.S. issuers also are subject to foreign political and economic risk not associated with U.S. investments, meaning that political events (civil unrest, national elections, changes in political conditions and foreign relations, imposition of exchange controls and repatriation restrictions), social and economic events (labor strikes, rising inflation) and natural disasters occurring in a country where a Fund invests could cause the Fund's investments in that country to experience gains or losses.

Real Estate Sector Risk . There are special risks associated with investment in securities of companies engaged in real property markets, including without limitation Real estate investment trusts (“REITs”) and real estate operating companies. An investment in a real property company may be subject to risks similar to those associated with direct ownership of real estate, including, by way of example, the possibility of declines in the value of real estate, losses from casualty or condemnation, and changes in local and general economic conditions, supply and demand, interest rates, environmental liability, zoning laws, regulatory limitations on rents, property taxes, and operating expenses. An investment in a real property company is subject to additional risks, such as poor performance by the manager of the real property company, adverse changes in tax laws, difficulties in valuing and disposing of real estate, and the effect of general declines in stock prices. Some real property companies have limited diversification because they invest in a limited number of properties, a narrow geographic area, or a single type of property. Also, the organizational documents of a real property company may contain provisions that make changes in control of the company difficult and time-consuming. As a shareholder in a real property company, a Fund, and indirectly a Fund's shareholders, would bear their ratable shares of the real property company's expenses and would at the same time continue to pay their own fees and expenses.

REIT Risk . REITs are subject to the risks associated with investing in the securities of real property companies. In particular, REITs may be affected by changes in the values of the underlying properties that they own or operate. Further, REITs are dependent upon specialized management skills, and their investments may be concentrated in relatively few properties, or in a small geographic area or a single property type. REITs are also subject to heavy cash flow dependency and, as a result, are particularly reliant on the proper functioning of capital markets, as well as defaults by borrowers and self-liquidation. A variety of economic and other factors may adversely affect a lessee's ability to meet its obligations to a REIT. In the event of a default by a lessee, the REIT may experience delays in enforcing its rights as a lessor and may incur substantial costs associated with protecting its investments. In addition, a REIT could possibly fail to qualify for favorable tax treatment under the Internal Revenue Code of 1986, as amended (the “Code”), or to maintain its exemptions from registration under the U.S. Investment Company Act of 1940, as amended (the “1940 Act”), which could have adverse consequences for a Fund. Investments in REITs are also subject to the risks affecting equity markets generally.

Reinvestment Risk. Income from a Fund's portfolio may decline when the Fund invests the proceeds from investment income, sales of portfolio securities or matured, traded or called debt obligations. For instance, during periods of declining interest rates, an issuer of debt obligations may exercise an option to redeem securities prior to maturity, forcing a Fund to reinvest the proceeds in lower-yielding securities. A decline in income received by a Fund from its investments is likely to have a negative effect on the yield and total return of the Fund Shares.

Restricted Securities Risk . A Fund may hold securities that have not been registered for sale to the public under the U.S. federal securities laws pursuant to an exemption from registration. These securities may be less liquid than securities registered for sale to the general public. The liquidity of a restricted security may be affected by a number of factors, including, among others: (i) the creditworthiness of the issuer; (ii) the frequency of trades and quotes for the security; (iii) the number of dealers willing to purchase or sell the security and the number of other potential purchasers; (iv) dealer undertakings to make a market in the security; (v) the nature of any legal restrictions governing trading in the security; and (vi) the nature of the security and the nature of marketplace trades. There can be no assurance that a liquid trading market will exist at any time for any particular restricted security. Also, restricted securities may be difficult to value because market quotations may not be readily available, and the securities may have significant volatility.

Risk of Investment in Other Pools . When a Fund invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected. A Fund is exposed indirectly to all of the risks applicable to an investment in such other pool. In addition, lack of liquidity in the underlying pool could result in its value being more volatile than the underlying portfolio of securities, and may limit the ability of a Fund to sell or redeem its interest in the pool at a time or at a price it might consider desirable. The investment policies and limitations of the other pool may not be the same as those of the Fund; as a result, the Fund may be subject to additional or different risks, or may achieve a reduced investment return, as a result of its investment in another pool. If a pool is an exchange-traded fund or other product traded on a securities exchange or otherwise actively traded, its shares may trade at a premium or discount to their NAV, an effect that might be more pronounced in less liquid markets. A Fund bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Fund may invest, leading to potential conflicts of interest. For example, the Adviser or its affiliates may receive fees based on the amount of assets invested in the pool. Investment by a Fund in the pool may be beneficial to the Adviser or an affiliate in the management of the pool, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest a Fund's assets in a pool sponsored or managed by the Adviser or its affiliates in lieu of investments

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by the Fund directly in portfolio securities, or may have an incentive to invest in the pool over a pool sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by a Fund in a pool sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Fund does so.

Settlement Risk . Markets in different countries have different clearance and settlement procedures and in certain markets there have been times when settlements have been unable to keep pace with the volume of transactions. Delays in settlement may increase credit risk to a Fund, limit the ability of a Fund to reinvest the proceeds of a sale of securities, hinder the ability of a Fund to lend its portfolio securities, and potentially subject a Fund to penalties for its failure to deliver to on-purchasers of securities whose delivery to a Fund was delayed. Delays in the settlement of securities purchased by a Fund may limit the ability of a Fund to sell those securities at times and prices it considers desirable, and may subject a Fund to losses and costs due to its own inability to settle with subsequent purchasers of the securities from it. A Fund may be required to borrow monies it had otherwise expected to receive in connection with the settlement of securities sold by it, in order to meet its obligations to others. Limits on the ability of a Fund to purchase or sell securities due to settlement delays could increase any variance between a Fund's performance and that of its benchmark index.

Small-, Mid- and Micro-Capitalization Securities Risk . The securities of small-, mid- and micro-capitalization companies may be more volatile and may involve more risk than the securities of larger companies. These companies may have limited product lines, markets or financial resources, may lack the competitive strength of larger companies, and may depend on a few key employees. In addition, these companies may have been recently organized and may have little or no track record of success. The securities of smaller companies may trade less frequently and in smaller volumes than more widely held securities. The prices of these securities may fluctuate more sharply than those of other securities, and a Fund may experience some difficulty in establishing or closing out positions in these securities at prevailing market prices. There may be less publicly available information about the issuers of these securities or less market interest in these securities than in the case of larger companies, both of which can cause significant price volatility. Some securities of smaller issuers may be illiquid or may be restricted as to resale. A Fund may be unable to liquidate its positions in such securities at any time, or at a favorable price, in order to meet a Fund's obligations. Returns on investments in securities of small-, mid- and micro-capitalization companies could trail the returns on investments in securities of larger companies.

Target Date Assumption Risk . This is the risk that assumptions and forecasts used by SSGA in developing the Fund's asset allocation glide path are not in line with actual future investment returns and participant savings activities, which could result in losses near, at, or after the target date year or could result in the Fund not providing adequate income at and through retirement.

Technology Sector Risk (principal risk for the Target Retirement 2050 Fund, Target Retirement 2055 Fund and Target Retirement 2060 Fund). Market or economic factors impacting technology companies and companies that rely heavily on technological advances could have a major effect on the value of the Fund's investments. The value of stocks of technology companies and companies that rely heavily on technology is particularly vulnerable to rapid changes in technology product cycles, rapid product obsolescence, government regulation and competition, both domestically and internationally, including competition from foreign competitors with lower production costs. Stocks of technology companies and companies that rely heavily on technology, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market. Technology companies are heavily dependent on patent and intellectual property rights, the loss or impairment of which may adversely affect profitability. Additionally, companies in the technology sector may face dramatic and often unpredictable changes in growth rates and competition for the services of qualified personnel.

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issuing agency, instrumentality, or enterprise. Although U.S. government-sponsored enterprises such as the Federal Home Loan Mortgage Corporation (“Freddie Mac”) and the Federal National Mortgage Association (“Fannie Mae”) may be chartered or sponsored by Congress, they are not funded by Congressional appropriations, and their securities are not issued by the U.S. Treasury nor supported by the full faith and credit of the U.S. government. There is no assurance that the U.S. government would provide financial support to its agencies and instrumentalities if not required to do so. In addition, certain governmental entities have been subject to regulatory scrutiny regarding their accounting policies and practices and other concerns that may result in legislation, changes in regulatory oversight and/or other consequences that could adversely affect the credit quality, availability, or investment character of securities issued by these entities. The value and liquidity of U.S. government securities may be affected adversely by changes in the ratings of those securities. Securities issued by the U.S. Treasury historically have been considered to present minimal credit risk. The downgrade in the long-term U.S. credit rating by at least one major rating agency has introduced greater uncertainty about the ability of the U.S. to repay its obligations. A further credit rating downgrade or a U.S. credit default could decrease the value and increase the volatility of a Fund's investments.

U.S. Treasury Obligations Risk . U.S. Treasury obligations may differ from other securities in their interest rates, maturities, times of issuance and other characteristics. Similar to other issuers, changes to the financial condition or credit rating of the U.S. government may cause the value of a Fund's U.S. Treasury obligations to decline. The total public debt of the United States as a percent of gross domestic product grew rapidly after the financial crisis of 2008 and has remained at a historically high level. Although high debt levels do not necessarily indicate or cause economic problems, they may create certain systemic risks if sound debt management practices are not implemented. A high national debt level may increase market pressures to meet government funding needs, which may drive debt cost higher and cause a country to sell additional debt, thereby increasing refinancing risk. A high national debt also raises concerns that a government will not be able to make principal or interest payments when they are due. In the worst case, unsustainable debt levels can cause a decline in the value of the dollar (which may lead to inflation), and can prevent the U.S. government from implementing effective counter-cyclical fiscal policy in economic downturns. On August 5, 2011, Standard & Poor's Ratings Services downgraded U.S. Treasury securities from AAA rating to AA+ rating. Standard & Poor's Ratings Services stated that its decision was prompted by its view on the rising public debt burden and its perception of greater policymaking uncertainty. A downgrade of the ratings of U.S. government debt obligations, which are often used as a benchmark for other borrowing arrangements, could result in higher interest rates for individual and corporate borrowers, cause disruptions in the international bond markets and have a substantial negative effect on the U.S. economy. A downgrade of U.S. Treasury securities from another ratings agency or a further downgrade below AA+ rating by Standard & Poor's Ratings Services may cause the value of the Fund's U.S. Treasury obligations to decline. In recent years, impasses in Congress regarding the federal budget have caused repeated temporary Federal government shutdowns. While Congress has temporarily suspended the debt limit from time to time, the risks that the U.S. government will not adopt a long-term budget or deficit reduction plan, of one or more additional Federal government shutdowns or of future failures to not increase the Federal government's debt limit, may affect investor and consumer confidence and may adversely impact financial markets and the broader economy, perhaps suddenly and to a significant degree.

Valuation Risk . Some portfolio holdings, potentially a large portion of a Fund's investment portfolio, may be valued on the basis of factors other than market quotations. This may occur more often in times of market turmoil or reduced liquidity. There are multiple methods that can be used to value a portfolio holding when market quotations are not readily available. The value established for any portfolio holding at a point in time might differ from what would be produced using a different methodology or if it had been priced using market quotations. Portfolio holdings that are valued using techniques other than market quotations, including “fair valued” securities, may be subject to greater fluctuation in their valuations from one day to the next than if market quotations were used. Technological issues or other service disruption issues involving third-party service providers may cause a Fund to value its investments incorrectly. In addition, there is no assurance that a Fund could sell or close out a portfolio position for the value established for it at any time, and it is possible that a Fund would incur a loss because a portfolio position is sold or closed out at a discount to the valuation established by a Fund at that time. Investors who purchase or redeem Fund Shares on days when a Fund is holding fair-valued investments may receive fewer or more shares or lower or higher redemption proceeds than they would have received if a Fund had not fair-valued the holding(s) or had used a different valuation methodology.

When-Issued, TBA and Delayed Delivery Securities Risk. A Fund may purchase securities on a when-issued, to be announced (“TBA”) or delayed delivery basis and may purchase securities on a forward commitment basis. The purchase price of the securities is typically fixed at the time of the commitment, but delivery and payment can take place a month or more after the date of the commitment. The prices of the securities so purchased or sold are subject to market fluctuations. At the time of delivery of the securities, the value may be more or less than the purchase or sale price. Purchase of securities on a when-issued, TBA, delayed delivery, or forward commitment basis may give rise to investment leverage, and may result in increased volatility of a Fund's net asset value. Default by, or bankruptcy of, a counterparty to a when-issued, TBA or delayed delivery transaction would expose a Fund to possible losses because of an adverse market action, expenses or delays in connection with the purchase or sale of the pools specified in such transaction. Recently finalized rules of the Financial Industry Regulatory Authority, Inc. would impose mandatory margin require-

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ments for certain types of when-issued, TBA delayed delivery or forward commitment transactions, with limited exceptions. Such transactions historically have not been required to be collateralized, and, if those rules are implemented, mandatory collateralization could increase the cost of such transactions and impose added operational complexity.

Additional Information About Non-Principal Investment Strategies and Risks

Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Funds) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, a Fund, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect a Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect a Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject a Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of a Fund inaccessible or inaccurate or incomplete. A Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. A Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. Each Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Funds. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which each Fund invest, which could result in material adverse consequences for such issuers, and may cause a Fund's investment in such securities to lose value.

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Portfolio Turnover Risk . A Fund may engage in frequent trading of its portfolio securities. Fund turnover generally involves a number of direct and indirect costs and expenses to a Fund, including, for example, brokerage commissions, dealer mark-ups and bid/asked spreads, and transaction costs on the sale of securities and reinvestment in other securities. The costs related to increased portfolio turnover have the effect of reducing a Fund's investment return, and the sale of securities by a Fund may result in the realization of taxable capital gains, including short-term capital gains, which are taxed to individuals as ordinary income.

Temporary Defensive Positions . In response to actual or perceived adverse market, economic, political, or other conditions, a Fund may (but will not necessarily), without notice, depart from its principal investment strategies by temporarily investing for defensive purposes. Temporary defensive positions may include, but are not limited to, cash, cash equivalents, U.S. government securities, repurchase agreements collateralized by such securities, money market funds, and high-quality debt investments. If a Fund invests for defensive purposes, it may not achieve its investment objective. In addition, the defensive strategy may not work as intended.

Portfolio Holdings Disclosure

The Funds' portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

Investment Adviser

Each Fund has entered into an investment advisory agreement with the Adviser, pursuant to which the Adviser will manage the Fund's assets for compensation paid at the annual rate, set forth below, of the Fund's average daily net assets.

Target Retirement 2015 Fund	0.05%
Target Retirement 2020 Fund	0.05%
Target Retirement 2025 Fund	0.05%
Target Retirement 2030 Fund	0.05%
Target Retirement 2035 Fund	0.05%
Target Retirement 2040 Fund	0.05%
Target Retirement 2045 Fund	0.05%
Target Retirement 2050 Fund	0.05%
Target Retirement 2055 Fund	0.05%
Target Retirement 2060 Fund	0.05%
Target Retirement Fund	0.05%

Total Annual Fund Operating Expense Waivers . SSGA FM, as the investment adviser to each Fund, is contractually obligated, through April 30, 2020, (i) to waive up to the full amount of the advisory fee payable by a Fund, and/or (ii) to reimburse a Fund to the extent that Total Annual Fund Operating Expenses (exclusive of nonrecurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.09% of average daily net assets on an annual basis. These waiver and/or reimbursement arrangements may not be terminated prior to April 30, 2020 except with approval of the Funds' Board of Trustees.

A discussion regarding the Board's consideration of the Funds' Investment Advisory Agreement is provided in the Funds' Semi-Annual Report to Shareholders for the period ended June 30, 2018.

Portfolio Management

Key professionals involved in the day-to-day portfolio management of the Funds include the following:

Charles McGinn is a Vice President of SSGA and the Adviser and a Senior Portfolio Manager in the Investment Solutions Group (ISG), where he manages a variety of portfolios. As a member of the Exposure Management Team within ISG, he is responsible for the oversight of over $10 billion worth of client assets with exposure to equities and fixed income invested globally. As a result, Mr. McGinn has extensive experience in trading derivatives. In addition to managing several of the group's separate accounts, he is part of the team responsible for managing the Target Retirement series of portfolios as well as being the lead portfolio manager of the group's Country Selection strategy. As the lead portfolio manager of the Country Selection strategy, Mr. McGinn is responsible for recommending all of the investment calls. He is also an active participant in making tactical calls in all of the portfolios where ISG

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has been given discretion. In addition, Mr. McGinn is responsible for the management of the SEI Dynamic Asset Allocation Funds registered in the United Sates and the United Kingdom. Prior to his current role, Mr. McGinn was an operations analyst at SSGA, where he specialized in developed and emerging market equity funds. He has been working in the investment management field since 1988. Mr. McGinn is a graduate of Salem State College, where he earned a Bachelor of Science in Business Administration.

Michael Narkiewicz is a Principal of SSGA and the Adviser and a Portfolio Manager in the Investment Solutions Group (ISG), where he is responsible for managing a variety of customized multi-asset class portfolios, including strategic, tactical and real asset strategies. Prior to his current role, Mr. Narkiewicz was a portfolio specialist within the Global Equity Beta Solutions Group. In that role, he focused on supporting index equity products as a subject matter expert and a liaison between the portfolio management team and the client-facing functions at SSGA. His responsibilities included investment research and analysis as well as product positioning and messaging across multiple investment strategies. Before joining SSGA in 2013, Mr. Narkiewicz was a senior portfolio analyst at Shepherd Kaplan and an equity trader at Congress Asset Management. He holds a Bachelor of Science degree in Finance from Bentley University and a Master of Business Administration with a concentration in Finance from the D'Amore-McKim School of Business at Northeastern University.

Additional information about the portfolio managers' compensation, other accounts managed by the portfolio managers, and the portfolio managers' ownership of the Funds is available in the SAI.

Other Fund Services

The Administrator, Sub-Administrator and Custodian

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Funds' transfer agent and dividend disbursing agent (the “Transfer Agent”).

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Funds' distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

Additional Information

Shareholder Information

Determination of Net Asset Value

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in a foreign market, and those securities may trade on weekends or other days when each Fund does not price its shares. Consequently, the NAV of each Fund's Shares may change on days when shareholders are not able to purchase or redeem the Fund's Shares. Purchase and redemption orders for Fund Shares are processed, respectively, at the NAV next determined after the Fund accepts a purchase order or receives a redemption request in good form. Each Fund values each security or other investment pursuant to guidelines adopted by the Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Funds' Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii) a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by a Fund occurs after the close of a related exchange but before the determination of a Fund's NAV. Attempts to determine the fair value of securities or other investments introduce an element of subjectivity to the pricing of securities or other investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the price a Fund would have received had it sold the investment. To the extent that a Fund invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the funds. The prospectuses of these funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

Investing in State Street Institutional Investment Trust Shares

Purchasing Shares

Choosing a Share Class

The Funds offer two classes of shares through this Prospectus: Class I and Class K, available to you subject to the eligibility requirements set forth below.

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	Class I	Class K
Availability	Limited to certain investors, including: • Certain banks, broker-dealers and other Financial Intermediaries. • Certain employer- sponsored retirement plans. • Certain employees or affiliates of State Street Corporation or its affiliates	Limited to certain investors, including certain qualified recordkeepers and employer-sponsored retirement plans.
Minimum Initial Investment	$1,000,000. The investment minimum may be modified, waived or reduced for certain types of investors (e.g., 401(k) or 403(b) plans) and investments as well as for certain fee- based programs where an agreement is in place.	$10,000,000. The investment minimum may be modified, waived or reduced for certain types of investors ( e.g ., 401(k) or 403(b) plans) and investments as well as for certain fee- based programs where an agreement is in place.
Maximum Investment	None.	None.
Initial (Front-End) Sales Charge	No. Entire purchase price is invested in shares of a Fund.	No. Entire purchase price is invested in shares of a Fund.
Deferred (CDSC) Sales Charge	No.	No.
Distribution and Service (Rule 12b-1) Fees	No.	No.
Redemption Fees	No.	No.

Class I

Class I shares are available to the following categories of investors and/or investments:

1.	Banks, broker-dealers and other financial institutions (including registered investment advisers and financial planners) purchasing shares on behalf of their clients in:

•	discretionary and non-discretionary advisory programs;
•	fund supermarkets;
•	asset allocation programs;
•	other programs in which the client pays an asset-based fee for advice or for executing transactions in Fund Shares or for otherwise participating in the program; or
•	certain other investment programs that do not charge an asset-based fee;

2.	Qualified state tuition plans described in Section 529 of the Code and donor-advised charitable gift funds (subject to all applicable terms and conditions);
3.	Defined contribution, defined benefit and other employer-sponsored employee benefit plans, whether or not qualified under the Code;
4.	Certain other registered open-end investment companies whose shares are distributed by SSGA FD;
5.	Certain retirement and deferred compensation programs established by State Street Corporation or its affiliates for their employees or the Funds' Trustees;
6.	Current or retired Directors or Trustees of the State Street Funds, officers and employees of SSGA, and any of its subsidiaries, such persons' spouses, and children under the age of 21, and trust accounts for which any of such person is a beneficiary;
7.	Investments made in connection with certain mergers and/or reorganizations as approved by the Adviser;

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8.	The reinvestment of dividends from Class I shares in additional Class I shares of a Fund; and
9.	Qualified recordkeepers with a distribution and/or fund servicing agreement maintained with SSGA FD.

The minimum investment for Class I shares is $1,000,000.

Class K

Class K shares are available to the following categories of investors:

1.	Qualified recordkeepers with an applicable agreement maintained with SSGA FD;
2.	Defined benefit plans, defined contribution plans, endowments and foundations with greater than $10,000,000 in a qualified tax-exempt plan;
3.	Employers with greater than $10,000,000 in the aggregate between qualified and non-qualified plans that they sponsor; and
4.	Defined contribution, defined benefit and other employer-sponsored employee benefit plans, whether or not qualified under the Code.

The minimum investment for Class K shares is $10,000,000.

How to Initiate a Purchase Request

Investing in the State Street Funds Through a Financial Intermediary

Please be sure to check Exchanging Shares and Frequent-Trading Limits below.

How to Pay for a Purchase

By Check . You may send a check to make initial or additional purchases to your fund account. Make your check payable to “State Street Funds” and include the appropriate fund name and account number ( e.g ., “State Street Target Retirement 2015 Fund—a/c #xxx”) in the memo section of the check.

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Trade Dates-Purchases

If your purchase request is not in good order, it may be rejected.

For further information about purchase transactions, consult our website at www.ssgafunds.com or see Contacting the State Street Funds.

Other Purchase Policies You Should Know

Redeeming Shares

By Telephone. You may call the State Street Funds to request a redemption of shares. See Contacting the State Street Funds .

By Mail. You may send a written request to the State Street Funds to redeem from a Fund account or to make an exchange. See Contacting the State Street Funds .

Please be sure to check Exchanging Shares and Frequent-Trading Limits below.

Trade Date-Redemptions

The trade date for any redemption request received in good order will depend on the day and time the State Street Funds receive your request in good order and the manner in which you are redeeming.

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How to Receive Redemption Proceeds

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Other Redemption Policies that You Should Know

Address Changes. If your address of record has been changed within thirty (30) days of the redemption request, the request must be in writing and bear a medallion guarantee.

Significant/Unusual Economic or Market Activity. During periods of significant or unusual economic or market activity, you may encounter delays attempting to give instructions by phone.

Minimum Account Size . If, due to your redemptions or exchanges, your account balance for a Fund falls below a minimum amount set by the Fund (presently, the minimum initial investment of your selected share class), the Fund may choose to redeem the shares in the account and mail you the proceeds. You will receive 60 days' notice that your account will be closed unless an investment is made to increase the account balance to the required minimum. Failure to bring your account balance to the required minimum within the prescribed period may result in the Fund closing your account at the NAV next determined on the day the account is closed, and mailing the proceeds to you at the address shown on the Fund's records.

Large Redemptions. Requests for redemptions over $50,000 must be in writing and bear a medallion guarantee.

Exchanging Shares

Share Class Conversions

Frequent-Trading Limits

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As a means to protect each State Street Fund and its shareholders from Excessive Trading:

•	The State Street Funds' transfer agent compiles, monitors and reports account-level information on omnibus and underlying shareholder/participant activity. Depending on the account type, monitoring will be performed on a daily, monthly, quarterly and/or annual basis;
•	The State Street Funds' distributor has obtained information from each Financial Intermediary holding shares in an omnibus account with the State Street Funds regarding whether the Financial Intermediary has adopted and maintains procedures that are reasonably designed to protect the Funds against harmful short-term trading; and
•	With respect to State Street Funds that invest in securities that trade on foreign markets, pursuant to the State Street Funds' fair valuation procedures, pricing adjustments may be made based on information received from a third-party, multi-factor fair valuation pricing service.

The State Street Funds' distributor has detailed procedures that document the transparency oversight and monitoring processes performed by the State Street Funds' transfer agent.

Service Options

Dividend and Capital Gain Distribution Option

Please refer to Dividends, Distributions and Tax Considerations below for additional information.

Automatic Withdrawal Plan

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Telephone Redemptions and Exchanges

Automatic Investment Plan

Additional Shareholder Information

Account Transfers

Responsibility for Fraud

Right to Change Policies

In addition to the rights expressly stated elsewhere in this Prospectus, the State Street Funds reserve the right, in the future, to:

1.	Alter, add, or discontinue any conditions of purchase (including eligibility requirements), redemption, exchange, service, or privilege at any time;
2.	Accept initial purchases by telephone;
3.	Freeze any account and/or suspend account services if the State Street Funds has received reasonable notice of a dispute regarding the assets in an account, including notice of a dispute between the registered or beneficial account owners, or if we reasonably believe a fraudulent transaction may occur or has occurred;
4.	Temporarily freeze any account and/or suspend account services upon initial notification to the State Street Funds of the death of the shareholder until the State Street Funds receive required documentation in good order;
5.	Alter, impose, discontinue, or waive any redemption fee, account service fee, or other fees charged to a group of shareholders; and
6.	Redeem an account or suspend account privileges, without the owner's permission to do so, in cases of threatening conduct or activity the State Street Funds believe to be suspicious, fraudulent, or illegal.

Unclaimed Property

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Dividends, Distributions and Tax Considerations

Distribution Options. You can choose from four different distribution options as indicated on the application:

•	Reinvestment Option—Dividends and capital gain distributions will be automatically reinvested in additional shares of a Fund. If you do not indicate a choice on the application, this option will be automatically assigned.
•	Income-Earned Option—Capital gain distributions will be automatically reinvested, but a check, direct deposit or wire will be sent for each dividend distribution.
•	Cash Option—A check, wire or direct deposit will be sent for each dividend and capital gain distribution.
•	Direct Dividends Option—Dividends and capital gain distributions will be automatically invested in another identically registered State Street Fund of the same share class.

Delivery of Documents to Accounts Sharing an Address

Tax Considerations

The following discussion is a summary of some important U.S. federal income tax considerations generally applicable to an investment in a Fund. Your investment in a Fund may have other tax implications. Please consult your tax advisor about federal, state, local, foreign or other tax laws applicable to you. Investors, including non-U.S. investors, may wish to consult the SAI tax section for additional disclosure. Each of the Funds seeks to achieve its investment objective by investing in a combination of Underlying Funds each of which intends to qualify and be treated as a regulated investment company for U.S. federal income tax purposes such that substantially all of the Funds' income will result from distributions from such Underlying Funds. Therefore, as applicable, and except as otherwise stated, references in this section to the assets owned or income earned by a Fund will include such assets and income of the corresponding Underlying Funds.

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deemed to have owned) for more than one year that are properly reported by a Fund as capital gain dividends generally will be treated as long-term capital gain includible in your net capital gain and taxed to individuals at reduced rates. Distributions of gains from investments that a Fund owned (or is deemed to have owned) for one year or less generally will be taxable to you as ordinary income. Distributions of investment income properly reported by a Fund as derived from “qualified dividend income,” which will not include income from the Fund's portfolio securities on loan, are taxed to individuals at the rates applicable to net capital gain, provided holding period and other requirements are met by both the shareholder and the Fund. Distributions are taxable to you even if they are paid from income or gains earned by a Fund before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares.

A Fund's income from or proceeds of dispositions of its investments in non-U.S. assets may be subject to non-U.S. withholding or other taxes, which will reduce the yield on those investments. In certain instances, a Fund may be entitled to elect to pass through to its shareholders a credit (or deduction, for a shareholder that itemizes deductions and so chooses) for foreign taxes (if any) borne with respect to foreign securities income earned by the Fund. If the Fund so elects, shareholders will include in gross income from foreign sources their pro rata shares of such taxes, if any, treated as paid by the Fund. There can be no assurance that a Fund will make such election, even if it is eligible to do so. If the Fund does not qualify for or does not make such election, shareholders will not be entitled separately to claim a credit or deduction with respect to foreign taxes paid by the Fund; in that case the foreign tax will nonetheless reduce the Fund's taxable income. Shareholders that are not subject to U.S. federal income tax, and those who invest in a Fund through tax-advantaged accounts (including those who invest through individual retirement accounts or other tax-advantaged retirement plans), generally will receive no benefit from any tax credit or deduction passed through by the Fund.

Certain of a Fund's investment practices, including derivative transactions and investments in debt obligations issued or purchased at a discount, will be subject to special and complex U.S. federal income tax provisions. These special rules may affect the timing, character, and/or amount of a Fund's distributions, and may require the Fund to sell its investments at a time when it is not advantageous to do so.

A Fund's investments in the Underlying Funds may cause the tax treatment of the Fund's gains, losses and distributions to differ from the tax treatment that would apply if the Fund invested directly in the types of securities held by the Underlying Funds. As a result, investors may receive taxable distributions earlier and recognize higher amounts of capital gain or ordinary income than they otherwise would.

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Financial Intermediary Arrangements

Payments to Financial Intermediaries

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Financial Highlights

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET TARGET RETIREMENT 2015 FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	State Street Target Retirement 2015 Fund Class I
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$10.85	$10.09	$ 9.72	$10.03	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.20	0.19	0.19	0.23	0.06
Net realized and unrealized gain (loss)	(0.52)	0.86	0.41	(0.31)	0.03
Total from investment operations	(0.32)	1.05	0.60	(0.08)	0.09
Distributions to shareholders from:
Net investment income	(0.28)	(0.19)	(0.16)	(0.18)	(0.06)
Net realized gains	(0.24)	(0.10)	(0.07)	(0.05)	(0.00)(b)
Total distributions	(0.52)	(0.29)	(0.23)	(0.23)	(0.06)
Net asset value, end of period	$ 10.01	$ 10.85	$ 10.09	$ 9.72	$ 10.03
Total return (c)	(2.89)%(d)	10.39%	6.19%	(0.75)%	0.87%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 42	$ 189	$ 819	$1,030	$ 585
Ratios to Average Net Assets:
Total expenses (e)	0.23%	0.27%	0.58%	5.07%	14.80%(f)
Net expenses (e)	0.03%	(0.05)%(g)	0.01%	0.02%	0.37%(f)
Net investment income (loss)	1.87%	1.79%	1.85%	2.32%	2.31%(f)
Portfolio turnover rate	29%	34%	49%	55%	39%(h)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Affiliates had not made a contribution during the period ended December 31, 2018, total return would have remained (2.89)%. See Note 3.
(e)	Does not include expenses of the Underlying Funds in which the Fund invests.
(f)	Annualized.
(g)	Due to the Fund waiving acquired Fund fees, the waiver exceeded total fund expenses.
(h)	Not annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET TARGET RETIREMENT 2015 FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	State Street Target Retirement 2015 Fund Class K
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$ 10.85	$ 10.09	$ 9.72	$10.03	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.28	0.29	0.28	0.22	0.06
Net realized and unrealized gain (loss)	(0.59)	0.76	0.32	(0.30)	0.03
Total from investment operations	(0.31)	1.05	0.60	(0.08)	0.09
Distributions to shareholders from:
Net investment income	(0.29)	(0.19)	(0.16)	(0.18)	(0.06)
Net realized gains	(0.24)	(0.10)	(0.07)	(0.05)	(0.00)(b)
Total distributions	(0.53)	(0.29)	(0.23)	(0.23)	(0.06)
Net asset value, end of period	$ 10.01	$ 10.85	$ 10.09	$ 9.72	$ 10.03
Total return (c)	(2.86)%(d)	10.39%	6.19%	(0.74)%	0.92%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$258,012	$246,006	$71,486	$3,707	$1,740
Ratios to Average Net Assets:
Total expenses (e)	0.21%	0.26%	0.58%	5.07%	18.68%(f)
Net expenses (e)	(0.00)%(g)(h)	(0.02)%(h)	(0.01)%(h)	0.02%	0.17%(f)
Net investment income (loss)	2.54%	2.71%	2.72%	2.19%	2.50%(f)
Portfolio turnover rate	29%	34%	49%	55%	39%(i)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Affiliates had not made a contribution during the period ended December 31, 2018, total return would have remained (2.86)%. See Note 3.
(e)	Does not include expenses of the Underlying Funds in which the Fund invests.
(f)	Annualized.
(g)	Ratio is less than 0.005%
(h)	Due to the Fund waiving acquired Fund fees, the waiver exceeded total fund expenses.
(i)	Not annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET TARGET RETIREMENT 2020 FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class I
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$11.34	$10.27	$ 9.75	$10.14	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.43	0.25	0.16	0.33	0.06
Net realized and unrealized gain (loss)	(0.90)	1.13	0.54	(0.49)	0.11
Total from investment operations	(0.47)	1.38	0.70	(0.16)	0.17
Distributions to shareholders from:
Net investment income	(0.29)	(0.23)	(0.17)	(0.22)	(0.03)
Net realized gains	(0.29)	(0.08)	(0.01)	(0.01)	(0.00)(b)
Total distributions	(0.58)	(0.31)	(0.18)	(0.23)	(0.03)
Net asset value, end of period	$ 10.29	$ 11.34	$ 10.27	$ 9.75	$ 10.14
Total return (c)	(4.17)%(d)	13.38%	7.34%	(1.56)%	1.72%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$1,798	$ 680	$ 797	$1,811	$ 845
Ratios to Average Net Assets:
Total expenses (e)	0.16%	0.15%	0.30%	0.55%	9.11%(f)
Net expenses (e)	0.02%	0.01%	0.07%	0.01%	0.37%(f)
Net investment income (loss)	3.85%	2.29%	1.54%	3.28%	2.57%(f)
Portfolio turnover rate	22%	18%	28%	39%	5%(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Affiliates had not made a contribution during the period ended December 31, 2018, total return would have remained (4.17)%. See Note 3.
(e)	Does not include expenses of the Underlying Funds in which the Fund invests.
(f)	Annualized.
(g)	Not annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET TARGET RETIREMENT 2020 FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class K
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$ 11.34	$ 10.28	$ 9.74	$ 10.13	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.29	0.29	0.27	0.23	0.04
Net realized and unrealized gain (loss)	(0.76)	1.08	0.45	(0.39)	0.13
Total from investment operations	(0.47)	1.37	0.72	(0.16)	0.17
Distributions to shareholders from:
Net investment income	(0.29)	(0.23)	(0.17)	(0.22)	(0.04)
Net realized gains	(0.29)	(0.08)	(0.01)	(0.01)	(0.00)(b)
Total distributions	(0.58)	(0.31)	(0.18)	(0.23)	(0.04)
Net asset value, end of period	$ 10.29	$ 11.34	$ 10.28	$ 9.74	$ 10.13
Total return (c)	(4.16)%(d)	13.38%	7.45%	(1.57)%	1.67%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$847,142	$775,643	$235,727	$52,303	$6,399
Ratios to Average Net Assets:
Total expenses (e)	0.15%	0.15%	0.24%	0.55%	11.13%(f)
Net expenses (e)	0.01%	0.02%	0.01%	0.01%	0.17%(f)
Net investment income (loss)	2.60%	2.67%	2.60%	2.29%	1.62%(f)
Portfolio turnover rate	22%	18%	28%	39%	5%(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Affiliates had not made a contribution during the period ended December 31, 2018, total return would have remained (4.16)%. See Note 3.
(e)	Does not include expenses of the Underlying Funds in which the Fund invests.
(f)	Annualized.
(g)	Not annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET TARGET RETIREMENT 2025 FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class I
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$11.74	$10.33	$ 9.74	$10.16	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.23	0.26	0.15	0.37	0.06
Net realized and unrealized gain (loss)	(0.87)	1.45	0.63	(0.56)	0.14
Total from investment operations	(0.64)	1.71	0.78	(0.19)	0.20
Distributions to shareholders from:
Net investment income	(0.29)	(0.23)	(0.16)	(0.20)	(0.04)
Net realized gains	(0.28)	(0.07)	(0.03)	(0.03)	(0.00)(b)
Total distributions	(0.57)	(0.30)	(0.19)	(0.23)	(0.04)
Net asset value, end of period	$ 10.53	$ 11.74	$ 10.33	$ 9.74	$ 10.16
Total return (c)	(5.48)%(d)	16.54%	8.01%	(1.87)%	1.99%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$1,155	$2,232	$2,110	$3,293	$ 677
Ratios to Average Net Assets:
Total expenses (e)	0.15%	0.15%	0.33%	1.31%	10.65%(f)
Net expenses (e)	0.05%	0.03%	0.08%	0.03%	0.37%(f)
Net investment income (loss)	1.98%	2.36%	1.53%	3.71%	5.10%(f)
Portfolio turnover rate	15%	10%	21%	51%	13%(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Affiliates had not made a contribution during the period ended December 31, 2018, total return would have remained (5.48)%. See Note 3.
(e)	Does not include expenses of the Underlying Funds in which the Fund invests.
(f)	Annualized.
(g)	Not annualized.

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FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class K
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$ 11.75	$ 10.34	$ 9.75	$ 10.16	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.31	0.30	0.29	0.29	0.05
Net realized and unrealized gain (loss)	(0.94)	1.41	0.49	(0.47)	0.15
Total from investment operations	(0.63)	1.71	0.78	(0.18)	0.20
Distributions to shareholders from:
Net investment income	(0.29)	(0.23)	(0.16)	(0.20)	(0.04)
Net realized gains	(0.28)	(0.07)	(0.03)	(0.03)	(0.00)(b)
Total distributions	(0.57)	(0.30)	(0.19)	(0.23)	(0.04)
Net asset value, end of period	$ 10.55	$ 11.75	$ 10.34	$ 9.75	$ 10.16
Total return (c)	(5.38)%(d)	16.52%	8.00%	(1.77)%	2.04%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$1,007,169	$830,080	$206,696	$21,815	$5,597
Ratios to Average Net Assets:
Total expenses (e)	0.14%	0.15%	0.28%	1.31%	11.75%(f)
Net expenses (e)	0.04%	0.04%	0.04%	0.03%	0.17%(f)
Net investment income (loss)	2.63%	2.63%	2.81%	2.86%	2.19%(f)
Portfolio turnover rate	15%	10%	21%	51%	13%(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Affiliates had not made a contribution during the period ended December 31, 2018, total return would have remained (5.38)%. See Note 3.
(e)	Does not include expenses of the Underlying Funds in which the Fund invests.
(f)	Annualized.
(g)	Not annualized.

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FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class I
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$11.98	$10.37	$ 9.76	$10.15	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.29	0.25	0.14	0.35	0.06
Net realized and unrealized gain (loss)	(1.05)	1.64	0.65	(0.54)	0.16
Total from investment operations	(0.76)	1.89	0.79	(0.19)	0.22
Distributions to shareholders from:
Net investment income	(0.27)	(0.23)	(0.16)	(0.20)	(0.07)
Net realized gains	(0.28)	(0.05)	(0.02)	(0.00)(b)	(0.00)(b)
Total distributions	(0.55)	(0.28)	(0.18)	(0.20)	(0.07)
Net asset value, end of period	$ 10.67	$ 11.98	$ 10.37	$ 9.76	$ 10.15
Total return (c)	(6.24)%	18.27%	8.10%	(1.83)%	2.18%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$1,768	$1,716	$1,522	$2,066	$ 676
Ratios to Average Net Assets:
Total expenses (d)	0.15%	0.15%	0.30%	0.59%	12.59%(e)
Net expenses (d)	0.07%	0.06%	0.08%	0.03%	0.37%(e)
Net investment income (loss)	2.44%	2.25%	1.39%	3.52%	2.30%(e)
Portfolio turnover rate	12%	7%	18%	33%	18%(f)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Does not include expenses of the Underlying Funds in which the Fund invests.
(e)	Annualized.
(f)	Not annualized.

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Selected data for a share outstanding throughout each period

	Class K
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$ 12.00	$ 10.38	$ 9.76	$ 10.15	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.29	0.28	0.25	0.25	0.07
Net realized and unrealized gain (loss)	(1.04)	1.62	0.55	(0.44)	0.15
Total from investment operations	(0.75)	1.90	0.80	(0.19)	0.22
Distributions to shareholders from:
Net investment income	(0.28)	(0.23)	(0.16)	(0.20)	(0.07)
Net realized gains	(0.28)	(0.05)	(0.02)	(0.00)(b)	(0.00)(b)
Total distributions	(0.56)	(0.28)	(0.18)	(0.20)	(0.07)
Net asset value, end of period	$ 10.69	$ 12.00	$ 10.38	$ 9.76	$ 10.15
Total return (c)	(6.22)%	18.35%	8.20%	(1.83)%	2.23%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$960,339	$778,969	$225,549	$48,114	$3,243
Ratios to Average Net Assets:
Total expenses (d)	0.14%	0.15%	0.26%	0.59%	14.05%(e)
Net expenses (d)	0.06%	0.06%	0.05%	0.03%	0.17%(e)
Net investment income (loss)	2.43%	2.46%	2.48%	2.42%	2.64%(e)
Portfolio turnover rate	12%	7%	18%	33%	18%(f)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Does not include expenses of the Underlying Funds in which the Fund invests.
(e)	Annualized.
(f)	Not annualized.

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FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class I
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$12.18	$10.43	$ 9.77	$10.17	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.30	0.13	0.11	0.31	0.07
Net realized and unrealized gain (loss)	(1.14)	1.91	0.74	(0.51)	0.15
Total from investment operations	(0.84)	2.04	0.85	(0.20)	0.22
Distributions to shareholders from:
Net investment income	(0.26)	(0.22)	(0.16)	(0.18)	(0.05)
Net realized gains	(0.28)	(0.07)	(0.03)	(0.02)	(0.00)(b)
Total distributions	(0.54)	(0.29)	(0.19)	(0.20)	(0.05)
Net asset value, end of period	$ 10.80	$ 12.18	$ 10.43	$ 9.77	$ 10.17
Total return (c)	(6.88)%(d)	19.56%	8.61%	(2.00)%	2.20%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 442	$ 371	$ 840	$1,416	$ 508
Ratios to Average Net Assets:
Total expenses (e)	0.16%	0.17%	0.36%	1.83%	16.79%(f)
Net expenses (e)	0.07%	0.07%	0.09%	0.03%	0.37%(f)
Net investment income (loss)	2.49%	1.10%	1.08%	3.07%	2.78%(f)
Portfolio turnover rate	13%	6%	18%	38%	7%(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Affiliates had not made a contribution during the period ended December 31, 2018, total return would have remained (6.88)%. See Note 3.
(e)	Does not include expenses of the Underlying Funds in which the Fund invests.
(f)	Annualized.
(g)	Not annualized.

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FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class K
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$ 12.21	$ 10.44	$ 9.78	$ 10.17	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.28	0.27	0.27	0.32	0.03
Net realized and unrealized gain (loss)	(1.12)	1.79	0.58	(0.51)	0.20
Total from investment operations	(0.84)	2.06	0.85	(0.19)	0.23
Distributions to shareholders from:
Net investment income	(0.26)	(0.22)	(0.16)	(0.18)	(0.06)
Net realized gains	(0.28)	(0.07)	(0.03)	(0.02)	(0.00)(b)
Total distributions	(0.54)	(0.29)	(0.19)	(0.20)	(0.06)
Net asset value, end of period	$ 10.83	$ 12.21	$ 10.44	$ 9.78	$ 10.17
Total return (c)	(6.85)%(d)	19.73%	8.60%	(1.90)%	2.25%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$796,187	$584,717	$165,008	$17,223	$3,208
Ratios to Average Net Assets:
Total expenses (e)	0.15%	0.17%	0.33%	1.83%	17.89%(f)
Net expenses (e)	0.07%	0.08%	0.06%	0.03%	0.17%(f)
Net investment income (loss)	2.30%	2.34%	2.64%	3.12%	1.28%(f)
Portfolio turnover rate	13%	6%	18%	38%	7%(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Affiliates had not made a contribution during the period ended December 31, 2018, total return would have remained (6.85)%. See Note 3.
(e)	Does not include expenses of the Underlying Funds in which the Fund invests.
(f)	Annualized.
(g)	Not annualized.

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FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class I
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$12.26	$10.39	$ 9.71	$10.13	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.31	0.24	0.09	0.40	0.06
Net realized and unrealized gain (loss)	(1.23)	1.91	0.78	(0.63)	0.16
Total from investment operations	(0.92)	2.15	0.87	(0.23)	0.22
Distributions to shareholders from:
Net investment income	(0.26)	(0.23)	(0.16)	(0.19)	(0.09)
Net realized gains	(0.29)	(0.05)	(0.03)	(0.00)(b)	(0.00)(b)
Total distributions	(0.55)	(0.28)	(0.19)	(0.19)	(0.09)
Net asset value, end of period	$ 10.79	$ 12.26	$ 10.39	$ 9.71	$ 10.13
Total return (c)	(7.46)%(d)	20.59%	9.00%	(2.28)%	2.23%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$1,247	$ 912	$ 708	$1,501	$ 506
Ratios to Average Net Assets:
Total expenses (e)	0.19%	0.17%	0.38%	0.79%	18.04%(f)
Net expenses (e)	0.09%	0.07%	0.10%	0.02%	0.37%(f)
Net investment income (loss)	2.50%	2.14%	0.86%	4.02%	2.53%(f)
Portfolio turnover rate	11%	6%	16%	38%	5%(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Affiliates had not made a contribution during the period ended December 31, 2018, total return would have remained (7.46)%. See Note 3.
(e)	Does not include expenses of the Underlying Funds in which the Fund invests.
(f)	Annualized.
(g)	Not annualized.

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FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class K
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$ 12.27	$ 10.40	$ 9.72	$ 10.13	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.28	0.26	0.24	0.25	0.05
Net realized and unrealized gain (loss)	(1.21)	1.89	0.63	(0.47)	0.18
Total from investment operations	(0.93)	2.15	0.87	(0.22)	0.23
Distributions to shareholders from:
Net investment income	(0.26)	(0.23)	(0.16)	(0.19)	(0.10)
Net realized gains	(0.29)	(0.05)	(0.03)	(0.00)(b)	(0.00)(b)
Total distributions	(0.55)	(0.28)	(0.19)	(0.19)	(0.10)
Net asset value, end of period	$ 10.79	$ 12.27	$ 10.40	$ 9.72	$ 10.13
Total return (c)	(7.52)%(d)	20.69%	8.89%	(2.18)%	2.28%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$636,762	$458,132	$143,526	$35,359	$1,512
Ratios to Average Net Assets:
Total expenses (e)	0.16%	0.17%	0.32%	0.79%	20.53%(f)
Net expenses (e)	0.07%	0.07%	0.05%	0.02%	0.17%(f)
Net investment income (loss)	2.24%	2.30%	2.31%	2.47%	1.90%(f)
Portfolio turnover rate	11%	6%	16%	38%	5%(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Affiliates had not made a contribution during the period ended December 31, 2018, total return would have remained (7.52)%. See Note 3.
(e)	Does not include expenses of the Underlying Funds in which the Fund invests.
(f)	Annualized.
(g)	Not annualized.

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FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class I
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$12.29	$10.36	$ 9.64	$10.06	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.33	0.20	0.15	0.30	0.06
Net realized and unrealized gain (loss)	(1.31)	2.02	0.75	(0.54)	0.16
Total from investment operations	(0.98)	2.22	0.90	(0.24)	0.22
Distributions to shareholders from:
Net investment income	(0.26)	(0.24)	(0.16)	(0.17)	(0.16)
Net realized gains	(0.28)	(0.05)	(0.02)	(0.01)	(0.00)(b)
Total distributions	(0.54)	(0.29)	(0.18)	(0.18)	(0.16)
Net asset value, end of period	$ 10.77	$ 12.29	$ 10.36	$ 9.64	$ 10.06
Total return (c)	(7.96)%(d)	21.45%	9.31%	(2.40)%	2.20%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 787	$ 762	$ 853	$ 782	$ 335
Ratios to Average Net Assets:
Total expenses (e)	0.20%	0.21%	0.59%	3.25%	30.22%(f)
Net expenses (e)	0.08%	0.06%	0.06%	0.01%	0.37%(f)
Net investment income (loss)	2.68%	1.73%	1.46%	2.97%	2.32%(f)
Portfolio turnover rate	11%	5%	17%	35%	5%(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Affiliates had not made a contribution during the period ended December 31, 2018, total return would have remained (7.96)%. See Note 3.
(e)	Does not include expenses of the Underlying Funds in which the Fund invests.
(f)	Annualized.
(g)	Not annualized.

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FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class K
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$ 12.29	$ 10.36	$ 9.63	$10.06	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.28	0.28	0.27	0.30	0.06
Net realized and unrealized gain (loss)	(1.26)	1.94	0.64	(0.55)	0.17
Total from investment operations	(0.98)	2.22	0.91	(0.25)	0.23
Distributions to shareholders from:
Net investment income	(0.26)	(0.24)	(0.16)	(0.17)	(0.17)
Net realized gains	(0.28)	(0.05)	(0.02)	(0.01)	(0.00)(b)
Total distributions	(0.54)	(0.29)	(0.18)	(0.18)	(0.17)
Net asset value, end of period	$ 10.77	$ 12.29	$ 10.36	$ 9.63	$ 10.06
Total return (c)	(7.94)%(d)	21.45%	9.31%	(2.40)%	2.25%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$465,425	$300,444	$76,304	$8,374	$ 335
Ratios to Average Net Assets:
Total expenses (e)	0.19%	0.21%	0.57%	3.25%	30.02%(f)
Net expenses (e)	0.07%	0.07%	0.05%	0.01%	0.17%(f)
Net investment income (loss)	2.29%	2.39%	2.62%	2.99%	2.53%(f)
Portfolio turnover rate	11%	5%	17%	35%	5%(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Affiliates had not made a contribution during the period ended December 31, 2018, total return would have remained (7.94)%. See Note 3.
(e)	Does not include expenses of the Underlying Funds in which the Fund invests.
(f)	Annualized.
(g)	Not annualized.

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STATE STREET TARGET RETIREMENT 2050 FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class I
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$12.24	$10.33	$ 9.62	$10.06	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.37	0.15	0.08	0.43	0.06
Net realized and unrealized gain (loss)	(1.37)	2.06	0.80	(0.69)	0.16
Total from investment operations	(1.00)	2.21	0.88	(0.26)	0.22
Distributions to shareholders from:
Net investment income	(0.26)	(0.25)	(0.15)	(0.18)	(0.16)
Net realized gains	(0.28)	(0.05)	(0.02)	(0.00)(b)	(0.00)(b)
Total distributions	(0.54)	(0.30)	(0.17)	(0.18)	(0.16)
Net asset value, end of period	$ 10.70	$ 12.24	$ 10.33	$ 9.62	$ 10.06
Total return (c)	(8.14)%	21.30%	9.34%	(2.61)%	2.20%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 374	$ 240	$ 366	$ 795	$ 168
Ratios to Average Net Assets:
Total expenses (d)	0.25%	0.25%	0.97%	4.65%	59.71%(e)
Net expenses (d)	0.08%	0.06%	0.12%	0.02%	0.37%(e)
Net investment income (loss)	3.05%	1.34%	0.76%	4.40%	2.28%(e)
Portfolio turnover rate	11%	5%	16%	35%	7%(f)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Does not include expenses of the Underlying Funds in which the Fund invests.
(e)	Annualized.
(f)	Not annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET TARGET RETIREMENT 2050 FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class K
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$ 12.24	$ 10.33	$ 9.61	$10.06	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.28	0.27	0.26	0.28	0.06
Net realized and unrealized gain (loss)	(1.28)	1.94	0.63	(0.55)	0.16
Total from investment operations	(1.00)	2.21	0.89	(0.27)	0.22
Distributions to shareholders from:
Net investment income	(0.26)	(0.25)	(0.15)	(0.18)	(0.16)
Net realized gains	(0.28)	(0.05)	(0.02)	(0.00)(b)	(0.00)(b)
Total distributions	(0.54)	(0.30)	(0.17)	(0.18)	(0.16)
Net asset value, end of period	$ 10.70	$ 12.24	$ 10.33	$ 9.61	$ 10.06
Total return (c)	(8.13)%	21.42%	9.35%	(2.71)%	2.25%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$300,431	$212,217	$48,016	$5,736	$ 168
Ratios to Average Net Assets:
Total expenses (d)	0.23%	0.25%	0.90%	4.65%	59.52%(e)
Net expenses (d)	0.07%	0.07%	0.05%	0.02%	0.17%(e)
Net investment income (loss)	2.30%	2.37%	2.61%	2.82%	2.48%(e)
Portfolio turnover rate	11%	5%	16%	35%	7%(f)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Does not include expenses of the Underlying Funds in which the Fund invests.
(e)	Annualized.
(f)	Not annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET TARGET RETIREMENT 2055 FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class I
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$12.25	$10.32	$ 9.60	$10.06	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.31	0.11	0.16	0.22	0.06
Net realized and unrealized gain (loss)	(1.29)	2.11	0.73	(0.49)	0.16
Total from investment operations	(0.98)	2.22	0.89	(0.27)	0.22
Distributions to shareholders from:
Net investment income	(0.25)	(0.24)	(0.15)	(0.18)	(0.16)
Net realized gains	(0.32)	(0.05)	(0.02)	(0.01)	(0.00)(b)
Total distributions	(0.57)	(0.29)	(0.17)	(0.19)	(0.16)
Net asset value, end of period	$ 10.70	$ 12.25	$ 10.32	$ 9.60	$ 10.06
Total return (c)	(7.93)%(d)	21.60%	9.33%	(2.65)%	2.20%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 130	$ 105	$ 271	$ 222	$ 168
Ratios to Average Net Assets:
Total expenses (e)	0.40%	0.52%	2.09%	7.69%	59.62%(f)
Net expenses (e)	0.07%	0.06%	0.04%	0.02%	0.37%(f)
Net investment income (loss)	2.53%	0.95%	1.58%	2.20%	2.28%(f)
Portfolio turnover rate	16%	7%	14%	40%	7%(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Affiliates had not made a contribution during the period ended December 31, 2018, total return would have remained (7.93)%. See Note 3.
(e)	Does not include expenses of the Underlying Funds in which the Fund invests.
(f)	Annualized.
(g)	Not annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET TARGET RETIREMENT 2055 FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class K
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$ 12.23	$ 10.31	$ 9.59	$10.06	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.30	0.31	0.26	0.27	0.06
Net realized and unrealized gain (loss)	(1.28)	1.90	0.63	(0.55)	0.16
Total from investment operations	(0.98)	2.21	0.89	(0.28)	0.22
Distributions to shareholders from:
Net investment income	(0.25)	(0.24)	(0.15)	(0.18)	(0.16)
Net realized gains	(0.32)	(0.05)	(0.02)	(0.01)	(0.00)(b)
Total distributions	(0.57)	(0.29)	(0.17)	(0.19)	(0.16)
Net asset value, end of period	$ 10.68	$ 12.23	$ 10.31	$ 9.59	$ 10.06
Total return (c)	(7.94)%(d)	21.53%	9.34%	(2.75)%	2.25%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$132,520	$81,529	$18,718	$3,043	$ 168
Ratios to Average Net Assets:
Total expenses (e)	0.40%	0.51%	2.09%	7.69%	59.42%(f)
Net expenses (e)	0.07%	0.07%	0.05%	0.02%	0.17%(f)
Net investment income (loss)	2.49%	2.67%	2.61%	2.64%	2.48%(f)
Portfolio turnover rate	16%	7%	14%	40%	7%(g)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Affiliates had not made a contribution during the period ended December 31, 2018, total return would have remained (7.94)%. See Note 3.
(e)	Does not include expenses of the Underlying Funds in which the Fund invests.
(f)	Annualized.
(g)	Not annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET TARGET RETIREMENT 2060 FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class I
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$11.91	$10.09	$ 9.50	$10.06	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.30	0.15	0.15	0.20	0.06
Net realized and unrealized gain (loss)	(1.27)	2.01	0.71	(0.46)	0.16
Total from investment operations	(0.97)	2.16	0.86	(0.26)	0.22
Distributions to shareholders from:
Net investment income	(0.24)	(0.23)	(0.14)	(0.19)	(0.16)
Net realized gains	(0.42)	(0.11)	(0.13)	(0.11)	(0.00)(b)
Total distributions	(0.66)	(0.34)	(0.27)	(0.30)	(0.16)
Net asset value, end of period	$ 10.28	$ 11.91	$ 10.09	$ 9.50	$ 10.06
Total return (c)	(8.13)%	21.45%	9.09%	(2.53)%	2.18%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 121	$ 103	$ 170	$ 162	$ 168
Ratios to Average Net Assets:
Total expenses (d)	1.56%	3.13%	11.36%	29.76%	59.48%(e)
Net expenses (d)	0.06%	0.06%	0.05%	0.02%	0.37%(e)
Net investment income (loss)	2.55%	1.31%	1.51%	1.96%	2.29%(e)
Portfolio turnover rate	38%	18%	55%	73%	7%(f)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Does not include expenses of the Underlying Funds in which the Fund invests.
(e)	Annualized.
(f)	Not annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET TARGET RETIREMENT 2060 FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class K
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$ 11.91	$ 10.08	$ 9.49	$10.06	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.34	0.33	0.29	0.19	0.06
Net realized and unrealized gain (loss)	(1.31)	1.84	0.57	(0.45)	0.16
Total from investment operations	(0.97)	2.17	0.86	(0.26)	0.22
Distributions to shareholders from:
Net investment income	(0.24)	(0.23)	(0.14)	(0.20)	(0.16)
Net realized gains	(0.42)	(0.11)	(0.13)	(0.11)	(0.00)(b)
Total distributions	(0.66)	(0.34)	(0.27)	(0.31)	(0.16)
Net asset value, end of period	$ 10.28	$ 11.91	$ 10.08	$ 9.49	$ 10.06
Total return (c)	(8.13)%	21.57%	8.98%	(2.53)%	2.24%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$25,829	$12,141	$3,344	$ 269	$ 168
Ratios to Average Net Assets:
Total expenses (d)	1.56%	3.07%	11.36%	29.76%	59.28%(e)
Net expenses (d)	0.06%	0.07%	0.06%	0.02%	0.17%(e)
Net investment income (loss)	2.87%	2.94%	2.91%	1.88%	2.49%(e)
Portfolio turnover rate	38%	18%	55%	73%	7%(f)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Does not include expenses of the Underlying Funds in which the Fund invests.
(e)	Annualized.
(f)	Not annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET TARGET RETIREMENT FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	State Street Target Retirement Fund Class I
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14*
Net asset value, beginning of period	$10.73	$10.12	$ 9.79	$10.03	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.28	0.19	0.19	0.19	0.05
Net realized and unrealized gain (loss)	(0.55)	0.71	0.32	(0.23)	0.02
Total from investment operations	(0.27)	0.90	0.51	(0.04)	0.07
Distributions to shareholders from:
Net investment income	(0.29)	(0.20)	(0.17)	(0.19)	(0.04)
Net realized gains	(0.15)	(0.09)	(0.01)	(0.01)	(0.00)(b)
Total distributions	(0.44)	(0.29)	(0.18)	(0.20)	(0.04)
Net asset value, end of period	$ 10.02	$ 10.73	$ 10.12	$ 9.79	$ 10.03
Total return (c)	(2.50)%(d)	8.92%	5.27%	(0.39)%	0.70%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 108	$ 139	$ 612	$ 653	$ 418
Ratios to Average Net Assets:
Total expenses (e)	0.25%	0.36%	0.66%	1.15%	21.40%(f)
Net expenses (e)	(0.03)%(g)	(0.05)%(g)	(0.03)%(g)	0.01%	0.37%(f)
Net investment income (loss)	2.62%	1.78%	1.89%	1.94%	2.07%(f)
Portfolio turnover rate	53%	25%	37%	31%	8%(h)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Affiliates had not made a contribution during the period ended December 31, 2018, total return would have remained (2.50)%. See Note 3.
(e)	Does not include expenses of the Underlying Funds in which the Fund invests.
(f)	Annualized.
(g)	Due to the Fund waiving acquired Fund fees, the waiver exceeded total fund expenses.
(h)	Not annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET TARGET RETIREMENT FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	State Street Target Retirement Fund Class K
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 9/30/14* - 12/31/14
Net asset value, beginning of period	$ 10.71	$ 10.12	$ 9.78	$ 10.03	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.29	0.28	0.23	0.20	0.06
Net realized and unrealized gain (loss)	(0.56)	0.60	0.29	(0.25)	0.02
Total from investment operations	(0.27)	0.88	0.52	(0.05)	0.08
Distributions to shareholders from:
Net investment income	(0.29)	(0.20)	(0.17)	(0.19)	(0.05)
Net realized gains	(0.15)	(0.09)	(0.01)	(0.01)	(0.00)(b)
Total distributions	(0.44)	(0.29)	(0.18)	(0.20)	(0.05)
Net asset value, end of period	$ 10.00	$ 10.71	$ 10.12	$ 9.78	$ 10.03
Total return (c)	(2.50)%(d)	8.83%	5.28%	(0.49)%	0.75%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$200,840	$135,420	$55,499	$22,265	$1,558
Ratios to Average Net Assets:
Total expenses (e)	0.24%	0.36%	0.66%	1.15%	25.06%(f)
Net expenses (e)	(0.04)%(g)	(0.02)%(g)	(0.04)%(g)	0.01%	0.17%(f)
Net investment income (loss)	2.69%	2.61%	2.23%	1.99%	2.59%(f)
Portfolio turnover rate	53%	25%	37%	31%	8%(h)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Amount is less than $0.005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	If the Affiliates had not made a contribution during the period ended December 31, 2018, total return would have remained (2.50)%. See Note 3.
(e)	Does not include expenses of the Underlying Funds in which the Fund invests.
(f)	Annualized.
(g)	Due to the Fund waiving acquired Fund fees, the waiver exceeded total fund expenses.
(h)	Not annualized.

159

Table of Contents

Appendix A – Underlying Funds

Target Retirement Funds

The following is a brief description of the investment objective and principal investment policies of certain of the Underlying Funds in which the Target Retirement Funds may invest. The Funds invest in the Underlying Funds in varying proportions.

You'll find more detailed information about each of these Underlying Fund's investment strategies and risks in its prospectus and SAI. Refer to SSGAFUNDS.com and www.spdrs.com, or contact your financial advisor for details.

State Street Equity 500 Index II Portfolio

The State Street Equity 500 Index II Portfolio seeks to provide investment results that, before expenses, correspond generally to the total return of the S&P 500 ^® Index. The Portfolio is not managed according to traditional methods of “active” investment management, which involve the buying and selling of securities based upon economic, financial and market analysis and investment judgment. Instead, the Portfolio, using a “passive” or “indexing” investment approach, seeks to provide investment results that, before expenses, correspond generally to the total return of the S&P 500. The Portfolio generally intends to invest in all stocks comprising the S&P 500 in approximate proportion to their weightings in the Index. However, under various circumstances, it may not be possible or practicable to purchase all stocks in those weightings. In those circumstances, the Portfolio may purchase a sample of the stocks in the Index in proportions expected by the Portfolio's investment adviser, SSGA Funds Management, Inc., to match generally the performance of the Index as a whole. In addition, from time to time stocks are added to or removed from the Index. The Portfolio may sell securities that are represented in the Index, or purchase securities that are not yet represented in the Index, in anticipation of their removal from or addition to the Index. Under normal circumstances, the Portfolio generally invests substantially all, but at least 80%, of its net assets (plus borrowings, if any) in securities comprising the Index or in securities that the Adviser determines have economic characteristics that are comparable to the economic characteristics of securities that comprise the Index. The notional value of the Portfolio's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. In addition, the Portfolio may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

The Portfolio may also enter into other derivatives transactions, including the use of options or swap transactions, in lieu of investing directly in the stocks making up the Index. The Portfolio may also, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Portfolio (including funds advised by the Adviser).

State Street Small/Mid Cap Equity Index Portfolio

The State Street Small/Mid Cap Equity Index Portfolio seeks to provide investment results that, before expenses, correspond generally to the total return of an index that tracks the performance of mid-to small- capitalization exchange traded U.S. equity securities. The Portfolio is not managed according to traditional methods of “active” investment management, which involve the buying and selling of securities based upon economic, financial and market analysis and investment judgment. Instead, the Portfolio, using a “passive” or “indexing” investment approach, seeks to provide investment results that, before expenses, correspond generally to the total return of the Russell Small Cap Completeness Index. The Portfolio generally intends to invest in all stocks comprising the Russell Small Cap Completeness Index in approximate proportion to their weightings in the Russell Small Cap Completeness Index. However, under various circumstances, it may not be possible or practicable to purchase all stocks in those weightings. In those circumstances, the Portfolio may purchase a sample of the stocks in the Russell Small Cap Completeness Index in proportions expected by SSGA FM, the investment adviser to the Portfolio, to match generally the performance of the Russell Small Cap Completeness Index as a whole. In addition, from time to time stocks are added to or removed from the Russell Small Cap Completeness Index. The Portfolio may sell securities that are represented in the Russell Small Cap Completeness Index, or purchase securities that are not yet represented in the Russell Small Cap Completeness Index, in anticipation of their removal from or addition to the Russell Small Cap Completeness Index. Under normal market conditions, the Portfolio invests at least 80% of its net assets (plus borrowings, if any) in stocks in the Russell Small Cap Completeness Index. The notional value of the Portfolio's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Russell Small

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Cap Completeness Index may be counted toward satisfaction of this 80% policy. In addition, the Fund may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser). The Portfolio may purchase or sell futures contracts on the Index, or options on those futures, in lieu of investing directly in the stocks making up the Index. The Portfolio might do so, for example, in order to increase its investment exposure pending investment of cash in the stocks comprising the Index. Alternatively, the Portfolio might use futures or options on futures to reduce its investment exposure in situations where it intends to sell a portion of the stocks in its portfolio but the sale has not yet been completed. The Portfolio may also enter into other derivatives transactions, including the use of options or swap transactions relating to the Index or any securities comprising the Index, in lieu of investing directly in the stocks making up the Index. The Portfolio may, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Portfolio (including funds advised by the Adviser).

State Street Global Equity ex-U.S. Index Portfolio

The State Street Global Equity ex-U.S. Index Portfolio seeks to provide investment results that, before fees and expenses, correspond generally to the total return performance of a broad-based index of world (ex-US) equity markets over the long term. The Portfolio is an “index” fund that seeks to track, before fees and expenses, the total return performance of the MSCI ACWI ex USA Index over the long term. As an “index” fund, the Portfolio is not managed according to traditional methods of “active” investment management, which involve the buying and selling of securities based upon economic, financial and market analysis and investment judgment.

In seeking to track the performance of the Index, the Portfolio employs a sampling strategy, which means that the Portfolio is not required to purchase all of the securities represented in the Index. Instead, the Portfolio may purchase a subset of the securities in the Index in an effort to hold a portfolio of securities with generally the same risk and return characteristics of the Index. The number of holdings in the Portfolio will be based on a number of factors, including asset size of the Portfolio. SSGA Funds Management, Inc., the investment adviser to the Portfolio, generally expects the Portfolio to hold fewer than the total number of securities in the Index, but reserves the right to hold as many securities as it believes necessary to achieve the Portfolio's investment objective. Under normal circumstances, the Portfolio generally invests substantially all, but at least 80%, of its net assets (plus borrowings, if any) in securities comprising the Index or in American Depositary Receipts or Global Depositary Receipts providing exposure to securities comprising the Index. The notional value of the Portfolio's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. In addition, the Portfolio may invest in equity securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser). The Portfolio may also purchase or sell futures contracts, or options on those futures, in lieu of investing directly in the stocks making up the Index. The Portfolio might do so, for example, in order to increase its investment exposure pending investment of cash in stocks or other investments. Alternatively, the Portfolio might use futures or options on futures to reduce its investment exposure in situations where it intends to sell a portion of the stocks in its portfolio but the sale has not yet been completed. The Portfolio may also enter into other derivatives transactions, including the use of options, forwards or swap transactions, in lieu of investing directly in the stocks making up the Index. The Portfolio may also, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Portfolio (including funds advised by the Adviser).

SPDR Dow Jones Global Real Estate ETF

The SPDR Dow Jones Global Real Estate ETF seeks to provide investment results that, before fees and expenses, correspond generally to the total return performance of an index based upon the global real estate market. In seeking to track the performance of the Dow Jones Global Select Real Estate Securities Index ^sm , the Fund employs a sampling strategy, which means that the Fund is not required to purchase all of the securities represented in the Index. Instead, the Fund may purchase a subset of the securities in the Index in an effort to hold a portfolio of securities with generally the same risk and return characteristics of the Index. The quantity of holdings in the Fund will be based on a number of factors, including asset size of the Fund. Based on its analysis of these factors, SSGA Funds Management, Inc., the investment adviser to the Fund, either may invest the Fund's assets in a subset of securities in the Index or may invest the Fund's assets in substantially all of the securities represented in the Index in approximately the same proportions as the Index, as determined by the Adviser to be in the best interest of the Fund in pursuing its objective. Under normal market conditions, the Fund generally invests substantially all, but at least 80%, of its total assets in the securities comprising the Index and in depositary receipts (including American Depositary Receipts (“ADRs”) or Global Depositary Receipts (“GDRs”)) based on securities comprising the Index. In addition, in seeking to track the Index, the Fund may invest in equity securities that are not included in the Index (including common stock, preferred stock, depositary receipts and shares of other investment companies), cash

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and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser). In seeking to track the Index, the Fund's assets will generally be concentrated in an industry or group of industries to the extent that the Index concentrates in a particular industry or group of industries.

SPDR Portfolio Long Term Treasury ETF

The SPDR Portfolio Long Term Treasury ETF seeks to provide investment results that, before fees and expenses, correspond generally to the price and yield performance of an index that tracks the long term (10+ years) sector of the United States Treasury market. In seeking to track the performance of the Bloomberg Barclays Long U.S. Treasury Index, the Fund employs a sampling strategy, which means that the Fund is not required to purchase all of the securities represented in the Index. Instead, the Fund may purchase a subset of the securities in the Index in an effort to hold a portfolio of securities with generally the same risk and return characteristics of the Index. The quantity of holdings in the Fund will be based on a number of factors, including asset size of the Fund. Based on its analysis of these factors, SSGA Funds Management, Inc., the investment adviser to the Fund, either may invest the Fund's assets in a subset of securities in the Index or may invest the Fund's assets in substantially all of the securities represented in the Index in approximately the same proportions as the Index, as determined by the Adviser to be in the best interest of the Fund in pursuing its objective. Under normal market conditions, the Fund generally invests substantially all, but at least 80%, of its total assets in the securities comprising the Index or in securities that the Adviser determines have economic characteristics that are substantially identical to the economic characteristics of the securities that comprise the Index. In addition, in seeking to track the Index, the Fund may invest in debt securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

State Street Aggregate Bond Index Portfolio

The State Street Aggregate Bond Index Portfolio seeks to provide investment results that, before fees and expenses, correspond generally to the price and yield performance of an index that tracks the U.S. dollar denominated investment-grade bond market over the long term. The Portfolio is an “index” fund that seeks to track, before fees and expenses, the total return performance of the Bloomberg Barclays U.S. Aggregate Bond Index over the long term. As an “index” fund, the Portfolio is not managed according to traditional methods of “active” investment management, which involve the buying and selling of securities based upon economic, financial and market analysis and investment judgment.

In seeking to track the performance of the Index, the Portfolio employs a sampling strategy, which means that the Portfolio will not typically purchase all of the securities represented in the Index. Instead, the Portfolio may purchase a subset of the securities in the Index, or securities the Adviser considers to be comparable to securities in the Index, in an effort to hold a portfolio of securities with generally the same risk and return characteristics of the Index. The number of holdings in the Portfolio will be based on a number of factors, including asset size of the Portfolio. SSGA Funds Management, Inc., the investment adviser to the Portfolio, generally expects the Portfolio to hold fewer than the total number of securities in the Index, but reserves the right to hold as many securities as it believes necessary to achieve the Portfolio's investment objective. Under normal circumstances, the Portfolio generally invests substantially all, but at least 80%, of its net assets (plus borrowings, if any) in securities comprising the Index or in securities that the Adviser determines have economic characteristics that are comparable to the economic characteristics of securities that comprise the Index. The notional value of the Portfolio's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. The Portfolio may also invest in other debt securities, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser). The Portfolio may at times purchase or sell futures contracts on fixed-income securities, or options on those futures, in lieu of investing directly in fixed-income securities themselves. The Portfolio may also purchase or sell futures contracts and related options on the Index (or other fixed-income securities indices). The Portfolio might do so, for example, in order to adjust the interest-rate sensitivity of the Portfolio to bring the characteristics of the Portfolio more closely in line with those of the Index. It might also do so to increase its investment exposure pending investment of cash in bonds or other investments or to reduce its investment exposure in situations where it intends to sell a portion of the securities in its portfolio but the sale has not yet been completed. The Portfolio may also enter into other derivatives transactions, including the use of options or swap transactions, in lieu of investing directly in the stocks making up the Index. The Portfolio may, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Portfolio (including funds advised by the Adviser).

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SPDR Bloomberg Barclays TIPS ETF

The SPDR Bloomberg Barclays TIPS ETF seeks to provide investment results that, before fees and expenses, correspond generally to the price and yield performance of an index that tracks the inflation protected sector of the United States Treasury market. In seeking to track the performance of the Bloomberg Barclays U.S. Government Inflation-Linked Bond Index, the Fund employs a sampling strategy, which means that the Fund is not required to purchase all of the securities represented in the Index. Instead, the Fund may purchase a subset of the securities in the Index in an effort to hold a portfolio of securities with generally the same risk and return characteristics of the Index. The quantity of holdings in the Fund will be based on a number of factors, including asset size of the Fund. Based on its analysis of these factors, SSGA Funds Management, Inc., the investment adviser to the Fund, either may invest the Fund's assets in a subset of securities in the Index or may invest the Fund's assets in substantially all of the securities represented in the Index in approximately the same proportions as the Index, as determined by the Adviser to be in the best interest of the Fund in pursuing its objective. Under normal market conditions, the Fund generally invests substantially all, but at least 80%, of its total assets in the securities comprising the Index or in securities that the Adviser determines have economic characteristics that are substantially identical to the economic characteristics of the securities that comprise the Index. In addition, in seeking to track the Index, the Fund may invest in debt securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

SPDR Bloomberg Barclays High Yield Bond ETF

The SPDR Bloomberg Barclays High Yield Bond ETF seeks to provide investment results that, before fees and expenses, correspond generally to the price and yield performance of an index that tracks the U.S. high yield corporate bond market. In seeking to track the performance of the Bloomberg Barclays High Yield Very Liquid Index, the Fund employs a sampling strategy, which means that the Fund is not required to purchase all of the securities represented in the Index. Instead, the Fund may purchase a subset of the securities in the Index in an effort to hold a portfolio of securities with generally the same risk and return characteristics of the Index. The quantity of holdings in the Fund will be based on a number of factors, including asset size of the Fund. Based on its analysis of these factors, SSGA Funds Management, Inc., the investment adviser to the Fund, either may invest the Fund's assets in a subset of securities in the Index or may invest the Fund's assets in substantially all of the securities represented in the Index in approximately the same proportions as the Index, as determined by the Adviser to be in the best interest of the Fund in pursuing its objective. Under normal market conditions, the Fund generally invests substantially all, but at least 80%, of its total assets in the securities comprising the Index or in securities that the Adviser determines have economic characteristics that are substantially identical to the economic characteristics of the securities that comprise the Index. In addition, in seeking to track the Index, the Fund may invest in debt securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser). In seeking to track the Index, the Fund's assets will generally be concentrated in an industry or group of industries to the extent that the Index concentrates in a particular industry or group of industries. The Fund may use derivatives, including credit default swaps and credit default index swaps, to obtain investment exposure that the Adviser expects to correlate closely with the Index, or a portion of the Index, and in managing cash flows.

SPDR Portfolio Short Term Treasury ETF

The SPDR Portfolio Short Term Treasury ETF seeks to provide investment results that, before fees and expenses, correspond generally to the price and yield performance of an index that tracks the short term sector of the United States Treasury market. In seeking to track the performance of the Bloomberg Barclays 1-3 Year U.S. Treasury Index, the Fund employs a sampling strategy, which means that the Fund is not required to purchase all of the securities represented in the Index. Instead, the Fund may purchase a subset of the securities in the Index in an effort to hold a portfolio of securities with generally the same risk and return characteristics of the Index. The quantity of holdings in the Fund will be based on a number of factors, including asset size of the Fund. Based on its analysis of these factors, SSGA Funds Management, Inc., the investment adviser to the Fund, either may invest the Fund's assets in a subset of securities in the Index or may invest the Fund's assets in substantially all of the securities represented in the Index in approximately the same proportions as the Index, as determined by the Adviser to be in the best interest of the Fund in pursuing its objective. Under normal market conditions, the Fund generally invests substantially all, but at least 80%, of its total assets in the securities comprising the Index or in securities that the Adviser determines have economic characteristics that are substantially identical to the economic characteristics of the securities that comprise the Index. In addition, in seeking to track the Index, the Fund may invest in debt securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

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SPDR Portfolio Short Term Corporate Bond ETF

The SPDR Portfolio Short Term Corporate Bond ETF seeks to provide investment results that, before fees and expenses, correspond generally to the price and yield performance of an index that tracks the short-term U.S. corporate bond market. In seeking to track the performance of the Bloomberg Barclays U.S. 1-3 Year Corporate Bond Index, the Fund employs a sampling strategy, which means that the Fund is not required to purchase all of the securities represented in the Index. Instead, the Fund may purchase a subset of the securities in the Index in an effort to hold a portfolio of securities with generally the same risk and return characteristics of the Index. The quantity of holdings in the Fund will be based on a number of factors, including asset size of the Fund. Based on its analysis of these factors, SSGA Funds Management, Inc., the investment adviser to the Fund, either may invest the Fund's assets in a subset of securities in the Index or may invest the Fund's assets in substantially all of the securities represented in the Index in approximately the same proportions as the Index, as determined by the Adviser to be in the best interest of the Fund in pursuing its objective.

Under normal market conditions, the Fund generally invests substantially all, but at least 80%, of its total assets in the securities comprising the Index or in securities that the Adviser determines have economic characteristics that are substantially identical to the economic characteristics of the securities that comprise the Index. In addition, in seeking to track the Index, the Fund may invest in debt securities that are not included in the Index, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser). In seeking to track the Index, the Fund's assets will generally be concentrated in an industry or group of industries to the extent that the Index concentrates in a particular industry or group of industries. The Fund may use derivatives, including credit default swaps and credit default index swaps, to obtain investment exposure that the Adviser expects to correlate closely with the Index, or a portion of the Index, and in managing cash flows.

SPDR Bloomberg Barclays 1-10 Year TIPS ETF

The SPDR Bloomberg Barclays 1-10 Year TIPS ETF seeks to provide investment results that, before fees and expenses, correspond generally to the price and yield performance of an index that tracks the 1-10 year inflation protected sector of the United States Treasury market. In seeking to track the performance of the Bloomberg Barclays 1-10 Year U.S. Government Inflation-Linked Bond Index, the Fund employs a sampling strategy, which means that the Fund is not required to purchase all of the securities represented in the Index. Instead, the Fund may purchase a subset of the securities in the Index in an effort to hold a portfolio of securities with generally the same risk and return characteristics of the Index. The quantity of holdings in the Fund will be based on a number of factors, including asset size of the Fund. Based on its analysis of these factors, SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, either may invest the Fund's assets in a subset of securities in the Index or may invest the Fund's assets in substantially all of the securities represented in the Index in approximately the same proportions as the Index, as determined by the Adviser to be in the best interest of the Fund in pursuing its objective.

Index/Trademark Licenses/Disclaimers

The Russell Small Cap Completeness ^® Index is not sponsored, endorsed, sold or marketed by Frank Russell Company (“Russell”). The Russell Small Cap Completeness ^® Index in no way suggests or implies an opinion by Russell as to the advisability of investment in any or all of the securities upon which the Russell Small Cap Completeness Index is based. Russell licenses to the Adviser certain trademarks and trade names of Russell and of the Russell Small Cap Completeness Index which are determined, composed and calculated by Russell without regard to the SPDR Russell Small Cap Completeness ETF. Russell is not responsible for and has not reviewed the Products nor any associated literature or publications and Russell makes no representation or warranty express or implied as to their accuracy or completeness, or otherwise. Russell reserves the right, at any time and without notice, to alter, amend, terminate or in any way change the Russell Small Cap Completeness Index. Russell has no obligation or liability in connection with the administration, marketing or trading of the Products.

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S&P INDICES: The S&P 500 Index and the Dow Jones Global Select Real Estate Securities Index (the “Indices”) are products of S&P Dow Jones Indices LLC, (“SPDJI”), a division of S&P Global or its affiliates, and have been licensed for use by the Adviser. “S&P”, “Standard & Poor's” are registered trademarks of Standard & Poor's Financial Services LLC (“S&P'), a division of S&P Global; "Global Dow” is a registered trademark of Dow Jones Trademark Holdings LLC (“Dow Jones”); and these marks, together with the names of the S& P Indices, have been licensed for use by SPDJI and sub-licensed for use by the Adviser.

The State Street Equity 500 Index II Portfolio and the SPDR Dow Jones Global Real Estate ETF are not sponsored, endorsed, sold or marketed by S&P Dow Jones Indices LLC, Dow Jones, S&P, any of their respective affiliates (collectively, “S&P Dow Jones Indices”). S&P Dow Jones Indices does not make any representation or warranty, express or implied, to the owners of the State Street Equity 500 Index II Portfolio and the SPDR Dow Jones Global Real Estate ETF or any member of the public regarding the advisability of investing in securities generally or in the State Street Equity 500 Index II Portfolio and the SPDR Dow Jones Global Real Estate ETF particularly or the ability of the Indices to track general market performance. S&P Dow Jones Indices licenses to Licensee the Index and certain trademarks, service marks and/or trade names of S&P Dow Jones Indices and/or its licensors. The Indices are determined, composed and calculated by S&P Dow Jones Indices without regard to Licensee or the State Street Equity 500 Index II Portfolio and the SPDR Dow Jones Global Real Estate ETF. S&P Dow Jones Indices have no obligation to take the needs of Licensee or the owners of the State Street Equity 500 Index II Portfolio and the SPDR Dow Jones Global Real Estate ETF into consideration in determining, composing or calculating the Indices. S&P Dow Jones Indices is not responsible for and has not participated in the determination of the prices, and amount of the State Street Equity 500 Index II Portfolio and the SPDR Dow Jones Global Real Estate ETF or the timing of the issuance or sale of the State Street Equity 500 Index II Portfolio and the SPDR Dow Jones Global Real Estate ETF or in the determination or calculation of the equation by which the State Street Equity 500 Index II Portfolio and the SPDR Dow Jones Global Real Estate ETF are to be converted into cash, surrendered or redeemed, as the case may be. S&P Dow Jones Indices has no obligation or liability in connection with the administration, marketing or trading of the State Street Equity 500 Index II Portfolio and the SPDR Dow Jones Global Real Estate ETF. S&P Dow Jones Indices LLC is not an investment or tax advisor. Inclusion of a security within an index is not a recommendation by S&P Dow Jones Indices to buy, sell, or hold such security, nor is it considered to be investment advice.

NEITHER S&P DOW JONES INDICES NOR THIRD PARTY LICENSOR GUARANTEES THE ADEQUACY, ACCURACY, TIMELINESS AND/OR THE COMPLETENESS OF THE INDICES OR ANY DATA RELATED THERETO OR ANY COMMUNICATION, INCLUDING BUT NOT LIMITED TO, ORAL OR WRITTEN COMMUNICATION (INCLUDING ELECTRONIC COMMUNICATIONS) WITH RESPECT THERETO. S&P DOW JONES INDICES AND THIRD PARTY LICENSOR SHALL NOT BE SUBJECT TO ANY DAMAGES OR LIABILITY FOR ANY ERRORS, OMISSIONS, OR DELAYS THEREIN. S&P DOW JONES INDICES AND THIRD PARTY LICENSOR MAKES NO EXPRESS OR IMPLIED WARRANTIES, AND EXPRESSLY DISCLAIMS ALL WARRANTIES, OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE OR AS TO RESULTS TO BE OBTAINED BY LICENSEE, OWNERS OF THE STATE STREET EQUITY 500 INDEX II PORTFOLIO AND THE SPDR DOW JONES GLOBAL REAL ESTATE ETF, OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE INDICES OR WITH RESPECT TO ANY DATA RELATED THERETO. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT WHATSOEVER SHALL S&P DOW JONES INDICES OR THIRD PARTY LICENSOR BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES INCLUDING BUT NOT LIMITED TO, LOSS OF PROFITS, TRADING LOSSES, LOST TIME OR GOODWILL, EVEN IF THEY HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, WHETHER IN CONTRACT, TORT, STRICT LIABILITY, OR OTHERWISE. THERE ARE NO THIRD PARTY BENEFICIARIES OF ANY AGREEMENTS OR ARRANGEMENTS BETWEEN S&P DOW JONES INDICES AND LICENSEE, OTHER THAN THE LICENSORS OF S&P DOW JONES INDICES.

BLOOMBERG ^® is a trademark and service mark of Bloomberg Finance L.P. BARCLAYS ^® is a trademark and service mark of Barclays Bank Plc, used under license. Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited (“BISL”) (collectively, “Bloomberg”), or Bloomberg's licensors own all proprietary rights in the Bloomberg Barclays 1-3 Month

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U.S. Treasury Bill Index, Bloomberg Barclays U.S. Government Inflation-Linked Bond Index, Bloomberg Barclays 1-10 Year U.S. Government Inflation-Linked Bond Index, Bloomberg Barclays 1-5 Year U.S. Treasury Index, Bloomberg Barclays Intermediate U.S. Treasury Index, Bloomberg Barclays Long U.S. Treasury Index, Bloomberg Barclays U.S. 1-3 Year Corporate Bond Index, Bloomberg Barclays U.S. Intermediate Corporate Bond Index, Bloomberg Barclays U.S. Long Term Corporate Bond Index, Bloomberg Barclays US Corporate Bond Index, Bloomberg Barclays U.S. Convertible Liquid Bond Index, Bloomberg Barclays U.S. MBS Index, Bloomberg Barclays U.S. Aggregate Bond Index, Bloomberg Barclays Municipal Managed Money Index, Bloomberg Barclays Managed Money Municipal Short Term Index, Bloomberg Barclays 1-3 Year Global Treasury ex-US Capped Index, Bloomberg Barclays Global Treasury ex-US Capped Index, Bloomberg Barclays Global Aggregate ex-USD >$1B: Corporate Bond Index, Bloomberg Barclays EM Local Currency Government Diversified Index, Bloomberg Barclays High Yield Very Liquid Index, Bloomberg Barclays US High Yield 350mn Cash Pay 0-5 Yr 2% Capped Index, Bloomberg Barclays U.S. Dollar Floating Rate Note < 5 Years Index, (collectively, the “Bloomberg Barclays Indices”).

The Bloomberg Barclays Indices are licensed for use by State Street Global Advisors (the “Licensee”) and its affiliates with respect to SPDR Bloomberg Barclays TIPS ETF, SPDR Bloomberg Barclays 1-10 Year TIPS ETF, and SPDR Bloomberg Barclays High Yield Bond ETF, along with other products advised by an affiliate of the Licensee (collectively, the “Products”).

Neither Barclays Bank Plc, Barclays Capital Inc., nor any affiliate (collectively “Barclays”) nor Bloomberg is the issuer or producer of the Products. The only relationship of Bloomberg and Barclays with the Licensee in respect of the Bloomberg Barclays Indices is the licensing of the Bloomberg Barclays Indices, which are determined, composed and calculated by BISL, or any successor thereto, without regard to the Licensee or the Products or the owners of the Products. In that capacity, neither Bloomberg nor Barclays has any responsibilities, obligations or duties to investors in the Products. Licensee may execute transaction(s) with Barclays on behalf of the Products.

Absent a separate relationship or arrangement with Bloomberg or Barclays, investors neither acquire any interest in the Bloomberg Barclays Indices nor enter into any relationship of any kind whatsoever with Bloomberg or Barclays upon making an investment in the Products. The Products are not sponsored by Bloomberg or Barclays or endorsed, sold or marketed by Bloomberg or Barclays in their capacity as index provider and/or licensor of the Bloomberg Barclays Indices. In that capacity, neither Bloomberg nor Barclays (i) makes any representation or warranty, express or implied, regarding the advisability of investing in the Products or the advisability of investing in securities generally or the ability of the Bloomberg Barclays Indices to track corresponding or relative market performance, (ii) has passed on the legality or suitability of the Products with respect to any person or entity, (iii) is responsible for or has participated in the determination of the timing of, prices at, or quantities of the Products to be issued, (iv) has any obligation to take the needs of the Licensee or the owners of the Products or any other third party into consideration in determining, composing or calculating the Bloomberg Barclays Indices, or (v) has any obligation or liability in connection with administration, marketing or trading of the Products.

The licensing agreement between Bloomberg and Barclays is solely for the benefit of Bloomberg and Barclays and not for the benefit of the owners of the Products, investors or other third parties. In addition, the licensing agreement between Licensee and Bloomberg is solely for the benefit of Licensee and Bloomberg and not for the benefit of the owners of the Products, investors or other third parties.

NEITHER BLOOMBERG NOR BARCLAYS SHALL HAVE ANY LIABILITY TO THE LICENSEE, INVESTORS OR OTHER THIRD PARTIES FOR THE QUALITY, ACCURACY AND/OR COMPLETENESS OF THE BLOOMBERG BARCLAYS INDICES OR ANY DATA INCLUDED THEREIN OR FOR INTERRUPTIONS IN THE DELIVERY OF THE BLOOMBERG BARCLAYS INDICES. NEITHER BLOOMBERG NOR BARCLAYS MAKES ANY WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY THE LICENSEE, THE INVESTORS OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE BLOOMBERG BARCLAYS INDICES OR ANY DATA INCLUDED THEREIN. NEITHER BLOOMBERG NOR BARCLAYS MAKES ANY EXPRESS OR IMPLIED WARRANTIES, AND EACH HEREBY EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO THE BLOOMBERG BARCLAYS INDICES OR ANY DATA INCLUDED THEREIN. BLOOMBERG RESERVES THE RIGHT TO CHANGE THE METHODS OF CALCULATION OR PUBLICATION, OR TO CEASE THE CALCULATION OR PUBLICATION OF THE BLOOMBERG BARCLAYS INDICES, AND NEITHER BLOOMBERG NOR BARCLAYS SHALL BE LIABLE FOR ANY MISCALCULATION OF OR ANY INCORRECT, DELAYED OR INTERRUPTED PUBLICATION WITH RESPECT TO ANY OF THE BLOOMBERG BARCLAYS INDICES. NEITHER BLOOMBERG NOR BARCLAYS SHALL BE LIABLE FOR ANY DAMAGES, INCLUDING, WITHOUT LIMITATION, ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY LOST PROFITS, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH, RESULTING FROM THE USE OF THE BLOOMBERG BARCLAYS INDICES OR ANY DATA INCLUDED THEREIN OR WITH RESPECT TO THE PRODUCTS.

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THE FUNDS ARE NOT SPONSORED, ENDORSED, SOLD OR PROMOTED BY MSCI INC. (“MSCI”), MSCI'S PARENT COMPANY, ANY OF MSCI'S OR MSCI'S PARENT COMPANY'S DIRECTLY OR INDIRECTLY HELD SUBSIDIARIES, ANY OF MSCI'S OR MSCI'S PARENT COMPANY'S INFORMATION PROVIDERS OR ANY THIRD PARTY INVOLVED IN, OR RELATED TO, COMPILING, COMPUTING OR CREATING ANY MSCI INDEX (COLLECTIVELY, THE “MSCI PARTIES”).THE MSCI INDICES ARE THE EXCLUSIVE PROPERTY OF MSCI. MSCI AND THE MSCI INDEX NAMES ARE SERVICE MARK(S) OF MSCI OR ITS AFFILIATES AND HAVE BEEN LICENSED FOR USE FOR CERTAIN PURPOSES BY THE LICENSEE. NONE OF THE MSCI PARTIES MAKES ANY REPRESENTATION OR WARRANTY, EXPRESS OR IMPLIED, TO THE ISSUER OR OWNERS OF THE MSCI FUNDS OR ANY OTHER PERSON OR ENTITY REGARDING THE ADVISABILITY OF INVESTING IN FUNDS GENERALLY OR IN THE MSCI FUNDS PARTICULARLY OR THE ABILITY OF ANY MSCI INDEX TO TRACK CORRESPONDING STOCK MARKET PERFORMANCE. MSCI OR ITS AFFILIATES ARE THE LICENSORS OF CERTAIN TRADEMARKS, SERVICE MARKS AND TRADE NAMES AND OF THE MSCI INDICES WHICH ARE DETERMINED, COMPOSED AND CALCULATED BY MSCI WITHOUT REGARD TO THE MSCI FUNDS OR THE ISSUER OR OWNERS OF THE MSCI FUNDS OR ANY OTHER PERSON OR ENTITY. NONE OF THE MSCI PARTIES HAS ANY OBLIGATION TO TAKE THE NEEDS OF THE ISSUER OR OWNERS OF THE MSCI FUNDS OR ANY OTHER PERSON OR ENTITY INTO CONSIDERATION IN DETERMINING, COMPOSING OR CALCULATING THE MSCI INDICES. NONE OF THE MSCI PARTIES IS RESPONSIBLE FOR OR HAS PARTICIPATED IN THE DETERMINATION OF THE TIMING OF, PRICES AT, OR QUANTITIES OF THE MSCI FUNDS TO BE ISSUED OR IN THE DETERMINATION OR CALCULATION OF THE EQUATION BY OR THE CONSIDERATION INTO WHICH THE MSCI FUNDS ARE REDEEMABLE. FURTHER, NONE OF THE MSCI PARTIES HAS ANY OBLIGATION OR LIABILITY TO THE ISSUER OR OWNERS OF THE MSCI FUNDS OR ANY OTHER PERSON OR ENTITY IN CONNECTION WITH THE ADMINISTRATION, MARKETING OR OFFERING OF THE MSCI FUNDS.

SPDR Trademark. The “SPDR” trademark is used under license from Standard & Poor's Financial Services LLC (“S&P”), a division of S&P Global. No Fund offered by the Trust or its affiliates is sponsored, endorsed, sold or marketed by S&P or its affiliates. S&P makes no representation or warranty, express or implied, to the owners of any Fund or any member of the public regarding the advisability of investing in securities generally or in the Funds particularly or the ability of the Index on which the Fund is based to track general stock market performance. S&P is not responsible for and has not participated in any determination or calculation made with respect to issuance or redemption of Fund Shares. S&P has no obligation or liability in connection with the administration, marketing or trading of the Funds.

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WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT SHALL S&P HAVE ANY LIABILITY FOR ANY SPECIAL, PUNITIVE, INDIRECT, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, LOST PROFITS), EVEN IF NOTIFIED OF THE POSSIBILITY OF SUCH DAMAGES.

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Contacting the State Street Funds

Online:	www.ssgafunds.com	24 hours a day, 7 days a week
Phone:	(800) 647-7327	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Overnight/ Registered, Express, Certified Mail
State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737	State Street Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407

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For more information about the Funds:

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

SSITTDSTATPRO

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Institutional U.S. Government Money Market Fund: Class G (SSOXX)

Beginning on January 1, 2021, as permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of the Fund's annual and semi- annual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Fund (or from your financial intermediary, such as a broker-dealer or bank). Instead, the reports will be made available on the Fund's website (www.ssga.com/cash), and you will be notified by mail each time a report is posted, and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Fund electronically by calling (866) 392-0869.

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with a Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling (866) 392-0869. Your election to receive reports in paper will apply to all funds held in your account, if you invest through your financial intermediary or all funds held with the fund complex if you invest directly with a Fund.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in the Fund offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

The Fund offers multiple classes of shares. This Prospectus covers only the Class G Shares.

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Fund Summary	1
State Street Institutional U.S. Government Money Market Fund	1
Additional Information About Investment Objective, Principal Strategies and Risks	6
Additional Information About Non-Principal Investment Strategies and Risks	11
Portfolio Holdings Disclosure	12
Management and Organization	13
Shareholder Information	14
Dividends, Distributions and Tax Considerations	19
Financial Intermediary Arrangements	20
Financial Highlights	22

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State Street Institutional U.S. Government Money Market Fund

Investment Objective

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%
Other Expenses	0.03%
Total Annual Fund Operating Expenses	0.08%

Example:

1 year		3 years		5 years		10 years
$8		$26		$45		$103

Principal Investment Strategies

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The Fund attempts to meet its investment objective by investing in:

•

•	Obligations issued or guaranteed by the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association, and U.S. government-sponsored entities such as the Federal Home Loan Bank, and the Federal Farm Credit Banks Funding Corporation, which are not backed by the full faith and credit of the United States; and
•	Repurchase agreements collateralized by U.S. government securities.

Principal Risks

In addition, the Fund is subject to the following principal risks:

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Performance

The bar chart and table below provide some indication of the risks of investing in the U.S. Government Fund by illustrating the variability of the Fund's returns for Class G shares from year-to-year. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.55% (Q4, 2018)
Lowest Quarterly Return: 0.00% (Q2, 2015)

Average Annual Total Returns (for periods ended 12/31/18)

		One Year		Since Inception		Inception Date
Class G		1.80%		0.69%		10/6/2014

To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Purchase and Sale of Fund Shares

Purchase Minimums

Class G
To establish an account	$1,000,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

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By Telephone:

By Intermediary:

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objective, Principal Strategies and Risks

Investment Objective

The investment objective of the U.S. Government Fund, as stated in the Fund Summary, may be changed without shareholder approval.

U.S. Government Fund

Principal Investment Strategies

The U.S. Government Fund is a government money market fund and invests only in obligations issued or guaranteed as to principal and/or interest, as applicable, by the U.S. government or its agencies and instrumentalities, as well as repurchase agreements secured by such instruments. The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

The Fund follows a disciplined investment process that attempts to provide stability of principal, liquidity and current income, by investing in U.S. government securities. Among other things, SSGA FM conducts its own credit analyses of potential investments and portfolio holdings, and relies substantially on a dedicated short-term credit research team. The Fund invests in accordance with regulatory requirements applicable to money market funds. Regulations require, among other things, a money market fund to invest only in short-term, high quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity. All securities held by the Fund are U.S. dollar-denominated, and they may have fixed, variable or floating interest rates.

The Fund attempts to meet its investment objective by investing in:

•

•	Obligations issued or guaranteed by the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association, and U.S. government-sponsored entities such as the Federal Home Loan Bank, and the Federal Farm Credit Banks Funding Corporation, which are not backed by the full faith and credit of the United States; and
•	Repurchase agreements collateralized by U.S. government securities.

Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure.

Call/Prepayment Risk . Call/prepayment risk is the risk that an issuer will exercise its right to pay principal on an obligation held by the Fund earlier than expected or required. This may occur, for example, when there is a decline in interest rates, and an issuer of bonds or preferred stock redeems the bonds or stock in order to replace them with obligations on which it is required to pay a lower interest or dividend rate. It may also occur when there is an unanticipated increase in the rate at which mortgages or other receivables underlying mortgage- or asset-backed securities held by the Fund are prepaid. In any such case, the Fund may be forced to invest the prepaid amounts in lower-yielding investments, resulting in a decline in the Fund's income.

Counterparty Risk . The Fund will be subject to credit risk with respect to the counterparties with which the Fund enters into repurchase agreements and other transactions. If a counterparty fails to meet its contractual obligations, the Fund may be unable to terminate the transaction, and it may be delayed or prevented from realizing on any collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty.

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Credit Risk . Credit risk is the risk that an issuer, guarantor or liquidity provider of a fixed-income security held by the Fund may be unable or unwilling, or may be perceived (whether by market participants, ratings agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. It includes the risk that the security will be downgraded by a credit rating agency; generally, lower credit quality issuers present higher credit risks. An actual or perceived decline in creditworthiness of an issuer of a fixed-income security held by the Fund may result in a decrease in the value of the security. It is possible that the ability of an issuer to meet its obligations will decline substantially during the period when the Fund owns securities of the issuer or that the issuer will default on its obligations or that the obligations of the issuer will be limited or restructured.

The credit rating assigned to any particular investment does not necessarily reflect the issuer's current financial condition and does not reflect an assessment of an investment's volatility or liquidity. Securities rated in the lowest category of investment-grade are considered to have speculative characteristics. If a security held by the Fund loses its rating or its rating is downgraded, the Fund may nonetheless continue to hold the security in the discretion of the Adviser. In the case of asset-backed or mortgage-related securities, changes in the actual or perceived ability of the obligors on the underlying assets or mortgages to make payments of interest and/or principal may affect the values of those securities.

Debt Securities Risk . The values of debt securities may increase or decrease as a result of the following: market fluctuations, increases in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments or illiquidity in debt securities markets; the risk of low rates of return due to reinvestment of securities during periods of falling interest rates or repayment by issuers with higher coupon or interest rates; and/or the risk of low income due to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of the Fund's fixed income securities to decrease, an adverse impact on the liquidity of the Fund's fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Fund may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

Income Risk. The Fund's income may decline due to falling interest rates or other factors. Issuers of securities held by the Fund may call or redeem the securities during periods of falling interest rates, and the Fund would likely be required to reinvest in securities paying lower interest rates. If an obligation held by the Fund is prepaid, the Fund may have to reinvest the prepayment in other obligations paying income at lower rates. A reduction in the income earned by the Fund may limit the Fund's ability to achieve its objective.

Interest Rate Risk . Interest rate risk is the risk that the securities held by the Fund will decline in value because of increases in market interest rates. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. Debt securities with longer durations tend to be more sensitive to changes in interest rates, usually making them more volatile than debt securities with shorter durations. For example, the value of a security with a duration of five years would be expected to decrease by 5% for every 1% increase in interest rates. Falling interest rates also create the potential for a decline in the Fund's income and yield. Interest-only and principal-only securities are especially sensitive to interest rate changes, which can affect not only their prices but can also change the income flows and repayment assumptions about those investments. Variable and floating rate securities also generally increase or decrease in value in response to changes in interest rates, although generally to a lesser degree than fixed-rate securities. A substantial increase in interest rates may also have an adverse impact on the liquidity of a security, especially those with longer durations. Changes in governmental policy, including changes in central bank monetary policy, could cause interest rates to rise rapidly, or cause investors to expect a rapid rise in interest rates. This could lead to heightened levels of interest rate, volatility and liquidity risks for the fixed income markets generally and could have a substantial and immediate effect on the values of the Fund's investments.

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including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of the Portfolio to conduct its investment program. For example, they could require the Portfolio to sell portfolio securities or purchase portfolio securities unexpectedly and incur substantial transaction costs and/or accelerate the realization of taxable income and/or gains to investors, or the Portfolio may be required to sell its more liquid portfolio investments to meet a large redemption, in which case the Portfolio's remaining assets may be less liquid, more volatile, and more difficult to price. The Portfolio may hold a relatively large proportion of its assets in cash in anticipation of large redemptions, diluting its investment returns.

Liquidity Risk . Liquidity risk is the risk that the Fund may not be able to dispose of securities readily at a favorable time or prices (or at all) or at prices approximating those at which the Fund currently values them. For example, certain investments may be subject to restrictions on resale, may trade in the over-the-counter market or in limited volume, or may not have an active trading market. Illiquid securities may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value. It may be difficult for the Fund to value illiquid securities accurately. The market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. Disposal of illiquid securities may entail registration expenses and other transaction costs that are higher than those for liquid securities. The Fund may seek to borrow money to meet its obligations (including among other things redemption obligations) if it is unable to dispose of illiquid investments, resulting in borrowing expenses and possible leveraging of the Fund. In some cases, due to unanticipated levels of illiquidity the Fund may choose to meet its redemption obligations wholly or in part by distributions of assets in-kind.

Low Short-Term Interest Rate Risk . During market conditions in which short-term interest rates are at low levels the Fund's yield can be very low. During these conditions, it is possible that the Fund will generate an insufficient amount of income to pay its expenses, and that it will not be able to pay a daily dividend and may have a negative yield (i.e., it may lose money on an operating basis). It is possible that the Fund would, during these conditions, maintain a substantial portion of its assets in cash, on which it may earn little, if any, income.

Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject the Fund to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and the Fund's investment program in particular can be uncertain. In recent periods, governmental and non-governmental issuers have defaulted on, or have been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including, without limitation, in Europe or Asia. Defaults or restructurings

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by governments or others of their debts could have substantial adverse effects on economies, financial markets, and asset valuations around the world. Further Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, or investor perception that these efforts are not succeeding, could negatively affect financial markets generally as well as the values and liquidity of certain securities.

Money Market Risk . An investment in a money market fund is not a deposit of any bank and is not insured or guaranteed by the FDIC or any other government agency. Although a money market fund generally seeks to preserve the value of its shares at $1.00 per share, there can be no assurance that it will do so, and it is possible to lose money by investing in a money market fund. A major or unexpected increase in interest rates or a decline in the credit quality of an issuer or entity providing credit support, an inactive trading market for money market instruments, or adverse market, economic, industry, political, regulatory, geopolitical, and other conditions could cause a money market fund's share price to fall below $1.00. It is possible that a money market fund will issue and redeem shares at $1.00 per share at times when the fair value of the money market fund's portfolio per share is more or less than $1.00. A money market fund may be permitted or required to impose redemption fees or to impose limitations on redemptions during periods of high illiquidity in the markets for the investments held by it. None of State Street Corporation, State Street, State Street Global Advisors, SSGA FM or their affiliates (collectively, the “State Street Entities”) guarantee the value of an investment in a money market fund at $1.00 per share. Investors should have no expectation of capital support to a money market fund from the State Street Entities.

Mortgage-Related and Other Asset-Backed Securities Risk . Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed income investments. The liquidity of mortgage-related and asset-backed securities may change over time. Mortgage-related securities represent a participation in, or are secured by, mortgage loans. Other asset-backed securities are typically structured like mortgage-related securities, but instead of mortgage loans or interests in mortgage loans, the underlying assets may include, for example, items such as motor vehicle installment sales or installment loan contracts, leases on various types of real and personal property, and receivables from credit card agreements. During periods of falling interest rates, mortgage-related and other asset-backed securities, which typically provide the issuer with the right to prepay the security prior to maturity, may be prepaid, which may result in the Fund having to reinvest the proceeds in other investments at lower interest rates. During periods of rising interest rates, the average life of mortgage-related and other asset-backed securities may extend because of slower-than expected principal payments. This may lock in a below market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. As a result, mortgage-related and other asset-backed securities may have less potential for capital appreciation during periods of declining interest rates than other debt securities of comparable maturities, although they may have a similar risk of decline in market values during periods of rising interest rates. Prepayment rates are difficult to predict and the potential impact of prepayments on the value of a mortgage-related or other asset-backed security depends on the terms of the instrument and can result in significant volatility. The price of a mortgage-related or other asset-backed security also depends on the credit quality and adequacy of the underlying assets or collateral. Mortgage-related or other asset-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) will generally entail greater credit risk than obligations guaranteed by the U.S. Government. Defaults on the underlying assets, if any, may impair the value of a mortgage-related or other asset-backed security. For some asset-backed securities in which the Fund invests, such as those backed by credit card receivables, the underlying cash flows may not be supported by a security interest in a related asset. Moreover, the values of mortgage-related and other asset-backed securities may be substantially dependent on the servicing of the underlying asset pools, and are therefore subject to risks associated with the negligence or malfeasance by their servicers and to

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the credit risk of their servicers. In certain situations, the mishandling of related documentation may also affect the rights of securities holders in and to the underlying collateral. There may be legal and practical limitations on the enforceability of any security interest granted with respect to underlying assets, or the value of the underlying assets, if any, may be insufficient if the issuer defaults.

Rapid Changes in Interest Rates . The values of most instruments held by the Fund are adversely affected by changes in interest rates generally, especially increases in interest rates. Rapid changes in interest rates may cause significant requests to redeem Fund Shares, and possibly cause the Fund to sell portfolio securities at a loss to satisfy those requests. Significant losses could impair the Fund's ability to maintain a stable share price of $1.00.

Reinvestment Risk. Income from the Fund's portfolio may decline when the Fund invests the proceeds from investment income, sales of portfolio securities or matured, traded or called debt obligations. For instance, during periods of declining interest rates, an issuer of debt obligations may exercise an option to redeem securities prior to maturity, forcing the Fund to reinvest the proceeds in lower-yielding securities. A decline in income received by the Fund from its investments is likely to have a negative effect on the yield and total return of the Fund Shares.

Repurchase Agreement Risk . A repurchase agreement is an agreement to buy a security from a seller at one price and a simultaneous agreement to sell it back to the original seller at an agreed-upon price, typically representing the purchase price plus interest. Repurchase agreements may be viewed as loans made by the Fund which are collateralized by the securities subject to repurchase. The Fund's investment return on such transactions will depend on the counterparty's willingness and ability to perform its obligations under a repurchase agreement. If the Fund's counterparty should default on its obligations and the Fund is delayed or prevented from recovering the collateral, or if the value of the collateral is insufficient, the Fund may realize a loss.

Significant Exposure to U.S. Government Agencies or Instrumentalities Risk . To the extent the Fund focuses its investments in securities issued or guaranteed by U.S. government agencies or instrumentalities, any market movements, regulatory changes or changes in political or economic conditions that affect the U.S. government agencies or instrumentalities in which the Fund invests may have a significant impact on the Fund's performance. Events that would adversely affect the market prices of securities issued or guaranteed by one government agency or instrumentality may adversely affect the market price of securities issued or guaranteed by other government agencies or instrumentalities.

Stable Share Price Risk . If the market value of one or more of the Fund's investments changes substantially, the Fund may not be able to maintain a stable share price of $1.00. This risk typically is higher during periods of rapidly changing interest rates or when issuer credit quality generally is falling, and is made worse when the Fund experiences significant redemption requests.

U.S. Government Securities Risk . U.S. government securities, such as Treasury bills, notes and bonds and mortgage-backed securities guaranteed by the Government National Mortgage Association (“Ginnie Mae”), are supported by the full faith and credit of the United States; others are supported by the right of the issuer to borrow from the U.S. Treasury; others are supported by the discretionary authority of the U.S. government to purchase the agency's obligations; and still others are supported only by the credit of the issuing agency, instrumentality, or enterprise. Although U.S. government-sponsored enterprises such as the Federal Home Loan Mortgage Corporation (“Freddie Mac”) and the Federal National Mortgage Association (“Fannie Mae”) may be chartered or sponsored by Congress, they are not funded by Congressional appropriations, and their securities are not issued by the U.S. Treasury nor supported by the full faith and credit of the U.S. government. There is no assurance that the U.S. government would provide financial support to its agencies and instrumentalities if not required to do so. In addition, certain governmental entities have been subject to regulatory scrutiny regarding their accounting policies and practices and other concerns that may result in legislation, changes in regulatory oversight and/or other consequences that could adversely affect the credit quality, availability, or investment character of securities issued by these entities. The value and liquidity of U.S. government securities may be affected adversely by changes in the ratings of those securities. Securities issued by the U.S. Treasury historically have been considered to present minimal credit risk. The downgrade in the long-term U.S. credit rating by at least one major rating agency has introduced greater uncertainty about the ability of the U.S. to repay its obligations. A further credit rating downgrade or a U.S. credit default could decrease the value and increase the volatility of the Fund's investments.

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increases in coupon rates. Alternatively, during periods of declining interest rates, the coupon rates on such securities will typically readjust downward resulting in a lower yield. The Fund may also invest in variable or floating rate equity securities, whose dividend payments vary based on changes in market rates of interest or other factors.

Additional Information About Non-Principal Investment Strategies and Risks

The investments described below reflect the Fund's and the Portfolio's current practices. In addition to the principal risks described above, other risks are described in some of the descriptions of the investments below:

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Fund. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for the Fund and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by the Fund. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Fund) or otherwise using such information for the benefit of its clients or itself.

Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Fund) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, the Fund, the Portfolio, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect the Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect the Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject the Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of the Fund inaccessible or inaccurate or incomplete. The Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. The Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. The Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put

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in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Fund. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which the Fund invests, which could result in material adverse consequences for such issuers, and may cause the Fund's investment in such securities to lose value.

Portfolio Holdings Disclosure

The Fund's portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

Investment Adviser

The Fund has entered into an investment advisory agreement with the Adviser pursuant to which the Adviser will manage the Fund's assets directly, for compensation paid at an annual rate of 0.05% of the Fund's average daily net assets, in the event that the Fund were to cease investing substantially all of its assets in its Portfolio or another investment company with essentially the same investment objectives and policies as the Fund. The Adviser does not receive any management fees from the Fund under that agreement so long as the Fund continues to invest substantially all of its assets in the Portfolio or in another investment company with essentially the same investment objectives and policies as the Fund. The Adviser places all orders for purchases and sales of the Portfolio's investments. For the year ended December 31, 2018, the effective management fee paid, reflecting certain fee waivers and expense reimbursements of the Adviser, was 0.05% for the Portfolio.

Total Annual Fund Operating Expense Waivers . SSGA FM, as the investment adviser to the Fund, is contractually obligated, through April 30, 2020, (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund for expenses to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.07% of average daily net assets on an annual basis. These waiver and/or reimbursement arrangements may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

A discussion regarding the Board's consideration of the Fund's Investment Advisory Agreement is provided in the Fund's Semi-Annual Report to Shareholders for the period ended June 30, 2018.

The Administrator, Sub-Administrator and Custodian

The Adviser serves as administrator of the Fund. The amount of the fee paid to the Adviser for administrative services may vary by share class. The Fund currently pays the Adviser an administrative fee at the annual rate of 0.01% in respect of the class of shares in this Prospectus. State Street Bank and Trust Company (“State Street”), a subsidiary of State Street Corporation, serves as the sub-administrator for the Fund for a fee that is paid by the Adviser. State Street also serves as custodian of the Fund for a separate fee that is paid by the Fund. SSGA FM serves as administrator of the Portfolio and State Street serves as sub-administrator and custodian of the Portfolio.

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Fund's transfer agent and dividend disbursing agent (the “Transfer Agent”).

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The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Fund's distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

The Shareholder Servicing Agent

SSGA FD serves as the Fund's shareholder servicing agent pursuant to the Shareholder Servicing Agreement between SSGA FD and the Trust and receives fees from the Fund for the provision and procurement of applicable services. Please see the SAI for more information on SSGA FD's role as the Fund's shareholder servicing agent.

Additional Information

Shareholder Information

Determination of Net Asset Value

The Fund determines its NAV per share once each day on which the New York Stock Exchange (the “NYSE”), the Federal Reserve banks and State Street are open for business (a “Business Day”) at 5:00 p.m. ET except for days when the NYSE closes earlier than its regular closing time, in which event the Fund will determine its NAV at the earlier closing time (the time when the Fund determines its NAV per share is referred to herein as the “Valuation Time”). Pricing does not occur on NYSE holidays.

The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. The Fund reserves the right to accept orders to purchase or redeem shares, or to continue to accept such orders following the close of the NYSE, on any day that is not a Business Day or any day on which the NYSE closes early, provided the Federal Reserve remains open. Consequently, the NAV of the Fund's shares may change on days when shareholders are not able to purchase or redeem the Fund's Shares. The Fund also may establish special hours on those days to determine the Fund's NAV. In the event that the Fund invokes the right to accept orders to purchase or redeem shares on any day that is not a Business Day or adopt special hours of operation, the Fund will post advance notice of these events at: www.ssga.com/cash.

The Fund seeks to maintain a $1.00 per share NAV and, accordingly, uses the amortized cost valuation method, in compliance with the risk limiting conditions of Rule 2a-7 under the Investment Company Act of 1940, as amended (the “1940 Act”), to value its portfolio instruments. The amortized cost valuation method initially prices an instrument at its cost and thereafter assumes a constant amortization to maturity of any discount or premium, regardless of the impact of fluctuating interest rates on the market value of the instrument.

If you hold shares of the Fund through a broker-dealer or other financial intermediary, your intermediary may offer additional services and account features that are not described in this Prospectus. Please contact your intermediary directly for an explanation of these services.

Investing in State Street Institutional Investment Trust Shares

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Purchasing Shares

The Fund offers one class of shares through this Prospectus: Class G shares, available to you subject to the eligibility requirements set forth below. All classes of the Fund share the same investment objective and investments, but the different share classes have different expense structures and eligibility requirements. You should choose the class with the expense structure that best meets your needs for which you are eligible. In choosing a share class, you should consider the amount you plan to invest. Your investment professional can help you choose the share class that best suits your investment needs.

The chart below summarizes the features of the share class. This chart is only a general summary, and you should read the description of the Fund's expenses in the Fund Summary in this Prospectus.

The minimum purchase amount may be waived for specific investors or types of investors, including, without limitation, retirement plans, employees of State Street Corporation and its affiliates and their family. In the case of shareholders purchasing shares through a Financial Intermediary, the minimum purchase amount may be applied at the level of the Financial Intermediary.

Minimum Initial Investment	$1,000,000,000
Maximum Investment	None.
Initial Sales Charge	No. Entire purchase price is invested in shares of a Fund.
Deferred (CDSC) Sales Charge	No.
Distribution and/or Service (12b-1) Fees	No.
Redemption Fees	No.

Investors pay no sales load to invest in Class G shares of the Fund. The price for Fund Shares is the NAV per share. Purchase requests received by the Fund in good order (a purchase request is in good order if it meets the requirements implemented from time to time by the Transfer Agent or authorized agent of the Fund, and for new accounts includes submission of a completed and signed application and all documentation necessary to open an account) on a business day will, if payment is received by FedWire, be priced at the NAV next determined after the order is accepted by the Fund. Payments received by FedWire prior to the last Valuation Times will earn dividend accrual for that purchase. All purchases that are made by check will be priced with the last valuation price and begin earning dividends the following business day after the day the order is accepted. (If you purchase shares by check, your order will not be in good form until the Transfer Agent receives federal funds for the check.) All purchase orders are subject to acceptance by the Fund. The Fund intends to be as fully invested as is practicable; therefore, investments must be made in Federal Funds (i.e., monies credited to the account of the Fund's custodian bank by a Federal Reserve Bank).

The minimum initial investment in Class G shares of the Fund is $1 billion although the Adviser may waive the minimum in its discretion. Holdings of related customer accounts may be aggregated for purposes of determining the minimum investment amount. “Related customer accounts” may include, but are not limited to, accounts held by the same investment or retirement plan, financial institution, broker, dealer or intermediary. The Fund and the Adviser reserve the right to increase or decrease the minimum amount required to open or maintain an account. There is no minimum subsequent investment, except in relation to maintaining certain minimum account balances (See “Redeeming Shares” below). The Fund requires prior notification of subsequent investments in excess of $50 million. The Fund reserves the right to cease accepting investments at any time or to reject any investment order. In addition, the Fund may limit the amount of a purchase order received after 3:00 p.m. ET.

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How to Purchase Shares

By Mail:

An initial investment in the Fund must be preceded or accompanied by a completed, signed Institutional Account Application Form, sent to:
State Street Funds
P.O. Box 219737
Kansas City, MO 64121‐9737

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone/Fax:

An initial investment in the Fund must be preceded or accompanied by a completed, signed Institutional Account Application Form, faxed to (816) 218-0400. Call the Fund at (866) 392-0869 between the hours of 7:00 a.m. ET and 5:00 p.m. ET to:

For your initial investment, send the original, signed Institutional Account Application Form to the address above.

Wire Instructions:

Instruct your bank to transfer money by Federal Funds wire to:
State Street Bank and Trust Company
1 Iron Street
Boston, MA 02110

ABA# 011000028
DDA# 9904-631-0
State Street Institutional Investment Trust
Fund Name
Class Name
Account Number
Account Registration

You will not be able to redeem shares from the account until the original Application has been received. The Fund and the Fund's agents are not responsible for transfer errors by the sending or receiving bank and will not be liable for any loss incurred due to a wire transfer not having been received.

Redeeming Shares

An investor may redeem all or any portion of its investment. Redemption orders are processed at the NAV next determined after the Fund receives a redemption order in good form. If the Fund receives a redemption order in good form prior to 5:00 p.m. ET on a business day, shares are redeemed and the Fund typically sends payment for redeemed shares on that day, but no later than the next business day (if redemption proceeds are sent by wire or ACH. If redemption proceeds are sent by check, the Fund typically expects to pay out redemption proceeds on the next business day. If a full redemption order is requested, no dividends will accrue with respect to shares on the day the redemption proceeds are sent. If a redemption order is placed after 5:00 p.m. ET the Fund typically expects to pay out redemption proceeds on the next business day (and dividends will accrue up to, but not including, the day that redemption proceeds are sent). The Fund reserves the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Fund.

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The Fund is a government money market fund that has not elected to be subject to the fees and gates provisions of Rule 2a-7. The right of any investor to receive payment with respect to any redemption may be suspended or the payment of the redemption proceeds postponed in accordance with Section 22(e) of the 1940 Act and the rules thereunder, including during any period in which the NYSE is closed (other than weekends or holidays) or trading on the NYSE is restricted or if an emergency exists as a result of which disposal by the Fund of securities owned by it is not reasonably practicable or it is not reasonably practicable for the Fund fairly to determine the value of its net assets. In addition, the SEC may by order permit suspension of redemptions for the protection of shareholders of the Fund. Although the Fund attempts to maintain its NAV at $1.00 per share, there can be no assurance that it will be successful, and there can be no assurance that a shareholder will receive $1.00 per share upon any redemption.

During periods of deteriorating or stressed market conditions or during extraordinary or emergency circumstances, the Fund may be more likely to pay redemption proceeds with cash obtained through short-term borrowing arrangements (if available) or by giving you securities.

A request for a partial redemption by an investor whose account balance is below a minimum amount or a request for partial redemption by an investor that would bring the account below a minimum amount may be treated as a request for a complete redemption of the account. These minimums may be different for investments made through certain financial intermediaries as determined by their policies and may be waived in the Adviser's discretion. The Fund reserves the right to modify minimum account requirements at any time with or without prior notice. The Fund also reserves the right to involuntarily redeem an investor's account if the investor's account balance falls below the applicable minimum amount due to transaction activity.

How to Redeem Shares


By Mail:	Send a signed letter to: State Street Institutional Investment Trust Funds P.O. Box 219737 Kansas City, MO 64121-9737
	The letter should include information necessary to process your request as described below. The Fund may require a medallion guarantee in certain circumstances. See “Medallion Guarantees” below.
By Overnight:	State Street Institutional Investment Trust Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407
By Telephone:	Please call (866) 392-0869 between the hours of 7:00 a.m. and 5:00 p.m. ET.
The Fund will need the following information to process your redemption request:
➣ name(s) of account owners; ➣ account number(s); ➣ the name of the Fund; ➣ your daytime telephone number; and ➣ the dollar amount or number of shares being redeemed.

On any day that the Fund calculates its NAV earlier than normal, the Fund reserves the right to adjust the times noted above for purchasing and redeeming shares.

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Medallion Guarantees . Certain redemption requests must include a medallion guarantee for each registered account owner if any of the following apply:

•	Your account address has changed within the last 10 Business Days.

•	Redemption proceeds are being transferred to an account with a different registration.
•	A wire is being sent to a financial institution other than the one that has been established on your Fund account.
•	Other unusual situations as determined by the Transfer Agent.

The Fund reserves the right to waive medallion guarantee requirements, require a medallion guarantee under other circumstances or reject or delay redemption if the medallion guarantee is not in good form. Medallion guarantees may be provided by an eligible financial institution such as a commercial bank, a Financial Industry Regulatory Authority, Inc. (“FINRA”) member firm such as a stock broker, a savings association or a national securities exchange. A notary public cannot provide a medallion guarantee. The Fund reserves the right to reject a medallion guarantee if it is not provided by a STAMP Medallion guarantor.

About Telephone Transactions . Telephone transactions are convenient but are not free from risk. Neither the Fund nor the Fund's agents will be responsible for any losses resulting from unauthorized telephone transactions if reasonable security procedures are followed. In addition, you are responsible for: (i) verifying the accuracy of all data and information transmitted by telephone, (ii) verifying the accuracy of your account statements immediately upon receipt, and (iii) promptly notifying the Fund of any errors or inaccuracies including, without limitation, any errors or inaccuracies relating to shareholder data or information transmitted by telephone. During periods of heavy market activity or other times, it may be difficult to reach the Fund by telephone. If you are unable to reach us by telephone, consider sending written instructions.

The Fund may terminate the receipt of redemption orders by telephone at any time, in which case you may redeem shares by other means.

If you choose to purchase or redeem shares by sending instructions by regular mail, they will not be deemed received in good order until they are released by the post office and redelivered to the Transfer Agent's physical location at 430 W 7th Street Suite 219737 in Kansas City, MO 64105-1407. There will be a time lag, which may be one or more days, between regular mail receipt at the post office box and redelivery to such physical location in Kansas City, and the Fund's NAV may change over those days. You might consider using express rather than regular mail if you believe the time of receipt of your transaction request to be sensitive.

Excessive Trading

Because the Fund is a money market fund, the Fund's Board of Trustees has not adopted policies and procedures with respect to frequent purchases and redemptions of Fund shares by Fund shareholders. Nonetheless, the Fund may take any reasonable action that it deems necessary or appropriate to prevent excessive trading in Fund shares without providing prior notification to the account holder. Such action may include rejecting any purchase, in whole or part, including, without limitation, by a person whose trading activity in Fund shares may be deemed harmful to the Fund. While the Fund attempts to discourage such excessive trading, there can be no guarantee that it will be able to identify investors who are engaging in excessive trading or limit their trading practices. Additionally, frequent trades of small amounts may not be detected. The Fund recognizes that it may not always be able to detect or prevent excessive trading or other activity that may disadvantage the Fund or its shareholders.

Delivery of Documents to Accounts Sharing an Address

To reduce expenses, we may mail only one copy of the Fund's Prospectus and the annual and semi-annual report to those addresses shared by two or more accounts. If you wish to receive individual copies of these documents, please call us at (877) 521-4083, or contact your financial institution. We will begin sending you individual copies thirty (30) days after receiving your request.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a State Street Fund identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

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If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Fund (if you hold shares directly with the Fund) or to your financial intermediary (if you do not hold shares directly with the Fund).

Dividends, Distributions and Tax Considerations

The Fund intends to declare dividends on shares from net investment income daily and pay them as of the last business day of each month. Distributions from capital gains, if any, will be made annually in December. Income dividends and capital gains distributions will be paid in additional shares on the reinvestment date unless you have elected to receive them in cash. No interest will accrue on the amounts represented by uncashed distribution checks. If you have elected to receive distributions by check, and the postal or other delivery service is unable to deliver the checks because of an incorrect mailing address, or if a distribution check remains uncashed for six months, the uncashed distribution and all future distributions will be reinvested at the then-current NAV of the Fund.

The Fund invests substantially all of its investible assets in a Portfolio that is treated as a partnership for U.S. federal income tax purposes. Therefore, the nature and character of the Fund's income, gains, losses and deductions generally will be determined at the Portfolio level, and the Fund will be allocated its share of the Portfolio's income, gains, losses and deductions. As applicable, references in this discussion to income, gains and losses of the Fund will be to income, gains and losses recognized and deductions accruing at the Portfolio level and allocated to or otherwise taken into account by the Fund, and references to assets of the Fund will be to the Fund's allocable share of the assets of the Portfolio.

For U.S. federal income tax purposes, distributions of investment income are generally taxable to you as ordinary income. Taxes on distributions of capital gains generally are determined by how long the Portfolio owned (or is deemed to have owned) the investments that generated them, rather than how long you have owned your Fund Shares. The Fund generally does not expect to make distributions that are eligible for taxation as long-term capital gains. Any net short-term gains the Fund distributes will be taxable to you as ordinary income. Distributions are taxable to you even if they are paid from income or gains earned by the Fund before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares.

If the NAV of Fund Shares were to vary from $1.0000 per share, shareholders generally would realize a gain or loss upon the redemption or other taxable disposition of such Fund Shares. Any such gains generally would be taxable to you as either short-term or long-term capital gain, depending upon how long you have held such Fund Shares.

The IRS has issued final regulations and published guidance that permit a simplified method of accounting for gains and losses realized upon the disposition of money market fund shares. Shareholders should see the SAI for further information.

An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by the Fund and net gains recognized on the redemption of shares of the Fund.

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Financial Intermediary Arrangements

Payments to Financial Intermediaries

The Financial Intermediary is often compensated by SSGA FD or its affiliates for the services it performs and in such cases is typically paid continually over time, during the period when the Financial Intermediary's clients hold investments in the Fund. The amount of continuing compensation paid by SSGA FD or its affiliates to different Financial Intermediaries for distribution and/or shareholder services varies. Any compensation is typically a percentage of the value of the Financial Intermediary's clients' investments in the Fund or a per account fee. The variation in compensation may, but will not necessarily, reflect enhanced or additional services provided by the Financial Intermediary.

If you invest through a Financial Intermediary and meet the eligibility criteria for more than one share class, you should discuss with your Financial Intermediary which share class is appropriate for you. Your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend one share class over another, when you are eligible to invest in more than one share class. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by the Fund or its affiliates with respect to the different share classes offered by the Fund.

SSGA FD and its affiliates (including SSGA FM), at their own expense and out of their own assets, may also provide other compensation to Financial Intermediaries in connection with sales of the Fund's shares or the servicing of shareholders or shareholder accounts. Such compensation may include, but is not limited to, financial assistance to Financial Intermediaries in connection with conferences, sales, or training programs for their employees; seminars for the public; advertising or sales campaigns; or other Financial Intermediary-sponsored special events. In some instances, this compensation may be made available only to certain Financial Intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the Fund's shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as FINRA.

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Financial Highlights

The financial highlight tables are intended to help you understand the Fund's Class G Shares financial performance for the past five fiscal years. Certain information reflects the performance results for a single Fund Share. The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in the Fund (assuming reinvestment of all dividends and distributions). This information has been audited by Ernst & Young LLP, the Trust's independent registered public accounting firm, whose report, along with the Fund's financial highlights and financial statements, is included in the annual report to shareholders, which is available upon request. Any references to Notes in these financial highlight tables refer to the “Notes to Financial Statements” section of the Fund's financial statements, and the financial information included in these tables should be read in conjunction with the financial statements incorporated by reference in the SAI.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL U.S. GOVERNMENT MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class G(a)
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	For the Period 10/5/14* - 12/31/14
Net asset value, beginning of period	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0180	0.0082	0.0029	0.0002(b)	0.0000(b)(c)
Net realized gain (loss)	—	0.0001	0.0000(c)	0.0000(c)	0.0000(c)
Total from investment operations	0.0180	0.0083	0.0029	0.0002	0.0000(c)
Distributions to shareholders from:
Net investment income	(0.0180)	(0.0083)	(0.0029)	(0.0002)	(0.0000)(c)
Net realized gains	—	(0.0000)(c)	—	—	—
Total distributions	(0.0180)	(0.0083)	(0.0029)	(0.0002)	(0.0000)(c)
Net asset value, end of period	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Total return (d)	1.80%	0.83%	0.29%	0.02%	0.00%(e)
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$3,065,834	$4,349,842	$581,991	$732,938	$872,335
Ratios to Average Net Assets:
Total expenses	0.08%	0.08%	0.08%	0.08%	0.09%(f)
Net expenses	0.08%	0.08%	0.08%	0.08%	0.08%(f)
Net investment income (loss)	1.74%	0.95%	0.29%	0.02%	0.00%(e)(f)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Per share numbers have been calculated using average shares outstanding, which more appropriately presents the per share data for the period.
(c)	Amount is less than $0.00005 per share.
(d)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(e)	Amount is less than 0.005%.
(f)	Annualized.

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Contacting the State Street Funds

Online:	www.ssga.com/cash	24 hours a day, 7 days a week
Phone:	(877) 521-4083	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Overnight/ Registered, Express, Certified Mail
State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737	State Street Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407

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For more information about the Fund:

The Fund's SAI includes additional information about the Fund and is incorporated by reference into this document. Additional information about the Fund's investments is available in the Fund's most recent annual and semi-annual reports to shareholders. The Fund's SAI is available, without charge, upon request. The Fund's annual and semi-annual reports are available, without charge, upon request. Shareholders in the Fund may make inquiries to the Fund to receive such information by calling (877) 521-4083 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. The Fund's Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, free of charge, on the Fund's website at www.ssga.com/cash.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

SSITCLGSTATPRO

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional Investment Trust

State Street Cash Reserves Fund

Institutional Class (CCQXX)

Administration Class (CCVXX)

Investment Class (CCWXX)

Investor Class (MMDXX)

Premier Class (MMEXX)

Beginning on January 1, 2021, as permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of the Fund’s annual and semiannual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Fund (or from your financial intermediary, such as a broker-dealer or bank). Instead, the reports will be made available on the Fund’s website (www.ssga.com/cash), and you will be notified by mail each time a report is posted, and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Fund electronically by calling (866) 392-0869.

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with a Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling (866) 392-0869. Your election to receive reports in paper will apply to all funds held in your account, if you invest through your financial intermediary or all funds held with the fund complex if you invest directly with the Fund.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in the Fund offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. It is possible to lose money by investing in the Fund offered in this Prospectus.

The Fund may offer multiple classes of shares. This Prospectus covers only the Institutional Class, Administration Class, Investment Class, Investor Class, and Premier Class Shares of the State Street Cash Reserves Fund.

LOGO

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Fund Summary			1

State Street Cash Reserves Fund			1

Additional Information About Investment Objective, Principal Strategies and Risks			7

Additional Information About Non-Principal Investment Strategies and Risks			13

Portfolio Holdings Disclosure			14

Management and Organization			15

Shareholder Information			16

Dividends, Distributions and Tax Considerations			22

Financial Intermediary Arrangements			23

Financial Highlights			24

STATE STREET CASH RESERVES FUND

Investment Objective

The investment objective of State Street Cash Reserves Fund (the “Fund”) is to seek to maximize current income, to the extent consistent with the preservation of capital and liquidity and the maintenance of a stable $1.00 per share net asset value (“NAV”) by investing in U.S. dollar-denominated money market securities.

Fees and Expenses of the Fund

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Cash Reserves Fund (“Fund Shares”). The expenses shown in the table and the Example reflect the expenses of the Fund and the Fund’s proportionate share of the expenses of the State Street Cash Reserves Portfolio (the “Cash Reserves Portfolio” or sometimes referred to in context as the “Portfolio”).

Shareholder Fees (fees paid directly from your investment)

Institutional

Administration

Investment

Investor

Premier

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)

None

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)

None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)


	Institutional			Administration			Investment			Investor			Premier
Management Fee		0.10	%		0.10	%		0.10	%		0.10	%		0.10	%

Distribution and/or Shareholder Service (12b-1) Fees		0.00	%		0.05	%		0.10	%		0.00	%		0.00	%

Other Expenses ¹		0.39	%		0.56	%		0.61	%		0.44	%		0.36	%

Total Annual Fund Operating Expenses		0.49	%		0.71	%		0.81	%		0.54	%		0.46	%


Less Fee Waivers and/or Expense Reimbursements ²		(0.29	)%		(0.29	)%		(0.29	)%		(0.29	)%		(0.29	)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements		0.20	%		0.42	%		0.52	%		0.25	%		0.17	%

¹	Other expenses are based on estimates for the current fiscal year.

The Fund’s investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund for expenses to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, extraordinary expenses, acquired fund fees, and any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.12% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund’s Board of Trustees.

Example:

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated, and then sell all of your Fund Shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. The calculation of costs for the one-year period takes into account the effect of any current contractual fee waivers and/or reimbursements; and the calculation of costs for the remaining periods takes such fee waivers and/or reimbursements into account only for the first year of each such period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:


	1 year		3 years

Institutional	$	20	$	128

Administration	$	43	$	198

Investment	$	53	$	230

Investor	$	26	$	144

Premier	$	17	$	118

Principal Investment Strategies

In managing the State Street Cash Reserves Fund, the Adviser follows a disciplined investment process, basing its decisions on the relative attractiveness of different money market instruments. Among other things, SSGA FM conducts its own credit analyses of potential investments and portfolio holdings, and relies substantially on a dedicated short term credit research team. In the Adviser’s opinion the attractiveness of an instrument may vary depending on a variety of factors, including for example the general level of interest rates, imbalances of supply and demand in the market, and the credit quality of the obligors.

The Fund is a retail money market fund and seeks to maintain its net asset value NAV at $1.00 per share, although there can be no assurance that it will be able to do so.

The Fund attempts to meet its investment objective by investing in a broad range of money market instruments. These may include U.S. Government securities (including U.S. Treasury bills, notes and bonds and other securities issued or guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities); certificates of deposit and time deposits of U.S. and foreign banks; commercial paper and other high quality obligations of U.S. or foreign companies; asset-backed securities, including asset backed commercial paper; mortgage-related securities; and repurchase agreements. These instruments may bear fixed, variable or floating rates of interest or may be zero-coupon securities. The Fund also may invest in shares of other money market funds, including funds advised by the Adviser. A substantial portion of the Fund may be invested in securities that are issued or traded pursuant to exemptions from registration under the federal securities laws.

The Fund purchases assets that have received a top tier (without regard to subcategories or gradations) short-term debt rating from one or more nationally recognized statistical rating organizations ( e.g ., those rated A-1 by Standard & Poor’s Rating Group (“S&P”), P-1 by Moody’s Investor Service, Inc. (“Moody’s”) or F1 by Fitch Ratings (“Fitch”)) or, if unrated, that are considered to be of comparable quality by the Adviser.

Under normal circumstances, the Fund intends to invest at least 25% of its assets in bank obligations.

The Fund invests in accordance with regulatory requirements applicable to money market funds, which require, among other things, the Fund to invest only in short-term, high quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk) to maintain a maximum dollar weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity. For the purposes of determining the Fund’s weighted average maturity, a security’s final maturity date will be used, unless the security is a floating rate or variable rate security in which case the maturity will be determined in accordance with the rules applicable to money market funds.

The Fund currently intends to invest nearly all of its assets in the State Street Cash Reserves Portfolio, another open-end investment company managed by the Adviser, with an investment objective and policies substantially identical to those of the Fund.

Principal Risks

In addition, the Fund is subject to the following risks. The risks are described in alphabetical order and not in the order of importance or potential exposure.

Counterparty Risk: The Fund will be subject to credit risk with respect to the counterparties with which the Fund enters into repurchase agreements and other transactions. If a counterparty fails to meet its contractual obligations, the Fund may be unable to terminate the transaction, and it may be delayed or prevented from realizing on any collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty.

A rising interest rate environment may cause the value of the Fund’s fixed income securities to decrease, an adverse impact on the liquidity of the Fund’s fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Fund may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

Financial Institutions Risk: Changes in the creditworthiness of financial institutions (such as banks and broker-dealers) may adversely affect the values of instruments of issuers in financial industries. Adverse developments in banking and other financial industries may cause the Fund to underperform relative to other funds that invest more broadly across different industries or have a smaller exposure to financial institutions. Changes in governmental regulation and oversight of financial institutions may have an adverse effect on the financial condition of a financial institution.

Income Risk: The Fund’s income may decline due to falling interest rates or other factors. Issuers of securities held by the Fund may call or redeem the securities during periods of falling interest rates, and the Fund would likely be required to reinvest in securities paying lower interest rates. If an obligation held by the Fund is prepaid, the Fund may have to reinvest the prepayment in other obligations paying income at lower rates.

Large Shareholder Risk: To the extent a large proportion of the shares of the Portfolio are held by a small number of shareholders (or a single shareholder), including funds or accounts over which the Adviser has investment discretion, the Portfolio is subject to the risk that these shareholders will purchase or redeem Portfolio shares in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of the Portfolio to conduct its investment program.

Liquidity Risk: Lack of a ready market or restrictions on resale may limit the ability of the Fund to sell a security at an advantageous time or price or at all. Illiquid securities may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value. Illiquidity of the Fund’s holdings may limit the ability of the Fund to obtain cash to meet redemptions on a timely basis. In addition, the Fund, due to limitations on investments in any illiquid securities and/or the difficulty in purchasing and selling such investments, may be unable to achieve its desired level of exposure to a certain market or sector.

Low Short-Term Interest Rates: During market conditions in which short-term interest rates are at low levels, the Fund’s yield can be very low. During these conditions, it is possible that the Fund will generate an insufficient amount of income to pay its expenses, and that it will not be able to pay a daily dividend and may have a negative yield (i.e., it may lose money on an operating basis). It is possible that the Fund would, during these conditions, maintain a substantial portion of its assets in cash, on which it may earn little, if any, income.

Market Risk: The Fund’s investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.

Master/Feeder Structure Risk : The Fund pursues its objective by investing substantially all of its assets in another pooled investment vehicle (a “master fund”). The ability of the Fund to meet its investment objective is directly related to the ability of the master fund to meet its investment objective. The Adviser serves as investment adviser to the master fund, leading to potential conflicts of interest. The Fund will bear its pro rata portion of the expenses incurred by the master fund. Substantial redemptions by other investors in a master fund may affect the master fund’s investment program adversely and limit the ability of the master fund to achieve its objective.

Mortgage-Related and Other Asset-Backed Securities Risk: Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed-income investments. During periods of falling interest rates, mortgage- and asset-backed securities may be called or prepaid, which may result in the Fund having to reinvest proceeds in other investments at a lower interest rate. During periods of rising interest rates, the average life of mortgage- and asset-backed securities may extend, which may lock in a below-market interest rate, increase the security’s duration and interest rate sensitivity, and reduce the value of the security. Enforcing rights against the underlying assets or collateral may be difficult, and the underlying assets or collateral may be insufficient if the issuer defaults.

Non-U.S. Securities Risk: Non-U.S. securities (including depositary receipts) are subject to political, regulatory, and economic risks not present in domestic investments. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, legal and financial report standards comparable to those in the United States. Further, such entities and/or their securities may be subject to risks associated with currency controls; expropriation; changes in tax policy; greater market volatility; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. Securities traded on foreign markets may be less liquid (harder to sell) than securities traded domestically. Foreign governments may impose restrictions on the repatriation of capital to the U.S. In addition, to the extent investments are made in a limited number of countries, events in those countries will have a more significant impact on the Fund. Investments in depositary receipts may be less liquid and more volatile than the underlying shares in their primary trading market.

Rapid Changes in Interest Rates Risk: Rapid changes in interest rates may cause significant requests to redeem Fund Shares, and possibly cause the Fund to sell portfolio securities at a loss to satisfy those requests.

Repurchase Agreement Risk: Repurchase agreements may be viewed as loans made by the Fund which are collateralized by the securities subject to repurchase. If the Fund’s counterparty should default on its obligations and the Fund is delayed or prevented from recovering the collateral, or if the value of the collateral is insufficient, the Fund may realize a loss.

Restricted Securities Risk: The Fund may hold securities that have not been registered for sale to the public under the U.S. federal securities laws. There can be no assurance that a trading market will exist at any time for any particular restricted security. Limitations on the resale of these securities may have an adverse effect on their marketability, and may prevent the Fund from disposing of them promptly at reasonable prices. The Fund may have to bear the expense of registering the securities for resale and the risk of substantial delays in effecting the registration. Also, restricted securities may be difficult to value because market quotations may not be readily available, and the securities may have significant volatility.

Risk of Investment in Other Pools: If the Fund invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected and is exposed indirectly to all of the risks applicable to an investment in such other pool. The investment policies of the other pool may not be the same as those of the Fund; as a result, an investment in the other pool may be subject to additional or different risks than those to which the Fund is typically subject. The Fund bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviserto a pool in which the Fund may invest, leading to potential conflicts of interest. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which the Fund does so.

Significant Exposure to U.S. Government Agencies or Instrumentalities Risk: To the extent the Fund focuses its investments in securities issued or guaranteed by U.S. government agencies or instrumentalities, any market movements, regulatory changes or changes in political or economic conditions that affect the U.S. government agencies or instrumentalities in which the Fund invests may have a significant impact on the Fund’s performance. Events that would adversely affect the market prices of securities issued or guaranteed by one government agency or instrumentality may adversely affect the market price of securities issued or guaranteed by other government agencies or instrumentalities.

Stable Share Price Risk: If the market value of one or more of the Fund’s investments changes substantially, the Fund may not be able to maintain a stable share price of $1.00. This risk typically is higher during periods of rapidly changing interest rates or when issuer credit quality generally is falling, and is made worse when the Fund experiences significant redemption requests.

U.S. Government Securities Risk: Certain U.S. government securities are supported by the full faith and credit of the United States; others are supported by the right of the issuer to borrow from the U.S. Treasury; others are supported by the discretionary authority of the U.S. government to purchase the agency’s obligations; and still others are supported only by the credit of the issuing agency, instrumentality, or enterprise. Although U.S. government-sponsored enterprises such as the Federal Home Loan Mortgage Corporation (Freddie Mac) and the Federal National Mortgage Association (Fannie Mae) may be chartered or sponsored by Congress, they are not funded by Congressional appropriations, and their securities are not issued by the U.S. Treasury, are not supported by the full faith and credit of the U.S. government, and involve increased credit risks.

Variable and Floating Rate Securities Risk: During periods of increasing interest rates, changes in the coupon rates of variable or floating rate securities may lag behind the changes in market rates or may have limits on the maximum increases in coupon rates. Alternatively, during periods of declining interest rates, the coupon rates on such securities will typically readjust downward resulting in a lower yield. In addition, investment in derivative variable rate securities, such as inverse floaters, whose rates vary inversely with market rates of interest, or range floaters or capped floaters, whose rates are subject to periodic or lifetime caps, or in securities that pay a rate of interest determined by applying a multiple to the variable rate involves special risks as compared to investment in a fixed-rate security and may involve leverage.

Zero-Coupon Bond Risk: Zero-coupon bonds usually trade at a deep discount from their face or par values and are subject to greater market value fluctuations from changing interest rates than debt obligations of comparable maturities that make current distributions of interest.

Performance

Performance information for the Fund has been omitted because the Fund had not commenced investment operations as of the date of this Prospectus. Once the Fund has completed a full calendar year of operations, a bar chart and table will be included that will provide some indication of the risks of investing in the Fund by showing the variability of the Fund’s returns based on net assets. The Fund will make updated performance information, including its current net asset value, available at the Fund’s website: www.ssga.com/cash.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Purchase and Sale of Fund Shares

Purchase Minimums


Institutional Class
To establish an account		$25,000,000
To add to an existing account		No minimum

Administration Class
To establish an account		$1,000
To add to an existing account		No minimum

Investment Class
To establish an account		$25,000,000
To add to an existing account		No minimum

Investor Class
To establish an account		$10,000,000
To add to an existing account		No minimum

Premier Class
To establish an account		$250,000,000
To add to an existing account		No minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Funds

P.O. Box 219737

Kansas City, MO 64121-9737

By Overnight:

State Street Funds

430 W 7 ^th Street Suite 219737

Kansas City, MO 64105-1407

By Telephone:

By Intermediary:

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Tax Information

The Fund’s distributions are expected to be taxed as ordinary income and/or capital gains, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or individual retirement account. Any withdrawals made from such tax-advantaged arrangement may be taxable to you.

Payments to Broker-Dealers and Other Financial Intermediaries

ADDITIONAL INFORMATION ABOUT INVESTMENT OBJECTIVE, PRINCIPAL STRATEGIES AND RISKS

Investment Objective

The investment objective of the Fund, as stated in the Fund’s Fund Summary, may be changed without shareholder approval.

State Street Cash Reserves Fund

Principal Investment Strategies

The Fund is a retail money market fund and seeks to maintain its net asset value NAV at $1.00 per share, although there can be no assurance that it will be able to do so.

Under normal circumstances, the Fund intends to invest at least 25% of its assets in bank obligations.

Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure.

Call/Prepayment Risk . Call/prepayment risk is the risk that an issuer will exercise its right to pay principal on an obligation held by the Fund earlier than expected or required. This may occur, for example, when there is a decline in interest rates, and an issuer of bonds or preferred stock redeems the bonds or stock in order to replace them with obligations on which it is required to pay a lower interest or dividend rate. It may also occur when there is an unanticipated increase in the rate at which mortgages or other receivables underlying mortgage- or asset-backed securities held by the Fund are prepaid. In any such case, the Fund may be forced to invest the prepaid amounts in lower-yielding investments, resulting in a decline in the Fund’s income.

Counterparty Risk . The Fund will be subject to credit risk with respect to the counterparties with which the Fund enters into derivatives contracts and other transactions such as repurchase agreements or reverse repurchase agreements. The Fund’s ability to profit from these types of investments and transactions will depend on the willingness and ability of its counterparty to perform its obligations. If a counterparty fails to meet its contractual obligations, the Fund may be unable to terminate or realize any gain on the investment or transaction, resulting in a loss to the Fund. The Fund may experience significant delays in obtaining any recovery in an insolvency, bankruptcy, or other reorganization proceeding involving its counterparty (including recovery of any collateral posted by it) and may

obtain only a limited recovery or may obtain no recovery in such circumstances. If the Fund holds collateral posted by its counterparty, it may be delayed or prevented from realizing on the collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty. Under applicable law or contractual provisions, including if the Fund enters into an investment or transaction with a financial institution and such financial institution (or an affiliate of the financial institution) experiences financial difficulties, then the Fund may in certain situations be prevented or delayed from exercising its rights to terminate the investment or transaction, or to realize on any collateral and may result in the suspension of payment and delivery obligations of the parties under such investment or transactions or in another institution being substituted for that financial institution without the consent of the Fund. Further, the Fund may be subject to “bail-in” risk under applicable law whereby, if required by the financial institution’s authority, the financial institution’s liabilities could be written down, eliminated or converted into equity or an alternative instrument of ownership. A bail-in of a financial institution may result in a reduction in value of some or all of its securities and, if the Fund holds such securities or has entered into a transaction with such a financial security when a bail-in occurs, the Fund may also be similarly impacted.

Credit Risk . Credit risk is the risk that an issuer, guarantor or liquidity provider of a fixed-income security held by the Fund may be unable or unwilling, or may be perceived (whether by market participants, ratings agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. It includes the risk that the security will be downgraded by a credit rating agency; generally, lower credit quality issuers present higher credit risks. An actual or perceived decline in creditworthiness of an issuer of a fixed-income security held by the Fund may result in a decrease in the value of the security. It is possible that the ability of an issuer to meet its obligations will decline substantially during the period when the Fund owns securities of the issuer or that the issuer will default on its obligations or that the obligations of the issuer will be limited or restructured.

The credit rating assigned to any particular investment does not necessarily reflect the issuer’s current financial condition and does not reflect an assessment of an investment’s volatility or liquidity. Securities rated in the lowest category of investment-grade are considered to have speculative characteristics. If a security held by the Fund loses its rating or its rating is downgraded, the Fund may nonetheless continue to hold the security in the discretion of the Adviser. In the case of asset-backed or mortgage-related securities, changes in the actual or perceived ability of the obligors on the underlying assets or mortgages to make payments of interest and/or principal may affect the values of those securities.

Debt Securities Risk . The values of debt securities may increase or decrease as a result of the following: market fluctuations, increases in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments or illiquidity in debt securities markets; the risk of low rates of return due to reinvestment of securities during periods of falling interest rates or repayment by issuers with higher coupon or interest rates; and/or the risk of low income due to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of the Fund’s fixed income securities to decrease, an adverse impact on the liquidity of the Fund’s fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Fund may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

Extension Risk. During periods of rising interest rates, the average life of certain types of securities may be extended because of slower-than-expected principal payments. This may increase the period of time during which an investment earns a below-market interest rate, increase the security’s duration and reduce the value of the security. Extension risk may be heightened during periods of adverse economic conditions generally, as payment rates decline due to higher unemployment levels and other factors.

Financial Institutions Risk . Some instruments are issued or guaranteed by financial institutions, such as banks and brokers, or are collateralized by securities issued or guaranteed by financial institutions. Changes in the creditworthiness of any of these institutions may adversely affect the values of instruments of issuers in financial industries. Financial institutions may be particularly sensitive to certain economic factors such as interest rate changes, adverse developments in the real estate market, fiscal and monetary policy and general economic cycles. Adverse developments in banking and other financial industries may cause the Fund to underperform relative to other funds that invest more broadly across different industries or have a smaller exposure to financial institutions. Changes in governmental regulation and oversight of financial institutions may have an adverse effect on the financial condition or the earnings or operations of a financial institution and on the types and amounts of businesses in which a financial institution may engage. An investor may be delayed or prevented from exercising certain remedies against a financial institution. The amount of the Fund’s assets that may be invested in any financial institution, or financial institutions generally, may be limited by applicable law.

Income Risk. The Fund’s income may decline due to falling interest rates or other factors. Issuers of securities held by the Fund may call or redeem the securities during periods of falling interest rates, and the Fund would likely be required to reinvest in securities paying lower interest rates. If an obligation held by the Fund is prepaid, the Fund may have to reinvest the prepayment in other obligations paying income at lower rates. A reduction in the income earned by the Fund may limit the Fund’s ability to achieve its objective.

Interest Rate Risk . Interest rate risk is the risk that the securities held by the Fund will decline in value because of increases in market interest rates. Duration is a measure used to determine the sensitivity of a security’s price to changes in interest rates. Debt securities with longer durations tend to be more sensitive to changes in interest rates, usually making them more volatile than debt securities with shorter durations. For example, the value of a security with a duration of five years would be expected to decrease by 5% for every 1% increase in interest rates. Falling interest rates also create the potential for a decline in the Fund’s income and yield. Interest-only and principal-only securities are especially sensitive to interest rate changes, which can affect not only their prices but can also change the income flows and repayment assumptions about those investments. Variable and floating rate securities also generally increase or decrease in value in response to changes in interest rates, although generally to a lesser degree than fixed-rate securities. A substantial increase in interest rates may also have an adverse impact on the liquidity of a security, especially those with longer durations. Changes in governmental policy, including changes in central bank monetary policy, could cause interest rates to rise rapidly, or cause investors to expect a rapid rise in interest rates. This could lead to heightened levels of interest rate, volatility and liquidity risks for the fixed income markets generally and could have a substantial and immediate effect on the values of the Fund’s investments.

Large Shareholder Risk . To the extent a large proportion of the shares of the Portfolio are highly concentrated or held by a small number of shareholders (or a single shareholder), including funds or accounts over which the Adviser has investment discretion, the Portfolio is subject to the risk that these shareholders will purchase or redeem Portfolio shares in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of the Portfolio to conduct its investment program. For example, they could require the Portfolio to sell portfolio securities or purchase portfolio securities unexpectedly and incur substantial transaction costs and/or accelerate the realization of taxable income and/or gains to shareholders, or the Portfolio may be required to sell its more liquid portfolio investments to meet a large redemption, in which case the Portfolio’s remaining assets may be less liquid, more volatile, and more difficult to price. A Portfolio may hold a relatively large proportion of its assets in cash in anticipation of large redemptions, diluting its investment returns.

Liquidity Risk . Liquidity risk is the risk that the Fund may not be able to dispose of securities readily at a favorable time or prices (or at all) or at prices approximating those at which the Fund currently values them. For example, certain investments may be subject to restrictions on resale, may trade in the over-the-counter market or in limited volume, or may not have an active trading market. Illiquid securities may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value. It may be difficult for the Fund to value illiquid securities accurately. The market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. Disposal of illiquid securities may entail registration expenses and other transaction costs that are higher than those for liquid securities. The Fund may seek to borrow money to meet its obligations (including among other things redemption obligations) if it is unable to dispose of illiquid investments, resulting in borrowing expenses and possible leveraging of the Fund. In some cases, due to unanticipated levels of illiquidity the Fund may choose to meet its redemption obligations wholly or in part by distributions of assets in-kind.

Low Short-Term Interest Rate Risk . During market conditions in which short-term interest rates are at low levels, as was the case until recent periods, the Fund’s yield can be very low. During these conditions, it is possible that the Fund will generate an insufficient amount of income to pay its expenses, and that it will not be able to pay a daily dividend and may have a negative yield (i.e., it may lose money on an operating basis). It is possible that the Fund will maintain a substantial portion of its assets in cash, on which it may earn little, if any, income.

Market Disruption and Geopolitical Risk. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets. War, terrorism, and related geopolitical events have led, and in the future may lead, to increased short-term market volatility and may have adverse long-term effects on U.S. and world economies and markets generally. Likewise, natural and environmental disasters and systemic market dislocations may be highly disruptive to economies and markets. Those events as well as other changes in foreign and domestic economic and political conditions also could adversely affect individual issuers or related groups of issuers, securities markets, interest rates, credit ratings, inflation, investor sentiment, and other factors affecting the value of the Fund’s investments. Given the increasing interdependence among global economies and markets, conditions in one country, market, or region might adversely affect markets, issuers, and/or foreign exchange rates in other countries, including the U.S. Any partial or complete dissolution of the Economic and Monetary Union of the European Union, or any increased uncertainty as to its status, could have significant adverse effects on currency and financial markets, and on the values of the Fund’s investments. Securities and financial markets may be susceptible to market manipulation or other fraudulent trade practices, which could disrupt the orderly functioning of these markets or adversely affect the values of investments traded in these markets, including investments held by the Fund. To the extent the Fund has focused its investments in the market or index of a particular region, adverse geopolitical and other events could have a disproportionate impact on the Fund.

Market Risk . Market prices of investments held by the Fund will go up or down, sometimes rapidly or unpredictably. The Fund’s investments are subject to changes in general economic conditions, general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in actual or perceived creditworthiness of issuers and general market liquidity. Even if general economic conditions do not change, the value of an investment in the Fund could decline if the particular industries, sectors or companies in which the Fund invests do not perform well or are adversely affected by events. Further, legal, political, regulatory and tax changes also may cause fluctuations in markets and securities prices.

Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject the Fund to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and the Fund’s investment program in particular can be uncertain. In recent periods, governmental and non-governmental issuers have defaulted on, or have been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including, without limitation, in Europe or Asia. Defaults or restructurings by governments or others of their debts could have substantial adverse effects on economies, financial markets, and asset valuations around the world. Further Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, or investor perception that these efforts are not succeeding, could negatively affect financial markets generally as well as the values and liquidity of certain securities.

Master/Feeder Structure Risk. The Fund pursues its objective by investing substantially all of its assets in another pooled investment vehicle (a “master fund”). The ability of the Fund to meet its investment objective is directly related to the ability of the master fund to meet its investment objective. The ability of the Fund to meet its objective may be adversely affected by the purchase and redemption activities of other investors in the master fund. The ability of the Fund to meet redemption requests will depend on its ability to redeem its interest in the master fund. The Adviser or an affiliate serves as investment adviser to the master fund, leading to potential conflicts of interest. For example, the Adviser or its affiliates will receive fees based on the amount of assets invested in the master fund. Investment by the Fund in the master fund may be beneficial in the management of the master fund, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest the Fund’s assets in a master fund sponsored or managed by the Adviser or its affiliates in lieu of investments by the Fund directly in portfolio securities, or may have an incentive to invest in such master fund over a master fund sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by the Fund in a master fund sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a master fund sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which the Fund does so. The Fund will bear its pro rata portion of the expenses incurred by the master fund.

Money Market Risk . An investment in a money market fund is not a deposit of any bank and is not insured or guaranteed by the FDIC or any other government agency. Although a money market fund generally seeks to preserve the value of its shares at $1.00 per share, there can be no assurance that it will do so, and it is possible to lose money by investing in a money market fund. A major or unexpected increase in interest rates or a decline in the credit quality of an issuer or entity providing credit support, an inactive trading market for money market instruments, or adverse market, economic, industry, political, regulatory, geopolitical, and other conditions could cause a money market fund’s share price to fall below $1.00. It is possible that a money market fund will issue and redeem shares at $1.00 per share at times when the fair value of the money market fund’s portfolio per share is more or less than $1.00. A money market fund may be permitted or required to impose redemption fees or to impose limitations on redemptions during periods of high illiquidity in the markets for the investments held by it. None of State Street Corporation, State Street Bank and Trust Company (“State Street”), State Street Global Advisors (“SSGA”), SSGA FM or their affiliates (“State Street Entities”) guarantee the value of an investment in a money market fund at $1.00 per share. Investors should have no expectation of capital support to a money market fund from State Street Entities.

Mortgage-Related and Other Asset-Backed Securities Risk . Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed income investments. The liquidity of mortgage-related and asset-backed securities may change over time. Mortgage-related securities represent a participation in, or are secured by, mortgage loans. Other asset-backed securities are typically structured like mortgage-related securities, but instead of mortgage loans or interests in mortgage loans, the underlying assets may include, for example, items such as motor vehicle installment sales or installment loan contracts, leases on various types of real and personal property, and receivables from credit card agreements. During periods of falling interest rates, mortgage-related and other asset-backed securities, which typically provide the issuer with the right to prepay the security prior to maturity, may be prepaid, which may result in the Fund having to reinvest the proceeds in other investments at lower interest rates. During periods of rising interest rates, the average life of mortgage-related and other asset-backed securities may extend because of slower-than expected principal payments. This may lock in a below market interest rate, increase the security’s duration and interest rate sensitivity, and reduce the value of the security. As a result, mortgage-related and other asset-backed securities may have less potential for capital appreciation during periods of declining interest rates than other debt securities of comparable maturities, although they may have a similar risk of decline in market values during periods of rising interest rates. Prepayment rates are difficult to predict and the potential impact of prepayments on the value of a mortgage-related or other asset-backed security depends on the terms of the instrument and can result in significant volatility. The price of a mortgage-related or other asset-backed security also depends on the credit quality and adequacy of the underlying assets or collateral. Mortgage-related or other asset-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) will generally entail greater credit risk than obligations guaranteed by the U.S. Government. Defaults on the underlying assets, if any, may impair the value of a mortgage-related or other asset-backed security. For some asset-backed securities in which the Fund invests, such as those backed by credit card receivables, the underlying cash flows may not be supported by a security interest in a related asset. Moreover, the values of mortgage-related and other asset-backed securities may be substantially dependent on the servicing of the underlying asset pools, and are therefore subject to risks associated with the negligence or malfeasance by their servicers and to the credit risk of their servicers. In certain situations, the mishandling of related documentation may also affect the rights of securities holders in and to the underlying collateral. There may be legal and practical limitations on the enforceability of any security interest granted with respect to underlying assets, or the value of the underlying assets, if any, may be insufficient if the issuer defaults.

Non-U.S. Securities Risk . Investments in securities of non-U.S. issuers (including depositary receipts) entail risks not typically associated with investing in securities of U.S. issuers. Similar risks may apply to securities traded on a U.S. securities exchange that are issued by entities with significant exposure to non-U.S. countries. In certain countries, legal remedies available to investors may be more limited than those available with regard to U.S. investments. Income and gains with respect to investments in certain countries may be subject to withholding and other taxes. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, and financial reporting standards, regulatory framework and practices comparable to those in the United States. The securities of some non-U.S. entities are less liquid and at times more volatile than securities of comparable U.S. entities, and could become subject to sanctions or embargoes that adversely affect the Fund’s investment. Non-U.S. transaction costs, such as brokerage commissions and custody costs may be higher than in the U.S. In addition, there may be a possibility of nationalization or expropriation of assets, imposition of currency exchange controls, confiscatory taxation, and diplomatic developments that could adversely affect the values of the Fund’s investments in certain non-U.S. countries. Investments in securities of non-U.S. issuers also are subject to foreign political and economic risk not associated with U.S. investments, meaning that political events (civil unrest, national elections, changes in political conditions and foreign relations, imposition of exchange controls and repatriation restrictions), social and economic events (labor strikes, rising inflation) and natural disasters occurring in a country where the Fund invests could cause the Fund’s investments in that country to experience gains or losses.

Rapid Changes in Interest Rates . The values of most instruments held by the Fund are adversely affected by changes in interest rates generally, especially increases in interest rates. Rapid changes in interest rates may cause significant requests to redeem Fund Shares, and possibly cause the Fund to sell portfolio securities at a loss to satisfy those requests.

Reinvestment Risk. Income from the Fund’s portfolio may decline when the Fund invests the proceeds from investment income, sales of portfolio securities or matured, traded or called debt obligations. For instance, during periods of declining interest rates, an issuer of debt obligations may exercise an option to redeem securities prior to maturity, forcing the Fund to reinvest the proceeds in lower-yielding securities. A decline in income received by the Fund from its investments is likely to have a negative effect on the yield and total return of the Fund Shares.

Repurchase Agreement Risk . A repurchase agreement is an agreement to buy a security from a seller at one price and a simultaneous agreement to sell it back to the original seller at an agreed-upon price, typically representing the purchase price plus interest. Repurchase agreements may be viewed as loans made by the Fund which are collateralized by the securities subject to repurchase. The Fund’s investment return on such transactions will depend on the counterparty’s willingness and ability to perform its obligations under a repurchase agreement. If the Fund’s counterparty should default on its obligations and the Fund is delayed or prevented from recovering the collateral, or if the value of the collateral is insufficient, the Fund may realize a loss.

Restricted Securities Risk . The Fund may hold securities that have not been registered for sale to the public under the U.S. federal securities laws pursuant to an exemption from registration. These securities may be less liquid than securities registered for sale to the general public. The liquidity of a restricted security may be affected by a number of factors, including, among others: (i) the creditworthiness of the issuer; (ii) the frequency of trades and quotes for the security; (iii) the number of dealers willing to purchase or sell the security and the number of other potential purchasers; (iv) dealer undertakings to make a market in the security; (v) the nature of any legal restrictions governing trading in the security; and (vi) the nature of the security and the nature of marketplace trades. There can be no assurance that a liquid trading market will exist at any time for any particular restricted security. Also, restricted securities may be difficult to value because market quotations may not be readily available, and the securities may have significant volatility.

Risk of Investment in Other Pools . If a Fund invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected. A Fund is exposed indirectly to all of the risks applicable to an investment in such other pool. In addition, lack of liquidity in the underlying pool could result in its value being more volatile than the underlying portfolio of securities, and may limit the ability of a Fund to sell or redeem its interest in the pool at a time or at a price it might consider desirable. The investment policies and limitations of the other pool may not be the same as those of the Fund; as a result, the Fund may be subject to additional or different risks, or may achieve a reduced investment return, as a result of its investment in another pool. If a pool is an exchange-traded fund or other product traded on a securities exchange or otherwise activelytraded, its shares may trade at a premium or discount to their NAV, an effect that might be more pronounced in less liquid markets. A Fund bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Fund may invest, leading to potential conflicts of interest. For example, the Adviser or its affiliates may receive fees based on the amount of assets invested in the pool. Investment by a Fund in the pool may be beneficial to the Adviser or an affiliate in the management of the pool, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest a Fund’s assets in a pool sponsored or managed by the Adviser or its affiliates in lieu of investments by the Fund directly in portfolio securities, or may have an incentive to invest in the pool over a pool sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by a Fund in a pool sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Fund does so.

Section 4(a)(2) Commercial Paper and Rule 144A Securities Risk . A Fund may invest in commercial paper issued in reliance on the private placement exemption from registration afforded by Section 4(a)(2) of the Securities Act of 1933, as amended (the “1933 Act”). This commercial paper is commonly called “Section 4(a)(2) paper.” A Fund may also invest in securities that may be offered and sold only to “qualified institutional buyers” under Rule 144A of the 1933 Act (“Rule 144A securities”).

Section 4(a)(2) paper and Rule 144A securities will not be considered illiquid for purposes of a Fund’s limitation on illiquid securities if the Adviser (pursuant to guidelines adopted by the Board) determines that a liquid trading market exists for the securities in question. There can be no assurance that a liquid trading market will exist at any time for any particular Section 4(a)(2) paper or Rule 144A securities.

Significant Exposure to U.S. Government Agencies or Instrumentalities Risk . To the extent a Fund focuses its investments in securities issued or guaranteed by U.S. Government agencies or instrumentalities, any market movements, regulatory changes or changes in political or economic conditions that affect the U.S. Government agencies or instrumentalities in which the Fund invests may have a significant impact on a Fund’s performance. Events that would adversely affect the market prices of securities issued or guaranteed by one government agency or instrumentality may adversely affect the market price of securities issued or guaranteed by other government agencies or instrumentalities.

Stable Share Price Risk Fund . If the market value of one or more of the Fund’s investments changes substantially, the Fund may not be able to maintain a stable share price of $1.00. This risk typically is higher during periods of rapidly changing interest rates or when issuer credit quality generally is falling, and is made worse when the Fund experiences significant redemption requests.

U.S. Government Securities Risk . U.S. government securities, such as Treasury bills, notes and bonds and mortgage-backed securities guaranteed by the Government National Mortgage Association (“Ginnie Mae”), are supported by the full faith and credit of the United States; others are supported by the right of the issuer to borrow from the U.S. Treasury; others are supported by the discretionary authority of the U.S. government to purchase the agency’s obligations; and still others are supported only by the credit of the issuing agency, instrumentality, or enterprise. Although U.S. government-sponsored enterprises such as the Federal Home Loan Mortgage Corporation (“Freddie Mac”) and the Federal National Mortgage Association (“Fannie Mae”) may be chartered or sponsored by Congress, they are not funded by Congressional appropriations, and their securities are not issued by the U.S. Treasury nor supported by the full faith and credit of the U.S. government. There is no assurance that the U.S. government would provide financial support to its agencies and instrumentalities if not required to do so. In addition, certain governmental entities have been subject to regulatory scrutiny regarding their accounting policies and practices and other concerns that may result in legislation, changes in regulatory oversight and/or other consequences that could adversely affect the credit quality, availability, or investment character of securities issued by these entities. The value and liquidity of U.S. government securities may be affected adversely by changes in the ratings of those securities. Securities issued by the U.S. Treasury historically have been considered to present minimal credit risk. The downgrade in the long-term U.S. credit rating by at least one major rating agency has introduced greater uncertainty about the ability of the U.S. to repay its obligations. A further credit rating downgrade or a U.S. credit default could decrease the value and increase the volatility of the Fund’s investments.

Variable and Floating Rate Securities Risk . Variable or floating rate securities are debt securities with variable or floating interest rates payments. Variable or floating rate securities bear rates of interest that are adjusted periodically according to formulae intended generally to reflect market rates of interest and allow the Fund to participate (determined in accordance with the terms of the securities) in increases in interest rates through upward adjustments of the coupon rates on the securities. However, during periods of increasing interest rates, changes in the coupon rates may lag behind the changes in market rates or may have limits on the maximum increases in coupon rates. Alternatively, during periods of declining interest rates, the coupon rates on such securities will typically readjust downward resulting in a lower yield. In addition, investment in derivative variable rate securities, such as inverse floaters, whose rates vary inversely with market rates of interest, or range floaters or capped floaters, whose rates are subject to periodic or lifetime caps, or in securities that pay a rate of interest determined by applying a multiple to the variable rate involves special risks as compared to investment in a fixed-rate security and may involve leverage.

Zero-Coupon Bond Risk . Zero-coupon bonds are debt obligations that are generally issued at a discount and payable in full at maturity, and that do not provide for current payments of interest prior to maturity. Zero-coupon bonds usually trade at a deep discount from their face or par values and are subject to greater market value fluctuations from changing interest rates than debt obligations of comparable maturities that make current distributions of interest. When interest rates rise, the values of zero-coupon bonds fall more rapidly than securities paying interest on a current basis, because the Fund is unable to reinvest interest payments at the higher rates.

ADDITIONAL INFORMATION ABOUT NON-PRINCIPAL INVESTMENT STRATEGIES AND RISKS

The investments described below reflect the Fund’s and the Portfolio’s current practices. In addition to the principal risks described above, other risks are described in some of the descriptions of the investments below:

Conflicts of Interest Risk. An investment in the Fund will be subject to a number of actual or potential conflicts of interest. For example, the Adviser or its affiliates may provide services to the Fund, such as securities lending agency services, custodial, administrative, bookkeeping, and accounting services, transfer agency and shareholder servicing, securities brokerage services, and other services for which the Fund would compensate the Adviser and/or such affiliates. The Fund may invest in other pooled investment vehicles sponsored, managed, or otherwise affiliated with the Adviser. There is no assurance that the rates at which the Fund pays fees or expenses

to the Adviser or its affiliates, or the terms on which it enters into transactions with the Adviser or its affiliates will be the most favorable available in the market generally or as favorable as the rates the Adviser makes available to other clients. Because of its financial interest, the Adviser will have an incentive to enter into transactions or arrangements on behalf of the Fund with itself or its affiliates in circumstances where it might not have done so in the absence of that interest, provided that the Adviser will comply with applicable regulatory requirements.

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Fund. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for the Fund and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by the Fund. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Fund) or otherwise using such information for the benefit of its clients or itself.

Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Fund) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, the Fund, the Portfolio, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect the Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect the Fund’s ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject the Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of the Fund inaccessible or inaccurate or incomplete. The Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. The Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. The Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Fund. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which the Fund invests, which could result in material adverse consequences for such issuers, and may cause the Fund’s investment in such securities to lose value.

Portfolio Turnover Risk . The Fund may engage in frequent trading of its portfolio securities. Fund turnover generally involves a number of direct and indirect costs and expenses to the Fund, including, for example, brokerage commissions, dealer mark-ups and bid/asked spreads, and transaction costs on the sale of securities and reinvestment in other securities. The costs related to increased portfolio turnover have the effect of reducing the Fund’s investment return, and the sale of securities by the Fund may result in the realization of taxable capital gains, including short-term capital gains, which are taxed to individuals as ordinary income.

PORTFOLIO HOLDINGS DISCLOSURE

The Fund’s portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

MANAGEMENT AND ORGANIZATION

The Fund invests as part of a “master/feeder” structure. The Fund currently seeks to achieve its investment objective by investing substantially all of its investable assets in the Portfolio, a separate mutual fund, that has substantially identical investment objective, investment policies, and risks as the Fund. All discussions about the Fund’s investment objective, policies and risks should be understood to refer also to the investment objectives, policies and risks of the Portfolio.

The Portfolio’s shares are offered exclusively to investors (including without limitation, registered investment companies, private investment pools, bank collective funds, and investment separate accounts) that, like the Fund, pay fees to SSGA FM or its affiliates. The fees paid by those investment vehicles to SSGA FM (or its affiliates) vary depending on a number of factors, including by way of example, the services provided, the risks borne by SSGA FM (or its affiliates), fee rates paid by competitive investment vehicles, and in some cases direct negotiation with investors in the Portfolio.

The Fund can withdraw its investment in the Portfolio if, at any time, the Fund’s Board of Trustees determines that it would be in the best interests of the Fund’s shareholders, or if the investment objectives of the Portfolio changed so that they were inconsistent with the objectives of the Fund. If the Fund withdraws its investment from the Portfolio, the Fund may invest all of its assets in another mutual fund that has the same investment objective as the Fund, the Adviser may directly manage the Fund’s assets, or the Board may take such other action it deems appropriate and in the best interests of shareholders of the Fund, which may include liquidation of the Fund.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund and Portfolio and, subject to the oversight of the Board, is responsible for the investment management of the Fund. The Adviser provides an investment management program for the Fund and manages the investment of the Fund’s assets. The Adviser is a wholly-owned subsidiary of State Street Global Advisors, Inc., which itself is a wholly-owned subsidiary of State Street Corporation. The Adviser is registered with the U.S. Securities and Exchange Commission (“SEC”) under the Investment Advisers Act of 1940, as amended. The Adviser and certain other affiliates of State Street Corporation make up SSGA. SSGA is one of the world’s largest institutional money managers and the investment management arm of State Street Corporation. As of December 31, 2018, the Adviser managed approximately $452.10 billion in assets and SSGA managed approximately $2.51 trillion in assets. The Adviser’s principal business address is One Iron Street, Boston, Massachusetts 02210.

The Fund has entered into an investment advisory agreement with the Adviser pursuant to which the Adviser will manage the Fund’s assets. For such management services, the Cash Reserves Fund will compensate the Adviser at the annual rate of 0.10% of the Fund’s average net daily assets. The Adviser places all orders for purchases and sales of the portfolio’s investments. The Portfolio pays no investment advisory fees to SSGA FM.

A summary of the factors considered by the Board of Trustees in connection with the initial approval of the investment advisory agreement for the Fund will be available in the Fund’s annual report or semi-annual report, as applicable, after the Fund commences operations.

Other Fund Services

Other accounts managed by the portfolio managers, and the portfolio managers’ ownership of the Fund is available in the SAI.

The Administrator, Sub-Administrator and Custodian

The Adviser serves as administrator of the Fund. The amount of the fee paid to the Adviser for administrative services may vary by share class. The Fund currently pays the Adviser an administrative fee at the annual rate of 0.05% with respect to each of its share classes. State Street Bank and Trust Company (“State Street”), a subsidiary of State Street Corporation, serves as the sub-administrator for the Fund for a fee that is paid by the Adviser. State Street also serves as custodian of the Fund for a separate fee that is paid by the Fund. SSGA FM serves as administrator of the Portfolio and State Street serves as sub-administrator and custodian of the Portfolio.

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Fund’s transfer agent and dividend disbursing agent (the “Transfer Agent”).

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Fund’s distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

Additional Information

The Trustees of the Trust oversee generally the operations of the Fund and the Trust. The Trust enters into contractual arrangements with various parties, including among others the Fund’s investment adviser, custodian, transfer agent, and accountants, who provide services to the Fund. Shareholders are not parties to any such contractual arrangements or intended beneficiaries of those contractual arrangements, and those contractual arrangements are not intended to create in any shareholder any right to enforce them directly against the service providers or to seek any remedy under them directly against the service providers.

SHAREHOLDER INFORMATION

Determination of Net Asset Value

The Fund determines its NAV per share at 5:00 pm Eastern Time (“ET”) on each day on which the New York Stock Exchange (“NYSE”), the Federal Reserve banks and State Street are open for business (a “Business Day”). In unusual circumstances, such as an emergency or an unscheduled close or halt of trading on the NYSE, the time at which share prices are determined may be changed. The Fund seeks to maintain a $1.00 per share NAV and, accordingly, uses the amortized cost valuation method, in compliance with the risk limiting conditions of Rule 2a-7 under the Investment Company Act of 1940 (the “1940 Act”), to value its portfolio instruments. The amortized cost valuation method initially prices an instrument at its cost and thereafter assumes a constant amortization to maturity of any discount or premium, regardless of the impact of fluctuating interest rates on the market value of the instrument.

The NAV of each class of the Fund’s shares is calculated by dividing the value of the assets of the Fund attributable to that class less the liabilities of the Fund attributable to that class by the number of shares in the class outstanding. As noted in this Prospectus, the Fund may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when the Fund does not price its shares. Consequently, the NAV of the Fund’s shares may change on days when shareholders are not able to purchase or redeem the Fund’s shares. Purchase and redemption orders for Fund Shares are processed, respectively, at the NAV next determined after the Fund accepts a purchase order or receives a redemption request in good form. The Fund values each security or other investment pursuant to guidelines adopted by the Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Portfolio’s Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii) a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by the Fund occurs after the close of a related exchange but before the determination of the Fund’s NAV. Attempts to determine the fair value of securities or other investments introduce an element of subjectivity to the pricing of securities or other investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the price the Fund would have received had it sold the investment. To the extent that the Fund invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the fund. The prospectuses of these funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

The Fund is open for regular trading each Business Day. The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. The Fund also may establish special hours on those days to determine the Fund’s NAV. In the event that the Fund invokes the right to accept orders to purchase or redeem shares on any day that is not a business day or adopt special hours of operation, the Fund will post advance notice of these events at www.ssga.com/cash.

Investing in State Street Institutional Investment Trust Shares

This section of the Prospectus explains the basics of doing business with the State Street Funds. Carefully read each topic. The policies set forth below regarding the purchase, redemption and exchange of State Street Fund shares are in addition to the “Purchase and Sale of Fund Shares” section contained in the “Fund Summary” portion of this Prospectus. The State Street Funds reserve the right to change the following policies, without notice to shareholders; except that any modification or termination of the exchange privileges described in this Prospectus will be preceded by 60 days’ advance notice to shareholders. Please call or check online for current information. Requests for transactions in the State Street Funds will be processed when they are received in “good order.” “Good order” means that the request is in an accurate and complete form, and all applicable documents have been received in such accurate and complete form (including typically, a signed application and medallion-guaranteed documents), and, for a purchase request, the check or wired funds have cleared.

Purchasing Shares

The Fund offers five classes of shares through this Prospectus: Institutional Class, Administration Class, Investment Class, Investor Class and Premier Class available to you subject to the eligibility requirements set forth below. All classes of the Fund share the same investment objective and investments, but the different share classes have different expense structures and eligibility requirements. You should choose the class with the expense structure that best meets your needs for which you are eligible. In choosing a share class, you should consider the amount you plan to invest. Your investment professional can help you choose the share class that best suits your investment needs.

The chart below summarizes the features of the different share classes. This chart is only a general summary, and you should read the description of the Fund’s expenses in the Fund Summary in this Prospectus.

The minimum purchase amount may be waived for specific investors or types of investors, including, without limitation, retirement plans, employees of State Street Corporation and its affiliates and their family. In the case of shareholders purchasing shares through a Financial Intermediary, the minimum purchase amount may be applied at the level of the Financial Intermediary.


	Institutional Class	Administration Class	Investment Class	Investor Class	Premier Class
Minimum Initial Investment	$25,000,000	$1,000	$25,000,000	$10,000,000	$250,000,000
Maximum Investment	None.	None.	None.	None.	None.
Initial Sales Charge	No. Entire purchase price is invested in shares of a Fund.	No. Entire purchase price is invested in shares of a Fund.	No. Entire purchase price is invested in shares of a Fund.	No. Entire purchase price is invested in shares of a Fund.	No. Entire purchase price is invested in shares of a Fund.
Deferred (CDSC) Sales Charge	No.	No.	No.	No.	No.
Distribution and/or Service (12b-1) Fees	No.	0.05% annual fee.	0.10% annual fee.	No.	No.
Redemption Fees	No.	No.	No.	No.	No.

Investors pay no sales load to invest in the shares of the Fund. The price for Fund Shares is the NAV per share.

Purchase requests received by the Fund in good order (a purchase request is in good order if it meets the requirements implemented from time to time by the Transfer Agent or authorized agent of the Fund, and for new accounts includes submission of a completed and signed application and all documentation necessary to open an account) on a business day will, if payment is received by FedWire, be priced at the NAV next determined after the order is accepted by the Fund. Payments received by FedWire prior to the last Valuation Times will earn dividend accrual for that purchase.

All purchases that are made by check will be priced with the last valuation price and begin earning dividends the following business day after the day the order is accepted. (If you purchase shares by check, your order will not be in good form until the Transfer Agent receives federal funds for the check.) All purchase orders are subject to acceptance by the Fund. The Fund intends to be as fully invested as is practicable; therefore, investments must be made in Federal Funds ( i.e ., monies credited to the account of the Fund’s custodian bank by a Federal Reserve Bank).

The Cash Reserves Fund may limit the amount of a purchase order received after 3:00pm.

“Related customer accounts” may include but are not limited to accounts held by the same investment or retirement plan, financial institution, broker, dealer or intermediary. The Funds and the Adviser reserve the right to increase or decrease the minimum amount required to open or maintain an account. There is no minimum subsequent investment, except in relation to maintaining certain minimum account balances (See “Redeeming Shares” below).

How to Purchase Shares

By Mail:

An initial investment in the Fund must be preceded or accompanied by a completed, signed Institutional Account Application Form, sent to:

State Street Funds

P.O. Box 219737

Kansas City, MO 64121-9737

By Overnight:

State Street Funds

430 W 7 ^th Street Suite 219737

Kansas City, MO 64105-1407

By Telephone/Fax:

Ø confirm receipt of the faxed Institutional Account Application Form (initial purchases only),

Ø request your new account number (initial purchases only),

Ø confirm the amount being wired and wiring bank, and

Ø receive a confirmation number for your purchase order (your trade is not effective until you have received a confirmation number from the Fund).

For your initial investment, send the original, signed Institutional Account Application Form to the address above.

Wire Instructions:

Instruct your bank to transfer money by Federal Funds wire to:

State Street Bank and Trust Company

1 Iron Street

Boston, MA 02110

ABA# 011000028

DDA# 9904-631-0

State Street Institutional Investment Trust

Fund Name

Class Name

Account Number

Account Registration

You will not be able to redeem shares from the account until the original Application has been received. The Fund and the Fund’s agents are not responsible for transfer errors by the sending or receiving bank and will not be liable for any loss incurred due to a wire transfer not having been received.

Redeeming Shares

An investor may redeem all or any portion of its investment at the NAV next determined after it submits a redemption request, in proper form, to the applicable Fund. Redemption orders are processed at the NAV next determined after a Fund receives a redemption order in good form. If the Fund receives a redemption order prior to its Valuation Time on a business day, the Fund typically expects to pay out redemption proceeds on that day, but no later than the next business day if redemption proceeds are sent by wire or ACH. If redemption proceeds are sent by check, the Fund typically expects to pay out redemption proceeds on the next business day. No dividends will accrue

on shares the day redemption proceeds are sent, including when redemption proceeds are wired the same day as the redemption order is received. Payment for redeemed shares is sent no later than the next business day following acceptance of the redemption order (unless redemption proceeds are sent by check). The Fund reserves the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Fund.

Certain special limitations affecting redemptions. The SEC has implemented a number of requirements, including liquidity fees and redemption gates, for money market funds based on the amount of fund assets are “weekly liquid assets,” which generally includes cash, direct obligations of the U.S. government, certain other U.S. government or agency securities, and securities that will mature or are subject to a demand feature that is exercisable and payable within five business days. Each Fund will pass through to its investors any liquidity fee or suspension of redemptions imposed by its Portfolio on the same terms and conditions as imposed by the Portfolio on the Fund.

If a Portfolio’s weekly liquid assets fall below 30% of its total assets and the Portfolio’s Board of Trustees determines it is in the best interests of the Portfolio, the Portfolio may immediately impose a liquidity fee of no more than 2% and/or temporarily suspend redemptions for up to 10 business days in any 90 day period. If a Portfolio’s weekly liquid assets fall below 10% of its total assets at the end of any business day, the Portfolio will impose a liquidity fee of 1% on all redemptions beginning on the next business day, unless the Portfolio’s Board determines that imposing such a fee would not be in the best interests of the Portfolio or determines that a lower or higher fee (not to exceed 2%) would be in the best interests of the Portfolio, which would remain in effect until weekly liquid assets return to 30% or the Portfolio’s Board determines that the fee is no longer in the best interests of the Portfolio. All liquidity fees payable by a Fund would be passed through to its shareholders, would be payable to the Portfolio and could offset any losses realized by the Portfolio when seeking to honor redemption requests. If liquidity fees are imposed or redemptions are suspended, by a Portfolio, the Fund will notify shareholders on the Fund’s website. The Funds expect to treat such liquidity fees paid to a Portfolio as reducing proceeds paid to shareholders in redemption of the Fund shares, and not constituting income to the Portfolio or the Fund. There may be circumstances under which a Fund may impose its own liquidity fees and/or suspend redemptions based on the level of the Fund’s own weekly liquid assets, in which case the Fund will also provide notice to shareholders.

If a Portfolio’s weekly liquid assets fall below 10% of its assets on a business day, the Portfolio may cease honoring redemptions and liquidate in the discretion of the Portfolio’s Board. If a Fund is notified that its Portfolio’s weekly liquid assets fall below 10% of the Portfolio’s assets and the Portfolio has suspended redemptions and intends to liquidate, the Fund may also do so in the discretion of the Fund’s Board. There may be circumstances under which a Fund may cease honoring redemptions and liquidate in the discretion of its Board based on the level of the Fund’s own weekly liquid assets. If the Fund ceases honoring redemptions and determines to liquidate, the Fund expects that it would notify shareholders on the Fund’s website. Distributions to shareholders of liquidation proceeds may occur in one or more disbursements.

If your account is held through an Intermediary, please contact them for additional assistance and advice on how to redeem your shares.

The right of any investor to receive payment with respect to any redemption may be suspended or the payment of the redemption proceeds postponed during any period in which the NYSE is closed (other than weekends or holidays) or trading on the NYSE is restricted or, to the extent otherwise permitted by the 1940 Act, if an emergency exists as a result of which disposal by the Fund of securities owned by it is not reasonably practicable or it is not reasonably practicable for the Fund fairly to determine the value of its net assets. In addition, the SEC may by order permit suspension of redemptions for the protection of shareholders of the Fund.

A request for a partial redemption by an investor whose account balance is below the minimum amount or a request for partial redemption by an investor that would bring the account below the minimum amount may be treated as a request for a complete redemption of the account. These minimums may be different for investments made through certain financial intermediaries as determined by their policies and may be waived in the Adviser’s discretion. The Fund reserves the right to modify minimum account requirements at any time with or without prior notice. The Fund also reserves the right to involuntarily redeem an investor’s account if the investor’s account balance falls below the applicable minimum amount due to transaction activity.

How to Redeem Shares




By Mail:		Send a signed letter to: State Street Institutional Investment Trust Funds P.O. Box 219737 Kansas City, MO 64121-9737

		The letter should include information necessary to process your request as described below. The Fund may require a medallion guarantee in certain circumstances. See “Medallion Guarantees” below.
By Overnight:		State Street Institutional Investment Trust Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407
By Telephone:		Please call (866) 392-0869 between the hours of 7:00 a.m. and 5:00 p.m. ET.
The Fund will need the following information to process your redemption request:

Ø name(s) of account owners; Ø account number(s); Ø the name of the Fund; Ø your daytime telephone number; and Ø the dollar amount or number of shares being redeemed.

On any day that the Fund calculates its NAVs earlier than normal, the Fund reserves the right to adjust the times noted above for purchasing and redeeming shares.

By Intermediary

If you wish to purchase or redeem Fund Shares through a broker, bank or other financial intermediary (“Intermediary”), please contact that Intermediary directly. Your Financial Intermediary may have different or additional requirements for opening an account and/or for the processing of purchase and redemption orders, or may be closed at times when the Fund is open.

Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Medallion Guarantees . Certain redemption requests must include a medallion guarantee for each registered account owner if any of the following apply:

Your account address has changed within the last 10 business days.

Redemption proceeds are being transferred to an account with a different registration.

A wire is being sent to a financial institution other than the one that has been established on your Fund account.

Other unusual situations as determined by the Transfer Agent.

About Telephone Transactions . Telephone transactions are convenient but are not free from risk. Neither the Fund nor the Fund’s agents will be responsible for any losses resulting from unauthorized telephone transactions if reasonable security procedures are followed. In addition, you are responsible for: (i) verifying the accuracy of all data and information transmitted by telephone, (ii) verifying the accuracy of your account statements immediately upon receipt, and (iii) promptly notifying the Fund of any errors or inaccuracies including, without limitation, any errors or inaccuracies relating to shareholder data or information transmitted by telephone. During periods of heavy market activity or other times, it may be difficult to reach the Fund by telephone. If you are unable to reach us by telephone, consider sending written instructions.

The Fund may terminate the receipt of redemption orders by telephone at any time, in which case you may redeem shares by other means.

If you choose to purchase or redeem shares by sending instructions by regular mail, they will not be deemed received in good order until they are released by the post office and redelivered to the Transfer Agent’s physical location at 430 W 7th Street Suite 219737, Kansas City, MO 64105-1407. There will be a time lag, which may be one or more days, between regular mail receipt at the Boston post office box and redelivery to such physical location in Canton, and the Fund’s NAV may change over those days. You might consider using express rather than regular mail if you believe the time of receipt of your transaction request to be sensitive.

Automatic Withdrawal Plan . An Automatic Withdrawal Plan is available for all operational State Street Funds that offer the Administration Class shares, except for the State Street Institutional Liquid Reserves Fund. If your account balance is over $10,000, you may request periodic (i.e., monthly, quarterly, semi-annually, or annually) automatic cash withdrawals on any business day of $100 or more, which can be mailed to you, or any person or entity, you designate or sent through Automated Clearing House (ACH) to your designated bank account. Proceeds from such withdrawals will be transmitted to your designated bank account two business days after the redemption of shares occurs. No interest will accrue on the amounts represented by the uncashed redemption check(s). Ask your financial adviser or financial intermediary for details.

Exchanging Shares

An exchange occurs when you use the proceeds from the redemption of shares of the Fund in the State Street Institutional Investment Trust to simultaneously purchase shares of a different Fund in the State Street Institutional Investment Trust. Exchanges may be made within the same class ( i.e . Institutional Class shares for Institutional Class shares). The account holding the original shares must be registered in the same name as the account holding the new shares received in the exchange. You may make exchange requests by telephone, or by mail. See Purchasing Shares and Redeeming Shares. Exchanges are subject to the terms applicable to the purchases of the fund into which you are exchanging. Exchange privileges may not be available for mutual funds advised by SSGA FM (the “State Street Funds”) and may be suspended or rejected. Effective October 12, 2016, exchanges from/to the State Street Institutional Liquid Reserves Fund is not permitted.

Excessive Trading

Because the Funds are money market funds, the Funds’ Board of Trustees has not adopted policies and procedures with respect to frequent purchases and redemptions of Fund shares by Fund shareholders. Nonetheless, the Funds may take any reasonable action that they deem necessary or appropriate to prevent excessive trading in Fund shares without providing prior notification to the account holder. Such action may include rejecting any purchase, in whole or part, including, without limitation, by a person whose trading activity in Fund shares may be deemed harmful to the Fund. While the Funds attempt to discourage such excessive trading, there can be no guarantee that they will be able to identify investors who are engaging in excessive trading or limit their trading practices. Additionally, frequent trades of small amounts may not be detected. The Funds recognize that they may not always be able to detect or prevent excessive trading or other activity that may disadvantage the Funds or their shareholders.

Delivery of Documents to Accounts Sharing an Address

To reduce expenses, we may mail only one copy of the Fund’s Prospectus and the annual and semi-annual report to those addresses shared by two or more accounts. If you wish to receive individual copies of these documents, please call us at (877) 521-4083, or contact your financial institution. We will begin sending you individual copies thirty (30) days after receiving your request.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a State Street Fund identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Fund (if you hold shares directly with the Fund) or to your financial intermediary (if you do not hold shares directly with the Fund).

DIVIDENDS, DISTRIBUTIONS AND TAX CONSIDERATIONS

The Fund invests substantially all of its assets in the Portfolio, which is expected to be treated as a regulated investment company for federal income tax purposes, and so substantially all of the Fund’s income will result from distributions or deemed distributions from the Portfolio. Therefore, as applicable, and except as otherwise stated, references in this section to the assets owned or income earned by the Fund will include such assets and income of the Portfolio. The Fund has elected to be treated as a regulated investment company and intends each year to qualify and to be eligible to be treated as such. A regulated investment company generally is not subject to tax at the corporate level on income and gains that are timely distributed to shareholders. In order to qualify and be eligible for treatment as a regulated investment company, the Fund must, among other things, satisfy diversification, 90% gross income and distribution requirements. The Fund’s failure to qualify as a regulated investment company would result in corporate level taxation, and consequently, a reduction in income available for distribution to shareholders.

For U.S. federal income tax purposes, distributions of investment income generally are taxable to you as ordinary income. Taxes on distributions of capital gains generally are determined by how long the Portfolio owned (or is deemed to have owned) the investments that generated them, rather than how long you have owned your Fund Shares. Distributions of net capital gains (that is, the excess of net long-term capital gains over net short-term capital losses) from the sale of investments that the Fund owned (or is deemed to have owned) for more than one year that are properly reported by the Fund as capital gain dividends generally will be treated as long-term capital gain includible in your net capital gain and taxed to individuals at reduced rates. Distributions of gains from investments that the Fund owned (or is deemed to have owned) for one year or less generally will be taxable to you as ordinary income when distributed to you by the Fund. Distributions of investment income properly reported by the Fund as derived from “qualified dividend income” are taxed to individuals at the rates applicable to net capital gain, provided holding period and other requirements are met by the shareholder, the Portfolio and the Fund. Distributions are taxable to you even if they are paid from income or gains earned by the Fund before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares.

The Fund’s income from or proceeds of investments in non-U.S. assets may be subject to non-U.S. withholding and other taxes. This will decrease the Fund’s return on securities subject to such taxes. Tax treaties between certain countries and the U.S. may reduce or eliminate such taxes. Although such taxes will reduce the Fund’s taxable income, shareholders generally will not be entitled separately to claim a credit or deduction with respect to foreign taxes incurred by the Fund.

When the NAV of Fund Shares varies from a shareholder’s tax basis in such shares, including in the case of a money market fund when the NAV of such Fund Shares varies from $1.0000 per share, the shareholder generally will realize a gain or loss upon the redemption or other taxable disposition of such Fund Shares. Any such gain generally would be taxable to you as either short-term or long-term capital gain, depending upon how long you held the Fund Shares. The IRS permits a simplified method of accounting for gains and losses realized upon the disposition of shares of a regulated investment company that is a money market fund. If you elect to adopt this simplified method of accounting, rather than compute gain or loss on every taxable disposition of Fund Shares,

you will determine your gain or loss based on the change in the aggregate value of your Fund Shares during a computation period (such as your taxable year), reduced by your net investment (purchase minus sales) in those shares during that period. Under this simplified method, any resulting net capital gain or loss would be treated as short-term capital gain or loss. Shareholders should see the SAI for further information.

An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by the Fund, including any capital gain dividends, and net gains recognized on the redemption of shares of the Fund.

Certain of the Portfolio’s investment practices, including derivative transactions and investments in debt obligations issued or purchased at a discount, will be subject to special and complex U.S. federal income tax provisions. These special rules may affect the timing, character, and/or amount of the Portfolio’s distributions to the Fund, and, in turn, the Fund’s distributions to shareholders, and may require the Fund or the Portfolio to sell its investments at a time when it is not advantageous to do so.

The Fund’s investments in the Portfolio may cause the tax treatment of the Fund’s gains, losses and distributions to differ at times from the tax treatment that would apply if the Fund invested directly in the types of securities held by the Portfolio. As a result, investors may receive taxable distributions earlier and recognize higher amounts of capital gain or ordinary income than they otherwise would.

If you are not a U.S. person, dividends paid by the Fund that the Fund properly reports as capital gain dividends, short-term capital gain dividends, or interest-related dividends, each as further defined in the SAI, are not subject to withholding of U.S. federal income tax, provided that certain other requirements are met. The Fund is permitted, but is not required, to report any part of its dividends as are eligible for such treatment. The Fund’s dividends other than those the Fund so reports as capital gain dividends, short-term capital gain dividends, or interest-related dividends generally will be subject to U.S. withholding tax at a 30% rate (or lower applicable treaty rate). See the Fund’s SAI for further information.

FINANCIAL INTERMEDIARY ARRANGEMENTS

Distribution Arrangements and Rule 12b-1 Fees

The Fund has adopted a distribution plan pursuant to Rule 12b-1 under the 1940 Act under which the Fund may compensate SSGA FD (or others) for services in connection with the distribution of the Fund’s shares and for services provided to Fund shareholders (the “Plan”). The Plan calls for payments at an annual rate (based on average daily net assets) of 0.10% of the Fund’s net assets attributable to its Investment Class shares. Because these fees are paid out of the assets of the Fund attributable to its shares on an ongoing basis, they will increase the cost of your investment and may cost you more over time than paying other types of sales charges. Long-term shareholders of the Fund may pay more in Rule 12b-1 fees than the economic equivalent of the maximum front-end sales charge permitted by the FINRA.

Because the Fund pays distribution and other fees for the sale of their shares and for services provided to shareholders out of the Fund’s assets on an ongoing basis, over time those fees will increase the cost of your investment and may cost you more than paying other types of sales loads.

The Fund may pay distribution fees and other amounts described in this Prospectus at a time when shares of that Fund are unavailable for purchase.

Other Payments to Financial Intermediaries

In some cases, a Financial Intermediary may hold its clients’ Fund Shares in nominee or street name and may utilize omnibus accounts. Shareholder services provided by a Financial Intermediary may (though they will not necessarily) include, among other things: establishing and maintaining shareholder account registrations; receiving and processing purchase and redemption orders, including

aggregated orders and delivering orders to the Fund’s transfer agent; processing and mailing trade confirmations, periodic statements, prospectuses, annual reports, semiannual reports, shareholder notices, and other SEC-required communications; capturing and processing tax data; issuing and mailing dividend checks to shareholders who have selected cash distributions; preparing record date shareholder lists for proxy solicitations; and collecting and posting distributions to shareholder accounts.

The Financial Intermediary is often compensated by SSGA FD or its affiliates for the services it performs and in such cases is typically paid continually over time, during the period when the Financial Intermediary’s clients hold investments in the Fund. The amount of continuing compensation paid by SSGA FD or its affiliates to different Financial Intermediaries for distribution and/or shareholder services varies. Any compensation is typically a percentage of the value of the Financial Intermediary’s clients’ investments in the Fund or a per account fee. The variation in compensation may, but will not necessarily, reflect enhanced or additional services provided by the Financial Intermediary.

If you invest through a Financial Intermediary and meet the eligibility criteria for more than one share class, you should discuss with your Financial Intermediary which share class is appropriate for you. Your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend one share class over another, when you are eligible to invest in more than one share class. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by the Fund or its affiliates with respect to the different share classes offered by the Fund.

SSGA FD and its affiliates (including SSGA FM), at their own expense and out of their own assets, may also provide other compensation to Financial Intermediaries in connection with sales of the Fund’s shares or the servicing of shareholders or shareholder accounts. Such compensation may include, but is not limited to, financial assistance to Financial Intermediaries in connection with conferences, sales, or training programs for their employees; seminars for the public; advertising or sales campaigns; or other Financial Intermediary-sponsored special events. In some instances, this compensation may be made available only to certain Financial Intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the Fund’s shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as FINRA.

Third-Party Transactions . The State Street Funds have authorized certain Financial Intermediaries to accept purchase, redemption and exchange orders on the State Street Funds’ behalf. Orders received for a State Street Fund by a Financial Intermediary that has been authorized to accept orders on the Fund’s behalf (or other Financial Intermediaries designated by the Financial Intermediary) will be deemed accepted by the Fund at the time they are received by the Financial Intermediary and will be priced based on the Fund’s next NAV determination as long as the Financial Intermediary transmits the order in good form and in a timely manner to the applicable State Street Fund(s). The Financial Intermediary is responsible for transmitting your orders and associated funds in good form and in a timely manner to the applicable State Street Fund(s). The State Street Funds will not be responsible for delays by the Financial Intermediary in transmitting your orders, including timely transfer of payment, to the Fund.

FINANCIAL HIGHLIGHTS

The Fund had not commenced operations prior to the date of this Prospectus and therefore does not have financial information.

Contacting the State Street Funds


Online:	www.ssga.com/cash	24 hours a day, 7 days a week
Phone:	(877) 521-4083	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail

Overnight/ Registered, Express, Certified Mail

State Street Funds

P.O. Box 219737

Kansas City, MO 64121-9737

State Street Funds

430 W 7 ^th Street Suite 219737

Kansas City, MO 64105-1407

The Fund does not consider the U.S. Postal Service or other independent delivery services to be its agents. Therefore, deposits in the mail or with such services, or receipt at the Fund’s post office box, of purchase orders or redemption requests, do not constitute receipt by the Fund or Transfer Agent.

For more information about the Fund:

The Fund’s SAI includes additional information about the Fund and is incorporated by reference into this document. Additional information about the Fund’s investments is available or will be available, in the Fund’s most recent annual and semi-annual reports to shareholders. The Fund’s SAI is available, without charge, upon request. The Fund’s annual and semi-annual reports are available, or will be available, without charge, upon request. Shareholders in the Fund may make inquiries to the Fund to receive such information by calling (877) 521-4083 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. The Fund’s Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, or will be available, free of charge, on the Fund’s website at www.ssga.com/cash.

Reports and other information about the Fund are available free of charge on the EDGAR Database on the SEC’s Internet site at http://www.sec.gov. Copies of this information also may be obtained, after paying a duplicating fee, by electronic request at the following E-mail address: publicinfo@sec.gov.

SSGA Funds Management, Inc.

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

The State Street Institutional Investment Trust’s

Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional Investment Trust

State Street Cash Reserves Portfolio (MMWXX)

Beginning on January 1, 2021, as permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of the Portfolio’s annual and semiannual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Portfolio (or from your financial intermediary, such as a broker-dealer or bank). Instead, the reports will be made available on the Portfolio’s website (www.ssga.com/cash), and you will be notified by mail each time a report is posted, and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Portfolio electronically by calling (866) 392-0869.

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with a Portfolio, you can inform the Portfolio that you wish to continue receiving paper copies of your shareholder reports by calling (866) 392-0869. Your election to receive reports in paper will apply to all funds held in your account, if you invest through your financial intermediary or all funds held with the fund complex if you invest directly with the Portfolio.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment the Portfolio offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. It is possible to lose money by investing the Portfolio offered in this Prospectus.

LOGO

TABLE OF CONTENTS



Fund Summary			1

State Street Cash Reserves Portfolio			1

Additional Information About Investment Objective, Principal Strategies and Risks			6

Additional Information About Non-Principal Investment Strategies and Risks			12

Portfolio Holdings Disclosure			13

Management and Organization			14

Shareholder Information			15

Dividends, Distributions and Tax Considerations			17

Financial Highlights			18

STATE STREET CASH RESERVES PORTFOLIO

Investment Objective

The investment objective of State Street Cash Reserves Portfolio (the “Portfolio”) is to seek to maximize current income, to the extent consistent with the preservation of capital and liquidity and the maintenance of a stable $1.00 per share net asset value (“NAV”) by investing in U.S. dollar-denominated money market securities.

Fees and Expenses of the Portfolio

The table below describes the fees and expenses that you may pay if you buy and hold shares of the State Street Cash Reserves Portfolio (“Portfolio Shares”). The Portfolio’s shares are offered exclusively to investors that pay fees to SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the Portfolio’s investment adviser, or its affiliates; the Portfolio pays no management fee to SSGA FM, as shown in the table below.

Shareholder Fees (fees paid directly from your investment)


Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)			None

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)			None

Annual Portfolio Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)


Management Fee	N/A

Distribution and/or Shareholder Service (12b-1) Fees	N/A

Other Expenses ¹	0.09	%

Total Annual Fund Operating Expenses	0.09	%

¹	Other expenses are based on estimates for the current fiscal year.

Example:


1 year		3 years
$9		$29

Principal Investment Strategies

In managing the State Street Cash Reserves Portfolio, the Adviser follows a disciplined investment process, basing its decisions on the relative attractiveness of different money market instruments. Among other things, SSGA FM conducts its own credit analyses of potential investments and portfolio holdings, and relies substantially on a dedicated short term credit research team. In the Adviser’s opinion the attractiveness of an instrument may vary depending on a variety of factors, including for example the general level of interest rates, imbalances of supply and demand in the market, and the credit quality of the obligors.

The Portfolio is a retail money market fund and seeks to maintain its net asset value NAV at $1.00 per share, although there can be no assurance that it will be able to do so.

The Portfolio attempts to meet its investment objective by investing in a broad range of money market instruments. These may include U.S. Government securities (including U.S. Treasury bills, notes and bonds and other securities issued or guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities); certificates of deposit and time deposits of U.S. and foreign banks; commercial paper and other high quality obligations of U.S. or foreign companies; asset-backed securities, including asset backed commercial paper; mortgage-related securities; and repurchase agreements. These instruments may bear fixed, variable orfloating rates of interest or may be zero-coupon securities. The Portfolio also may invest in shares of other money market funds, including funds advised by the Adviser. A substantial portion of the Portfolio may be invested in securities that are issued or traded pursuant to exemptions from registration under the federal securities laws.

The Portfolio purchases assets that have received a top tier (without regard to subcategories or gradations) short-term debt rating from one or more nationally recognized statistical rating organizations ( e.g ., those rated A-1 by Standard & Poor’s Rating Group (“S&P”), P-1 by Moody’s Investor Service, Inc. (“Moody’s”) or F1 by Fitch Ratings (“Fitch”)) or, if unrated, that are considered to be of comparable quality by the Adviser.

Under normal circumstances, the Portfolio intends to invest at least 25% of its assets in bank obligations.

The Portfolio invests in accordance with regulatory requirements applicable to money market funds, which require, among other things, the Portfolio to invest only in short-term, high quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk) to maintain a maximum dollar weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity. For the purposes of determining the Portfolio’s weighted average maturity, a security’s final maturity date will be used, unless the security is a floating rate or variable rate security in which case the maturity will be determined in accordance with the rules applicable to money market funds.

Principal Risks

You could lose money by investing in the Portfolio. An investment in the Portfolio is subject to investment risks, including possible loss of principal, is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency . The Portfolio may not achieve its investment objective. General risks associated with the Portfolio’s investment policies and investment strategies are discussed below. The Portfolio is not intended to be a complete investment program, but rather is intended for investment as part of a diversified investment portfolio. Investors should consult their own advisers as to the role of the Portfolio in their overall investment programs.

In addition, the Portfolio is subject to the following risks:

Counterparty Risk: The Portfolio will be subject to credit risk with respect to the counterparties with which the Portfolio enters into derivatives contracts, repurchase agreements, reverse repurchase agreements, and other transactions. If a counterparty fails to meet its contractual obligations, the Portfolio may be unable to terminate or realize any gain on the investment or transaction, or to recover collateral posted to the counterparty, resulting in a loss to the Portfolio. If the Portfolio holds collateral posted by its counterparty, it may be delayed or prevented from realizing on the collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty.

Debt Securities Risk: The values of debt securities may increase or decrease as a result of the following: market fluctuations, increases in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments or illiquidity in debt securities markets; the risk of low rates of return due to reinvestment of securities during periods of falling interest rates or repayment by issuers with higher coupon or interest rates; and/or the risk of low income due to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. In recent years, the U.S. Federal Reserve Board has continued to increase interest rates, following several years of historically low interest rate levels. A rising interest rate environment may cause the value of the Portfolio’s fixed income securities to decrease, an adverse impact on the liquidity of the Portfolio’s fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Portfolio may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

Financial Institutions Risk: Changes in the creditworthiness of financial institutions (such as banks and broker-dealers) may adversely affect the values of instruments of issuers in financial industries. Adverse developments in banking and other financial industries may cause the Portfolio to underperform relative to other funds that invest more broadly across different industries or have a smaller exposure to financial institutions. Changes in governmental regulation and oversight of financial institutions may have an adverse effect on the financial condition of a financial institution.

Income Risk: The Portfolio’s income may decline due to falling interest rates or other factors. Issuers of securities held by the Portfolio may call or redeem the securities during periods of falling interest rates, and the Portfolio would likely be required to reinvest in securities paying lower interest rates. If an obligation held by the Portfolio is prepaid, the Portfolio may have to reinvest the prepayment in other obligations paying income at lower rates.

Liquidity Risk: Lack of a ready market or restrictions on resale may limit the ability of the Portfolio to sell a security at an advantageous time or price or at all. Illiquid securities may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value. Illiquidity of the Portfolio’s holdings may limit the ability of the Portfolio to obtain cash to meet redemptions on a timely basis. In addition, the Portfolio, due to limitations on investments in any illiquid securities and/or the difficulty in purchasing and selling such investments, may be unable to achieve its desired level of exposure to a certain market or sector.

Low Short-Term Interest Rates: At the date of this Prospectus, short-term interest rates are at low levels, and so the Portfolio’s yield is very low. It is possible that the Portfolio will generate an insufficient amount of income to pay its expenses, and that it will not be able to pay a daily dividend and may have a negative yield (i.e., it may lose money on an operating basis). It is possible that the Portfolio will maintain a substantial portion of its assets in cash, on which it would earn little, if any, income.

Market Risk: The Portfolio’s investments are subject to changes in general economic conditions, and general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Portfolio is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets.

Money Market Fund Regulatory Risk: The U.S. Securities and Exchange Commission (“SEC”) has recently implemented regulatory changes that will affect the structure and operation of money market funds. The revised regulations impose new liquidity requirements on money market funds, permit (and in some cases require) money market funds to impose “liquidity fees” on redemptions, and permit money market funds to impose “gates” restricting redemptions from the funds. Institutional money market funds are now required to have a floating NAV. (U.S. government money market funds are exempt from a number of the new regulations.) There are a number of other changes under the revised regulations that relate to diversification, disclosure, reporting and stress testing requirements. These changes have been implemented recently and they could significantly affect the money market fund industry generally and the operation or performance of the Portfolio specifically and may have significant adverse effects on a money market fund’s investment return and on the liquidity of investments in money market funds

Mortgage-Related and Other Asset-Backed Securities Risk: Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed-income investments. The liquidity of mortgage-related and asset-backed securities may change over time. During periods of falling interest rates, mortgage- and asset-backed securities may be called or prepaid, which may result in the Portfolio having to reinvest proceeds in other investments at a lower interest rate. During periods of rising interest rates, the average life of mortgage- and asset-backed securities may extend, which may lock in a below-market interest rate, increase the security’s duration and interest rate sensitivity, and reduce the value of the security. Enforcing rights against the underlying assets or collateral may be difficult, and the underlying assets or collateral may be insufficient if the issuer defaults.

Non-U.S. Securities Risk: Non-U.S. securities (including depositary receipts) are subject to political, regulatory, and economic risks not present in domestic investments. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, legal and financial report standards comparable to those in the United States. Further, such entities and/or their securities may be subject to risks associated with currency controls; expropriation; changes in tax policy; greater market volatility; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. Securities traded on foreign markets may be less liquid (harder to sell) than securities traded domestically. Foreign governments may impose restrictions on the repatriation of capital to the U.S. In addition, to the extent investments are made in a limited number of countries, events in those countries will have a more significant impact on the Portfolio. Investments in depositary receipts may be less liquid and more volatile than the underlying shares in their primary trading market.

Rapid Changes in Interest Rates Risk: Rapid changes in interest rates may cause significant requests to redeem Portfolio Shares, and possibly cause the Portfolio to sell portfolio securities at a loss to satisfy those requests.

Repurchase Agreement Risk: Repurchase agreements may be viewed as loans made by the Portfolio which are collateralized by the securities subject to repurchase. If the Portfolio’s counterparty should default on its obligations and the Portfolio is delayed or prevented from recovering the collateral, or if the value of the collateral is insufficient, the Portfolio may realize a loss.

Restricted Securities Risk: The Portfolio may hold securities that have not been registered for sale to the public under the U.S. federal securities laws. There can be no assurance that a trading market will exist at any time for any particular restricted security. Limitations on the resale of these securities may have an adverse effect on their marketability, and may prevent the Portfolio from disposing of them promptly at reasonable prices. The Portfolio may have to bear the expense of registering the securities for resale and the risk of substantial delays in effecting the registration. Also, restricted securities may be difficult to value because market quotations may not be readily available, and the securities may have significant volatility.

Risk of Investment in Other Pools: If the Portfolio invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected and is exposed indirectly to all of the risks applicable to an investment in such other pool. The investment policies of the other pool may not be the same as those of the Portfolio; as a result, an investment in the other pool may be subject to additional or different risks than those to which the Portfolio is typically subject. The Portfolio bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Portfolio may invest, leading to potential conflicts of interest. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which the Portfolio does so.

Significant Exposure to U.S. Government Agencies or Instrumentalities Risk: To the extent the Portfolio focuses its investments in securities issued or guaranteed by U.S. government agencies or instrumentalities, any market movements, regulatory changes or changes in political or economic conditions that affect the U.S. government agencies or instrumentalities in which the Portfolio invests may have a significant impact on the Portfolio’s performance. Events that would adversely affect the market prices of securities issued or guaranteed by one government agency or instrumentality may adversely affect the market price of securities issued or guaranteed by other government agencies or instrumentalities.

Stable Share Price Risk: If the market value of one or more of the Portfolio’s investments changes substantially, the Portfolio may not be able to maintain a stable share price of $1.00. This risk typically is higher during periods of rapidly changing interest rates or when issuer credit quality generally is falling, and is made worse when the Portfolio experiences significant redemption requests.

Portfolio Performance

Performance information for the Portfolio has been omitted because the Portfolio had not commenced investment operations as of the date of this Prospectus. Once the Portfolio has completed a full calendar year of operations, a bar chart and table will be included that will provide some indication of the risks of investing in the Portfolio by showing the variability of the Portfolio’s returns based on net assets. The Portfolio will make updated performance information, including its current net asset value, available at the Portfolio’s website: www.ssga.com/cash.

Investment Adviser

SSGA FM serves as the investment adviser to the Portfolio.

Purchase and Sale of Portfolio Shares

Generally, shares of the Portfolio may be purchased only by or on behalf of other registered investment companies or private clients that compensate the Adviser or its affiliates directly. You may redeem Portfolio shares on any day the Portfolio is open for business. You may redeem Portfolio shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Corporation

Attention: Transfer Agent

Box 5493

Mail Code: OHD0100

North Quincy, MA 02171

By Overnight:

State Street Corporation

Attention: Transfer Agent

1 Heritage Drive

North Quincy, MA 02171

By Intermediary:

Financial Intermediaries may contact State Street Dealer Services Group at 617-662-7300 or email them at broker-dealerservices@statestreet.com with questions.

Tax Information

The Portfolio’s distributions are expected to be taxed as ordinary income and/or capital gains, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or individual retirement account. Any withdrawals made from such tax-advantaged arrangement may be taxable to you.

Payments to Broker-Dealers and Other Financial Intermediaries

ADDITIONAL INFORMATION ABOUT INVESTMENT OBJECTIVE, PRINCIPAL STRATEGIES AND RISKS

Investment Objective

The investment objective of the Portfolio, as stated in the Portfolio’s Fund Summary, may be changed without shareholder approval.

State Street Cash Reserves Portfolio

Principal Investment Strategies

The Portfolio is a retail money market fund and seeks to maintain its net asset value NAV at $1.00 per share, although there can be no assurance that it will be able to do so.

Under normal circumstances, the Portfolio intends to invest at least 25% of its assets in bank obligations.

Additional Information About Risks

Call/Prepayment Risk . Call/prepayment risk is the risk that an issuer will exercise its right to pay principal on an obligation held by the Portfolio earlier than expected or required. This may occur, for example, when there is a decline in interest rates, and an issuer of bonds or preferred stock redeems the bonds or stock in order to replace them with obligations on which it is required to pay a lower interest or dividend rate. It may also occur when there is an unanticipated increase in the rate at which mortgages or other receivables underlying mortgage- or asset-backed securities held by the Portfolio are prepaid. In any such case, the Portfolio may be forced to invest the prepaid amounts in lower-yielding investments, resulting in a decline in the Portfolio’s income.

Counterparty Risk . The Portfolio will be subject to credit risk with respect to the counterparties with which the Portfolio enters into derivatives contracts and other transactions such as repurchase agreements or reverse repurchase agreements. The Portfolio’s ability to profit from these types of investments and transactions will depend on the willingness and ability of its counterparty to perform its obligations. If a counterparty fails to meet its contractual obligations, the Portfolio may be unable to terminate or realize any gain on the investment or transaction, resulting in a loss to the Portfolio. The Portfolio may experience significant delays in obtaining any recovery in an insolvency, bankruptcy, or other reorganization proceeding involving its counterparty (including recovery of any collateral posted by it) and may obtain only a limited recovery or may obtain no recovery in such circumstances. If the Portfolio holds collateral posted by its counterparty, it may be delayed or prevented from realizing on the collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty. Under applicable law or contractual provisions, including if the Portfolio enters into an investment or

transaction with a financial institution and such financial institution (or an affiliate of the financial institution) experiences financial difficulties, then the Portfolio may in certain situations be prevented or delayed from exercising its rights to terminate the investment or transaction, or to realize on any collateral and may result in the suspension of payment and delivery obligations of the parties under such investment or transactions or in another institution being substituted for that financial institution without the consent of the Portfolio. Further, the Portfolio may be subject to “bail-in” risk under applicable law whereby, if required by the financial institution’s authority, the financial institution’s liabilities could be written down, eliminated or converted into equity or an alternative instrument of ownership. A bail-in of a financial institution may result in a reduction in value of some or all of its securities and, if the Portfolio holds such securities or has entered into a transaction with such a financial security when a bail-in occurs, the Portfolio may also be similarly impacted.

Credit Risk . Credit risk is the risk that an issuer, guarantor or liquidity provider of a fixed-income security held by the Portfolio may be unable or unwilling, or may be perceived (whether by market participants, ratings agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. It includes the risk that the security will be downgraded by a credit rating agency; generally, lower credit quality issuers present higher credit risks. An actual or perceived decline in creditworthiness of an issuer of a fixed-income security held by the Portfolio may result in a decrease in the value of the security. It is possible that the ability of an issuer to meet its obligations will decline substantially during the period when the Portfolio owns securities of the issuer or that the issuer will default on its obligations or that the obligations of the issuer will be limited or restructured.

The credit rating assigned to any particular investment does not necessarily reflect the issuer’s current financial condition and does not reflect an assessment of an investment’s volatility or liquidity. Securities rated in the lowest category of investment-grade are considered to have speculative characteristics. If a security held by the Portfolio loses its rating or its rating is downgraded, the Portfolio may nonetheless continue to hold the security in the discretion of the Adviser. In the case of asset-backed or mortgage-related securities, changes in the actual or perceived ability of the obligors on the underlying assets or mortgages to make payments of interest and/or principal may affect the values of those securities.

Debt Securities Risk . The values of debt securities may increase or decrease as a result of the following: market fluctuations, increases in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments or illiquidity in debt securities markets; the risk of low rates of return due to reinvestment of securities during periods of falling interest rates or repayment by issuers with higher coupon or interest rates; and/or the risk of low income due to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of the Portfolio’s fixed income securities to decrease, an adverse impact on the liquidity of the Portfolio’s fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Portfolio may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

Financial Institutions Risk . Some instruments are issued or guaranteed by financial institutions, such as banks and brokers, or are collateralized by securities issued or guaranteed by financial institutions. Changes in the creditworthiness of any of these institutions may adversely affect the values of instruments of issuers in financial industries. Financial institutions may be particularly sensitive to certain economic factors such as interest rate changes, adverse developments in the real estate market, fiscal and monetary policy and general economic cycles. Adverse developments in banking and other financial industries may cause the Portfolio to underperform relative to other funds that invest more broadly across different industries or have a smaller exposure to financial institutions. Changes in governmental regulation and oversight of financial institutions may have an adverse effect on the financial condition or the earnings or operations of a financial institution and on the types and amounts of businesses in which a financial institution may engage. An investor may be delayed or prevented from exercising certain remedies against a financial institution. The amount of the Portfolio’s assets that may be invested in any financial institution, or financial institutions generally, may be limited by applicable law.

Income Risk. The Portfolio’s income may decline due to falling interest rates or other factors. Issuers of securities held by the Portfolio may call or redeem the securities during periods of falling interest rates, and the Portfolio would likely be required to reinvest in securities paying lower interest rates. If an obligation held by the Portfolio is prepaid, the Portfolio may have to reinvest the prepayment in other obligations paying income at lower rates. A reduction in the income earned by the Portfolio may limit the Portfolio’s ability to achieve its objective.

Interest Rate Risk . Interest rate risk is the risk that the securities held by the Portfolio will decline in value because of increases in market interest rates. Duration is a measure used to determine the sensitivity of a security’s price to changes in interest rates. Debt securities with longer durations tend to be more sensitive to changes in interest rates, usually making them more volatile than debt securities with shorter durations. For example, the value of a security with a duration of five years would be expected to decrease by 5% for every 1% increase in interest rates. Falling interest rates also create the potential for a decline in the Portfolio’s income and yield. Interest-only and principal-only securities are especially sensitive to interest rate changes, which can affect not only their prices but can also change the income flows and repayment assumptions about those investments. Variable and floating rate securities also generally increase or decrease in value in response to changes in interest rates, although generally to a lesser degree than fixed-rate securities. A substantial increase in interest rates may also have an adverse impact on the liquidity of a security, especially those with longer durations. In recent years, the U.S. Federal Reserve Board has continued to increase interest rates, following several years of historically low interest rate levels. Changes in governmental policy, including changes in central bank monetary policy, could cause interest rates to rise rapidly, or cause investors to expect a rapid rise in interest rates. This could lead to heightened levels of interest rate, volatility and liquidity risks for the fixed income markets generally and could have a substantial and immediate effect on the values of the Portfolio’s investments.

Large Shareholder Risk . To the extent a large proportion of the shares of the Portfolio are highly concentrated or held by a small number of shareholders (or a single shareholder), including funds or accounts over which the Adviser has investment discretion, the Portfolio is subject to the risk that these shareholders will purchase or redeem Portfolio shares in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of the Portfolio to conduct its investment program. For example, they could require the Portfolio to sell portfolio securities or purchase portfolio securities unexpectedly and incur substantial transaction costs and/or accelerate the realization of taxable income and/or gains to shareholders, or the Portfolio may be required to sell its more liquid portfolio investments to meet a large redemption, in which case the Portfolio’s remaining assets may be less liquid, more volatile, and more difficult to price. The Portfolio may hold a relatively large proportion of its assets in cash in anticipation of large redemptions, diluting its investment returns.

Liquidity Risk . Liquidity risk is the risk that the Portfolio may not be able to dispose of securities readily at a favorable time or prices (or at all) or at prices approximating those at which the Portfolio currently values them. For example, certain investments may be subject to restrictions on resale, may trade in the over-the-counter market or in limited volume, or may not have an active trading market. Illiquid securities may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value. It may be difficult for the Portfolio to value illiquid securities accurately. The market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. Disposal of illiquid securities may entail registration expenses and other transaction costs that are higher than those for liquid securities. The Portfolio may seek to borrow money to meet its obligations (including among other things redemption obligations) if it is unable to dispose of illiquid investments, resulting in borrowing expenses and possible leveraging of the Portfolio. In some cases, due to unanticipated levels of illiquidity the Portfolio may choose to meet its redemption obligations wholly or in part by distributions of assets in-kind.

Low Short-Term Interest Rate Risk . During market conditions in which short-term interest rates are at low levels, as was the case until recent periods, the Portfolio’s yield can be very low. During these conditions, it is possible that the Portfolio will generate an insufficient amount of income to pay its expenses, and that it will not be able to pay a daily dividend and may have a negative yield (i.e., it may lose money on an operating basis). It is possible that the Portfolio will maintain a substantial portion of its assets in cash, on which it may earn little, if any, income.

Market Disruption and Geopolitical Risk. The Portfolio is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets. War, terrorism, and related geopolitical events have led, and in the future may lead, to increased short-term market volatility and may have adverse long-term effects on U.S. and world economies and markets generally. Likewise, natural and environmental disasters and systemic market dislocations may be highly disruptive to economies and markets. Those events as well as other changes in foreign and domestic economic and political conditions also could adversely affect individual issuers or related groups of issuers, securities markets, interest rates, credit ratings, inflation, investor sentiment, and other factors affecting the value of the Portfolio’s investments. Given the increasing interdependence among global economies and markets, conditions in one country, market, or region might adversely affect markets, issuers, and/or foreign exchange rates in other countries, including the U.S. Any partial or complete dissolution of the Economic and Monetary Union of the European Union, or any increased uncertainty as to its status, could have significant adverse effects on currency and financial markets, and on the values of the Portfolio’s investments. Securities and financial markets may be susceptible to market manipulation or other fraudulent trade practices, which could disrupt the orderly functioning of these markets or adversely affect the values of investments traded in these markets, including investments held by the Portfolio. To the extent the Portfolio has focused its investments in the market or index of a particular region, adverse geopolitical and other events could have a disproportionate impact on the Portfolio.

Market Risk . Market prices of investments held by the Portfolio will go up or down, sometimes rapidly or unpredictably. The Portfolio’s investments are subject to changes in general economic conditions, general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in actual or perceived creditworthiness of issuers and general market liquidity. Even if general economic conditions do not change, the value of an investment in the Portfolio could decline if the particular industries, sectors or companies in which the Portfolio invests do not perform well or are adversely affected by events. Further, legal, political, regulatory and tax changes also may cause fluctuations in markets and securities prices.

Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject the Portfolio to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and the Portfolio’s investment program in particular can be uncertain. In recent periods, governmental and non-governmental issuers have defaulted on, or have been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including, without limitation, in Europe or Asia. Defaults or restructurings by governments or others of their debts could have substantial adverse effects on economies, financial markets, and asset valuations around the world. Further Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, or investor perception that these efforts are not succeeding, could negatively affect financial markets generally as well as the values and liquidity of certain securities.

Mortgage-Related and Other Asset-Backed Securities Risk . Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed income investments. The liquidity of mortgage-related and asset-backed securities may change over time. Mortgage-related securities represent a participation in, or are secured by, mortgage loans. Other asset-backed securities are typically structured like mortgage-related securities, but instead of mortgage loans or interests in mortgage loans, the underlying assets may include, for example, items such as motor vehicle installment sales or installment loan contracts, leases on various types of real and personal property, and receivables from credit card agreements. During periods of falling interest rates, mortgage-related and other asset-backed securities, which typically provide the issuer with the right to prepay the security prior to maturity, may be prepaid, which may result in the Portfolio having to reinvest the proceeds in other investments at lower interest rates. During periods of rising interest rates, the average life of mortgage-related and other asset-backed securities may extend because of slower-than expected principal payments. This may lock in a below market interest rate, increase the security’s duration and interest rate sensitivity, and reduce the value of the security. As a result, mortgage-related and other asset-backed securities may have less potential for capital appreciation during periods of declining interest rates than other debt securities of comparable maturities, although they may have a similar risk of decline in market values during periods of rising interest rates. Prepayment rates are difficult to predict and the potential impact of prepayments on the value of a mortgage-related or other asset-backed security depends on the terms of the instrument and can result in significant volatility. The price of a mortgage-related or other asset-backed security also depends on the credit quality and adequacy of the underlying assets or collateral. Mortgage-related or other asset-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) will generally entail greater credit risk than obligations guaranteed by the U.S. Government. Defaults on the underlying assets, if any, may impair the value of a mortgage-related or other asset-backed security. For some asset-backed securities in which the Portfolio invests, such as those backed by credit card receivables, the underlying cash flows may not be supported by a security interest in a related asset. Moreover, the values of mortgage-related and other asset-backed securities may be substantially dependent on the servicing of the underlying asset pools, and are therefore subject to risks associated with the negligence or malfeasance by their servicers and to the credit risk of their servicers. In certain situations, the mishandling of related documentation may also affect the rights of securities holders in and to the underlying collateral. There may be legal and practical limitations on the enforceability of any security interest granted with respect to underlying assets, or the value of the underlying assets, if any, may be insufficient if the issuer defaults.

Non-U.S. Securities Risk . Investments in securities of non-U.S. issuers (including depositary receipts) entail risks not typically associated with investing in securities of U.S. issuers. Similar risks may apply to securities traded on a U.S. securities exchange that are issued by entities with significant exposure to non-U.S. countries. In certain countries, legal remedies available to investors may be more limited than those available with regard to U.S. investments. Income and gains with respect to investments in certain countries may be subject to withholding and other taxes. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, and financial reporting standards, regulatory framework and practices comparable to those in the United States. The securities of some non-U.S. entities are less liquid and at times more volatile than securities of comparable U.S. entities, and could become subject to sanctions or embargoes that adversely affect the Portfolio’s investment. Non-U.S. transaction costs, such as brokerage commissions and custody costs may be higher than in the U.S. In addition, there may be a possibility of nationalization or expropriation of assets, imposition of currency exchange controls, confiscatory taxation, and diplomatic developments that could adversely affect the values of the Portfolio’s investments in certain non-U.S. countries. Investments in securities of non-U.S. issuers also are subject to foreign political and economic risk not associated with U.S. investments, meaning that political events (civil unrest, national elections, changes in political conditions and foreign relations, imposition of exchange controls and repatriation restrictions), social and economic events (labor strikes, rising inflation) and natural disasters occurring in a country where the Portfolio invests could cause the Portfolio’s investments in that country to experience gains or losses.

Rapid Changes in Interest Rates . The values of most instruments held by the Portfolio are adversely affected by changes in interest rates generally, especially increases in interest rates. Rapid changes in interest rates may cause significant requests to redeem Portfolio Shares, and possibly cause the Portfolio to sell portfolio securities at a loss to satisfy those requests.

Reinvestment Risk. Income from the Portfolio may decline when the Portfolio invests the proceeds from investment income, sales of portfolio securities or matured, traded or called debt obligations. For instance, during periods of declining interest rates, an issuer of debt obligations may exercise an option to redeem securities prior to maturity, forcing the Portfolio to reinvest the proceeds in lower-yielding securities. A decline in income received by the Portfolio from its investments is likely to have a negative effect on the yield and total return of the Portfolio Shares.

Portfolio’s investment return on such transactions will depend on the counterparty’s willingness and ability to perform its obligations under a repurchase agreement. If the Portfolio’s counterparty should default on its obligations and the Portfolio is delayed or prevented from recovering the collateral, or if the value of the collateral is insufficient, the Portfolio may realize a loss.

Restricted Securities Risk . The Portfolio may hold securities that have not been registered for sale to the public under the U.S. federal securities laws pursuant to an exemption from registration. These securities may be less liquid than securities registered for sale to the general public. The liquidity of a restricted security may be affected by a number of factors, including, among others: (i) the creditworthiness of the issuer; (ii) the frequency of trades and quotes for the security; (iii) the number of dealers willing to purchase or sell the security and the number of other potential purchasers; (iv) dealer undertakings to make a market in the security; (v) the nature of any legal restrictions governing trading in the security; and (vi) the nature of the security and the nature of marketplace trades. There can be no assurance that a liquid trading market will exist at any time for any particular restricted security. Also, restricted securities may be difficult to value because market quotations may not be readily available, and the securities may have significant volatility.

Section 4(a)(2) Commercial Paper and Rule 144A Securities Risk . The Portfolio may invest in commercial paper issued in reliance on the private placement exemption from registration afforded by Section 4(a)(2) of the Securities Act of 1933, as amended (the “1933 Act”). This commercial paper is commonly called “Section 4(a)(2) paper.” The Portfolio may also invest in securities that may be offered and sold only to “qualified institutional buyers” under Rule 144A of the 1933 Act (“Rule 144A securities”).

Significant Exposure to U.S. Government Agencies or Instrumentalities Risk . To the extent the Portfolio focuses its investments in securities issued or guaranteed by U.S. Government agencies or instrumentalities, any market movements, regulatory changes or changes in political or economic conditions that affect the U.S. Government agencies or instrumentalities in which the Portfolio invests may have a significant impact on the Portfolio’s performance. Events that would adversely affect the market prices of securities issued or guaranteed by one government agency or instrumentality may adversely affect the market price of securities issued or guaranteed by other government agencies or instrumentalities.

Stable Share Price Risk Fund . If the market value of one or more of the Portfolio’s investments changes substantially, the Portfolio may not be able to maintain a stable share price of $1.00. This risk typically is higher during periods of rapidly changing interest rates or when issuer credit quality generally is falling, and is made worse when the Portfolio experiences significant redemption requests.

Variable and Floating Rate Securities Risk . Variable or floating rate securities are debt securities with variable or floating interest rates payments. Variable or floating rate securities bear rates of interest that are adjusted periodically according to formulae intended generally to reflect market rates of interest and allow the Portfolio to participate (determined in accordance with the terms of the securities) in increases in interest rates through upward adjustments of the coupon rates on the securities. However, during periods of increasing interest rates, changes in the coupon rates may lag behind the changes in market rates or may have limits on the maximum increases in coupon rates. Alternatively, during periods of declining interest rates, the coupon rates on such securities will typically readjust downward resulting in a lower yield. In addition, investment in derivative variable rate securities, such as inverse floaters, whose rates vary inversely with market rates of interest, or range floaters or capped floaters, whose rates are subject to periodic or lifetime caps, or in securities that pay a rate of interest determined by applying a multiple to the variable rate involves special risks as compared to investment in a fixed-rate security and may involve leverage.

Zero-Coupon Bond Risk . Zero-coupon bonds are debt obligations that are generally issued at a discount and payable in full at maturity, and that do not provide for current payments of interest prior to maturity. Zero-coupon bonds usually trade at a deep discount from their face or par values and are subject to greater market value fluctuations from changing interest rates than debt obligations of comparable maturities that make current distributions of interest. When interest rates rise, the values of zero-coupon bonds fall more rapidly than securities paying interest on a current basis, because the Portfolio is unable to reinvest interest payments at the higher rates.

ADDITIONAL INFORMATION ABOUT NON-PRINCIPAL INVESTMENT STRATEGIES AND RISKS

The investments described below reflect the Portfolio’s current practices. In addition to the principal risks described above, other risks are described in some of the descriptions of the investments below:

Conflicts of Interest Risk. An investment in the Portfolio will be subject to a number of actual or potential conflicts of interest. For example, the Adviser or its affiliates may provide services to the Portfolio, such as securities lending agency services, custodial, administrative, bookkeeping, and accounting services, transfer agency and shareholder servicing, securities brokerage services, and other services for which the Portfolio would compensate the Adviser and/or such affiliates. The Portfolio may invest in other pooled investment vehicles sponsored, managed, or otherwise affiliated with the Adviser. There is no assurance that the rates at which the Portfolio pays fees or expenses to the Adviser or its affiliates, or the terms on which it enters into transactions with the Adviser or its affiliates will be the most favorable available in the market generally or as favorable as the rates the Adviser makes available to other clients. Because of its financial interest, the Adviser will have an incentive to enter into transactions or arrangements on behalf of the Portfolio with itself or its affiliates in circumstances where it might not have done so in the absence of that interest, provided that the Adviser will comply with applicable regulatory requirements.

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Portfolio. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for the Portfolio and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by the Portfolio. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Portfolio) or otherwise using such information for the benefit of its clients or itself.

The foregoing does not purport to be a comprehensive list or complete explanation of all potential conflicts of interests which may affect the Portfolio. The Portfolio may encounter circumstances, or enter into transactions, in which conflicts of interest that are not listed or discussed above may arise.

affect the Portfolio’s ability to calculate its NAV, cause the release of private shareholder information or confidential Portfolio information, impede trading, cause reputational damage, and subject the Portfolio to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Portfolio assets and transactions, shareholder ownership of Portfolio Shares, and other data integral to the functioning of the Portfolio inaccessible or inaccurate or incomplete. The Portfolio may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. The Portfolio and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. The Portfolio relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Portfolio from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Portfolio. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which the Portfolio invests, which could result in material adverse consequences for such issuers, and may cause the Portfolio’s investment in such securities to lose value.

Portfolio Turnover Risk . The Portfolio may engage in frequent trading of its portfolio securities. Portfolio turnover generally involves a number of direct and indirect costs and expenses to the Portfolio, including, for example, brokerage commissions, dealer mark-ups and bid/asked spreads, and transaction costs on the sale of securities and reinvestment in other securities. The costs related to increased portfolio turnover have the effect of reducing the Portfolio’s investment return, and the sale of securities by the Portfolio may result in the realization of taxable capital gains, including short-term capital gains, which are taxed to individuals as ordinary income.

Temporary Defensive Positions . In response to actual or perceived adverse market, economic, political, or other conditions, the Portfolio may (but will not necessarily), without notice, depart from its principal investment strategies by temporarily investing for defensive purposes. Temporary defensive positions may include, but are not limited to, cash, cash equivalents, U.S. government securities, repurchase agreements collateralized by such securities, money market funds, and high-quality debt investments. If the Portfolio invests for defensive purposes, it may not achieve its investment objective. In addition, the defensive strategy may not work as intended.

PORTFOLIO HOLDINGS DISCLOSURE

The Portfolio’s portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

MANAGEMENT AND ORGANIZATION

The Portfolio is a separate, diversified series of the State Street Institutional Investment Trust (the “Trust”), which is an open-end management investment company organized as a business trust under the laws of The Commonwealth of Massachusetts.

Investment Adviser

SSGA FM serves as the investment adviser to the Portfolio and, subject to the oversight of the Board, is responsible for the investment management of the Portfolio. The Adviser provides an investment management program for the Portfolio and manages the investment of the Portfolio’s assets. The Adviser is a wholly-owned subsidiary of State Street Global Advisors, Inc., which itself is a wholly-owned subsidiary of State Street Corporation. The Adviser is registered with the U.S. Securities and Exchange Commission (“SEC”) under the Investment Advisers Act of 1940, as amended. The Adviser and certain other affiliates of State Street Corporation make up SSGA. SSGA is one of the world’s largest institutional money managers and the investment management arm of State Street Corporation. As of December 31, 2018, the Adviser managed approximately $452.10 billion in assets and SSGA managed approximately $2.51 trillion in assets. The Adviser’s principal business address is One Iron Street, Boston, Massachusetts 02210.

The Portfolio’s shares are offered exclusively to investors (including without limitation, registered investment companies, private investment pools, bank collective funds, and investment separate accounts) that pay fees to SSGA FM or its affiliates. The fees paid by those investment vehicles to SSGA FM (or its affiliates) vary depending on a number of factors, including by way of example, the services provided, the risks borne by SSGA FM (or its affiliates), fee rates paid by competitive investment vehicles, and in some cases direct negotiation with investors in the Portfolio. The Portfolio pays no investment advisory fees to SSGA FM.

A summary of the factors considered by the Board of Trustees in connection with the initial approval of the investment advisory agreement for the Portfolio will be available in the Portfolio’s annual report or semi-annual report, as applicable, after the Portfolio commences operations.

Other Fund Services

The Adviser manages the Portfolio using a team of investment professionals. The team approach is used to create an environment that encourages the flow of investment ideas. The portfolio managers within the team work together in a cohesive manner to develop and enhance techniques that drive the investment process for the respective investment strategy. This approach requires portfolio managers to share a variety of responsibilities including investment strategy and analysis while retaining responsibility for the implementation of the strategy within any particular portfolio. The approach also enables the team to draw upon the resources of other groups within SSGA. The portfolio management team is overseen by the SSGA Investment Committee.

The Administrator, Sub-Administrator, Custodian, Transfer Agent and Dividend Disbursing Agent

The Adviser serves as administrator of the Portfolio. State Street, a subsidiary of State Street Corporation, serves as sub-administrator, custodian, transfer agent and dividend disbursing agent (the “Transfer Agent”) for the Portfolio. The Portfolio pays an annual fee that is accrued daily and payable monthly for the administration, sub-administration, custody and transfer agency services SSGA FM and State Street provide.

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Portfolio’s distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

Additional Information

The Trustees of the Trust oversee generally the operations of the Portfolio and the Trust. The Trust enters into contractual arrangements with various parties, including among others the Portfolio’s investment adviser, custodian, transfer agent, and accountants, who provide services to the Portfolio. Shareholders are not parties to any such contractual arrangements or intended beneficiaries of those contractual arrangements, and those contractual arrangements are not intended to create in any shareholder any right to enforce them directly against the service providers or to seek any remedy under them directly against the service providers.

This Prospectus provides information concerning the Trust and the Portfolio that you should consider in determining whether to purchase shares of the Portfolio. Neither this Prospectus, nor the related SAI, is intended, or should be read, to be or to give rise to an agreement or contract between the Trust or the Portfolio and any investor, or to give rise to any rights in any shareholder or other person other than any rights under federal or state law that may not be waived.

SHAREHOLDER INFORMATION

Determination of Net Asset Value

The Portfolio determines its NAV per share at 5:00 pm Eastern Time (“ET”) on each day on which the New York Stock Exchange (“NYSE”), the Federal Reserve banks and State Street are open for business (a “Business Day”). In unusual circumstances, such as an emergency or an unscheduled close or halt of trading on the NYSE, the time at which share prices are determined may be changed. The Portfolio seeks to maintain a $1.00 per share NAV and, accordingly, uses the amortized cost valuation method, in compliance with the risk limiting conditions of Rule 2a-7 under the Investment Company Act of 1940 (the “1940 Act”), to value its portfolio instruments. The amortized cost valuation method initially prices an instrument at its cost and thereafter assumes a constant amortization to maturity of any discount or premium, regardless of the impact of fluctuating interest rates on the market value of the instrument.

The NAV of each class of the Portfolio’s shares is calculated by dividing the value of the assets of the Portfolio attributable to that class less the liabilities of the Portfolio attributable to that class by the number of shares in the class outstanding. As noted in this Prospectus, the Portfolio may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when the Portfolio does not price its shares. Consequently, the NAV of the Portfolio’s shares may change on days when shareholders are not able to purchase or redeem the Portfolio’s shares. Purchase and redemption orders for Portfolio Shares are processed, respectively, at the NAV next determined after the Portfolio accepts a purchase order or receives a redemption request in good form. The Portfolio values each security or other investment pursuant to guidelines adopted by the Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Portfolio’s Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii) a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by the Portfolio occurs after the close of a related exchange but before the determination of the Portfolio’s NAV. Attempts to determine the fair value of securities or other investments introduce an element of subjectivity to the pricing of securities or other investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the price the Portfolio would have received had it sold the investment. To the extent that the Portfolio invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the fund. The prospectuses of these funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

Purchasing Shares

Generally, shares of the Portfolio may be purchased only by or on behalf of other registered investment companies or private clients for which the Adviser or an affiliate serves as investment adviser (or in a similar capacity). The price for Portfolio Shares is the NAV per share. Orders received in good form (a purchase order is in good form if it meets the requirements implemented from time to time by the Portfolio or its Transfer Agent, and for new accounts includes submission of a completed and signed application and all documentation necessary to open an account) will be priced at the NAV next calculated after the order is accepted by the Portfolio.

There is no minimal initial investment in the Portfolio and there is no minimum subsequent investment. (If you purchase shares by check, your order will not be in good form until the Portfolio’s transfer agent receives federal funds for the check.) The Portfolio reserve the right to cease accepting investments at any time or to reject any purchase order.

In accordance with certain federal regulations, the Trust is required to obtain, verify and record information that identifies each entity that applies to open an account. For this reason, when you open (or change ownership of) an account, the Trust will request certain information, including your name, residential/business address, date of birth (for individuals) and taxpayer identification number or other government identification number and other information that will allow us to identify you which will be used to verify your identity. The Trust may also request to review other identification documents such as driver license, passport or documents showing the existence of the business entity. If you do not provide sufficient information to verify your identity, the Trust will not open an account for you. As required by law, the Trust may employ various procedures, such as comparing your information to fraud databases or requesting additional information and documentation from you, to ensure that the information supplied by you is correct. The Trust reserves the right to reject any purchase order for any reason, including failure to provide the Trust with information necessary to confirm your identity as required by law.

If you are purchasing through a Financial Intermediary, please contact your intermediary as their requirements may differ.

Redeeming Shares

An investor may redeem all or any portion of its investment at the NAV next determined after it submits a redemption request, in proper form, to the applicable Portfolio. Redemption orders are processed at the NAV next determined after a Portfolio receives a redemption order in good form. If a Portfolio receives a redemption order prior to its Valuation Time on a business day, the Portfolio typically expects to pay out redemption proceeds on that day, but no later than the next business day if redemption proceeds are sent by wire or ACH. If redemption proceeds are sent by check, the Portfolio typically expects to pay out redemption proceeds on the next business day. No dividends will accrue on shares the day redemption proceeds are sent, including when redemption proceeds are wired the same day as the redemption order is received. Payment for redeemed shares is sent no later than the next business day following acceptance of the redemption order (unless redemption proceeds are sent by check). The Portfolio reserves the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Portfolio.

If your account is held through an Intermediary, please contact them for additional assistance and advice on how to redeem your shares.

The right of any investor to receive payment with respect to any redemption may be suspended or the payment of the redemption proceeds postponed during any period in which the NYSE is closed (other than weekends or holidays) or trading on the NYSE is restricted or, to the extent otherwise permitted by the 1940 Act, if an emergency exists as a result of which disposal by the Portfolio of securities owned by it is not reasonably practicable or it is not reasonably practicable for the Portfolio fairly to determine the value of its net assets. In addition, the SEC may by order permit suspension of redemptions for the protection of shareholders of the Portfolio.

Under normal circumstances, the Portfolio expects to meet redemption requests by using cash or cash equivalents in its portfolio and/or selling portfolio assets to generate cash. The Portfolio also may pay redemption proceeds using cash obtained through borrowing arrangements that may be available from time to time.

The Portfolio may pay all or a portion of your redemption proceeds by giving you securities (for example, if the Portfolio reasonably believes that a cash redemption may have a substantial impact on the Portfolio and its remaining shareholders). You may pay transaction costs to dispose of the securities, and you may receive less for them than the price at which they were valued for purposes of the redemption. In addition, you will be subject to the market risks associated with such securities until such time as you choose to dispose of the security.

During periods of deteriorating or stressed market conditions or during extraordinary or emergency circumstances, the Portfolio may be more likely to pay redemption proceeds with cash obtained through short-term borrowing arrangements (if available) or by giving you securities.

A request for a partial redemption by an investor whose account balance is below the minimum amount or a request for partial redemption by an investor that would bring the account below the minimum amount may be treated as a request for a complete redemption of the account. These minimums may be different for investments made through certain financial intermediaries as determined by their policies and may be waived in the Adviser’s discretion. The Portfolio reserves the right to modify minimum account requirements at any time with or without prior notice. The Portfolio also reserves the right to involuntarily redeem an investor’s account if the investor’s account balance falls below the applicable minimum amount due to transaction activity.

About Mail Transactions

If you choose to purchase or redeem shares by sending instructions by regular mail, they will not be deemed received in good order until they are released by the post office and redelivered to the Transfer Agent’s physical location at 1 Heritage Drive, North Quincy, MA 02171. There will be a time lag, which may be one or more days, between regular mail receipt at the post office box and redelivery to such physical location and the Portfolio’s net asset value may change over those days. You might consider using express rather than regular mail if you believe the time of receipt of your transaction request to be sensitive.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a State Street Fund (as defined below) identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Portfolio (if you hold shares directly with the Portfolio) or to your financial intermediary (if you do not hold shares directly with the Portfolio).

Excessive Trading

Because the Portfolio is a money market fund, the Portfolio’s Board of Trustees has not adopted policies and procedures with respect to frequent purchases and redemptions of Portfolio shares by Portfolio shareholders. Nonetheless, the Portfolio may take any reasonable action that they deem necessary or appropriate to prevent excessive trading in Fund shares without providing prior notification to the account holder. Such action may include rejecting any purchase, in whole or part, including, without limitation, by a person whose trading activity in Portfolio shares may be deemed harmful to the Fund. While the Funds attempt to discourage such excessive trading, there can be no guarantee that they will be able to identify investors who are engaging in excessive trading or limit their trading practices. Additionally, frequent trades of small amounts may not be detected. The Funds recognize that they may not always be able to detect or prevent excessive trading or other activity that may disadvantage the Funds or their shareholders.

DIVIDENDS, DISTRIBUTIONS AND TAX CONSIDERATIONS

The Portfolio intends to declare dividends on shares from net investment income daily and pay them as of the last business day of each month. Distributions from capital gains, if any, will be made annually in December. Income dividends and capital gains distributions will be paid in additional shares on the reinvestment date unless you have elected to receive them in cash. No interest will accrue on the amounts represented by uncashed distribution checks. If you have elected to receive distributions by check, and the postal or other delivery service is unable to deliver the checks because of an incorrect mailing address, or if a distribution check remains uncashed for six months, the uncashed distribution and all future distributions will be reinvested at the then-current NAV of the Portfolio.

The following discussion is a summary of some important U.S. federal income tax considerations generally applicable to an investment in the Portfolio. Your investment in the Portfolio may have other tax implications. Please consult your tax advisor about federal, state, local, foreign or other tax laws applicable to you. Investors, including non-U.S. investors, may wish to consult the SAI tax section for additional disclosure.

The Portfolio intends to elect to be treated as a regulated investment company and intends each year to qualify and to be eligible to be treated as such. A regulated investment company generally is not subject to tax at the corporate level on income and gains that are timely distributed to shareholders. In order to qualify and be eligible for treatment as a regulated investment company, the Portfolio must, among other things, satisfy diversification, 90% gross income and distribution requirements. The Portfolio’s failure to qualify as a regulated investment company would result in corporate level taxation, and consequently, a reduction in income available for distribution to shareholders.

For U.S. federal income tax purposes, distributions of investment income generally are taxable to you as ordinary income. Taxes on distributions of capital gains generally are determined by how long the Portfolio owned (or is deemed to have owned) the investments that generated them, rather than how long you have owned your Portfolio Shares. Distributions of net capital gains (that is, the excess of net long-term capital gains over net short-term capital losses) from the sale of investments that the Portfolio owned (or is deemed to have owned) for more than one year that are properly reported by the Portfolio as capital gain dividends generally will be treated as long-term capital gain includible in your net capital gain and taxed to individuals at reduced rates. Distributions of gains from investments that the Portfolio owned (or is deemed to have owned) for one year or less generally will be taxable to you as ordinary income when distributed to you by the Portfolio. Distributions of investment income properly reported by the Portfolio as derived from “qualified dividend income” are taxed to individuals at the rates applicable to net capital gain, provided holding period and other requirements are met by the shareholder and the Portfolio. Distributions are taxable to you even if they are paid from income or gains earned by the Portfolio before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares.

When the NAV of Portfolio Shares varies from a shareholder’s tax basis in such shares, including in the case of a money market fund when the NAV of such Portfolio Shares varies from $1.0000 per share, the shareholder generally will realize a gain or loss upon the redemption or other taxable disposition of such Portfolio Shares. Any such gain generally would be taxable to you as either short-term or long-term capital gain, depending upon how long you held the Portfolio Shares. The IRS permits a simplified method of accounting for gains and losses realized upon the disposition of shares of a regulated investment company that is a money market fund. If you elect to adopt this simplified method of accounting, rather than compute gain or loss on every taxable disposition of

Portfolio Shares, you will determine your gain or loss based on the change in the aggregate value of your fund shares during a computation period (such as your taxable year), reduced by your net investment (purchase minus sales) in those shares during that period. Under this simplified method, any resulting net capital gain or loss would be treated as short-term capital gain or loss. Shareholders should see the SAI for further information.

An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by the Portfolio and net gains recognized on the redemption of shares of the Portfolio.

The Portfolio’s income from or on proceeds of its investments in non-U.S. assets may be subject to non-U.S. withholding and other taxes. This will decrease the Portfolio’s return on securities subject to such taxes. Tax treaties between certain countries and the U.S. may reduce or eliminate such taxes. Although such taxes will reduce the Portfolio’s taxable income, shareholders generally will not be entitled separately to claim a credit or deduction with respect to foreign taxes incurred by the Portfolio.

Certain of the Portfolio’s investment practices, including derivative transactions and investments in debt obligations issued or purchased at a discount, will be subject to special and complex U.S. federal income tax provisions. These special rules may affect the timing, character, and/or amount of the Portfolio’s distributions, and may require the Portfolio to sell its investments at a time when it is not advantageous to do so.

If you are not a U.S. person, dividends paid by the Portfolio that the Portfolio properly reports as capital gain dividends, short-term capital gain dividends, or interest-related dividends, each as further defined in the SAI, are not subject to withholding of U.S. federal income tax, provided that certain other requirements are met. The Portfolio is permitted, but is not required, to report any part of its dividends as are eligible for such treatment. The Portfolio’s dividends other than those the Portfolio so reports as capital gain dividends, short-term capital gain dividends, or interest-related dividends generally will be subject to U.S. withholding tax at a 30% rate (or lower applicable treaty rate). See the Portfolio’s SAI for further information.

The U.S. Treasury and IRS generally require the Portfolio to obtain information sufficient to identify the status of each shareholder under sections 1471-1474 of the Internal Revenue Code of 1986, as amended, and the U.S. Treasury and IRS guidance issued thereunder (collectively, the “Foreign Account Tax Compliance Act” or “FATCA”) or under an applicable intergovernmental agreement between the United States and a foreign government. Please see the SAI for more information on FATCA reporting requirements.

Cost Basis Reporting . Department of the Treasury regulations mandate cost basis reporting to shareholders and the IRS for redemptions of Portfolio shares. If you acquire and hold shares directly through the Portfolio and not through a Financial Intermediary, State Street will use a default average cost basis methodology for tracking and reporting your cost basis, unless you request, in writing, another cost basis reporting methodology.

FINANCIAL HIGHLIGHTS

The Portfolio had not commenced operations prior to the date of this Prospectus and therefore does not have financial information.

Contacting the State Street Funds


Online:	www.ssga.com/cash	24 hours a day, 7 days a week
Phone:	(800) 997-7327	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:


Regular mail		Registered, Express, Certified Mail
State Street Corporation Attention: Transfer Agent Box 5493 Mail Code: OHD0100 North Quincy, MA 02171		State Street Corporation Attention: Transfer Agent Box 5493 Mail Code: OHD0100 North Quincy, MA 02171

The Portfolio does not consider the U.S. Postal Service or other independent delivery services to be its agents. Therefore, deposits in the mail or with such services, or receipt at the Portfolio’s post office box, of purchase orders or redemption requests, do not constitute receipt by the Portfolio or Transfer Agent.

For more information about the Portfolio:

The Portfolio’s SAI includes additional information about the Portfolio and is incorporated by reference into this document. Additional information about the Portfolio’s investments is available or will be available, in the Portfolio’s most recent annual and semi-annual reports to shareholders. The Portfolio’s SAI is available, without charge, upon request. The Portfolio’s annual and semi-annual reports are available, or will be available, without charge, upon request. Shareholders in the Portfolio may make inquiries to the Portfolio to receive such information by calling (877) 521-4083 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. The Portfolio’s Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, or will be available, free of charge, on the Portfolio’s website at www.ssga.com/cash.

Reports and other information about the Portfolio are available free of charge on the EDGAR Database on the SEC’s Internet site at http://www.sec.gov. Copies of this information also may be obtained, after paying a duplicating fee, by electronic request at the following E-mail address: publicinfo@sec.gov.

SSGA Funds Management, Inc.

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210


		The State Street Institutional Investment Trust’s Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Ultra Short Term Bond Fund

Institutional Class (SSTUX) Investment Class (SSUTX)

Beginning on January 1, 2021, as permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of the Fund's annual and semi- annual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Fund (or from your financial intermediary, such as a broker-dealer or bank). Instead, the reports will be made available on the Fund's website (www.ssga.com/cash), and you will be notified by mail each time a report is posted, and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Fund electronically by calling (866) 392-0869.

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with a Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling (866) 392-0869. Your election to receive reports in paper will apply to all funds held in your account, if you invest through your financial intermediary or all funds held with the fund complex if you invest directly with a Fund.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

The Fund may offer multiple classes of shares. This Prospectus covers only the Institutional Class and Investment Class Shares of the State Street Ultra Short Term Bond Fund.

TABLE OF CONTENTS

Fund Summary	1
State Street Ultra Short Term Bond Fund	1
Additional Information About Investment Objective, Principal Strategies and Risks	7
Additional Information About Non-Principal Investment Strategies and Risks	13
Portfolio Holdings Disclosure	14
Management and Organization	15
Shareholder Information	17
Dividends, Distributions and Tax Considerations	23
Financial Intermediary Arrangements	24
Financial Highlights	26

Table of Contents

State Street Ultra Short Term Bond Fund

Investment Objective

The State Street Ultra Short Term Bond Fund (the “Fund”) will seek to provide current income and total return.

Fees and Expenses of the Fund

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Ultra Short Term Bond Fund (“Fund Shares”). The expenses shown in the table and the Example reflect the expenses of the Fund and the Fund's proportionate share of the expenses of the State Street Ultra Short Term Bond Portfolio (the “Ultra Short Term Bond Portfolio” or sometimes referred to in context as the “Portfolio”).

Shareholder Fees (fees paid directly from your investment)

	Institutional	Investment
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Institutional	Investment
Management Fee	0.25%	0.25%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%	0.10%
Other Expenses ¹	1.00%	1.22%
Total Annual Fund Operating Expenses	1.25%	1.57%
Less Fee Waivers and/or Expense Reimbursements ²	(0.87)%	(0.87)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.38%	0.70%

¹	Other expenses are based on estimates for the current fiscal year.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.30% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

	1 year	3 years
Institutional	$39	$310
Investment	$72	$410

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Principal Investment Strategies

The State Street Ultra Short Term Bond Fund seeks to achieve its investment objective by investing in a diversified portfolio of U.S. dollar denominated, investment grade fixed income securities. Under normal circumstances, the average effective duration of the Fund is expected to be one year or less. Effective duration is a measure of the expected sensitivity of market price of an investment to changes in interest rates, taking into account the anticipated effects of structural complexities (for example, some bonds can be prepaid by the issuer). Generally, the longer a portfolio's duration, the more sensitive its value will be to changes in interest rates.

The Fund's investments include, among other things, fixed and floating rate securities of varying maturities, such as corporate obligations (including commercial paper of U.S. and foreign entities, master notes, and medium term notes); U.S. Government securities (including U.S. Treasury bills, notes and bonds and other securities issued or guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities); mortgage-backed and other asset backed securities; money market instruments (including U.S. and foreign bank time deposits, certificates of deposit, and banker acceptances) and securities of other investment companies including investment companies advised by the Adviser.

The Adviser buys and sells securities for the Fund based on its analysis of credit quality and the Fund's overall duration. The Adviser follows a disciplined investment process, basing its investment decisions on the relative attractiveness of different instruments. In the Adviser's opinion the attractiveness of an instrument may vary depending on a variety of factors, including for example the general level of interest rates, imbalances of supply and demand in the market, and the credit quality of the obligors. Under normal circumstances the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in bonds. The Fund will provide shareholders with at least sixty (60) days' notice prior to any change in this 80% investment policy. “Bonds” include debt securities and fixed income and income-producing instruments of any kind issued by governmental or private-sector entities. Most bonds consist of a security or instrument having one or more of the following characteristics: a fixed-income security, a security issued at a discount to its face value, a security that pays interest, whether fixed, floating or variable, or a security with a stated principal amount that requires repayment of some or all of that principal amount to the holder of the security. The Adviser interprets the term bond broadly as an instrument or security evidencing what is commonly referred to as an IOU rather than evidencing the corporate ownership of equity unless that equity represents an indirect or derivative interest in one or more debt securities.

Investment grade securities are (i) rated BBB-/Baa3 or higher or in the top three short term rating categories by at least one nationally recognized statistical rating organization (an “NRSRO”); or (ii) if not rated, are of comparable quality, as determined by the Adviser. If a security is downgraded and is no longer investment grade, the Fund may continue to hold the security if the Adviser determines that to be in the best interest of the Fund.

The Fund currently intends to invest nearly all of its assets in the State Street Ultra Short Term Bond Portfolio, another open-end investment company managed by the Adviser, with an investment objective and policies substantially identical to those of the Fund.

Principal Risks

In addition, the Fund is subject to the following risks:

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risk of low income due to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of the Fund's fixed income securities to decrease, an adverse impact on the liquidity of the Fund's fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Fund may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

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Non-U.S. Securities Risk: Non-U.S. securities (including depositary receipts) are subject to political, regulatory, and economic risks not present in domestic investments. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, legal and financial report standards comparable to those in the United States. Further, such entities and/or their securities may be subject to risks associated with currency controls; expropriation; changes in tax policy; greater market volatility; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. Securities traded on foreign markets may be less liquid (harder to sell) than securities traded domestically. Foreign governments may impose restrictions on the repatriation of capital to the U.S. In addition, to the extent investments are made in a limited number of countries, events in those countries will have a more significant impact on the Fund. Investments in depositary receipts may be less liquid and more volatile than the underlying shares in their primary trading market.

Performance

Performance information for the Fund has been omitted because the Fund had not commenced investment operations as of the date of this Prospectus. Once the Fund has completed a full calendar year of operations, a bar chart and table will be included that will provide some indication of the risks of investing in the Fund by showing the variability of the Fund's returns based on net assets. The Fund will make updated performance information, including its current net asset value, available at the Fund's website: www.ssga.com/cash.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

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The professionals primarily responsible for the day-to-day management of the Portfolio and the Fund are Todd Bean, Sean Lussier and Thomas Connelley. Mr. Bean and Mr. Lussier have each served as a portfolio manager of the Fund and Portfolio since organization in 2015. Mr. Connelley has served as portfolio manager of the Fund and Portfolio since 2019.

Todd Bean, CFA, is a Vice President of SSGA and the Adviser and Head of U.S. Traditional Cash Strategies in the Global Fixed Income, Cash and Currency Team. He joined the Adviser in 2002.

Sean Lussier is a Vice President of SSGA and the Adviser and a Senior Portfolio Manager in the Global Fixed Income, Cash and Currency Team. He joined the Adviser in 2004.

Thomas Connelley, CFA, is a Vice President of the Adviser and a Senior Portfolio Manager in the Global Fixed Income, Cash and Currency Team. He joined the Adviser in 2003.

Purchase and Sale of Fund Shares

Purchase Minimums

Institutional Class
To establish an account	$25,000,000
To add to an existing account	No minimum
Investment Class
To establish an account	$25,000,000
To add to an existing account	No minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone:

By Intermediary:

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Tax Information

The Fund's distributions are expected to be taxed as ordinary income and/or capital gains, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or individual retirement account. Any withdrawals made from such tax-advantaged arrangement may be taxable to you.

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Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objective, Principal Strategies and Risks

Investment Objective

The investment objective of the Fund, as stated in the Fund's Fund Summary, may be changed without shareholder approval.

State Street Ultra Short Term Bond Fund

Principal Investment Strategies

Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure.

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The credit rating assigned to any particular investment does not necessarily reflect the issuer's current financial condition and does not reflect an assessment of an investment's volatility or liquidity. Securities rated in the lowest category of investment-grade are considered to have speculative characteristics. If a security held by the Fund loses its rating or its rating is downgraded, the Fund may nonetheless continue to hold the security in the discretion of the Adviser. In the case of asset-backed or mortgage-related securities, changes in the actual or perceived ability of the obligors on the underlying assets or mortgages to make payments of interest and/or principal may affect the values of those securities.

Debt Securities Risk . The values of debt securities may increase or decrease as a result of the following: market fluctuations, increases in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments or illiquidity in debt securities markets; the risk of low rates of return due to reinvestment of securities during periods of falling interest rates or repayment by issuers with higher coupon or interest rates; and/or the risk of low income due to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of the Fund's fixed income securities to decrease, an adverse impact on the liquidity of the Fund's fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Fund may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

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and general economic cycles. Adverse developments in banking and other financial industries may cause the Fund to underperform relative to other funds that invest more broadly across different industries or have a smaller exposure to financial institutions. Changes in governmental regulation and oversight of financial institutions may have an adverse effect on the financial condition or the earnings or operations of a financial institution and on the types and amounts of businesses in which a financial institution may engage. An investor may be delayed or prevented from exercising certain remedies against a financial institution. The amount of the Fund's assets that may be invested in any financial institution, or financial institutions generally, may be limited by applicable law.

Large Shareholder Risk . To the extent a large proportion of the shares of the Portfolio are highly concentrated or held by a small number of shareholders (or a single shareholder), including funds or accounts over which the Adviser has investment discretion, the Portfolio is subject to the risk that these shareholders will purchase or redeem Portfolio shares in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of the Portfolio to conduct its investment program. For example, they could require the Portfolio to sell portfolio securities or purchase portfolio securities unexpectedly and incur substantial transaction costs and/or accelerate the realization of taxable income and/or gains to shareholders, or the Portfolio may be required to sell its more liquid portfolio investments to meet a large redemption, in which case the Portfolio's remaining assets may be less liquid, more volatile, and more difficult to price. A Portfolio may hold a relatively large proportion of its assets in cash in anticipation of large redemptions, diluting its investment returns.

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In compliance with the U.S. Securities and Exchange Commission's (“SEC”) new liquidity risk management rule applicable to open-end mutual funds, the Fund recently established a liquidity risk management program. The rule's impact on the Fund, and on the open-end fund industry in general, is not yet fully known, but the rule could affect the Fund's performance and its ability to achieve its investment objectives. While the liquidity risk management program attempts to assess and manage liquidity risk, there is no guarantee it will be effective in its operations and may not reduce the liquidity risk inherent in a Fund's investments.

Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject the Fund to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and the Fund's investment program in particular can be uncertain. In recent periods, governmental and non-governmental issuers have defaulted on, or have been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including, without limitation, in Europe or Asia. Defaults or restructurings by governments or others of their debts could have substantial adverse effects on economies, financial markets, and asset valuations around the world. Further Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, or investor perception that these efforts are not succeeding, could negatively affect financial markets generally as well as the values and liquidity of certain securities.

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assets in a master fund sponsored or managed by the Adviser or its affiliates in lieu of investments by the Fund directly in portfolio securities, or may have an incentive to invest in such master fund over a master fund sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by the Fund in a master fund sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a master fund sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which the Fund does so. The Fund will bear its pro rata portion of the expenses incurred by the master fund.

Mortgage-Related and Other Asset-Backed Securities Risk . Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed income investments. The liquidity of mortgage-related and asset-backed securities may change over time. Mortgage-related securities represent a participation in, or are secured by, mortgage loans. Other asset-backed securities are typically structured like mortgage-related securities, but instead of mortgage loans or interests in mortgage loans, the underlying assets may include, for example, items such as motor vehicle installment sales or installment loan contracts, leases on various types of real and personal property, and receivables from credit card agreements. During periods of falling interest rates, mortgage-related and other asset-backed securities, which typically provide the issuer with the right to prepay the security prior to maturity, may be prepaid, which may result in the Fund having to reinvest the proceeds in other investments at lower interest rates. During periods of rising interest rates, the average life of mortgage-related and other asset-backed securities may extend because of slower-than expected principal payments. This may lock in a below market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. As a result, mortgage-related and other asset-backed securities may have less potential for capital appreciation during periods of declining interest rates than other debt securities of comparable maturities, although they may have a similar risk of decline in market values during periods of rising interest rates. Prepayment rates are difficult to predict and the potential impact of prepayments on the value of a mortgage-related or other asset-backed security depends on the terms of the instrument and can result in significant volatility. The price of a mortgage-related or other asset-backed security also depends on the credit quality and adequacy of the underlying assets or collateral. Mortgage-related or other asset-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) will generally entail greater credit risk than obligations guaranteed by the U.S. Government. Defaults on the underlying assets, if any, may impair the value of a mortgage-related or other asset-backed security. For some asset-backed securities in which the Fund invests, such as those backed by credit card receivables, the underlying cash flows may not be supported by a security interest in a related asset. Moreover, the values of mortgage-related and other asset-backed securities may be substantially dependent on the servicing of the underlying asset pools, and are therefore subject to risks associated with the negligence or malfeasance by their servicers and to the credit risk of their servicers. In certain situations, the mishandling of related documentation may also affect the rights of securities holders in and to the underlying collateral. There may be legal and practical limitations on the enforceability of any security interest granted with respect to underlying assets, or the value of the underlying assets, if any, may be insufficient if the issuer defaults.

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U.S. investments, meaning that political events (civil unrest, national elections, changes in political conditions and foreign relations, imposition of exchange controls and repatriation restrictions), social and economic events (labor strikes, rising inflation) and natural disasters occurring in a country where the Fund invests could cause the Fund's investments in that country to experience gains or losses.

Restricted Securities Risk . The Fund may hold securities that have not been registered for sale to the public under the U.S. federal securities laws pursuant to an exemption from registration. These securities may be less liquid than securities registered for sale to the general public. The liquidity of a restricted security may be affected by a number of factors, including, among others: (i) the creditworthiness of the issuer; (ii) the frequency of trades and quotes for the security; (iii) the number of dealers willing to purchase or sell the security and the number of other potential purchasers; (iv) dealer undertakings to make a market in the security; (v) the nature of any legal restrictions governing trading in the security; and (vi) the nature of the security and the nature of marketplace trades. There can be no assurance that a liquid trading market will exist at any time for any particular restricted security. Also, restricted securities may be difficult to value because market quotations may not be readily available, and the securities may have significant volatility.

Section 4(a)(2) Commercial Paper and Rule 144A Securities Risk (principal risk for the Cash Reserves Fund) . The Fund may invest in commercial paper issued in reliance on the private placement exemption from registration afforded by Section 4(a)(2) of the Securities Act of 1933, as amended (the “1933 Act”). This commercial paper is commonly called “Section 4(a)(2) paper.” The Fund may also invest in securities that may be offered and sold only to “qualified institutional buyers” under Rule 144A of the 1933 Act (“Rule 144A securities”).

Section 4(a)(2) paper is sold to institutional investors who must agree to purchase the paper for investment and not with a view to public distribution. Any resale by the purchaser must be in a transaction exempt from the registration requirements of the 1933 Act. Section 4(a)(2) paper normally is resold to other institutional investors like the Fund through or with the assistance of the issuer or investment dealers that make a market in Section 4(a)(2) paper. As a result it suffers from liquidity risk, the risk that the securities may be difficult to value because of the absence of an active market and the risk that it may be sold only after considerable expense and delay, if at all. Rule 144A securities generally must be sold only to other qualified institutional buyers.

Section 4(a)(2) paper and Rule 144A securities will not be considered illiquid for purposes of the Fund's limitation on illiquid securities if the Adviser (pursuant to guidelines adopted by the Board) determines that a liquid trading market exists for the securities in question. There can be no assurance that a liquid trading market will exist at any time for any particular Section 4(a)(2) paper or Rule 144A securities.

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cial support to its agencies and instrumentalities if not required to do so. In addition, certain governmental entities have been subject to regulatory scrutiny regarding their accounting policies and practices and other concerns that may result in legislation, changes in regulatory oversight and/or other consequences that could adversely affect the credit quality, availability, or investment character of securities issued by these entities. The value and liquidity of U.S. government securities may be affected adversely by changes in the ratings of those securities. Securities issued by the U.S. Treasury historically have been considered to present minimal credit risk. The downgrade in the long-term U.S. credit rating by at least one major rating agency has introduced greater uncertainty about the ability of the U.S. to repay its obligations. A further credit rating downgrade or a U.S. credit default could decrease the value and increase the volatility of the Fund's investments.

Variable and Floating Rate Securities Risk . Variable or floating rate securities are debt securities with variable or floating interest rates payments. Variable or floating rate securities bear rates of interest that are adjusted periodically according to formulae intended generally to reflect market rates of interest and allow the Fund to participate (determined in accordance with the terms of the securities) in increases in interest rates through upward adjustments of the coupon rates on the securities. However, during periods of increasing interest rates, changes in the coupon rates may lag behind the changes in market rates or may have limits on the maximum increases in coupon rates. Alternatively, during periods of declining interest rates, the coupon rates on such securities will typically readjust downward resulting in a lower yield. In addition, investment in derivative variable rate securities, such as inverse floaters, whose rates vary inversely with market rates of interest, or range floaters or capped floaters, whose rates are subject to periodic or lifetime caps, or in securities that pay a rate of interest determined by applying a multiple to the variable rate involves special risks as compared to investment in a fixed-rate security and may involve leverage.

Zero-Coupon Bond Risk . Zero-coupon bonds are debt obligations that are generally issued at a discount and payable in full at maturity, and that do not provide for current payments of interest prior to maturity. Zero-coupon bonds usually trade at a deep discount from their face or par values and are subject to greater market value fluctuations from changing interest rates than debt obligations of comparable maturities that make current distributions of interest. When interest rates rise, the values of zero-coupon bonds fall more rapidly than securities paying interest on a current basis, because the Fund is unable to reinvest interest payments at the higher rates.

Additional Information About Non-Principal Investment Strategies and Risks

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Fund. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for the Fund and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by the Fund. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Fund) or otherwise using such information for the benefit of its clients or itself.

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Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Fund) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, the Fund, the Portfolio, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect the Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect the Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject the Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of the Fund inaccessible or inaccurate or incomplete. The Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. The Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. The Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Fund. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which the Fund invests, which could result in material adverse consequences for such issuers, and may cause the Fund's investment in such securities to lose value.

Portfolio Turnover Risk . The Fund may engage in frequent trading of its portfolio securities. Fund turnover generally involves a number of direct and indirect costs and expenses to the Fund, including, for example, brokerage commissions, dealer mark-ups and bid/asked spreads, and transaction costs on the sale of securities and reinvestment in other securities. The costs related to increased portfolio turnover have the effect of reducing the Fund's investment return, and the sale of securities by the Fund may result in the realization of taxable capital gains, including short-term capital gains, which are taxed to individuals as ordinary income.

Temporary Defensive Positions . In response to actual or perceived adverse market, economic, political, or other conditions, the Fund may (but will not necessarily), without notice, depart from its principal investment strategies by temporarily investing for defensive purposes. While investing defensively, the Fund may maintain a substantial portion of its assets in cash, on which the Fund may earn little if any income. If the Fund invests for defensive purposes, it may not achieve its investment objective. In addition, the defensive strategy may not work as intended.

Portfolio Holdings Disclosure

The Fund's portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

Investment Adviser

The Fund has entered into an investment advisory agreement with the Adviser pursuant to which the Adviser will manage the Fund's assets. For such management services, the Ultra Short Term Bond Fund will compensate the Adviser at the annual rate of 0.25% of the Fund's average net daily assets. The Adviser places all orders for purchases and sales of the portfolio's investments. The Portfolio pays no investment advisory fees to SSGA FM.

Total Annual Fund Operating Expense Waivers . SSGA FM, as the investment adviser to the Fund, is contractually obligated, though April 30, 2020, to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund for expenses to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, extraordinary expenses, acquired fund fees, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed an average daily net assets on an annual basis of 0.30% for the Ultra Short Term Bond Fund. This waiver and/or reimbursement arrangement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

A summary of the factors considered by the Board of Trustees in connection with the initial approval of the investment advisory agreement for the Fund will be available in the Fund's annual report or semi-annual report, as applicable, after the Fund commences operations.

Other Fund Services

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The professionals primarily responsible for the day-to-day management of the Fund are Todd Bean, Sean Lussier and Thomas Connelley.

Todd Bean, CFA, is a Vice President of SSGA and the Adviser and Head of U.S. Traditional Cash Strategies in the Global Fixed Income, Cash and Currency Team. He began his career at State Street Corporation in 1999, joining the firm as an analyst in the firm's custody and accounting area. Following a period on the cash operations staff, Mr. Bean joined the Cash Management Group as a portfolio manager in 2004. He received Bachelor's degrees in Economics and Government from St. Lawrence University and a Master of Science in Finance from Northeastern University. He has earned the Chartered Financial Analyst (CFA) designation and is a member of CFA Society Boston, Inc.

Sean Lussier is a Vice President of SSGA and the Adviser and a Senior Portfolio Manager in the North America Cash Management Group within the Global Fixed Income, Cash and Currency Team. He has experience in managing registered taxable and tax-exempt money market funds, as well as U.S. and Canada domiciled separately managed cash and securities lending mandates. He has also been a member of the Global Fixed Income Beta Solutions Group and was responsible for the transition and management of several Canadian passive fixed income strategies. Prior to joining SSGA, Mr. Lussier worked as an account manager at State Street Bank and Trust where his primary responsibilities were the custody and accounting operations of the SSGA money market and securities lending collateral accounts. He holds a Bachelor of Science from Massachusetts College of Liberal Arts.

Thomas Connelley, CFA, is a Vice President of SSGA and the Adviser and a Senior Portfolio Manager within the Global Fixed Income, Cash and Currency Team. He is responsible for total rate of return short duration strategies such as ultra-short term fixed income and 1-3 year multi-sector funds that help clients bridge the gap between traditional cash portfolios and longer dated fixed income solutions. Prior to his current role, Mr. Connelley was a senior portfolio manager for the U.S. Cash Management Group where he managed a variety of cash portfolios and securities lending cash collateral pools. Prior to joining SSGA in 2003, Mr. Connelley was a portfolio manager at Standish Mellon Asset Management, where he was responsible for a variety of short- and intermediate-term fixed income mandates. Mr. Connelley received a Bachelor of Science in Management, with a concentration in Finance, from Bryant University. He has earned the Chartered Financial Analyst (CFA) designation and is a member of CFA Society Boston, Inc.

Additional information about the portfolio managers' compensation, other accounts managed by the portfolio managers, and the portfolio managers' ownership of the Fund is available in the SAI.

The Administrator, Sub-Administrator and Custodian

The Adviser serves as administrator of the Fund. The amount of the fee paid to the Adviser for administrative services may vary by share class. The Fund currently pays the Adviser an administrative fee at the annual rate of 0.05% with respect to each of its share classes. State Street Bank and Trust Company (“State Street”), a subsidiary of State Street Corporation, serves as the sub-administrator for the Fund for a fee that is paid by the Adviser. State Street also serves as custodian of the Fund for a separate fee that is paid by the Fund. SSGA FM serves as administrator of the Portfolio and State Street serves as sub-administrator and custodian of the Portfolio.

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Fund's transfer agent and dividend disbursing agent (the “Transfer Agent”).

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Fund's distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

Additional Information

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Shareholder Information

Determination of Net Asset Value

The Fund determines its NAV per share once each business day as of the close of regular trading on the NYSE. Pricing does not occur on NYSE holidays. The NAV per share of the Fund is based on the market value of the investments held in the Fund.

The NAV of each class of the Fund's shares is calculated by dividing the value of the assets of the Fund attributable to that class less the liabilities of the Fund attributable to that class by the number of shares in the class outstanding. As noted in this Prospectus, the Fund may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when the Fund does not price its shares. Consequently, the NAV of the Fund's shares may change on days when shareholders are not able to purchase or redeem the Fund's shares. Purchase and redemption orders for Fund Shares are processed, respectively, at the NAV next determined after the Fund accepts a purchase order or receives a redemption request in good form. The Fund values each security or other investment pursuant to guidelines adopted by the Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Portfolio's Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii) a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by the Fund occurs after the close of a related exchange but before the determination of the Fund's NAV. Attempts to determine the fair value of securities or other investments introduce an element of subjectivity to the pricing of securities or other investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the price the Fund would have received had it sold the investment. To the extent that the Fund invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the fund. The prospectuses of these funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

A business day is one on which the NYSE is open for regular trading. The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. The Fund also may establish special hours on those days to determine the Fund's NAV. In the event that the Fund invokes the right to accept orders to purchase or redeem shares on any day that is not a business day or adopt special hours of operation, the Fund will post advance notice of these events at www.ssga.com/cash. [SSGA please confirm the paragraphs above]

Investing in State Street Institutional Investment Trust Shares

Purchasing Shares

The Fund offers two classes of shares through this Prospectus: Institutional Class and Investment Class Shares. Fund Shares are available to you subject to the eligibility requirements set forth below. All classes of the Fund share the same investment objective and investments, but the different share classes have different expense structures and eligibility requirements. You should choose the class with the expense structure that best meets your needs for which you are eligible. In choosing a share class, you should consider the amount you plan to invest. Your investment professional can help you choose the share class that best suits your investment needs.

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The minimum purchase amount may be waived for specific investors or types of investors, including, without limitation, retirement plans, employees of State Street Corporation and its affiliates and their family. In the case of shareholders purchasing shares through a Financial Intermediary, the minimum purchase amount may be applied at the level of the Financial Intermediary.

	Institutional Class	Investment Class
Minimum Initial Investment	$25,000,000	$25,000,000
Maximum Investment	None.	None.
Initial Sales Charge	No. Entire purchase price is invested in shares of the Fund.	No. Entire purchase price is invested in shares of the Fund.
Deferred (CDSC) Sales Charge	No.	No.
Distribution and/or Service (12b-1) Fees	No.	0.10% annual fee.
Redemption Fees	No.	No.

Investors pay no sales load to invest in the shares of the Fund. The price for Fund Shares is the NAV per share.

Purchase requests received by the Fund in good order (a purchase request is in good order if it meets the requirements implemented from time to time by the Transfer Agent or authorized agent of the Fund, and for new accounts includes submission of a completed and signed application and all documentation necessary to open an account) on a Business Day will, if payment is received by FedWire, be priced at the NAV next determined after the order is accepted by the Fund. Payments received by FedWire prior to the last Valuation Times will earn dividend accrual for that purchase.

All purchases that are made by check will be priced with the last valuation price and begin earning dividends the following business day after the day the order is accepted. (If you purchase shares by check, your order will not be in good form until the Transfer Agent receives federal funds for the check.) All purchase orders are subject to acceptance by the Fund. The Fund intends to be as fully invested as is practicable; therefore, investments must be made in Federal Funds ( i.e ., monies credited to the account of the Fund's custodian bank by a Federal Reserve Bank).

The minimum initial investment in Institutional Class and Investment Class shares of the Fund is $25 million, although the Adviser may waive the minimum in its discretion. Holdings of related customer accounts may be aggregated for purposes of determining the minimum investment amount. “Related customer accounts” may include but are not limited to accounts held by the same investment or retirement plan, financial institution, broker, dealer or intermediary. The Fund and the Adviser reserve the right to increase or decrease the minimum amount required to open or maintain an account. There is no minimum subsequent investment, except in relation to maintaining certain minimum account balances (See “Redeeming Shares” below).

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How to Purchase Shares

By Mail:

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone/Fax:

For your initial investment, send the original, signed Institutional Account Application Form to the address above.

Wire Instructions:

Instruct your bank to transfer money by Federal Funds wire to:
State Street Bank and Trust Company
1 Iron Street
Boston, MA 02110

ABA# 011000028
DDA# 9904-631-0
State Street Institutional Investment Trust
Fund Name
Class Name
Account Number
Account Registration

You will not be able to redeem shares from the account until the original Application has been received. The Fund and the Fund ' s agents are not responsible for transfer errors by the sending or receiving bank and will not be liable for any loss incurred due to a wire transfer not having been received.

Redeeming Shares

An investor may redeem all or any portion of its investment at the NAV next determined after it submits a redemption request, in good form, to the Fund. The Fund typically expects to pay the proceeds of the redemption either in Federal Funds or in securities at the discretion of the Adviser, on the next Fund business day after the redemption. The Fund reserves the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Fund.

If your account is held through an Intermediary, please contact them for additional assistance and advice on how to redeem your shares.

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A request for a partial redemption by an investor whose account balance is below the minimum amount or a request for partial redemption by an investor that would bring the account below the minimum amount may be treated as a request for a complete redemption of the account. These minimums may be different for investments made through certain financial intermediaries as determined by their policies and may be waived in the Adviser's discretion. The Fund reserves the right to modify minimum account requirements at any time with or without prior notice. The Fund also reserves the right to involuntarily redeem an investor's account if the investor's account balance falls below the applicable minimum amount due to transaction activity.

How to Redeem Shares


By Mail:	Send a signed letter to: State Street Institutional Investment Trust Funds P.O. Box 219737 Kansas City, MO 64121-9737
	The letter should include information necessary to process your request as described below. The Fund may require a medallion guarantee in certain circumstances. See “Medallion Guarantees” below.
By Overnight:	State Street Institutional Investment Trust Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407
By Telephone:	Please call (866) 392-0869 between the hours of 7:00 a.m. and 5:00 p.m. ET.
The Fund will need the following information to process your redemption request:
➣ name(s) of account owners; ➣ account number(s); ➣ the name of the Fund; ➣ your daytime telephone number; and ➣ the dollar amount or number of shares being redeemed.

On any day that the Fund calculates its NAVs earlier than normal, the Fund reserves the right to adjust the times noted above for purchasing and redeeming shares.

By Intermediary

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Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Medallion Guarantees . Certain redemption requests must include a medallion guarantee for each registered account owner if any of the following apply:

•	Your account address has changed within the last 10 Business Days.

•	Redemption proceeds are being transferred to an account with a different registration.
•	A wire is being sent to a financial institution other than the one that has been established on your Fund account.
•	Other unusual situations as determined by the Transfer Agent.

The Fund may terminate the receipt of redemption orders by telephone at any time, in which case you may redeem shares by other means.

If you choose to purchase or redeem shares by sending instructions by regular mail, they will not be deemed received in good order until they are released by the post office and redelivered to the Transfer Agent's physical location at 430 W 7th Street Suite 219737 in Kansas City, MO 64105-1407. There will be a time lag, which may be one or more days, between regular mail receipt at the post office box and redelivery to such physical location in Kansas City, and the Fund's NAV may change over those days. You might consider using express rather than regular mail if you believe the time of receipt of your transaction request to be sensitive.

Excessive Trading

Frequent, short-term trading, abusive trading practices and market timing (together, “Excessive Trading”), often in response to short-term fluctuations in the market, are not knowingly permitted by the State Street Funds. The State Street Funds do not accommodate frequent purchases and redemptions of fund shares by fund shareholders. Excessive Trading into and out of a State Street Fund may harm the fund's performance by disrupting portfolio management strategies and by increasing expenses. These expenses are borne by all fund shareholders, including long-term investors who do not generate such costs.

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As a means to protect each State Street Fund and its shareholders from Excessive Trading:

•	The State Street Funds' transfer agent compiles, monitors and reports account-level information on omnibus and underlying shareholder/participant activity. Depending on the account type, monitoring will be performed on a daily, monthly, quarterly and/or annual basis;
•	The State Street Funds' distributor has obtained information from each Financial Intermediary holding shares in an omnibus account with the State Street Funds regarding whether the Financial Intermediary has adopted and maintains procedures that are reasonably designed to protect the Funds against harmful short-term trading; and
•	With respect to State Street Funds that invest in securities that trade on foreign markets, pursuant to the State Street Funds' fair valuation procedures, pricing adjustments may be made based on information received from a third-party, multi-factor fair valuation pricing service.

The State Street Funds' distributor has detailed procedures that document the transparency oversight and monitoring processes performed by the State Street Funds' transfer agent.

Exchanging Shares

An exchange occurs when you use the proceeds from the redemption of shares of the Fund in the State Street Institutional Investment Trust to simultaneously purchase shares of a different Fund in the State Street Institutional Investment Trust. Exchanges may be made within the same class ( i.e . Institutional Class shares for Institutional Class shares). The account holding the original shares must be registered in the same name as the account holding the new shares received in the exchange. You may make exchange requests by telephone, or by mail. See Purchasing Shares and Redeeming Shares. Exchanges are subject to the terms applicable to the purchases of the fund into which you are exchanging. Exchange privileges may not be available for mutual funds advised by SSGA FM (the “State Street Funds”) and may be suspended or rejected. Effective October 12, 2016, exchanges from/to the State Street Institutional Liquid Reserves Fund is not permitted.

Delivery of Documents to Accounts Sharing an Address

To reduce expenses, we may mail only one copy of the Fund's Prospectus and the annual and semi-annual report to those addresses shared by two or more accounts. If you wish to receive individual copies of these documents, please call us at (877) 521-4083, or contact your financial institution. We will begin sending you individual copies thirty (30) days after receiving your request.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a State Street Fund identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Fund (if you hold shares directly with the Fund) or to your financial intermediary (if you do not hold shares directly with the Fund).

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Dividends, Distributions and Tax Considerations

The Fund invests substantially all of its assets in the Portfolio, which is expected to be treated as a regulated investment company for federal income tax purposes, and so substantially all of the Fund's income will result from distributions or deemed distributions from the Portfolio. Therefore, as applicable, and except as otherwise stated, references in this section to the assets owned or income earned by the Fund will include such assets and income of the Portfolio. The Fund has elected to be treated as a regulated investment company and intends each year to qualify and to be eligible to be treated as such. A regulated investment company generally is not subject to tax at the corporate level on income and gains that are timely distributed to shareholders. In order to qualify and be eligible for treatment as a regulated investment company, the Fund must, among other things, satisfy diversification, 90% gross income and distribution requirements. The Fund's failure to qualify as a regulated investment company would result in corporate level taxation, and consequently, a reduction in income available for distribution to shareholders.

For U.S. federal income tax purposes, distributions of investment income generally are taxable to you as ordinary income. Taxes on distributions of capital gains generally are determined by how long the Portfolio owned (or is deemed to have owned) the investments that generated them, rather than how long you have owned your Fund Shares. Distributions of net capital gains (that is, the excess of net long-term capital gains over net short-term capital losses) from the sale of investments that the Fund owned (or is deemed to have owned) for more than one year that are properly reported by the Fund as capital gain dividends generally will be treated as long-term capital gain includible in your net capital gain and taxed to individuals at reduced rates. Distributions of gains from investments that the Fund owned (or is deemed to have owned) for one year or less generally will be taxable to you as ordinary income when distributed to you by the Fund. Distributions are taxable to you even if they are paid from income or gains earned by the Fund before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares.

The Fund's income from or proceeds of investments in non-U.S. assets may be subject to non-U.S. withholding and other taxes. This will decrease the Fund's return on securities subject to such taxes. Tax treaties between certain countries and the U.S. may reduce or eliminate such taxes. Although such taxes will reduce the Fund's taxable income, shareholders generally will not be entitled separately to claim a credit or deduction with respect to foreign taxes incurred by the Fund.

When the NAV of Fund Shares varies from a shareholder's tax basis in such shares, including in the case of a money market fund when the NAV of such Fund Shares varies from $1.0000 per share, the shareholder generally will realize a gain or loss upon the redemption or other taxable disposition of such Fund Shares. Any such gain generally would be taxable to you as either short-term or long-term capital gain, depending upon how long you held the Fund Shares. The IRS permits a simplified method of accounting for gains and losses realized upon the disposition of shares of a regulated investment company that is a money market fund. If you elect to adopt this simplified method of accounting, rather than compute gain or loss on every taxable disposition of Fund Shares, you will determine your gain or loss based on the change in the aggregate value of your Fund Shares during a computation period (such as your taxable year), reduced by your net investment (purchase minus sales) in those shares during that period. Under this simplified method, any resulting net capital gain or loss would be treated as short-term capital gain or loss. Shareholders should see the SAI for further information.

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An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by the Fund, including any capital gain dividends, and net gains recognized on the redemption of shares of the Fund.

The Fund's investments in the Portfolio may cause the tax treatment of the Fund's gains, losses and distributions to differ at times from the tax treatment that would apply if the Fund invested directly in the types of securities held by the Portfolio. As a result, investors may receive taxable distributions earlier and recognize higher amounts of capital gain or ordinary income than they otherwise would.

Financial Intermediary Arrangements

Distribution Arrangements and Rule 12b-1 Fees

The Fund has adopted a distribution plan pursuant to Rule 12b-1 under the 1940 Act under which the Fund may compensate SSGA FD (or others) for services in connection with the distribution of the Fund's shares and for services provided to Fund shareholders (the “Plan”). The Plan calls for payments at an annual rate (based on average daily net assets) of 0.10% of the Fund's net assets attributable to its Investment Class shares. Because these fees are paid out of the assets of the Fund attributable to its shares on an ongoing basis, they will increase the cost of your investment and may cost you more over time than paying other types of sales charges. Long-term shareholders of the Fund may pay more in Rule 12b-1 fees than the economic equivalent of the maximum front-end sales charge permitted by the FINRA.

Because the Fund pays distribution and other fees for the sale of their shares and for services provided to shareholders out of the Fund's assets on an ongoing basis, over time those fees will increase the cost of your investment and may cost you more than paying other types of sales loads.

The Fund may pay distribution fees and other amounts described in this Prospectus at a time when shares of that Fund are unavailable for purchase.

Other Payments to Financial Intermediaries

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The Financial Intermediary is often compensated by SSGA FD or its affiliates for the services it performs and in such cases is typically paid continually over time, during the period when the Financial Intermediary's clients hold investments in the Fund. The amount of continuing compensation paid by SSGA FD or its affiliates to different Financial Intermediaries for distribution and/or shareholder services varies. Any compensation is typically a percentage of the value of the Financial Intermediary's clients' investments in the Fund or a per account fee. The variation in compensation may, but will not necessarily, reflect enhanced or additional services provided by the Financial Intermediary.

If you invest through a Financial Intermediary and meet the eligibility criteria for more than one share class, you should discuss with your Financial Intermediary which share class is appropriate for you. Your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend one share class over another, when you are eligible to invest in more than one share class. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by the Fund or its affiliates with respect to the different share classes offered by the Fund.

SSGA FD and its affiliates (including SSGA FM), at their own expense and out of their own assets, may also provide other compensation to Financial Intermediaries in connection with sales of the Fund's shares or the servicing of shareholders or shareholder accounts. Such compensation may include, but is not limited to, financial assistance to Financial Intermediaries in connection with conferences, sales, or training programs for their employees; seminars for the public; advertising or sales campaigns; or other Financial Intermediary-sponsored special events. In some instances, this compensation may be made available only to certain Financial Intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the Fund's shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as FINRA.

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Financial Highlights

The Fund had not commenced operations prior to the date of this Prospectus and therefore does not have financial information.

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Contacting the State Street Funds

Online:	www.ssga.com/cash	24 hours a day, 7 days a week
Phone:	(877) 521-4083	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Overnight/ Registered, Express, Certified Mail
State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737	State Street Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407

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For more information about the Fund:

The Fund's SAI includes additional information about the Fund and is incorporated by reference into this document. Additional information about the Fund's investments is available or will be available, in the Fund's most recent annual and semi-annual reports to shareholders. The Fund's SAI is available, without charge, upon request. The Fund's annual and semi-annual reports are available, or will be available, without charge, upon request. Shareholders in the Fund may make inquiries to the Fund to receive such information by calling (877) 521-4083 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. The Fund's Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, or will be available, free of charge, on the Fund's website at www.ssga.com/cash.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

SSITCASHSTATPRO

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Ultra Short Term Bond Portfolio (SSTEX)

Beginning on January 1, 2021, as permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of the Portfolio's annual and semi- annual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Portfolio (or from your financial intermediary, such as a broker-dealer or bank). Instead, the reports will be made available on the Portfolio's website (www.ssga.com/cash), and you will be notified by mail each time a report is posted, and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Portfolio electronically by calling (866) 392-0869.

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with the Portfolio, you can inform the Portfolio that you wish to continue receiving paper copies of your shareholder reports by calling (866) 392-0869. Your election to receive reports in paper will apply to all funds held in your account, if you invest through your financial intermediary or all funds held with the fund complex if you invest directly with the Portfolio.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

The Portfolio may offer multiple classes of shares. This Prospectus covers only the Institutional Class and Investment Class Shares of the Portfolio.

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Fund Summary	1
State Street Ultra Short Term Bond Portfolio	1
Additional Information About Investment Objective, Principal Strategies and Risks	6
Additional Information About Non-Principal Investment Strategies and Risks	12
Portfolio Holdings Disclosure	13
Management and Organization	14
Shareholder Information	15
Dividends, Distributions and Tax Considerations	18
Financial Highlights	20

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State Street Ultra Short Term Bond Portfolio

Investment Objective

The State Street Ultra Short Term Bond Portfolio (the “Portfolio”) will seek to provide current income and total return.

Fees and Expenses of the Portfolio

The table below describes the fees and expenses that you may pay if you buy and hold shares of the State Street Ultra Short Term Bond Portfolio (“Portfolio Shares”). The Portfolio's shares are offered exclusively to investors that pay fees to SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the Portfolio's investment adviser, or its affiliates; the Portfolio pays no management fee to SSGA FM, as shown in the table below.

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Portfolio Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	N/A
Distribution and/or Shareholder Service (12b-1) Fees	N/A
Other Expenses ¹	0.27%
Total Annual Fund Operating Expenses	0.27%

¹	Other expenses are based on estimates for the current fiscal year.

Example:

1 year		3 years
$28		$87

Principal Investment Strategies

The State Street Ultra Short Term Bond Portfolio seeks to achieve its investment objective by investing in a diversified portfolio of U.S. dollar denominated, investment grade fixed income securities. Under normal circumstances, the average effective duration of the Portfolio is expected to be one year or less. Effective duration is a measure of the expected sensitivity of market price of an investment to changes in interest rates, taking into account the anticipated effects of structural complexities (for example, some bonds can be prepaid by the issuer). Generally, the longer a portfolio's duration, the more sensitive its value will be to changes in interest rates.

The Portfolio's investments include, among other things, fixed and floating rate securities of varying maturities, such as corporate obligations (including commercial paper of U.S. and foreign entities, master notes, and medium term notes); U.S. Government securities (including U.S. Treasury bills, notes and bonds and other securities issued or guaranteed as to principal or interest by the U.S. government or its agencies or instrumentalities); mortgage-backed and other asset backed securities; money market instruments (including U.S. and foreign bank time deposits, certificates of deposit, and banker acceptances) and securities of other investment companies including investment companies advised by the Adviser.

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mal circumstances the Portfolio invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in bonds. The Portfolio will provide shareholders with at least sixty (60) days' notice prior to any change in this 80% investment policy. “Bonds” include debt securities and fixed income and income-producing instruments of any kind issued by governmental or private-sector entities. Most bonds consist of a security or instrument having one or more of the following characteristics: a fixed-income security, a security issued at a discount to its face value, a security that pays interest, whether fixed, floating or variable, or a security with a stated principal amount that requires repayment of some or all of that principal amount to the holder of the security. The Adviser interprets the term bond broadly as an instrument or security evidencing what is commonly referred to as an IOU rather than evidencing the corporate ownership of equity unless that equity represents an indirect or derivative interest in one or more debt securities.

Investment grade securities are (i) rated BBB-/Baa3 or higher or in the top three short term rating categories by at least one nationally recognized statistical rating organization (an “NRSRO”); or (ii) if not rated, are of comparable quality, as determined by the Adviser. If a security is downgraded and is no longer investment grade, the Portfolio may continue to hold the security if the Adviser determines that to be in the best interest of the Portfolio.

Principal Risks

You could lose money by investing in the Portfolio. An investment in the Portfolio is subject to investment risks, including possible loss of principal, is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency . The Portfolio may not achieve its investment objective. The Fund and the Portfolio are subject to the following principal risks. The Portfolio is not intended to be a complete investment program, but rather is intended for investment as part of a diversified investment portfolio. Investors should consult their own advisers as to the role of the Portfolio in their overall investment programs. The risks are described in alphabetical order and not in the order of importance or potential exposure.

In addition, the Portfolio is subject to the following risks:

Debt Securities Risk: The values of debt securities may increase or decrease as a result of the following: market fluctuations, increases in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments or illiquidity in debt securities markets; the risk of low rates of return due to reinvestment of securities during periods of falling interest rates or repayment by issuers with higher coupon or interest rates; and/or the risk of low income due to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of the Portfolio's fixed income securities to decrease, an adverse impact on the liquidity of the Portfolio's fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Portfolio may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

Financial Institutions Risk: Changes in the creditworthiness of financial institutions (such as banks and broker-dealers) may adversely affect the values of instruments of issuers in financial industries. Adverse developments in banking and other financial industries may cause the Portfolio to underperform relative to other funds that invest more broadly across different industries or have a smaller exposure to financial institutions. Changes in governmental regulation and oversight of financial institutions may have an adverse effect on the financial condition of a financial institution.

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Low Short-Term Interest Rates: During market conditions in which short-term interest rates are at low levels, the Fund's yield can be very low. During these conditions, it is possible that the Portfolio will generate an insufficient amount of income to pay its expenses, and that it will not be able to pay a daily dividend and may have a negative yield (i.e., it may lose money on an operating basis). It is possible that the Portfolio would, during these conditions, maintain a substantial portion of its assets in cash, on which it may earn little, if any, income.

Mortgage-Related and Other Asset-Backed Securities Risk: Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed-income investments. The liquidity of mortgage-related and asset-backed securities may change over time. During periods of falling interest rates, mortgage- and asset-backed securities may be called or prepaid, which may result in the Portfolio having to reinvest proceeds in other investments at a lower interest rate. During periods of rising interest rates, the average life of mortgage- and asset-backed securities may extend, which may lock in a below-market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. Enforcing rights against the underlying assets or collateral may be difficult, and the underlying assets or collateral may be insufficient if the issuer defaults.

Non-U.S. Securities Risk: Non-U.S. securities (including depositary receipts) are subject to political, regulatory, and economic risks not present in domestic investments. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, legal and financial report standards comparable to those in the United States. Further, such entities and/or their securities may be subject to risks associated with currency controls; expropriation; changes in tax policy; greater market volatility; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. Securities traded on foreign markets may be less liquid (harder to sell) than securities traded domestically. Foreign governments may impose restrictions on the repatriation of capital to the U.S. In addition, to the extent investments are made in a limited number of countries, events in those countries will have a more significant impact on the Portfolio. Investments in depositary receipts may be less liquid and more volatile than the underlying shares in their primary trading market.

Rapid Changes in Interest Rates Risk: Rapid changes in interest rates may cause significant requests to redeem Portfolio Shares, and possibly cause the Portfolio to sell portfolio securities at a loss to satisfy those requests.

Repurchase Agreement Risk: Repurchase agreements may be viewed as loans made by the Portfolio which are collateralized by the securities subject to repurchase. If the Portfolio's counterparty should default on its obligations and the Portfolio is delayed or prevented from recovering the collateral, or if the value of the collateral is insufficient, the Portfolio may realize a loss.

Restricted Securities Risk: The Portfolio may hold securities that have not been registered for sale to the public under the U.S. federal securities laws. There can be no assurance that a trading market will exist at any time for any particular restricted security. Limitations on the resale of these securities may have an adverse effect on their marketability, and may prevent the Portfolio from disposing of them promptly at reasonable prices. The Portfolio may have to bear the expense of registering the securi-

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ties for resale and the risk of substantial delays in effecting the registration. Also, restricted securities may be difficult to value because market quotations may not be readily available, and the securities may have significant volatility.

Portfolio Performance

Performance information for the Portfolio has been omitted because the Portfolio had not commenced investment operations as of the date of this Prospectus. Once the Portfolio has completed a full calendar year of operations, a bar chart and table will be included that will provide some indication of the risks of investing in the Portfolio by showing the variability of the Portfolio's returns based on net assets. The Portfolio will make updated performance information, including its current net asset value, available at the Portfolio's website: www.ssga.com/cash.

Investment Adviser

SSGA FM serves as the investment adviser to the Portfolio.

The professionals primarily responsible for the day-to-day management of the Portfolio are Todd Bean, Sean Lussier and Thomas Connelley. Mr. Bean and Mr. Lussier have each served as a portfolio manager of the Portfolio since organization in 2015. Mr. Connelley has served as portfolio manager of the Portfolio since 2019.

Todd Bean, CFA, is a Vice President of SSGA and the Adviser and Head of U.S. Traditional Cash Strategies in the Global Fixed Income, Cash and Currency Team. He joined the Adviser in 2002.

Sean Lussier is a Vice President of SSGA and the Adviser and a Senior Portfolio Manager in the Global Fixed Income, Cash and Currency Team. He joined the Adviser in 2004.

Thomas Connelley, CFA, is a Vice President of the Adviser and a Senior Portfolio Manager in the Global Fixed Income, Cash and Currency Team. He joined the Adviser in 2003.

Purchase and Sale of Portfolio Shares

By Mail:

State Street Corporation
Attention: Transfer Agent
Box 5493
Mail Code: OHD0100
North Quincy, MA 02171

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By Overnight:

State Street Corporation
Attention: Transfer Agent
1 Heritage Drive
North Quincy, MA 02171

By Intermediary:

Financial Intermediaries may contact State Street Dealer Services Group at 617-662-7300 or email them at broker-dealerservices@statestreet.com with questions.

Tax Information

The Portfolio's distributions are expected to be taxed as ordinary income and/or capital gains, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or individual retirement account. Any withdrawals made from such tax-advantaged arrangement may be taxable to you.

Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objective, Principal Strategies and Risks

Investment Objective

The investment objective of the Portfolio, as stated in the Portfolio's Fund Summary, may be changed without shareholder approval.

State Street Ultra Short Term Bond Portfolio

Principal Investment Strategies

The Adviser buys and sells securities for the Portfolio based on its analysis of credit quality and the Portfolio's overall duration. The Adviser follows a disciplined investment process, basing its investment decisions on the relative attractiveness of different instruments. In the Adviser's opinion the attractiveness of an instrument may vary depending on a variety of factors, including for example the general level of interest rates, imbalances of supply and demand in the market, and the credit quality of the obligors. Under normal circumstances the Portfolio invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in bonds. The Portfolio will provide shareholders with at least sixty (60) days' notice prior to any change in this 80% investment policy. “Bonds” include debt securities and fixed income and income-producing instruments of any kind issued by governmental or private-sector entities. Most bonds consist of a security or instrument having one or more of the following characteristics: a fixed-income security, a security issued at a discount to its face value, a security that pays interest, whether fixed, floating or variable, or a security with a stated principal amount that requires repayment of some or all of that principal amount to the holder of the security. The Adviser interprets the term bond broadly as an instrument or security evidencing what is commonly referred to as an IOU rather than evidencing the corporate ownership of equity unless that equity represents an indirect or derivative interest in one or more debt securities.

Investment grade securities are (i) rated BBB-/Baa3 or higher or in the top three short term rating categories by at least one nationally recognized statistical rating organization (an “NRSRO”); or (ii) if not rated, are of comparable quality, as determined by the Adviser. If a security is downgraded and is no longer investment grade, the Portfolio may continue to hold the security if the Adviser determines that to be in the best interest of the Portfolio.

Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure.

Call/Prepayment Risk . Call/prepayment risk is the risk that an issuer will exercise its right to pay principal on an obligation held by the Portfolio earlier than expected or required. This may occur, for example, when there is a decline in interest rates, and an issuer of bonds or preferred stock redeems the bonds or stock in order to replace them with obligations on which it is required to pay a lower interest or dividend rate. It may also occur when there is an unanticipated increase in the rate at which mortgages or other receivables underlying mortgage- or asset-backed securities held by the Portfolio are prepaid. In any such case, the Portfolio may be forced to invest the prepaid amounts in lower-yielding investments, resulting in a decline in the Portfolio's income.

Counterparty Risk . The Portfolio will be subject to credit risk with respect to the counterparties with which the Portfolio enters into derivatives contracts and other transactions such as repurchase agreements or reverse repurchase agreements. The Portfolio's ability to profit from these types of investments and transactions will depend on the willingness and ability of its counterparty to perform its obligations. If a counterparty fails to meet its contractual obligations, the Portfolio may be unable to terminate or realize any gain

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on the investment or transaction, resulting in a loss to the Portfolio. The Portfolio may experience significant delays in obtaining any recovery in an insolvency, bankruptcy, or other reorganization proceeding involving its counterparty (including recovery of any collateral posted by it) and may obtain only a limited recovery or may obtain no recovery in such circumstances. If the Portfolio holds collateral posted by its counterparty, it may be delayed or prevented from realizing on the collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty. Under applicable law or contractual provisions, including if the Portfolio enters into an investment or transaction with a financial institution and such financial institution (or an affiliate of the financial institution) experiences financial difficulties, then the Portfolio may in certain situations be prevented or delayed from exercising its rights to terminate the investment or transaction, or to realize on any collateral and may result in the suspension of payment and delivery obligations of the parties under such investment or transactions or in another institution being substituted for that financial institution without the consent of the Portfolio. Further, the Portfolio may be subject to “bail-in” risk under applicable law whereby, if required by the financial institution's authority, the financial institution's liabilities could be written down, eliminated or converted into equity or an alternative instrument of ownership. A bail-in of a financial institution may result in a reduction in value of some or all of its securities and, if the Portfolio holds such securities or has entered into a transaction with such a financial security when a bail-in occurs, the Portfolio may also be similarly impacted.

Credit Risk . Credit risk is the risk that an issuer, guarantor or liquidity provider of a fixed-income security held by the Portfolio may be unable or unwilling, or may be perceived (whether by market participants, ratings agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. It includes the risk that the security will be downgraded by a credit rating agency; generally, lower credit quality issuers present higher credit risks. An actual or perceived decline in creditworthiness of an issuer of a fixed-income security held by the Portfolio may result in a decrease in the value of the security. It is possible that the ability of an issuer to meet its obligations will decline substantially during the period when the Portfolio owns securities of the issuer or that the issuer will default on its obligations or that the obligations of the issuer will be limited or restructured.

The credit rating assigned to any particular investment does not necessarily reflect the issuer's current financial condition and does not reflect an assessment of an investment's volatility or liquidity. Securities rated in the lowest category of investment-grade are considered to have speculative characteristics. If a security held by the Portfolio loses its rating or its rating is downgraded, the Portfolio may nonetheless continue to hold the security in the discretion of the Adviser. In the case of asset-backed or mortgage-related securities, changes in the actual or perceived ability of the obligors on the underlying assets or mortgages to make payments of interest and/or principal may affect the values of those securities.

Debt Securities Risk . The values of debt securities may increase or decrease as a result of the following: market fluctuations, increases in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments or illiquidity in debt securities markets; the risk of low rates of return due to reinvestment of securities during periods of falling interest rates or repayment by issuers with higher coupon or interest rates; and/or the risk of low income due to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of the Portfolio's fixed income securities to decrease, an adverse impact on the liquidity of the Portfolio's fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Portfolio may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

Financial Institutions Risk . Some instruments are issued or guaranteed by financial institutions, such as banks and brokers, or are collateralized by securities issued or guaranteed by financial institutions. Changes in the creditworthiness of any of these institutions may adversely affect the values of instruments of issuers in financial industries. Financial institutions may be particularly sensitive to certain economic factors such as interest rate changes, adverse developments in the real estate market, fiscal and monetary policy and general economic cycles. Adverse developments in banking and other financial industries may cause the Portfolio to underperform relative to other funds that invest more broadly across different industries or have a smaller exposure to financial institutions. Changes in governmental regulation and oversight of financial institutions may have an adverse effect on the financial condition or

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the earnings or operations of a financial institution and on the types and amounts of businesses in which a financial institution may engage. An investor may be delayed or prevented from exercising certain remedies against a financial institution. The amount of the Portfolio's assets that may be invested in any financial institution, or financial institutions generally, may be limited by applicable law.

Income Risk. The Portfolio's income may decline due to falling interest rates or other factors. Issuers of securities held by the Portfolio may call or redeem the securities during periods of falling interest rates, and the Portfolio would likely be required to reinvest in securities paying lower interest rates. If an obligation held by the Portfolio is prepaid, the Portfolio may have to reinvest the prepayment in other obligations paying income at lower rates. A reduction in the income earned by the Portfolio may limit the Portfolio's ability to achieve its objective.

Interest Rate Risk . Interest rate risk is the risk that the securities held by the Portfolio will decline in value because of increases in market interest rates. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. Debt securities with longer durations tend to be more sensitive to changes in interest rates, usually making them more volatile than debt securities with shorter durations. For example, the value of a security with a duration of five years would be expected to decrease by 5% for every 1% increase in interest rates. Falling interest rates also create the potential for a decline in the Portfolio's income and yield. Interest-only and principal-only securities are especially sensitive to interest rate changes, which can affect not only their prices but can also change the income flows and repayment assumptions about those investments. Variable and floating rate securities also generally increase or decrease in value in response to changes in interest rates, although generally to a lesser degree than fixed-rate securities. A substantial increase in interest rates may also have an adverse impact on the liquidity of a security, especially those with longer durations. Changes in governmental policy, including changes in central bank monetary policy, could cause interest rates to rise rapidly, or cause investors to expect a rapid rise in interest rates. This could lead to heightened levels of interest rate, volatility and liquidity risks for the fixed income markets generally and could have a substantial and immediate effect on the values of the Portfolio's investments.

Large Shareholder Risk . To the extent a large proportion of the shares of the Portfolio are highly concentrated or held by a small number of shareholders (or a single shareholder), including funds or accounts over which the Adviser has investment discretion, the Portfolio is subject to the risk that these shareholders will purchase or redeem Portfolio shares in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of the Portfolio to conduct its investment program. For example, they could require the Portfolio to sell portfolio securities or purchase portfolio securities unexpectedly and incur substantial transaction costs and/or accelerate the realization of taxable income and/or gains to shareholders, or the Portfolio may be required to sell its more liquid portfolio investments to meet a large redemption, in which case the Portfolio's remaining assets may be less liquid, more volatile, and more difficult to price. The Portfolio may hold a relatively large proportion of its assets in cash in anticipation of large redemptions, diluting its investment returns.

Liquidity Risk . Liquidity risk is the risk that the Portfolio may not be able to dispose of securities readily at a favorable time or prices (or at all) or at prices approximating those at which the Portfolio currently values them. For example, certain investments may be subject to restrictions on resale, may trade in the over-the-counter market or in limited volume, or may not have an active trading market. Illiquid securities may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value. It may be difficult for the Portfolio to value illiquid securities accurately. The market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. Disposal of illiquid securities may entail registration expenses and other transaction costs that are higher than those for liquid securities. The Portfolio may seek to borrow money to meet its obligations (including among other things redemption obligations) if it is unable to dispose of illiquid investments, resulting in borrowing expenses and possible leveraging of the Portfolio. In some cases, due to unanticipated levels of illiquidity the Portfolio may choose to meet its redemption obligations wholly or in part by distributions of assets in-kind.

The term “illiquid securities” for this purpose means securities that the Portfolio reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the securities. If the Portfolio determines at any time that it owns illiquid securities in excess of 15% of its net assets, it will cease to undertake new commitments to acquire illiquid securities until its holdings are no longer in excess of 15% of its NAV, report the occurrence in compliance with Rule 30b1-10 under the 1940 Act and, depending on circumstances, may take additional steps to reduce its holdings of illiquid securities.

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In compliance with the SEC's new liquidity risk management rule applicable to open-end mutual funds, the Portfolio recently established a liquidity risk management program. The rule's impact on the Portfolio, and on the open-end fund industry in general, is not yet fully known, but the rule could affect the Portfolio's performance and its ability to achieve its investment objectives. While the liquidity risk management program attempts to assess and manage liquidity risk, there is no guarantee it will be effective in its operations and may not reduce the liquidity risk inherent in the Portfolio's investments.

Low Short-Term Interest Rate Risk . During market conditions in which short-term interest rates are at low levels the Portfolio's yield can be very low. During these conditions, it is possible that the Portfolio will generate an insufficient amount of income to pay its expenses, and that it will not be able to pay a daily dividend and may have a negative yield (i.e., it may lose money on an operating basis). It is possible that the Portfolio would, during these conditions, maintain a substantial portion of its assets in cash, on which it may earn little, if any, income.

Market Disruption and Geopolitical Risk. The Portfolio is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets. War, terrorism, and related geopolitical events have led, and in the future may lead, to increased short-term market volatility and may have adverse long-term effects on U.S. and world economies and markets generally. Likewise, natural and environmental disasters and systemic market dislocations may be highly disruptive to economies and markets. Those events as well as other changes in foreign and domestic economic and political conditions also could adversely affect individual issuers or related groups of issuers, securities markets, interest rates, credit ratings, inflation, investor sentiment, and other factors affecting the value of the Portfolio's investments. Given the increasing interdependence among global economies and markets, conditions in one country, market, or region might adversely affect markets, issuers, and/or foreign exchange rates in other countries, including the U.S. Any partial or complete dissolution of the Economic and Monetary Union of the European Union, or any increased uncertainty as to its status, could have significant adverse effects on currency and financial markets, and on the values of the Portfolio's investments. Securities and financial markets may be susceptible to market manipulation or other fraudulent trade practices, which could disrupt the orderly functioning of these markets or adversely affect the values of investments traded in these markets, including investments held by the Portfolio. To the extent the Portfolio has focused its investments in the market or index of a particular region, adverse geopolitical and other events could have a disproportionate impact on the Portfolio.

Market Risk . Market prices of investments held by the Portfolio will go up or down, sometimes rapidly or unpredictably. The Portfolio's investments are subject to changes in general economic conditions, general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors including, but not limited to, economic growth or recession, changes in interest rates, changes in actual or perceived creditworthiness of issuers and general market liquidity. Even if general economic conditions do not change, the value of an investment in the Portfolio could decline if the particular industries, sectors or companies in which the Portfolio invests do not perform well or are adversely affected by events. Further, legal, political, regulatory and tax changes also may cause fluctuations in markets and securities prices.

Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject the Portfolio to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and the Portfolio's investment program in particular can be uncertain. In recent periods, governmental and non-governmental issuers have defaulted on, or have been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including, without limitation, in Europe or Asia. Defaults or restructurings by governments or others of their debts could have substantial adverse effects on economies, financial markets, and asset valuations around the world. Further Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, or investor perception that these efforts are not succeeding, could negatively affect financial markets generally as well as the values and liquidity of certain securities.

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cally provide the issuer with the right to prepay the security prior to maturity, may be prepaid, which may result in the Portfolio having to reinvest the proceeds in other investments at lower interest rates. During periods of rising interest rates, the average life of mortgage-related and other asset-backed securities may extend because of slower-than expected principal payments. This may lock in a below market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. As a result, mortgage-related and other asset-backed securities may have less potential for capital appreciation during periods of declining interest rates than other debt securities of comparable maturities, although they may have a similar risk of decline in market values during periods of rising interest rates. Prepayment rates are difficult to predict and the potential impact of prepayments on the value of a mortgage-related or other asset-backed security depends on the terms of the instrument and can result in significant volatility. The price of a mortgage-related or other asset-backed security also depends on the credit quality and adequacy of the underlying assets or collateral. Mortgage-related or other asset-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) will generally entail greater credit risk than obligations guaranteed by the U.S. Government. Defaults on the underlying assets, if any, may impair the value of a mortgage-related or other asset-backed security. For some asset-backed securities in which the Portfolio invests, such as those backed by credit card receivables, the underlying cash flows may not be supported by a security interest in a related asset. Moreover, the values of mortgage-related and other asset-backed securities may be substantially dependent on the servicing of the underlying asset pools, and are therefore subject to risks associated with the negligence or malfeasance by their servicers and to the credit risk of their servicers. In certain situations, the mishandling of related documentation may also affect the rights of securities holders in and to the underlying collateral. There may be legal and practical limitations on the enforceability of any security interest granted with respect to underlying assets, or the value of the underlying assets, if any, may be insufficient if the issuer defaults.

Non-U.S. Securities Risk . Investments in securities of non-U.S. issuers (including depositary receipts) entail risks not typically associated with investing in securities of U.S. issuers. Similar risks may apply to securities traded on a U.S. securities exchange that are issued by entities with significant exposure to non-U.S. countries. In certain countries, legal remedies available to investors may be more limited than those available with regard to U.S. investments. Income and gains with respect to investments in certain countries may be subject to withholding and other taxes. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, and financial reporting standards, regulatory framework and practices comparable to those in the United States. The securities of some non-U.S. entities are less liquid and at times more volatile than securities of comparable U.S. entities, and could become subject to sanctions or embargoes that adversely affect the Portfolio's investment. Non-U.S. transaction costs, such as brokerage commissions and custody costs may be higher than in the U.S. In addition, there may be a possibility of nationalization or expropriation of assets, imposition of currency exchange controls, confiscatory taxation, and diplomatic developments that could adversely affect the values of the Portfolio's investments in certain non-U.S. countries. Investments in securities of non-U.S. issuers also are subject to foreign political and economic risk not associated with U.S. investments, meaning that political events (civil unrest, national elections, changes in political conditions and foreign relations, imposition of exchange controls and repatriation restrictions), social and economic events (labor strikes, rising inflation) and natural disasters occurring in a country where the Portfolio invests could cause the Portfolio's investments in that country to experience gains or losses.

Rapid Changes in Interest Rates . The values of most instruments held by the Portfolio are adversely affected by changes in interest rates generally, especially increases in interest rates. Rapid changes in interest rates may cause significant requests to redeem Portfolio Shares, and possibly cause the Portfolio to sell portfolio securities at a loss to satisfy those requests.

Reinvestment Risk. Income from the Portfolio may decline when the Portfolio invests the proceeds from investment income, sales of portfolio securities or matured, traded or called debt obligations. For instance, during periods of declining interest rates, an issuer of debt obligations may exercise an option to redeem securities prior to maturity, forcing the Portfolio to reinvest the proceeds in lower-yielding securities. A decline in income received by the Portfolio from its investments is likely to have a negative effect on the yield and total return of the Portfolio Shares.

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Repurchase Agreement Risk . A repurchase agreement is an agreement to buy a security from a seller at one price and a simultaneous agreement to sell it back to the original seller at an agreed-upon price, typically representing the purchase price plus interest. Repurchase agreements may be viewed as loans made by the Portfolio which are collateralized by the securities subject to repurchase. The Portfolio's investment return on such transactions will depend on the counterparty's willingness and ability to perform its obligations under a repurchase agreement. If the Portfolio's counterparty should default on its obligations and the Portfolio is delayed or prevented from recovering the collateral, or if the value of the collateral is insufficient, the Portfolio may realize a loss.

Restricted Securities Risk . The Portfolio may hold securities that have not been registered for sale to the public under the U.S. federal securities laws pursuant to an exemption from registration. These securities may be less liquid than securities registered for sale to the general public. The liquidity of a restricted security may be affected by a number of factors, including, among others: (i) the creditworthiness of the issuer; (ii) the frequency of trades and quotes for the security; (iii) the number of dealers willing to purchase or sell the security and the number of other potential purchasers; (iv) dealer undertakings to make a market in the security; (v) the nature of any legal restrictions governing trading in the security; and (vi) the nature of the security and the nature of marketplace trades. There can be no assurance that a liquid trading market will exist at any time for any particular restricted security. Also, restricted securities may be difficult to value because market quotations may not be readily available, and the securities may have significant volatility.

Section 4(a)(2) Commercial Paper and Rule 144A Securities Risk . The Portfolio may invest in commercial paper issued in reliance on the private placement exemption from registration afforded by Section 4(a)(2) of the Securities Act of 1933, as amended (the “1933 Act”). This commercial paper is commonly called “Section 4(a)(2) paper.” The Portfolio may also invest in securities that may be offered and sold only to “qualified institutional buyers” under Rule 144A of the 1933 Act (“Rule 144A securities”).

Section 4(a)(2) paper is sold to institutional investors who must agree to purchase the paper for investment and not with a view to public distribution. Any resale by the purchaser must be in a transaction exempt from the registration requirements of the 1933 Act. Section 4(a)(2) paper normally is resold to other institutional investors like the Portfolio through or with the assistance of the issuer or investment dealers that make a market in Section 4(a)(2) paper. As a result it suffers from liquidity risk, the risk that the securities may be difficult to value because of the absence of an active market and the risk that it may be sold only after considerable expense and delay, if at all. Rule 144A securities generally must be sold only to other qualified institutional buyers.

Section 4(a)(2) paper and Rule 144A securities will not be considered illiquid for purposes of the Portfolio's limitation on illiquid securities if the Adviser (pursuant to guidelines adopted by the Board) determines that a liquid trading market exists for the securities in question. There can be no assurance that a liquid trading market will exist at any time for any particular Section 4(a)(2) paper or Rule 144A securities.

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cally readjust downward resulting in a lower yield. In addition, investment in derivative variable rate securities, such as inverse floaters, whose rates vary inversely with market rates of interest, or range floaters or capped floaters, whose rates are subject to periodic or lifetime caps, or in securities that pay a rate of interest determined by applying a multiple to the variable rate involves special risks as compared to investment in a fixed-rate security and may involve leverage.

Zero-Coupon Bond Risk . Zero-coupon bonds are debt obligations that are generally issued at a discount and payable in full at maturity, and that do not provide for current payments of interest prior to maturity. Zero-coupon bonds usually trade at a deep discount from their face or par values and are subject to greater market value fluctuations from changing interest rates than debt obligations of comparable maturities that make current distributions of interest. When interest rates rise, the values of zero-coupon bonds fall more rapidly than securities paying interest on a current basis, because the Portfolio is unable to reinvest interest payments at the higher rates.

Additional Information About Non-Principal Investment Strategies and Risks

The investments described below reflect the Portfolio's current practices. In addition to the principal risks described above, other risks are described in some of the descriptions of the investments below:

Conflicts of Interest Risk. An investment in the Portfolio will be subject to a number of actual or potential conflicts of interest. For example, the Adviser or its affiliates may provide services to the Portfolio, such as securities lending agency services, custodial, administrative, bookkeeping, and accounting services, transfer agency and shareholder servicing, securities brokerage services, and other services for which the Portfolio would compensate the Adviser and/or such affiliates. The Portfolio may invest in other pooled investment vehicles sponsored, managed, or otherwise affiliated with the Adviser. There is no assurance that the rates at which the Portfolio pays fees or expenses to the Adviser or its affiliates, or the terms on which it enters into transactions with the Adviser or its affiliates will be the most favorable available in the market generally or as favorable as the rates the Adviser makes available to other clients. Because of its financial interest, the Adviser will have an incentive to enter into transactions or arrangements on behalf of the Portfolio with itself or its affiliates in circumstances where it might not have done so in the absence of that interest, provided that the Adviser will comply with applicable regulatory requirements.

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Portfolio. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for the Portfolio and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by the Portfolio. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Portfolio) or otherwise using such information for the benefit of its clients or itself.

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a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. The Portfolio relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Portfolio from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Portfolio. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which the Portfolio invests, which could result in material adverse consequences for such issuers, and may cause the Portfolio's investment in such securities to lose value.

Portfolio Turnover Risk . The Portfolio may engage in frequent trading of its portfolio securities. Portfolio turnover generally involves a number of direct and indirect costs and expenses to the Portfolio, including, for example, brokerage commissions, dealer mark-ups and bid/asked spreads, and transaction costs on the sale of securities and reinvestment in other securities. The costs related to increased portfolio turnover have the effect of reducing the Portfolio's investment return, and the sale of securities by the Portfolio may result in the realization of taxable capital gains, including short-term capital gains, which are taxed to individuals as ordinary income.

Temporary Defensive Positions . In response to actual or perceived adverse market, economic, political, or other conditions, a Portfolio may (but will not necessarily), without notice, depart from its principal investment strategies by temporarily investing for defensive purposes. While investing defensively, the Portfolio may maintain a substantial portion of its assets in cash, on which the Portfolio may earn little if any income. If a Portfolio invests for defensive purposes, it may not achieve its investment objective. In addition, the defensive strategy may not work as intended.

Portfolio Holdings Disclosure

The Portfolio's portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

Investment Adviser

SSGA FM serves as the investment adviser to the Portfolio and, subject to the oversight of the Board, is responsible for the investment management of the Portfolio. The Adviser provides an investment management program for the Portfolio and manages the investment of the Portfolio's assets. The Adviser is a wholly-owned subsidiary of State Street Global Advisors, Inc., which itself is a wholly-owned subsidiary of State Street Corporation. The Adviser is registered with the U.S. Securities and Exchange Commission (“SEC”) under the Investment Advisers Act of 1940, as amended. The Adviser and certain other affiliates of State Street Corporation make up SSGA. SSGA is one of the world's largest institutional money managers and the investment management arm of State Street Corporation. As of December 31, 2018, the Adviser managed approximately $452.10 billion in assets and SSGA managed approximately $2.51 trillion in assets. The Adviser's principal business address is One Iron Street, Boston, Massachusetts 02210.

The Portfolio's shares are offered exclusively to investors (including without limitation, registered investment companies, private investment pools, bank collective funds, and investment separate accounts) that pay fees to SSGA FM or its affiliates. The fees paid by those investment vehicles to SSGA FM (or its affiliates) vary depending on a number of factors, including by way of example, the services provided, the risks borne by SSGA FM (or its affiliates), fee rates paid by competitive investment vehicles, and in some cases direct negotiation with investors in the Portfolio. The Portfolio pays no investment advisory fees to SSGA FM.

A summary of the factors considered by the Board of Trustees in connection with the initial approval of the investment advisory agreement for the Portfolio will be available in the Portfolio's annual report or semi-annual report, as applicable, after the Portfolio commences operations.

Other Fund Services

The professionals primarily responsible for the day-to-day management of the Portfolio are Todd Bean, Sean Lussier and Thomas Connelley.

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was a portfolio manager at Standish Mellon Asset Management, where he was responsible for a variety of short- and intermediate-term fixed income mandates. Mr. Connelley received a Bachelor of Science in Management, with a concentration in Finance, from Bryant University. He has earned the Chartered Financial Analyst (CFA) designation and is a member of CFA Society Boston, Inc.

Additional information about the portfolio managers' compensation, other accounts managed by the portfolio managers, and the portfolio managers' ownership of the Portfolio is available in the SAI.

The Administrator, Sub-Administrator, Custodian, Transfer Agent and Dividend Disbursing Agent

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Portfolio's distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

Additional Information

The Trustees of the Trust oversee generally the operations of the Portfolio and the Trust. The Trust enters into contractual arrangements with various parties, including among others the Portfolio's investment adviser, custodian, transfer agent, and accountants, who provide services to the Portfolio. Shareholders are not parties to any such contractual arrangements or intended beneficiaries of those contractual arrangements, and those contractual arrangements are not intended to create in any shareholder any right to enforce them directly against the service providers or to seek any remedy under them directly against the service providers.

Shareholder Information

Determination of Net Asset Value

The Portfolio determines its NAV per share once each business day as of the close of regular trading on the NYSE. Pricing does not occur on NYSE holidays. The NAV per share of the Portfolio is based on the market value of the investments held in the Portfolio.

The NAV of each class of the Portfolio's shares is calculated by dividing the value of the assets of the Portfolio attributable to that class less the liabilities of the Portfolio attributable to that class by the number of shares in the class outstanding. As noted in this Prospectus, the Portfolio may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when the Portfolio does not price its shares. Consequently, the NAV of the Portfolio's shares may change on days when shareholders are not able to purchase or redeem the Portfolio's shares. Purchase and redemption orders for Portfolio Shares are processed, respectively, at the NAV next determined after the Portfolio accepts a purchase order or receives a redemption request in good form. The Portfolio values each security or other investment pursuant to guidelines adopted by the Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Portfolio's Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii) a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by the Portfolio occurs after the close of a related exchange but before the determination of the Portfolio's NAV. Attempts to determine the fair value of securities or other investments introduce an element of subjectivity to the pricing of securities or other investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the price the Portfolio would have received had it sold the investment. To the extent that the Portfolio invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the fund. The prospectuses of these funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

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may establish special hours on those days to determine the Portfolio's NAV. In the event that the Portfolio invokes the right to accept orders to purchase or redeem shares on any day that is not a business day or adopt special hours of operation, the Portfolio will post advance notice of these events at www.ssga.com/cash. [SSGA please confirm the paragraphs above]

Purchasing Shares

There is no minimal initial investment in the Portfolio and there is no minimum subsequent investment. (If you purchase shares by check, your order will not be in good form until the Portfolio's transfer agent receives federal funds for the check.) The Portfolio reserve the right to cease accepting investments at any time or to reject any purchase order.

In accordance with certain federal regulations, the Trust is required to obtain, verify and record information that identifies each entity that applies to open an account. For this reason, when you open (or change ownership of) an account, the Trust will request certain information, including your name, residential/business address, date of birth (for individuals) and taxpayer identification number or other government identification number and other information that will allow us to identify you which will be used to verify your identity. The Trust may also request to review other identification documents such as driver license, passport or documents showing the existence of the business entity. If you do not provide sufficient information to verify your identity, the Trust will not open an account for you. As required by law, the Trust may employ various procedures, such as comparing your information to fraud databases or requesting additional information and documentation from you, to ensure that the information supplied by you is correct. The Trust reserves the right to reject any purchase order for any reason, including failure to provide the Trust with information necessary to confirm your identity as required by law.

If you are purchasing through a Financial Intermediary, please contact your intermediary as their requirements may differ.

Redeeming Shares

An investor may redeem all or any portion of its investment at the NAV next determined after it submits a redemption request, in good form, to the Portfolio. The Portfolio typically expects to pay the proceeds of the redemption either in Federal Funds or in securities at the discretion of the Adviser, on the next Portfolio business day after the redemption. The Portfolio reserves the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Portfolio.

If your account is held through an Intermediary, please contact them for additional assistance and advice on how to redeem your shares.

The right of any investor to receive payment with respect to any redemption may be suspended or the payment of the redemption proceeds postponed during any period in which the NYSE is closed (other than weekends or holidays) or trading on the NYSE is restricted or, to the extent otherwise permitted by the 1940 Act, if an emergency exists as a result of which disposal by the Portfolio of securities owned by it is not reasonably practicable or it is not reasonably practicable for the Portfolio fairly to determine the value of its net assets. In addition, the SEC may by order permit suspension of redemptions for the protection of shareholders of the Portfolio.

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A request for a partial redemption by an investor whose account balance is below the minimum amount or a request for partial redemption by an investor that would bring the account below the minimum amount may be treated as a request for a complete redemption of the account. These minimums may be different for investments made through certain financial intermediaries as determined by their policies and may be waived in the Adviser's discretion. The Portfolio reserves the right to modify minimum account requirements at any time with or without prior notice. The Portfolio also reserves the right to involuntarily redeem an investor's account if the investor's account balance falls below the applicable minimum amount due to transaction activity.

About Mail Transactions

If you choose to purchase or redeem shares by sending instructions by regular mail, they will not be deemed received in good order until they are released by the post office and redelivered to the Transfer Agent's physical location at 1 Heritage Drive, North Quincy, MA 02171. There will be a time lag, which may be one or more days, between regular mail receipt at the post office box and redelivery to such physical location and the Portfolio's net asset value may change over those days. You might consider using express rather than regular mail if you believe the time of receipt of your transaction request to be sensitive.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a State Street Fund (as defined below) identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Portfolio (if you hold shares directly with the Portfolio) or to your financial intermediary (if you do not hold shares directly with the Portfolio).

Excessive Trading

Frequent, short-term trading, abusive trading practices and market timing (together, “Excessive Trading”), often in response to short-term fluctuations in the market, are not knowingly permitted by the State Street Funds. The State Street Funds do not accommodate frequent purchases and redemptions of fund shares by fund shareholders. Excessive Trading into and out of a State Street Fund may harm the fund's performance by disrupting portfolio management strategies and by increasing expenses. These expenses are borne by all fund shareholders, including long-term investors who do not generate such costs.

As a means to protect each State Street Fund and its shareholders from Excessive Trading:

•	The State Street Funds' transfer agent compiles, monitors and reports account-level information on omnibus and underlying shareholder/participant activity. Depending on the account type, monitoring will be performed on a daily, monthly, quarterly and/or annual basis;

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•	The State Street Funds' distributor has obtained information from each Financial Intermediary holding shares in an omnibus account with the State Street Funds regarding whether the Financial Intermediary has adopted and maintains procedures that are reasonably designed to protect the Funds against harmful short-term trading; and
•	With respect to State Street Funds that invest in securities that trade on foreign markets, pursuant to the State Street Funds' fair valuation procedures, pricing adjustments may be made based on information received from a third-party, multi-factor fair valuation pricing service.

The State Street Funds' distributor has detailed procedures that document the transparency oversight and monitoring processes performed by the State Street Funds' transfer agent.

Dividends, Distributions and Tax Considerations

The Portfolio intends to elect to be treated as a regulated investment company and intends each year to qualify and to be eligible to be treated as such. A regulated investment company generally is not subject to tax at the corporate level on income and gains that are timely distributed to shareholders. In order to qualify and be eligible for treatment as a regulated investment company, the Portfolio must, among other things, satisfy diversification, 90% gross income and distribution requirements. The Portfolio's failure to qualify as a regulated investment company would result in corporate level taxation, and consequently, a reduction in income available for distribution to shareholders.

For U.S. federal income tax purposes, distributions of investment income generally are taxable to you as ordinary income. Taxes on distributions of capital gains generally are determined by how long the Portfolio owned (or is deemed to have owned) the investments that generated them, rather than how long you have owned your Portfolio Shares. Distributions of net capital gains (that is, the excess of net long-term capital gains over net short-term capital losses) from the sale of investments that the Portfolio owned (or is deemed to have owned) for more than one year that are properly reported by the Portfolio as capital gain dividends generally will be treated as long-term capital gain includible in your net capital gain and taxed to individuals at reduced rates. Distributions of gains from investments that the Portfolio owned (or is deemed to have owned) for one year or less generally will be taxable to you as ordinary income when distributed to you by the Portfolio. Distributions are taxable to you even if they are paid from income or gains earned by the Portfolio before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares.

When the NAV of Portfolio Shares varies from a shareholder's tax basis in such shares, including in the case of a money market fund when the NAV of such Portfolio Shares varies from $1.0000 per share, the shareholder generally will realize a gain or loss upon the redemption or other taxable disposition of such Portfolio Shares. Any such gain generally would be taxable to you as either short-term or long-term capital gain, depending upon how long you held the Portfolio Shares. The IRS permits a simplified method of accounting for gains and losses realized upon the disposition of shares of a regulated investment company that is a money market fund. If you elect to adopt this simplified method of accounting, rather than compute gain or loss on every taxable disposition of

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An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by the Portfolio and net gains recognized on the redemption of shares of the Portfolio.

The Portfolio's income from or on proceeds of its investments in non-U.S. assets may be subject to non-U.S. withholding and other taxes. This will decrease the Portfolio's return on securities subject to such taxes. Tax treaties between certain countries and the U.S. may reduce or eliminate such taxes. Although such taxes will reduce the Portfolio's taxable income, shareholders generally will not be entitled separately to claim a credit or deduction with respect to foreign taxes incurred by the Portfolio.

Certain of the Portfolio's investment practices, including derivative transactions and investments in debt obligations issued or purchased at a discount, will be subject to special and complex U.S. federal income tax provisions. These special rules may affect the timing, character, and/or amount of the Portfolio's distributions, and may require the Portfolio to sell its investments at a time when it is not advantageous to do so.

If you are not a U.S. person, dividends paid by the Portfolio that the Portfolio properly reports as capital gain dividends, short-term capital gain dividends, or interest-related dividends, each as further defined in the SAI, are not subject to withholding of U.S. federal income tax, provided that certain other requirements are met. The Portfolio is permitted, but is not required, to report any part of its dividends as are eligible for such treatment. The Portfolio's dividends other than those the Portfolio so reports as capital gain dividends, short-term capital gain dividends, or interest-related dividends generally will be subject to U.S. withholding tax at a 30% rate (or lower applicable treaty rate). See the Portfolio's SAI for further information.

Cost Basis Reporting . Department of the Treasury regulations mandate cost basis reporting to shareholders and the IRS for redemptions of Portfolio shares. If you acquire and hold shares directly through the Portfolio and not through a Financial Intermediary, State Street will use a default average cost basis methodology for tracking and reporting your cost basis, unless you request, in writing, another cost basis reporting methodology.

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Financial Highlights

The Portfolio had not commenced operations prior to the date of this Prospectus and therefore does not have financial information.

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Contacting the State Street Funds

Online:	www.ssga.com/cash	24 hours a day, 7 days a week
Phone:	(800) 997-7327	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Registered, Express, Certified Mail
State Street Corporation Attention: Transfer Agent Box 5493 Mail Code: OHD0100 North Quincy, MA 02171	State Street Corporation Attention: Transfer Agent Box 5493 Mail Code: OHD0100 North Quincy, MA 02171

The Portfolio does not consider the U.S. Postal Service or other independent delivery services to be its agents. Therefore, deposits in the mail or with such services, or receipt at the Portfolio's post office box, of purchase orders or redemption requests, do not constitute receipt by the Portfolio or Transfer Agent.

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For more information about the Portfolio:

The Portfolio's SAI includes additional information about the Portfolio and is incorporated by reference into this document. Additional information about the Portfolio's investments is available or will be available, in the Portfolio's most recent annual and semi-annual reports to shareholders. The Portfolio's SAI is available, without charge, upon request. The Portfolio's annual and semi-annual reports are available, or will be available, without charge, upon request. Shareholders in the Portfolio may make inquiries to the Portfolio to receive such information by calling (877) 521-4083 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. The Portfolio's Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, or will be available, free of charge, on the Portfolio's website at www.ssga.com/cash.

Reports and other information about the Portfolio are available free of charge on the EDGAR Database on the SEC's Internet site at http://www.sec.gov. Copies of this information also may be obtained, after paying a duplicating fee, by electronic request at the following E-mail address: publicinfo@sec.gov.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

SSITPORTSTATPRO2

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Hedged International Developed Equity Index Fund

Class A (SSHEX) Class I (SSHNX) Class K (SSHQX)

State Street International Developed Equity Index Fund

Class A (SSIHX) Class I (SSIKX) Class K (SSIWX)

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in any of the Funds offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Each Fund may offer multiple classes of shares. This Prospectus covers only the Class A, Class I and Class K Shares of the applicable Funds.

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Fund Summaries	1
State Street Hedged International Developed Equity Index Fund	1
State Street International Developed Equity Index Fund	10
Additional Information About Investment Objectives, Principal Strategies and Risks	18
Additional Information About Non-Principal Investment Strategies and Risks	28
Portfolio Holdings Disclosure	30
Management and Organization	31
Shareholder Information	33
Dividends, Distributions and Tax Considerations	45
Financial Intermediary Arrangements	47
Financial Highlights	49
Index/Trademark Licenses/Disclaimers	51

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State Street Hedged International Developed Equity Index Fund

Investment Objective

The State Street Hedged International Developed Equity Index Fund (the “Hedged International Developed Equity Index Fund” or sometimes referred to in context as the “Fund”) seeks to provide investment results that, before fees and expenses, correspond generally to the total return performance of a broad-based developed market (ex-U.S. and Canada) large and mid capitalization equity index, hedged to the U.S. dollar, over the long term.

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment)

	Class A	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	5.25%	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None ¹	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class A	Class I	Class K
Management Fee ²	0.14%	0.14%	0.14%
Distribution and/or Shareholder Service (12b-1) Fees	0.25%	0.00%	0.00%
Other Expenses ³	0.42%	0.42%	0.22%
Total Annual Fund Operating Expenses	0.81%	0.56%	0.36%
Less Fee Waivers and/or Expense Reimbursements ⁴	(0.16)%	(0.16)%	(0.16)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.65%	0.40%	0.20%

¹	A contingent deferred sales charge (“CDSC”) of 1.00% may be assessed on redemptions of Class A shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase as part of an investment of $1,000,000 or more.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 to waive the portion of the Fund's management fee attributable to the Fund's assets invested in State Street International Developed Equity Index Portfolio, a separate series of State Street Master Funds (the “Portfolio”). This arrangement may not be terminated prior to April 30, 2020 except with the approval of the Fund's Board of Trustees.

³	Other expenses are based on estimates for the current fiscal year for Class A and Class I shares.

⁴

The Adviser is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees other than the fees of the Portfolio, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.15% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

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	1 year	3 years	5 years	10 years
Class A	$588	$755	$936	$1,460
Class I	$ 41	$163	$297	$ 686
Class K	$ 20	$ 99	$186	$ 440

Portfolio Turnover:

Principal Investment Strategies

The Fund is an “index” fund that seeks to track, before fees and expenses, the total return of the MSCI EAFE (Europe, Australasia, Far East) 100% Hedged to USD Index (the “Index”) over the long term. As an “index” fund, the Fund is not managed according to traditional methods of “active” investment management, which involve the buying and selling of securities based upon economic, financial and market analysis and investment judgment. The return of the Index is affected by the performance of Index constituents and the hedging strategy. In general, the Index would have higher returns than an equivalent unhedged index when the component currencies are weakening relative to the U.S. dollar. Conversely, the Index generally would have lower returns than an equivalent unhedged index when the component currencies are rising relative to the U.S. dollar.

In seeking to track the performance of the Index, the Fund expects to employ a sampling strategy, which means that the Fund will not typically purchase all of the securities represented in the Index. Instead, the Fund may purchase a subset of the securities in the Index or other investments in an effort to create a portfolio of securities with generally the same risk and return characteristics of the Index. The number of holdings in the Fund will be based on a number of factors, including the asset size of the Fund. Based on its analysis of these factors, SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, may, instead, invest the Fund's assets in substantially all of the securities represented in the Index in approximately the same proportions as the Index.

Under normal circumstances, the Fund invests substantially all, but as a matter of policy no less than 80%, of its net assets (plus borrowings, if any) in securities, or American Depositary Receipts (“ADRs”) or Global Depositary Receipts (“GDRs”) based on securities, comprising the Index, or in other funds, including funds sponsored by the Adviser or its affiliates, in currency hedging instruments (and related collateral, if any), or in other investments, that the Adviser expects to provide a return highly correlated to the Index or a portion of the Index. The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposure comparable, in the judgment of the Adviser, to the foregoing types of investments may be counted toward satisfaction of this 80% policy. The Fund will provide shareholders with at least sixty (60) days' notice prior to any change in its policy to invest at least 80% of its assets as described in the foregoing. The Fund may invest in equity securities that are not included in the Index (including common stock, preferred stock, depositary receipts and shares of other investment companies), currency transactions, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser). The Fund may use derivatives, including futures contracts and options, swaps, and contracts for differences, to obtain investment exposures that the Adviser expects to correlate closely with the Index or a portion of the Index.

Under normal circumstances, the Fund will invest at least 80% of its net assets (plus borrowings, if any) in equity securities of issuers in developed economies or securities markets. For this purpose, countries with “developed economies or securities markets” refers to countries that are included in the Index, or a global developed markets equity index, and countries with similar characteristics (countries that have sustained economic development, sufficient liquidity for listed companies and accessible markets). The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in equity securities of issuers in developing economies or securities markets may be counted toward satisfaction of this 80% policy. The Fund will provide shareholders with at least 60 days' notice prior to any change in this 80% investment policy.

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The Fund currently intends to gain all of its investment exposure to, and track the performance of, the Index constituents by investing in the State Street International Developed Equity Index Portfolio (the “Portfolio”) and employ its currency hedging strategy by directly entering into currency hedging transactions. The Adviser also serves as investment adviser to the Portfolio. When the Fund invests in the Portfolio, the Fund participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” with respect to the Index constituents also generally describe the expected investment activities of the Portfolio.

The Fund intends to hedge its non-U.S. currency exposure to the U.S. dollar, in a manner intended to replicate the currency hedge reflected in the Index. For this purpose, the Fund may enter into foreign currency forward contracts, forward currency futures and options, and currency swaps. The Index hedges each foreign currency in the Index back to the U.S. dollar by selling foreign currency forwards at the one-month forward rate. The size and exchange rate of each currency hedge is reset by the Index one time per month. Even if the Fund's hedging strategy works as intended, changes in currency exchange rates will still affect Fund returns (see “Currency Hedging Risk” below). The Fund's performance, like that of the Index, will depend on both the performance of the stocks comprising the Fund and the performance of the U.S. dollar relative to foreign currencies.

The Index is designed to capture the performance that can be achieved by hedging the currency exposures of its parent index, the MSCI EAFE Index, to the U.S. dollar. The MSCI EAFE Index is a free float-adjusted market capitalization index that is designed to capture large and mid-cap securities in developed market countries, excluding the United States and Canada. As of February 28, 2019, the MSCI EAFE Index comprised 921 securities covering companies across 21 countries and represented 85.50% of the free float-adjusted market capitalization of those countries. As of February 28, 2019, a significant portion of the MSCI EAFE Index comprised companies in the financial sector, and companies located in Japan, the United Kingdom and Europe and a significant portion of the Index constituents are denominated in the Yen, the Great Britain Pound and the Euro, although this may change from time to time. As of February 28, 2019, the full market capitalization of the companies included in the MSCI EAFE Index ranged from $1.31 billion to $277.83 billion. As of February 28, 2019, countries covered in the MSCI EAFE Index included Australia, Austria, Belgium, Denmark, Finland, France, Germany, Hong Kong, Ireland, Israel, Italy, Japan, the Netherlands, New Zealand, Norway, Portugal, Singapore, Spain, Sweden, Switzerland and the United Kingdom, although this may change from time to time.

Principal Risks

In addition, the Fund is subject to the following risks:

Currency Hedging Risk: When a derivative is used as a hedge against a position that the Fund holds, any gain generated by the derivative generally should be substantially offset by losses on the hedged investment, and vice versa. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. Hedges are sometimes subject to imperfect matching between a derivative and its reference asset. For example, because the Fund's currency hedge is reset on a monthly basis, based on the size of the Fund's exposure to a currency at a certain point in time, the size of each currency hedge could be greater or less than the Fund's total exposure in that currency intra-month and currency risk may develop or increase between resets. Furthermore, while the Fund is designed to hedge against currency fluctuations, it is possible that a degree of currency exposure may remain even at the

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time a hedging transaction is implemented. As a result, changes in currency exchange rates may affect Fund returns even when the hedge works as intended. The effectiveness of the Fund's currency hedging strategy will also generally be affected by both the volatility of the securities included in the Index, and the volatility of the U.S. dollar relative to the currencies to be hedged. Increased volatility may reduce the effectiveness of the Fund's currency hedging strategy and may impact the costs associated with hedging transactions. The effectiveness of the Fund's currency hedging strategy and the costs associated with hedging transactions may also in general be affected by interest rates. Significant differences between U.S. dollar interest rates and foreign currency interest rates may further impact the effectiveness of the Fund's currency hedging strategy. There can be no assurance that the Fund's hedging transactions will be effective. The Fund's currency hedging activities will potentially increase or accelerate distributions to shareholders, increase distributions taxed to individuals as ordinary income, result in the re-characterization of prior ordinary income distributions as return of capital, or generate losses that cannot be used to offset income or capital gain in subsequent years. The Fund will bear the costs associated with any such hedging transaction, regardless of any gain or loss experienced on the hedging transaction.

Currency Risk: Despite the Fund's currency hedging strategy, the value of the Fund's assets may be affected favorably or unfavorably by currency exchange rates, currency exchange control regulations, and restrictions or prohibitions on the repatriation of foreign currencies. Foreign currency exchange rates may have significant volatility, and changes in the values of foreign currencies against the U.S. dollar may result in substantial declines in the values of the Fund's, or the Portfolio's, assets denominated in foreign currencies. Because the Fund's, or the Portfolio's, net asset values (“NAVs”) are determined in U.S. dollars, the Fund's NAV could decline if the currency of a non-U.S. market in which the Fund invests depreciates against the U.S. dollar and the Fund's attempt to hedge currency exposure is unsuccessful. Generally, an increase in the value of the U.S. dollar against a foreign currency will reduce the value of a security denominated in that foreign currency when measured in U.S. dollars, thereby decreasing the Fund's overall NAV. A foreign currency may be affected favorably or unfavorably by currency exchange rates, currency control regulations and restrictions or prohibitions on the repatriation of the foreign currency. Fluctuations in the exchange values of currencies could affect the economy or particular business operations of companies in a geographic region in which the Fund or the Portfolio invests, causing an adverse impact on the Fund's, or the Portfolio's, investments in the affected region and the United States. As a result, investors have the potential for losses regardless of the length of time they intend to hold Fund Shares.

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resulting from financial difficulties of borrowers and financial losses associated with investment activities can negatively impact the sector. Insurance companies may be subject to severe price competition. Adverse economic, business or political developments could adversely affect financial institutions engaged in mortgage finance or other lending or investing activities directly or indirectly connected to the value of real estate.

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achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. The Adviser may attempt to replicate the Index return by investing in fewer than all of the securities in the Index, or in some securities not included in the Index, potentially increasing the risk of divergence between the Fund's return and that of the Index.

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to a pool in which the Fund may invest, leading to potential conflicts of interest. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which the Fund does so.

Underlying Fund Risk: The Fund currently intends to gain all of its investment exposure to, and track the performance of, the index constituents by investing in another pooled investment vehicle (an “underlying fund”). The ability of the Fund to meet its investment objective with respect to the index constituents is directly related to the ability of the underlying fund to meet its investment objective. The Adviser serves as investment adviser to the underlying fund, leading to potential conflicts of interest. The Fund will bear its pro rata portion of the expenses incurred by the underlying fund. Substantial redemptions by other investors in an underlying fund may affect the underlying fund's investment program adversely and limit the ability of the underlying fund to achieve its objective.

Performance

The bar chart and table below provide some indication of the risks of investing in the Hedged International Developed Equity Index Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of the Index. The bar chart shows how the Class K shares' returns have varied for each full calendar year shown. Except for differences in returns resulting from differences in fees and expenses, all share classes would have substantially similar returns because all share classes invest in the same portfolio of securities. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Return (years ended 12/31)

Highest Quarterly Return: 6.62% (Q4, 2016)
Lowest Quarterly Return: -11.71% (Q4, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. After-tax returns depend on an investor's tax situation and may differ from those shown below, and after-tax returns are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts (IRAs). Except for differences in returns resulting from differences in fees, expenses, and sales charges (as applicable), all share classes would have substantially similar returns because all share classes invest in the same portfolio of securities.

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	One Year	Since Inception	Inception Date
Class K			5/29/2015
Return Before Taxes	-9.25%	0.70%
Return After Taxes on Distributions	-10.76%	-0.36%
Return After Taxes on Distributions and Sale of Fund Shares	-4.46%	0.47%
MSCI EAFE 100% Hedged to USD Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-8.96%	1.18%

The Fund will make updated performance information, including its current net asset value, available at the Fund's website: www.ssgafunds.com.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

The professionals primarily responsible for the day-to-day management of the Fund are Michael Feehily, Karl Schneider and David Chin, each of which has served as a portfolio manager of the Fund since inception in 2015.

Michael Feehily, CFA, is a Senior Managing Director of the Adviser and the Head of Global Equity Beta Solutions in the Americas. He worked at the Adviser from 1997 to 2006 and rejoined in 2010.

Karl Schneider, CAIA, is a Managing Director of the Adviser and Deputy Head of Global Equity Beta Solutions in the Americas. He joined the Adviser in 1997.

David Chin is a Vice President of the Adviser and a Senior Portfolio Manager in the Global Equity Beta Solutions Group. He joined the Adviser in 1999.

Purchase and Sale of Fund Shares

Purchase Minimums

Class A
To establish an account	$2,000
To add to an existing account	None
Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

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By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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State Street International Developed Equity Index Fund

Investment Objective

The State Street International Developed Equity Index Fund (the “International Developed Equity Index Fund” or sometimes referred to in context as the “Fund”) seeks to provide investment results that, before fees and expenses, correspond generally to the total return performance of a broad-based developed market (ex-U.S. and Canada) large and mid-capitalization equity index over the long term.

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). You may qualify for sales charge discounts on purchases of Class A shares if you agree to invest in the future, or if you and your family currently invest, at least $50,000 in State Street Funds that offer Class A shares. More information about these and other discounts is available from your financial professional and in Choosing a Share Class – Reducing Your Class A Sales Charge on page 35 of the Fund's Prospectus. The expenses shown in the table and the Example reflect the expenses of both the Fund and the Fund's proportionate share of the expenses of the State Street International Developed Equity Index Portfolio (the “Portfolio”).

Shareholder Fees (fees paid directly from your investment)

	Class A	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	5.25%	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None ¹	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class A	Class I	Class K
Management Fee ²	0.11%	0.11%	0.11%
Distribution and/or Shareholder Service (12b-1) Fees	0.25%	0.00%	0.00%
Other Expenses ³	0.95%	0.95%	0.75%
Total Annual Fund Operating Expenses	1.31%	1.06%	0.86%
Less Fee Waivers and/or Expense Reimbursements ⁴	(0.72)%	(0.72)%	(0.72)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.59%	0.34%	0.14%

¹	A contingent deferred sales charge (“CDSC”) of 1.00% may be assessed on redemptions of Class A shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase as part of an investment of $1,000,000 or more.

³	Other expenses are based on estimates for the current fiscal year.

⁴

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.09% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

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	1 year	3 years
Class A	$582	$851
Class I	$ 35	$265
Class K	$ 14	$202

Portfolio Turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund Shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Fund's performance. The Fund's portfolio turnover rate has been omitted because the Fund had not commenced investment operations prior to the end of the most recent fiscal year.

Principal Investment Strategies

The Fund is an “index” fund that seeks to track, before fees and expenses, the total return of the MSCI EAFE (Europe, Australasia, Far East) Index (the “Index”) over the long term. As an “index” fund, the Fund is not managed according to traditional methods of “active” investment management, which involve the buying and selling of securities based upon economic, financial and market analysis and investment judgment.

Under normal circumstances, the Fund invests substantially all, but as a matter of policy no less than 80%, of its net assets (plus borrowings, if any) in securities, or American Depositary Receipts (“ADRs”) or Global Depositary Receipts (“GDRs”) based on securities, comprising the Index, or in other funds, including funds sponsored by the Adviser or its affiliates, or in other investments, that the Adviser expects to provide a return highly correlated to the Index or a portion of the Index. The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposure comparable, in the judgment of the Adviser, to the foregoing types of investments may be counted toward satisfaction of this 80% policy. The Fund will provide shareholders with at least sixty (60) days' notice prior to any change in its policy to invest at least 80% of its assets as described in the foregoing. The Fund may invest in equity securities that are not included in the Index (including common stock, preferred stock, depositary receipts and shares of other investment companies), cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser). The Fund may use derivatives, including futures contracts and options, swaps, and contracts for differences, to obtain investment exposures that the Adviser expects to correlate closely with the Index or a portion of the Index.

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The Fund currently intends to invest nearly all of its assets in the Portfolio, another open-end investment company managed by the Adviser, with an investment objective and policies substantially identical to those of the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio and it participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Portfolio.

The Index is a free float-adjusted market capitalization index that is designed to capture large and mid-cap securities in developed market countries, excluding the United States and Canada. As of February 28, 2019, the Index comprised 921 securities covering companies across 21 countries and represented 85.50% of the free float-adjusted market capitalization of those countries. As of February 28, 2019, a significant portion of the Index comprised companies in the financial sector and companies located in Japan, the United Kingdom and Europe and a significant portion of the Index constituents are denominated in the Yen, the Great Britain Pound and the Euro, although this may change from time to time. As of February 28, 2019, the full market capitalization of the companies included in the Index ranged from $1.31 billion to $277.83 billion. As of February 28, 2019, countries covered in the Index included Australia, Austria, Belgium, Denmark, Finland, France, Germany, Hong Kong, Ireland, Israel, Italy, Japan, the Netherlands, New Zealand, Norway, Portugal, Singapore, Spain, Sweden, Switzerland and the United Kingdom, although this may change from time to time.

Principal Risks

In addition, the Fund is subject to the following risks:

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Performance

Performance information for the Fund has been omitted because the Fund had not commenced investment operations as of the date of this Prospectus. Once the Fund has completed a full calendar year of operations, a bar chart and table will be included that will provide some indication of the risks of investing in the Fund by showing the variability of the Fund's returns based on net assets and comparing the Fund's performance to the Index. The Fund will make updated performance information, including its current net asset value, available at the Fund's website: www.ssgafunds.com.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund and the Portfolio.

The professionals primarily responsible for the day-to-day management of the Portfolio and the Fund are Michael Feehily, Karl Schneider and David Chin, each of which has served as a portfolio manager of the Fund since organization in 2015.

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Michael Feehily, CFA, is a Senior Managing Director of the Adviser and the Head of Global Equity Beta Solutions in the Americas. He worked at the Adviser from 1997 to 2006 and rejoined in 2010.

Karl Schneider, CAIA, is a Managing Director of the Adviser and Deputy Head of Global Equity Beta Solutions in the Americas. He joined the Adviser in 1997.

David Chin is a Vice President of the Adviser and a Senior Portfolio Manager in the Global Equity Beta Solutions Group. He joined the Adviser in 1999.

Purchase and Sale of Fund Shares

Purchase Minimums

Class A
To establish an account	$2,000
To add to an existing account	None
Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

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Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objectives, Principal Strategies and Risks

Investment Objective

State Street Hedged International Developed Equity Index Fund

Principal Investment Strategies

In seeking to track the performance of the Index, the Fund expects to employ a sampling strategy, which means that the Fund will not typically purchase all of the securities represented in the Index. Instead, the Fund may purchase a subset of the securities in the Index or other investments in an effort to create a portfolio of securities with generally the same risk and return characteristics of the Index. The number of holdings in the Fund will be based on a number of factors, including the asset size of the Fund. Based on its analysis of these factors, SSGA FM may, instead, invest the Fund's assets in substantially all of the securities represented in the Index in approximately the same proportions as the Index.

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forwards at the one-month forward rate. The size and exchange rate of each currency hedge is reset by the Index one time per month. Even if the Fund's hedging strategy works as intended, changes in currency exchange rates will still affect Fund returns (see “Currency Hedging Risk” below). The Fund's performance, like that of the Index, will depend on both the performance of the stocks comprising the Fund and the performance of the U.S. dollar relative to foreign currencies.

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State Street International Developed Equity Index Fund

Principal Investment Strategies

In seeking to track the performance of the Index, the Fund expects to employ a sampling strategy, which means that the Fund will not typically purchase all of the securities represented in the Index. Instead, the Fund may purchase a subset of the securities in the Index or other investments in an effort to create a portfolio of securities with generally the same risk and return characteristics of the Index. The number of holdings in the Fund will be based on a number of factors, including the asset size of the Fund. Based on its analysis of these factors, SSGA FM may, instead, invest the Fund's assets in substantially all of the securities represented in the Index in approximately the same proportions as the Index.

Under normal circumstances, the Fund invests substantially all, but as a matter of policy no less than 80%, of its net assets (plus borrowings, if any) in securities, or American Depositary Receipts (“ADRs”) or Global Depositary Receipts (“GDRs”) based on securities, comprising the Index, or in other funds, including funds sponsored by the Adviser or its affiliates, or in other investments, that the Adviser expects to provide a return highly correlated to the Index or a portion of the Index. The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposure comparable, in the judgment of the Adviser, to the foregoing types of investments may be counted toward satisfaction of this 80% policy. The Fund will provide shareholders with at least sixty (60) days' notice prior to any change in its policy to invest at least 80% of its assets as described in the foregoing. The Fund may invest in equity securities that are not included in the Index (including common stock, preferred stock, depositary receipts and shares of other investment companies), cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser). The Fund may use derivatives, including futures contracts and options, swaps, and contracts for differences, to obtain investment exposures that the Adviser expects to correlate closely with the Index or a portion of the Index.

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Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure.

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Currency Hedging Risk (principal risk for the Hedged International Developed Equity Index Fund) . When a derivative is used as a hedge against a position that a Fund holds, any gain generated by the derivative generally should be substantially offset by losses on the hedged investment, and vice versa. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. Hedges are sometimes subject to imperfect matching between a derivative and its reference asset. For example, because the Fund's currency hedge is reset on a monthly basis, based on the size of the Fund's exposure to a currency at a certain point in time, the size of each currency hedge could be greater or less than the Fund's total exposure in that currency intra-month and currency risk may develop or increase between resets. Furthermore, while the Fund is designed to hedge against currency fluctuations, it is possible that a degree of currency exposure may remain even at the time a hedging transaction is implemented. As a result, changes in currency exchange rates may affect Fund returns even when the hedge works as intended. The effectiveness of a Fund's currency hedging strategy will also generally be affected by the volatility of both the securities included in the Index, and the volatility of the U.S. dollar relative to the currencies to be hedged. Increased volatility may reduce the effectiveness of a Fund's currency hedging strategy and may impact the costs associated with hedging transactions. The effectiveness of a Fund's currency hedging strategy and the costs associated with hedging transactions may also in general be affected by interest rates. Significant differences between U.S. dollar interest rates and foreign currency interest rates may further impact the effectiveness of a Fund's currency hedging strategy. There can be no assurance that a Fund's hedging transactions will be effective. A Fund's currency hedging activities will potentially increase or accelerate distributions to shareholders, increase distributions taxed to individuals as ordinary income, result in the re-characterization of prior ordinary income distributions as return of capital, or generate losses that cannot be used to offset income or capital gain in subsequent years. A Fund will bear the costs associated with any such hedging transaction, regardless of any gain or loss experienced on the hedging transaction.

Currency Risk. Investments in issuers in different countries are often denominated in currencies other than the U.S. dollar. Changes in the values of those currencies relative to the U.S. dollar may have a positive or negative effect on the values of a Fund's investments denominated in those currencies. The values of other currencies relative to the U.S. dollar may fluctuate in response to, among other factors, interest rate changes, intervention (or failure to intervene) by national governments, central banks, or supranational entities such as the International Monetary Fund, the imposition of currency controls, and other political or regulatory developments. Currency values can decrease significantly both in the short term and over the long term in response to these and other developments. Continuing uncertainty as to the status of the Euro and the Economic and Monetary Union of the European Union (the “EMU”) has created significant volatility in currency and financial markets generally. Any partial or complete dissolution of the EMU, or any continued uncertainty as to its status, could have significant adverse effects on currency and financial markets, and on the values of a Fund's portfolio investments. With respect to the Hedged International Developed Equity Index Fund, to the extent the Adviser seeks to hedge against adverse changes in the values of currencies on the value of the Fund's assets, such hedging transactions may not have the desired effect or may cause the Fund to lose money.

Depositary Receipts Risk . American Depositary Receipts (“ADRs”) are typically trust receipts issued by a U.S. bank or trust company that evidence an indirect interest in underlying securities issued by a foreign entity. Global Depositary Receipts (“GDRs”), European Depositary Receipts (“EDRs”), and other types of depositary receipts are typically issued by non-U.S. banks or financial institutions to evidence an interest in underlying securities issued by either a U.S. or a non-U.S. entity. Investments in non-U.S. issuers through ADRs, GDRs, EDRs, and other types of depositary receipts generally involve risks applicable to other types of investments in non-U.S. issuers. Investments in depositary receipts may be less liquid and more volatile than the underlying securities in their primary trading market. If a depositary receipt is denominated in a different currency than its underlying securities, a Fund will be subject to the currency risk of both the investment in the depositary receipt and the underlying security. There may be less publicly available information regarding the issuer of the securities underlying a depositary receipt than if those securities were traded directly in U.S. securities markets. Depositary receipts may or may not be sponsored by the issuers of the underlying securities, and information regarding issuers of securities underlying unsponsored depositary receipts may be more limited than for sponsored depositary receipts. The values of depositary receipts may decline for a number of reasons relating to the issuers or sponsors of the depositary receipts, including, but not limited to, insolvency of the issuer or sponsor. Holders of depositary receipts may have limited or no rights to take action with respect to the underlying securities or to compel the issuer of the receipts to take action. The prices of depositary receipts may differ from the prices of securities upon which they are based. To the extent the Fund invests in depositary receipts based on securities included in the Index, such differences in prices may increase index tracking risk.

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sible mispricing or improper valuation of the derivative instrument; imperfect correlation in the value of a derivative with the asset, rate, or index underlying the derivative; the risk that a Fund may be required to post collateral or margin with its counterparty, and will not be able to recover the collateral or margin in the event of the counterparty's insolvency or bankruptcy; the risk that a Fund will experience losses on its derivatives investments and on its other portfolio investments, even when the derivatives investments may be intended in part or entirely to hedge those portfolio investments; the risks specific to the asset underlying the derivative instrument; lack of liquidity for the derivative instrument, including without limitation absence of a secondary trading market; the potential for reduced returns to a Fund due to losses on the transaction and an increase in volatility; the potential for the derivative transaction to have the effect of accelerating the recognition of gain; and legal risks arising from the documentation relating to the derivative transaction.

Europe. The Economic and Monetary Union of the EU requires compliance with restrictions on inflation rates, deficits, interest rates, debt levels and fiscal and monetary controls, each of which may significantly affect every country in Europe. Decreasing imports or exports, changes in governmental or EU regulations on trade, changes in the exchange rate of the euro (the common currency of certain EU countries), the default or threat of default by an EU member country on its sovereign debt, and/or an economic recession in an EU member country may have a significant adverse effect on the economies of EU member countries and their trading partners. The European financial markets have recently experienced volatility and adverse trends due to concerns about economic downturns or rising government debt levels in several European countries, including Greece, Ireland, Italy, Portugal and Spain. These events have adversely affected the exchange rate of the euro and may continue to significantly affect every country in Europe, including countries that do not use the euro.

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drawal negotiations will be conducted and what the potential consequences may be. Any exits from the EU, or the possibility of such exits, may have a significant impact on the United Kingdom, Europe, and global economies, which may result in increased volatility and illiquidity, new legal and regulatory uncertainties and potentially lower economic growth for such economies that could potentially have an adverse effect on the value of the Fund's investments. In addition, a number of countries in Europe have suffered terrorist attacks and additional attacks may occur in the future. Such attacks may cause uncertainty in financial markets and may adversely affect the performance of the issuers to which the Fund has exposure.

Indexing Strategy/Index Tracking Risk . The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities. The Fund will seek to replicate Index returns, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. The Fund generally will buy and will not sell a security included in the Index as long as the security is part of the Index regardless of any sudden or material decline in value or foreseeable material decline in value of the security, even though the Adviser may make a different investment decision for other actively managed accounts or portfolios that hold the security. As a result, a Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index (in absolute terms and by comparison with other indices) and, consequently, the performance, volatility, and risk of a Fund. While the Adviser seeks to track the performance of the Index (i.e., achieve a high degree of correlation with the Index), a Fund's return may not match the return of the Index for a number of reasons. For example, the return on the sample of securities purchased by a Fund (or the return on securities not included in the Index) to replicate the performance of the Index may not correlate precisely with the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. In addition, a Fund may not be fully invested at times, either as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. The Adviser may attempt to replicate the Index return by investing in fewer than all of the securities in the Index, or in some securities not included in the Index, potentially increasing the risk of divergence between a Fund's return and that of the Index. Changes in the composition of the Index and regulatory requirements also may impact a Fund's ability to match the return of the Index. The Adviser may apply one or more “screens” or investment techniques to refine or limit the number or types

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of issuers included in the Index in which a Fund may invest. Application of such screens or techniques may result in investment performance below that of the Index and may not produce results expected by the Adviser. Index tracking risk may be heightened during times of increased market volatility or other unusual market conditions.

Large-Capitalization Securities Risk. Securities issued by large-capitalization companies may present risks not present in smaller companies. For example, larger companies may be unable to respond as quickly as smaller and mid-sized companies to competitive challenges or to changes in business, product, financial, or other market conditions. Larger companies may not be able to maintain growth at the high rates that may be achieved by well-managed smaller and mid-sized companies, especially during strong economic periods. Returns on investments in securities of large companies could trail the returns on investments in securities of smaller and mid-sized companies.

In compliance with the U.S. Securities and Exchange Commission's (“SEC”) new liquidity risk management rule applicable to open-end mutual funds, the Funds recently established a liquidity risk management program. The rule's impact on the Funds, and on the open-end fund industry in general, is not yet fully known, but the rule could affect a Fund's performance and its ability to achieve its investment objectives. While the liquidity risk management program attempts to assess and manage liquidity risk, there is no guarantee it will be effective in its operations and may not reduce the liquidity risk inherent in a Fund's investments.

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Master/Feeder Structure Risk (principal risk for the International Developed Equity Index Fund). The Fund pursues its objective by investing substantially all of its assets in another pooled investment vehicle (a “master fund”). The ability of a Fund to meet its investment objective is directly related to the ability of the master fund to meet its investment objective. The ability of a Fund to meet its objective may be adversely affected by the purchase and redemption activities of other investors in the master fund. The ability of a Fund to meet redemption requests will depend on its ability to redeem its interest in the master fund. The Adviser or an affiliate serves as investment adviser to the master fund, leading to potential conflicts of interest. For example, the Adviser or its affiliates will receive fees based on the amount of assets invested in the master fund. Investment by a Fund in the master fund may be beneficial in the management of the master fund, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest a Fund's assets in a master fund sponsored or managed by the Adviser or its affiliates in lieu of investments by a Fund directly in portfolio securities, or may have an incentive to invest in such master fund over a master fund sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by a Fund in a master fund sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a master fund sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Fund does so. A Fund will bear its pro rata portion of the expenses incurred by the master fund.

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and in smaller volumes than more widely held securities. The prices of these securities may fluctuate more sharply than those of other securities, and a Fund may experience some difficulty in establishing or closing out positions in these securities at prevailing market prices. There may be less publicly available information about the issuers of these securities or less market interest in these securities than in the case of larger companies, both of which can cause significant price volatility. Some securities of mid-sized issuers may be illiquid or may be restricted as to resale. Returns on investments in securities of mid-capitalization companies could trail the returns on investments in securities of larger or smaller companies.

Non-U.S. Securities Risk . Investments in securities of non-U.S. issuers (including depositary receipts) entail risks not typically associated with investing in securities of U.S. issuers. Similar risks may apply to securities traded on a U.S. securities exchange that are issued by entities with significant exposure to non-U.S. countries. In certain countries, legal remedies available to investors may be more limited than those available with regard to U.S. investments. Because non-U.S. securities are typically denominated and traded in currencies other than the U.S. dollar, the value of the Fund's assets, to the extent they are non-U.S. dollar denominated, may be affected favorably or unfavorably by currency exchange rates, exchange control regulations, and restrictions or prohibitions on the repatriation of non-U.S. currencies. Income and gains with respect to investments in certain countries may be subject to withholding and other taxes. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, and financial reporting standards, regulatory framework and practices comparable to those in the United States. The securities of some non-U.S. entities are less liquid and at times more volatile than securities of comparable U.S. entities, and could become subject to sanctions or embargoes that adversely affect a Fund's investment. Non-U.S. transaction costs, such as brokerage commissions and custody costs may be higher than in the U.S. In addition, there may be a possibility of nationalization or expropriation of assets, imposition of currency exchange controls, confiscatory taxation, and diplomatic developments that could adversely affect the values of a Fund's investments in certain non-U.S. countries. Investments in securities of non-U.S. issuers also are subject to foreign political and economic risk not associated with U.S. investments, meaning that political events (civil unrest, national elections, changes in political conditions and foreign relations, imposition of exchange controls and repatriation restrictions), social and economic events (labor strikes, rising inflation) and natural disasters occurring in a country where a Fund invests could cause the Fund's investments in that country to experience gains or losses.

Settlement Risk . Markets in different countries have different clearance and settlement procedures and in certain markets there have been times when settlements have been unable to keep pace with the volume of transactions. Delays in settlement may increase credit risk to a Fund, limit the ability of a Fund to reinvest the proceeds of a sale of securities, hinder the ability of a Fund to lend its portfolio securities, and potentially subject a Fund to penalties for its failure to deliver to on-purchasers of securities whose delivery to a Fund was delayed. Delays in the settlement of securities purchased by a Fund may limit the ability of a Fund to sell those securities at times and prices it considers desirable, and may subject a Fund to losses and costs due to its own inability to settle with subsequent purchasers of the securities from it. A Fund may be required to borrow monies it had otherwise expected to receive in connection with the settlement of securities sold by it, in order to meet its obligations to others. Limits on the ability of a Fund to purchase or sell securities due to settlement delays could increase any variance between a Fund's performance and that of its benchmark index.

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Underlying Fund Risk (principal risk for the Hedged International Developed Equity Index Fund) . The Fund currently intends to gain all of its investment exposure to, and track the performance of, the Index constituents by investing in another pooled investment vehicle (an “underlying fund”). The ability of the Fund to meet its investment objective with respect to the Index constituents is directly related to the ability of the underlying fund to meet its investment objective. The ability of the Fund to meet its objective may be adversely affected by the purchase and redemption activities of other investors in the underlying fund. The ability of the Fund to meet redemption requests will depend on its ability to redeem its interest in the underlying fund. The Adviser serves as investment adviser to the underlying fund, leading to potential conflicts of interest. For example, the Adviser or its affiliates will receive fees based on the amount of assets invested in the underlying fund. Investment by the Fund in the underlying fund may be beneficial in the management of the underlying fund, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest the Fund's assets in a master fund sponsored or managed by the Adviser or its affiliates in lieu of investments by the Fund directly in portfolio securities, or may have an incentive to invest in such underlying fund over a underlying fund sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by the Fund in a underlying fund sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a underlying fund sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which the Fund does so. The Fund will bear its pro rata portion of the expenses incurred by the underlying fund.

Additional Information About Non-Principal Investment Strategies and Risks

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Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Funds and the Portfolio) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, a Fund, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect a Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect a Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject a Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of a Fund inaccessible or inaccurate or incomplete. A Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. A Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. Each Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Funds. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which each Fund invests, which could result in material adverse consequences for such issuers, and may cause a Fund's investment in such securities to lose value.

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may be unsuccessful, especially for foreign securities or thinly traded securities, and may involve expenses to a Fund. Securities lending involves the risk that the Fund may lose money because the borrower of the loaned securities fails to return the securities in a timely manner or at all. Should the borrower of the securities fail financially, a Fund may experience delays in recovering the securities or exercising its rights in the collateral. Loans are made only to borrowers that are deemed by the securities lending agent to be of good financial standing. In a loan transaction, a Fund will also bear the risk of any decline in value of securities acquired with cash collateral. Each Fund expects to invest cash collateral in a pooled investment vehicle advised by the Adviser. With respect to index funds, to the extent the collateral provided or investments made with cash collateral differ from securities included in the relevant Index, such collateral or investments may have a greater risk of loss than the securities included in the Index. In addition, a Fund will be subject to the risk that any income generated by reinvesting cash collateral is lower than any fees the Fund has agreed to pay a borrower.

Portfolio Holdings Disclosure

The Funds' portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

The International Developed Equity Index Fund invests through a “master-feeder” structure. The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the Portfolio, a separate mutual fund, that has substantially similar investment strategies and risks as the Fund. Descriptions of the investment activities of the Fund also generally describe the expected investment activities of the Portfolio. The Hedged International Developed Equity Index Fund gains all of its investment exposure to the Index constituents by investing in the Portfolio, a separate mutual fund that, aside from the currency hedging activities performed by the Fund, has substantially similar investment strategies and risks as the Fund. Descriptions of the investment activities of the Fund also generally describe the expected investment activities of the Portfolio. Either Fund can withdraw its investment in the Portfolio if, at any time, the Fund's Board of Trustees determines that it would be in the best interests of the Fund's shareholders, or if the investment objectives or strategies of the Portfolio changed so that they were inconsistent with the objectives or strategies of the Fund. If a Fund withdraws its investment from the Portfolio, the Fund may invest all of its assets in another mutual fund that has substantially similar investment strategies to those of the Fund, the Adviser may directly manage the Fund's assets, or the Board may take such other action it deems appropriate and in the best interests of shareholders of the Fund, which may include liquidation of the Fund.

Investment Adviser

State Street Hedged International Developed Equity Index Fund	0.14%
State Street International Developed Equity Index Fund	0.11%

The amount each Fund pays under its Investment Advisory Agreement is reduced by the amount of the advisory fee it bears indirectly through its investment in the Portfolio. For the services provided under its Investment Advisory Agreement, the Portfolio pays the Adviser a management fee at an annual rate of 0.11% of the Portfolio's average daily net assets.

Total Annual Fund Operating Expense Waiver . For the Hedged International Developed Equity Index Fund, SSGA FM, as the investment adviser to the Fund, is contractually obligated, through April 30, 2020, (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund for expenses to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees other than the fees of the Portfolio, and any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.15% of average daily net assets on an annual basis. Additionally, for the International Developed Equity Index Fund, SSGA FM, as the investment adviser to the Fund, is contractually obligated, through April 30, 2020, (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund for expenses to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees, and any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.09% of average daily net assets on an annual basis. These waiver and/or reimbursement arrangements may not be terminated prior to April 30, 2020 except with approval of the Funds' Board of Trustees.

A discussion regarding the Board's consideration of the Funds' Investment Advisory Agreement is provided in the Fund's Semi-Annual Report to Shareholders for the period ended June 30, 2018 for the Hedged International Developed Equity Index Fund and, for the International Developed Equity Index Fund, will be included in that Fund's annual report or semi-annual report, as applicable, after that Fund commences operations.

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Key professionals involved in the day-to-day portfolio management of the Funds include the following:

David Chin is a Vice President of SSGA and the Adviser and a Senior Portfolio Manager in the Global Equity Beta Solutions Group. He is responsible for managing both U.S. and international funds. Prior to joining SSGA in 1999, Mr. Chin was a product analyst in the Analytical Services Group at Frank Russell Company. Before this, he worked at OneSource Information Systems developing investment software. Preceding this, he was affiliated with PanAgora Asset Management in the Research and Development group creating quantitative investment models for international equities. Mr. Chin has been working in the investment management field since 1992. Mr. Chin holds a Bachelor of Science in Management Information Systems from the University of Massachusetts/Boston and a Master of Business Administration from the University of Arizona.

Additional information about the portfolio managers' compensation, other accounts managed by the portfolio managers, and the portfolio managers' ownership of the Funds is available in the SAI.

Other Fund Services

The Administrator, Sub-Administrator and Custodian

The Adviser serves as administrator of each Fund. The amount of the fee paid to the Adviser for administrative services may vary by share class. Each Fund currently pays the Adviser an administrative fee at the annual rate of 0.05% with respect to each of its share classes. State Street, a subsidiary of State Street Corporation, serves as sub-administrator for the Funds for a fee that is paid by the Adviser. State Street also serves as custodian of the Funds for a separate fee that is paid by the Funds. SSGA FM serves as administrator of the Portfolio and State Street serves as sub-administrator and custodian of the Portfolio.

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Funds' transfer agent and dividend disbursing agent (the “Transfer Agent”).

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Funds' distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

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Additional Information

Shareholder Information

Determination of Net Asset Value

Each Fund determines its net asset value (“NAV”) per share once each business day as of the scheduled close of regular trading on the New York Stock Exchange (the “NYSE”). Pricing does not occur on NYSE holidays. A business day is one on which the NYSE is open for regular trading. The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. In unusual circumstances, such as an emergency or an unscheduled close or halt of trading on the NYSE, the time at which share prices are determined may be changed. The NAV per share is based on the market value of the investments held in a Fund. The NAV of each class of a Fund's Shares is calculated by dividing the value of the assets of the Fund attributable to that class less the liabilities of the Fund attributable to that class by the number of shares in the class outstanding.As noted in this Prospectus, each Fund may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when each Fund does not price its shares. Consequently, the NAV of each Fund's Shares may change on days when shareholders are not able to purchase or redeem the Fund's Shares. Purchase and redemption orders for Fund Shares are processed, respectively, at the NAV next determined after the Fund accepts a purchase order or receives a redemption request in good form. Each Fund values each security or other investment pursuant to guidelines adopted by the Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Funds' Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii) a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by a Fund occurs after the close of a related exchange but before the determination of a Fund's NAV. Attempts to determine the fair value of securities or other investments introduce an element of subjectivity to the pricing of securities or other investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the price a Fund would have received had it sold the investment. To the extent that a Fund invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the funds. The prospectuses of these funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

Investing in State Street Institutional Investment Trust Shares

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Purchasing Shares

Choosing a Share Class

The Funds offer three classes of shares through this Prospectus: Class A, Class I and Class K, available to you subject to the eligibility requirements set forth below.

	Class A	Class I	Class K
Availability	Available to the general public through certain Financial Intermediaries.	Limited to certain investors, including: • Certain banks, broker-dealers and other Financial Intermediaries. • Certain employer- sponsored retirement plans. • Certain employees or affiliates of State Street Corporation or its affiliates	Limited to certain investors, including certain qualified recordkeepers and employer-sponsored retirement plans.
Minimum Initial Investment	$2,000. The investment minimum may be modified, waived or reduced for certain types of investors ( e.g ., 401(k) or 403(b) plans) and investments as well as for certain fee-based programs where an agreement is in place.	$1,000,000. The investment minimum may be modified, waived or reduced for certain types of investors (e.g., 401(k) or 403(b) plans) and investments as well as for certain fee- based programs where an agreement is in place.	$10,000,000. The investment minimum may be modified, waived or reduced for certain types of investors ( e.g ., 401(k) or 403(b) plans) and investments as well as for certain fee- based programs where an agreement is in place.
Maximum Investment	None.	None.	None.
Initial (Front-End) Sales Charge	Yes. 5.25%, payable at time of purchase. Lower sales charges are available for larger investments. See the chart under “Class A” section of this Prospectus.	No. Entire purchase price is invested in shares of a Fund.	No. Entire purchase price is invested in shares of a Fund.

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	Class A	Class I	Class K
Deferred (CDSC) Sales Charge	No, except for purchases of $1,000,000 or more that are redeemed within 18 months after purchase.	No.	No.
Distribution and Service (Rule 12b-1) Fees	0.25% annual fee.	No.	No.
Redemption Fees	No.	No.	No.

Class A

Class A shares are available to the general public for investment through qualified recordkeepers with a distribution and/or fund servicing agreement maintained with SSGA FD.

When you buy Class A shares, you pay an initial (or front-end) sales charge at the time of your investment, which is included in the offering price, unless you qualify for a sales charge reduction or waiver. This fee is deducted from the amount you invest, and the remainder of your money is used to buy shares in the Fund. The table below shows the amount of sales charge you would pay at different levels of investment and the commissions paid to Financial Intermediaries at each level of investment. The actual sales charge you pay may vary slightly from the rates disclosed due to rounding.

Amount of Purchase Payment	Sales Charge as a % of Offering Price	Sales Charge as a % of Net Amount Invested	Financial Intermediary Compensation as a % of Offering Price
Less than $50,000	5.25%	5.54%	4.75%
$50,000-$99,999	4.50%	4.71%	4.00%
$100,000-$249,999	3.50%	3.63%	3.25%
$250,000-$499,999	2.50%	2.56%	2.25%
$500,000-$999,999	2.00%	2.04%	1.75%
$1,000,000 or more	None	None	Advanced Commission ^{1, 2}

¹	Class A advanced commission for purchases over $1 million:

1.00%	First $3 million
Plus 0.50%	Next $12 million
Plus 0.25%	Over $15 million

Reducing Your Class A Sales Charge

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1.	Your account(s);
2.	Account(s) of your spouse or domestic partner;
3.	Account(s) of children under the age of 21 who share your residential address;
4.	Trust accounts established by any of the individuals in items (1) through (3) above. If the person(s) who established the trust is deceased, the trust account may be aggregated with the account(s) of the primary beneficiary of the trust;
5.	Solely controlled business accounts; and
6.	Single-participant retirement plans of any of the individuals in items (1) through (3) above.

Waiver Of The Class A Sales Charge

A sales charge (“load”) may not be imposed on Class A shares of the Funds if the shares were:

1.	Acquired through the reinvestment of dividends and capital gain distributions.
2.	Acquired in exchange for shares of another Class A State Street Fund that were previously assessed a sales charge. However, if your shares are subject to CDSC, the CDSC will continue to apply to your new shares at the same CDSC rate.

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•	The State Street Funds
•	State Street Corporation and its subsidiaries and affiliates

4.	Bought by employees of:

•	DST Asset Manager Solutions, Inc. and its subsidiaries and affiliates.

•

5.	Bought by:

•	Authorized retirement plans serviced or sponsored by a Financial Intermediary, provided that such Financial Intermediary has entered into an agreement with SSGA FD or with the Fund with respect to such purchases at NAV.
•	Investors who are directly rolling over or transferring shares from an established State Street Fund or State Street qualified retirement plan. Rolling over or transferring shares involves the transferring of shares (in-kind); there is no cash movement associated with the transaction.
•	Clients of Financial Intermediaries that (i) charge an ongoing fee for advisory, management, consulting or similar services, or (ii) have entered into an agreement with SSGA FD to offer Class A shares through a no-load network or platform, or self-directed brokerage accounts that may or may not charge transaction fees to customers.
•	Insurance company separate accounts.
•	Tuition Programs that qualify under Section 529 of the Code.

6.	Bought with proceeds from the sale of Class A shares of a State Street Fund, but only if the purchase is made within 90 days of the sale or distribution. Appropriate documentation may be required. Please refer to Class A Account Reinstatement Privileges below.
7.	Bought in connection with plans of reorganization of a State Street Fund, such as mergers, asset acquisitions and exchange offers to which a Fund is a party. However, you may pay a CDSC when you sell the Fund Shares you received in connection with the plan of reorganization.

Additional Sales Charge Waiver Disclosure

¹	State Street Funds that offer Class N Shares include: State Street Dynamic Small Cap Fund (SVSCX), State Street Defensive Emerging Markets Equity Fund (SSEMX), State Street International Stock Selection Fund (SSAIX) and State Street S&P 500 Index Fund (SVSPX).

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How the CDSC is Calculated

The State Street Funds calculate the CDSC by treating all purchases made in a given month as though they were made on the first day of the month.

You should retain any records necessary to substantiate historical costs because SSGA FD, the Funds, the transfer agent and your Financial Intermediary may not maintain such information.

Waiver of the CDSC

In the following situations, no CDSC is imposed on redemptions of Class A shares of the Funds:

1.	If you participate in the Automatic Withdrawal Plan (AWP). Redemptions made on a regular periodic basis ( e.g . monthly) will not be subject to any applicable CDSC if they are, in the aggregate, less than or equal to 10% annually of the current market value of the account balance. Redemptions made as part of a required minimum distribution are also included in calculating amounts eligible for this waiver. For information on the Automatic Withdrawal Plan, please see Service Options.
2.	If you are a registered participant or beneficial owner of an account and you die or become disabled (as defined in Section 72(m)(7) of the Code). This waiver is only available for accounts open prior to the shareholder's or beneficiary's death or disability, and the redemption must be made within one year of such event. Subsequent purchases into such account are not eligible for the CDSC waiver. In order to qualify for this waiver, SSGA FD must be notified of such death or disability at the time of the redemption order and be provided with satisfactory evidence of such death or disability.
3.	Redemptions that represent a required minimum distribution from your IRA Account or other qualifying retirement plan but only if you are at least age 70 1/2. If you maintain more than one IRA, only the assets credited to the IRA that is invested in one or more of the State Street Funds are considered when calculating that portion of your minimum required distribution that qualifies for the waiver.
4.	A distribution from a qualified retirement plan by reason of the participant's retirement.
5.	Redemptions that are involuntary and result from a failure to maintain the required minimum balance in an account.
6.	Exchanges in connection with plans of reorganization of a State Street Fund, such as mergers, asset acquisitions and exchange offers to which a Fund is a party. However, you may pay a sales charge when you redeem the Fund Shares you receive in connection with the plan of reorganization.
7.	Exchanges for shares of the same class of another State Street Fund. However, if your shares are subject to CDSC, the CDSC will continue to apply to your new shares. For purposes of the CDSC, shares will continue to age from the date of the original purchase of the Fund Shares.
8.	Redemption of shares purchased through employer sponsored retirement plans and deferred compensation plans. The CDSC, however, will not be waived if the plan redeems all of the shares that it owns on behalf of participants prior to the applicable CDSC period, as defined above.
9.	Redemptions as part of annual IRA custodial fees.
10.	Acquired through the reinvestment of dividends and capital gains distributions.

Appropriate documentation may be required. Please refer to Class A Account Reinstatement Privileges below.

Class A Account Reinstatement Privileges

Class I

Class I shares are available to the following categories of investors and/or investments:

1.	Banks, broker-dealers and other financial institutions (including registered investment advisers and financial planners) purchasing shares on behalf of their clients in:

•	discretionary and non-discretionary advisory programs;

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•	fund supermarkets;
•	asset allocation programs;
•	other programs in which the client pays an asset-based fee for advice or for executing transactions in Fund Shares or for otherwise participating in the program; or
•	certain other investment programs that do not charge an asset-based fee;

2.	Qualified state tuition plans described in Section 529 of the Code and donor-advised charitable gift funds (subject to all applicable terms and conditions);
3.	Defined contribution, defined benefit and other employer-sponsored employee benefit plans, whether or not qualified under the Code;
4.	Certain other registered open-end investment companies whose shares are distributed by SSGA FD;
5.	Certain retirement and deferred compensation programs established by State Street Corporation or its affiliates for their employees or the Funds' Trustees;
6.	Current or retired Directors or Trustees of the State Street Funds, officers and employees of SSGA, and any of its subsidiaries, such persons' spouses, and children under the age of 21, and trust accounts for which any of such person is a beneficiary;
7.	Investments made in connection with certain mergers and/or reorganizations as approved by the Adviser;
8.	The reinvestment of dividends from Class I shares in additional Class I shares of a Fund; and
9.	Qualified recordkeepers with a distribution and/or fund servicing agreement maintained with SSGA FD.

The minimum investment for Class I shares is $1,000,000.

Class K

Class K shares are available to the following categories of investors:

1.	Qualified recordkeepers with an applicable agreement maintained with SSGA FD;
2.	Defined benefit plans, defined contribution plans, endowments and foundations with greater than $10,000,000 in a qualified tax-exempt plan;
3.	Employers with greater than $10,000,000 in the aggregate between qualified and non-qualified plans that they sponsor; and
4.	Defined contribution, defined benefit and other employer-sponsored employee benefit plans, whether or not qualified under the Code.

The minimum investment for Class K shares is $10,000,000.

How to Initiate a Purchase Request

Investing in the State Street Funds Through a Financial Intermediary

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Please be sure to check Exchanging Shares and Frequent-Trading Limits below.

How to Pay for a Purchase

By Check . You may send a check to make initial or additional purchases to your fund account. Make your check payable to “State Street Funds” and include the appropriate fund name and account number ( e.g ., “State Street International Developed Equity Index Fund—a/c #xxx”) in the memo section of the check.

Trade Dates-Purchases

If your purchase request is not in good order, it may be rejected.

For further information about purchase transactions, consult our website at www.ssgafunds.com or see Contacting the State Street Funds.

Other Purchase Policies You Should Know

Redeeming Shares

By Telephone. You may call the State Street Funds to request a redemption of shares. See Contacting the State Street Funds .

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By Mail. You may send a written request to the State Street Funds to redeem from a Fund account or to make an exchange. See Contacting the State Street Funds .

Please be sure to check Exchanging Shares and Frequent-Trading Limits below.

Trade Date-Redemptions

The trade date for any redemption request received in good order will depend on the day and time the State Street Funds receive your request in good order and the manner in which you are redeeming.

How to Receive Redemption Proceeds

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Other Redemption Policies that You Should Know

Address Changes. If your address of record has been changed within thirty (30) days of the redemption request, the request must be in writing and bear a medallion guarantee.

Significant/Unusual Economic or Market Activity. During periods of significant or unusual economic or market activity, you may encounter delays attempting to give instructions by phone.

Large Redemptions. Requests for redemptions over $50,000 must be in writing and bear a medallion guarantee.

Exchanging Shares

Share Class Conversions

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Frequent-Trading Limits

As a means to protect each State Street Fund and its shareholders from Excessive Trading:

•	The State Street Funds' transfer agent compiles, monitors and reports account-level information on omnibus and underlying shareholder/participant activity. Depending on the account type, monitoring will be performed on a daily, monthly, quarterly and/or annual basis;
•	The State Street Funds' distributor has obtained information from each Financial Intermediary holding shares in an omnibus account with the State Street Funds regarding whether the Financial Intermediary has adopted and maintains procedures that are reasonably designed to protect the Funds against harmful short-term trading; and
•	With respect to State Street Funds that invest in securities that trade on foreign markets, pursuant to the State Street Funds' fair valuation procedures, pricing adjustments may be made based on information received from a third-party, multi-factor fair valuation pricing service.

The State Street Funds' distributor has detailed procedures that document the transparency oversight and monitoring processes performed by the State Street Funds' transfer agent.

Service Options

Dividend and Capital Gain Distribution Option

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Please refer to Dividends, Distributions and Tax Considerations below for additional information.

Automatic Withdrawal Plan

Telephone Redemptions and Exchanges

Automatic Investment Plan

Additional Shareholder Information

Account Transfers

Responsibility for Fraud

Right to Change Policies

In addition to the rights expressly stated elsewhere in this Prospectus, the State Street Funds reserve the right, in the future, to:

1.	Alter, add, or discontinue any conditions of purchase (including eligibility requirements), redemption, exchange, service, or privilege at any time;
2.	Accept initial purchases by telephone;
3.	Freeze any account and/or suspend account services if the State Street Funds has received reasonable notice of a dispute regarding the assets in an account, including notice of a dispute between the registered or beneficial account owners, or if we reasonably believe a fraudulent transaction may occur or has occurred;
4.	Temporarily freeze any account and/or suspend account services upon initial notification to the State Street Funds of the death of the shareholder until the State Street Funds receive required documentation in good order;
5.	Alter, impose, discontinue, or waive any redemption fee, account service fee, or other fees charged to a group of shareholders; and
6.	Redeem an account or suspend account privileges, without the owner's permission to do so, in cases of threatening conduct or activity the State Street Funds believe to be suspicious, fraudulent, or illegal.

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Unclaimed Property

Dividends, Distributions and Tax Considerations

Distribution Options. You can choose from four different distribution options as indicated on the application:

•	Reinvestment Option—Dividends and capital gain distributions will be automatically reinvested in additional shares of a Fund. If you do not indicate a choice on the application, this option will be automatically assigned.
•	Income-Earned Option—Capital gain distributions will be automatically reinvested, but a check, direct deposit or wire will be sent for each dividend distribution.
•	Cash Option—A check, wire or direct deposit will be sent for each dividend and capital gain distribution.
•	Direct Dividends Option—Dividends and capital gain distributions will be automatically invested in another identically registered State Street Fund of the same share class.

Delivery of Documents to Accounts Sharing an Address

Tax Considerations

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Each Fund invests substantially all of its assets in the Portfolio, which is treated as a partnership for U.S. federal income tax purposes, and the Hedged International Developed Equity Index Fund will use the balance of its assets to enter into foreign currency forward contracts, forward currency futures and options, and currency swaps or purchase currency structured notes, in order to hedge the non-U.S. currency exposure to the U.S. dollar created by the Portfolio's investment in foreign equities. Because each Fund invests substantially all of its assets in the Portfolio, the nature and character of each Fund's income, gains, losses and deductions generally will be determined at the Portfolio level, and each Fund will be allocated its share of the Portfolio's income, gains, losses and deductions. As applicable, references in this discussion to income, gains and losses of a Fund will include references to income, gains and losses recognized and deductions accruing at the Portfolio level and allocated to or otherwise taken into account by the Fund, and references to assets of a Fund will include references to the Fund's allocable share of the assets of the Portfolio.

For U.S. federal income tax purposes, distributions of investment income generally are taxable to you as ordinary income. Taxes on distributions of capital gains generally are determined by how long the Fund or Portfolio owned (or is deemed to have owned) the investments that generated them, rather than how long you have owned your Fund Shares. Distributions of net capital gains (that is, the excess of net long-term capital gains over net short-term capital losses) from the sale of investments that a Fund or the Portfolio owned (or is deemed to have owned) for more than one year that are properly reported by a Fund as capital gain dividends generally will be treated as long-term capital gain includible in your net capital gain and taxed to individuals at reduced rates. Distributions of gains from investments that a Fund or Portfolio owned (or is deemed to have owned) for one year or less generally will be taxable to you as ordinary income. Distributions of investment income properly reported by a Fund as derived from “qualified dividend income,” which will not include income from the Fund's or the Portfolio's portfolio securities on loan, are taxed to individuals at the rates applicable to net capital gain, provided holding period and other requirements are met by both the shareholder and the Fund or the Portfolio, as applicable. Distributions are taxable to you even if they are paid from income or gains earned by a Fund, including through the Portfolio, before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares.

Certain of a Fund's or the Portfolio's investment practices, including derivative transactions and investments in debt obligations issued or purchased at a discount, will be subject to special and complex U.S. federal income tax provisions. These special rules may affect the timing, character, and/or amount of a Portfolio's or Fund's income or gains, and, in turn, a Fund's distributions to shareholders, and may require the Fund or the Portfolio to sell its investments at a time when it is not advantageous to do so.

In particular, the Hedged International Developed Equity Index Fund's transactions in respect of foreign currencies will potentially give rise to ordinary income and loss to the extent such income or loss results from fluctuations in the value of the foreign currency concerned. Such activities will potentially increase distributions to shareholders, including at the end of the year, accelerate distributions to shareholders, and increase the distributions taxed to shareholders as ordinary income. Moreover, any net losses arising from such activities will generally reduce and potentially require the recharacterization of prior ordinary income distributions, including in whole or in part as a return of capital. Any net ordinary losses so created cannot be carried forward by the Fund to offset income or gains earned in subsequent taxable years. The Hedged International Developed Equity Index Fund makes an election to

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treat currency gains and losses derived from certain eligible foreign currency forward contracts as capital gains and losses. It is possible that the Hedged International Developed Equity Index Fund will elect, on a prospective basis, to treat currency gains and losses derived from futures contracts or options as capital gains and losses; not all currency gains and losses derived from foreign currency contracts are eligible for this treatment.

Financial Intermediary Arrangements

Distribution Arrangements and Rule 12b-1 Fees

A Fund may pay distribution fees and other amounts described in this Prospectus at a time when shares of that Fund are unavailable for purchase.

Other Payments to Financial Intermediaries

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Financial Highlights

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET HEDGED INTERNATIONAL DEVELOPED EQUITY INDEX FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	State Street Hedged International Developed Equity Index Fund Class K
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended(a) 12/31/16	For the Period 5/29/15* - 12/31/15
Net asset value, beginning of period	$ 10.40	$ 9.18	$ 9.00	$ 10.00
Income (loss) from investment operations:
Net investment income (loss) (b)	0.29	0.27	0.24	0.09
Net realized and unrealized gain (loss)	(1.26)	1.27	0.34	(1.00)
Total from investment operations	(0.97)	1.54	0.58	(0.91)
Distributions to shareholders from:
Net investment income	(0.50)	—	(0.20)	(0.06)
Net realized gains	(0.14)	(0.32)	(0.20)	(0.03)
Total distributions	(0.64)	(0.32)	(0.40)	(0.09)
Net asset value, end of period	$ 8.79	$ 10.40	$ 9.18	$ 9.00
Total return (c)	(9.25)%	16.85%	6.27%	(9.01)%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$2,922,844	$2,894,400	$2,113,394	$958,544
Ratios to Average Net Assets:
Total expenses	0.36%	0.35%	0.34%	0.38%(d)
Net expenses	0.20%	0.20%	0.20%	0.20%(d)
Net investment income (loss)	2.85%	2.69%	2.79%	1.60%(d)
Portfolio turnover rate (e)	14%	4%	1%	1%(f)

*	Commencement of operations.
(a)	Prior to April 29, 2016, the per share amounts and ratios included the Fund's standalone performance. Effective April 29, 2016, the per share amounts and ratios include the Fund's proportionate share of the income and expenses of the affiliated Portfolio.
(b)	Net investment income per share is calculated using the average shares method.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Annualized.
(e)	Portfolio turnover rate is from the corresponding Portfolio.
(f)	Not annualized.

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Index/Trademark Licenses/Disclaimers

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Contacting the State Street Funds

Online:	www.ssgafunds.com	24 hours a day, 7 days a week
Phone:	(800) 647-7327	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Overnight/ Registered, Express, Certified Mail
State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737	State Street Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407

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For more information about the Funds:

The Funds' SAI includes additional information about the Funds and is incorporated by reference into this document. Additional information about the Funds' investments is available or will be available, in the Funds' most recent annual and semi-annual reports to shareholders. In a Fund's annual report, you will find a discussion of the market conditions and investment strategies that significantly affected the Fund's performance during its last fiscal year. The Funds' SAI is available, without charge, upon request. The Funds' annual and semi-annual reports are available, or will be available, without charge, upon request. Shareholders in the Funds may make inquiries to the Funds to receive such information by calling (800) 997-7327 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. Each Fund's Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, or will be available, free of charge, on the Funds' website at www.ssgafunds.com.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

SSITSTATPRO2

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Defensive Global Equity Fund (formerly, State Street Disciplined Global Equity Fund)

Class A (SSGGX) Class I (SSGMX) Class K (SSGKX)

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with the Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling (800) 647-7327.Your election to receive reports in paper will apply to all funds held in your account.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in the Fund offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

The Fund may offer multiple classes of shares. This Prospectus covers only the Class A, Class I and Class K Shares of the Fund.

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Fund Summary	1
State Street Defensive Global Equity Fund (formerly, State Street Disciplined Global Equity Fund)	1
Additional Information About Investment Objectives, Principal Strategies and Risks	8
Additional Information About Non-Principal Investment Strategies and Risks	16
Portfolio Holdings Disclosure	17
Management and Organization	18
Shareholder Information	19
Dividends, Distributions and Tax Considerations	31
Financial Intermediary Arrangements	33
Financial Highlights	36

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State Street Defensive Global Equity Fund
(formerly, State Street Disciplined Global Equity Fund)

Investment Objective

The State Street Defensive Global Equity Fund (the “Defensive Global Equity Fund” or the “Fund”) seeks to provide competitive long-term returns while maintaining low long-term volatility relative to the broad global equity market.

Fees and Expenses of the Fund

The tables below describe the fees and expenses that you may pay if you buy and hold shares of the Fund (“Fund Shares”). You may qualify for sales charge discounts on purchases of Class A shares if you agree to invest in the future, or if you and your family currently invest, at least $50,000 in State Street Funds that offer Class A shares. More information about these and other discounts is available from your financial professional and in Choosing a Share Class – Reducing Your Class A Sales Charge on page 22 of the Fund's Prospectus. The expenses shown in the table and the Example reflect the expenses of the Fund and the Fund's proportionate share of the expenses of State Street Defensive Global Equity Portfolio (the “Defensive Global Equity Portfolio” or sometimes referred to in context as the “Portfolio”).

Shareholder Fees (fees paid directly from your investment)

	Class A	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	5.25%	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None ¹	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class A	Class I	Class K
Management Fee	0.75%	0.75%	0.75%
Distribution and/or Shareholder Service (12b-1) Fees	0.25%	0.00%	0.00%
Other Expenses ²	2.87%	2.87%	2.67%
Total Annual Fund Operating Expenses	3.87%	3.62%	3.42%
Less Fee Waivers and/or Expense Reimbursements ³	(2.67%)	(2.67%)	(2.67%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	1.20%	0.95%	0.75%

¹	A contingent deferred sales charge (“CDSC”) of 1.00% may be assessed on redemptions of Class A shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase as part of an investment of $1,000,000 or more.
²	Other Expenses are based on estimates for the current fiscal year for Class A and Class K shares and have been restated to reflect current fees for Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.75% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

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	1 year	3 years	5 years	10 years
Class A	$641	$1,411	$2,198	$4,246
Class I	$ 97	$ 861	$1,646	$3,705
Class K	$ 77	$ 801	$1,548	$3,523

Portfolio Turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). As a shareholder of the Defensive Global Equity Portfolio the Fund bears its ratable share of the transaction costs associated with the portfolio turnover of the Portfolio. A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund Shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 64% of the average value of its portfolio.

Principal Investment Strategies

Under normal circumstances, the Fund will invest at least 80% of its net assets (plus borrowings, if any, for investment purposes) in equity securities. The Fund will provide shareholders with at least sixty (60) days' notice prior to any change in its 80% policy. The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposure comparable, in the judgment of the Adviser, to the foregoing types of investments may be counted toward satisfaction of the Fund's 80% policy. SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), the investment adviser to the Fund, seeks to select a portfolio of securities that it expects over the long term to exhibit low volatility both in absolute terms and in comparison with the MSCI World Index (the “Index”) and provide competitive returns as compared with the Index.

In seeking to identify stocks offering the potential for capital growth, the Adviser employs a proprietary quantitative process. The process evaluates the relative attractiveness of eligible securities based on the correlation of certain historical economic and financial factors (such as measures of growth potential, valuation, quality and investor sentiment), and other historical quantitative metrics. Additionally, the process may incorporate an element designed to evaluate the macroeconomic environment and prevailing market conditions. The process is intended to allow the Adviser to evaluate eligible securities and then rank eligible securities in the Fund's investment universe in the order of their attractiveness as potential Fund investments.

The Adviser also uses a quantitative analysis to determine the expected volatility of a stock's market price. Volatility is a statistical measurement of up and down fluctuations in the value of a security over time. Volatility may result in rapid and dramatic price swings. The Adviser seeks to favor securities with low exposure to market risk factors and low security-specific risk. In determining the exposure of a security to such risk factors, the Adviser may take into account, among other things, such considerations as a security's market capitalization, its price momentum, the security's valuation, the liquidity of the security, the degree to which the issuer is leveraged, and the issuer's growth prospects. The Adviser also implements risk constraints at the overall portfolio level by periodic testing of the portfolio's composition against proprietary risk models, focusing on such factors as industry and sector exposures, portfolio diversification levels, market capitalization exposure, and geographic exposures.

Through these quantitative processes of security selection and portfolio diversification, the Adviser expects that the portfolio will be subject to a relatively low level of absolute risk (as defined by statistical measures of volatility, such as standard deviation of returns) and that the portfolio should exhibit relatively low volatility compared with the Index over the long term. The Adviser will make changes over time in the Fund's portfolio to reflect changes in the various risk factors described above. From time to time, the Adviser may make a qualitative judgment not to implement fully the results of the quantitative investment process if it believes that the process did not take into account all of the information relevant to a particular investment or the Fund's portfolio in the aggregate, or that a different investment might be more appropriate.

Although the Fund pursues a defensive style of investing and targets a low level of volatility in absolute terms and in comparison to the Index, there is no assurance that the Fund will outperform the Index during market downturns or achieve its target volatility, and the Fund may be subject to significant changes in value over short or longer timeframes. There also can be no assurance that the Fund will produce returns in excess of the Index.

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tains a principal place of business in such country; (ii) the issuer's securities are traded principally in such country; or (iii) during the issuer's most recent fiscal year, it derived at least 50% of its revenues or profits from goods produced or sold, investments made, or services performed in such country or has at least 50% of its assets in such country.

The Fund expects to invest primarily in common stocks. The Fund may purchase securities in their initial public offerings, and may hold securities that are restricted as to resale. The Fund may invest in other investment companies, including exchange-traded funds, to the extent permitted by applicable law (including those advised by the Adviser). The Fund may hold a portion of its assets in cash and cash instruments. While the Fund may invest in companies of any market capitalization, it expects to primarily invest in large capitalization companies. The Fund may invest in derivatives, such as futures contracts, in order to gain broad equity market exposures pending investments of cash, or to reduce market exposures pending the sales of securities. The Fund reserves the right to enter into foreign currency futures and forward contracts to hedge currency risk, although the Adviser does not currently anticipate that such transactions will play any significant role in the investment process.

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the Defensive Global Equity Portfolio, which has substantially identical investment policies to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio and it participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Portfolio.

Principal Risks

In addition, the Fund is subject to the following risks:

Currency Hedging Risk: If the Fund enters into currency hedging transactions, any loss generated by those transactions generally should be substantially offset by gains on the hedged investment, and vice versa. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. Hedges are sometimes subject to imperfect matching between the hedging transaction and the risk sought to be hedged. There can be no assurance that the Fund's hedging transactions will be effective.

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Growth Stock Risk: The prices of growth stocks may be based largely on expectations of future earnings, and their prices can decline rapidly and significantly in reaction to negative news. Growth stocks may underperform value stocks and stocks in other broad style categories (and the stock market as a whole) over any period of time and may shift in and out of favor with investors generally, sometimes rapidly, depending on changes in market, economic, and other factors.

Leveraging Risk: Use of leverage by the Fund may have the effect of increasing the volatility of the value of the Fund's portfolio, and may entail risk of loss in excess of the Fund's invested capital. To the extent the Fund uses leverage, the Fund's losses (and gains) may be greater than if the Fund had not used leverage.

Management Risk: The Portfolio is actively managed. The Adviser's judgments about the attractiveness, relative value, or potential appreciation of a particular sector, security, commodity or investment strategy may prove to be incorrect, and may cause the Portfolio and, therefore, the Fund to incur losses. There can be no assurance that the Adviser's investment techniques and decisions will produce the desired results.

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Volatility Risk: Because the Fund seeks to exhibit relative low volatility and excess returns as compared to the Index over the long term, both its portfolio investments and its returns may differ, potentially greatly, from those of the Index. There can be no assurance that the Fund will in fact experience lower volatility than the Index nor can there be any assurance that the Fund will produce returns in excess of the benchmark. The application of the Adviser's active stock selection model may lead to a degree of added risk in exchange for the potential outperformance relative to the Index. Because the Fund is managed to limit volatility, it is likely that in periods of rapidly rising markets the Fund will experience less favorable returns than the Index.

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Performance

The bar chart and table below provide some indication of the risks of investing in the Defensive Global Equity Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of the Index. The bar chart shows how the Class I shares' returns have varied for each full calendar year shown. Except for differences in returns resulting from differences in fees and expenses, all share classes would have substantially similar returns because all share classes invest in the same portfolio of securities. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Return (years ended 12/31)

Highest Quarterly Return: 7.23% (Q1, 2017)
Lowest Quarterly Return: -9.81% (Q4, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. After-tax returns depend on an investor's tax situation and may differ from those shown below, and after-tax returns are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts (IRAs). Except for differences in returns resulting from differences in fees, expenses, and sales charges (as applicable), all share classes would have substantially similar returns because all share classes invest in the same portfolio of securities.

	One Year	Since Inception	Inception Date
Class I			2/18/2016
Return Before Taxes	-6.27%	8.04%
Return After Taxes on Distributions	-8.20%	6.51%
Return After Taxes on Distributions and Sale of Fund Shares	-2.43%	6.01%
MSCI World Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-8.71%	9.33%

The Fund will make updated performance information, including its current net asset value, available at the Fund's website: www.ssgafunds.com.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund and the Portfolio.

The professionals primarily responsible for the day-to-day management of the Fund are Chee Ooi and Adel Daghmouri, each of which has served as a portfolio manager of the Fund since inception in 2016.

Chee Ooi is a Managing Director of the Adviser and a Senior Portfolio Manager in the Active Quantitative Equity Group. He joined the Adviser in 2008.

Adel Daghmouri is a Vice President of the Adviser and a Senior Portfolio Manager in the Active Quantitative Equity Group. He joined the Adviser in 1998.

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Purchase and Sale of Fund Shares

Purchase Minimums

Class A
To establish an account	$2,000
To add to an existing account	None
Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objectives, Principal Strategies and Risks

Investment Objective

Principal Investment Strategies

Under normal circumstances, the Fund will invest at least 80% of its net assets (plus borrowings, if any, for investment purposes) in equity securities. The Fund will provide shareholders with at least sixty (60) days' notice prior to any change in its 80% policy. The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposure comparable, in the judgment of the Adviser, to the foregoing types of investments may be counted toward satisfaction of the Fund's 80% policy. SSGA FM seeks to select a portfolio of securities that it expects over the long term to exhibit low volatility both in absolute terms and in comparison with the MSCI World Index (the “Index”) and provide competitive returns as compared with the Index.

The Fund will generally invest at least 40% of its assets in securities of issuers economically tied to countries other than the United States and will generally hold securities of issuers economically tied to at least three countries, including the United States. The Fund will generally consider an investment in an issuer to be tied to a particular country if (i) the issuer is organized in such country or maintains a principal place of business in such country; (ii) the issuer's securities are traded principally in such country; or (iii) during the issuer's most recent fiscal year, it derived at least 50% of its revenues or profits from goods produced or sold, investments made, or services performed in such country or has at least 50% of its assets in such country.

The Fund expects to invest primarily in common stocks. The Fund may also invest in other equity securities including depositary receipts having characteristics similar to common stocks, preferred stocks, convertible securities, and rights or warrants to buy common stocks. The Fund may purchase securities in their initial public offerings, and may hold securities that are restricted as to resale. The Fund may invest in other investment companies, including exchange-traded funds, to the extent permitted by applicable law (including those advised by the Adviser). The Fund may hold a portion of its assets in cash and cash instruments. While the Fund may invest in companies of any market capitalization, it expects to primarily invest in large capitalization companies. The Fund may

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invest in derivatives, such as futures contracts, in order to gain broad equity market exposures pending investments of cash, or to reduce market exposures pending the sales of securities. The Fund reserves the right to enter into foreign currency futures and forward contracts to hedge currency risk, although the Adviser does not currently anticipate that such transactions will play any significant role in the investment process.

Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure.

Convertible Securities Risk . Convertible securities are bonds, debentures, notes, preferred stocks or other securities that may be converted or exchanged (by the holder or by the issuer, depending on the terms of the securities) into shares of the underlying common stock (or cash or securities of equivalent value) at a stated exchange ratio. Convertible securities may be subordinate to other debt securities issued by the same issuer. Issuers of convertible securities are often not as strong financially as issuers with higher credit ratings. Convertible securities typically provide yields lower than comparable non-convertible securities. Their values may be more volatile than those of non-convertible securities, reflecting changes in the values of the securities into which they are convertible.

Currency Hedging Risk . If a derivative is used as a hedge against a position that the Fund holds, any gain generated by the derivative generally should be substantially offset by losses on the hedged investment, and vice versa. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. Hedges are sometimes subject to imperfect matching between a derivative and its reference asset. Furthermore, while the Fund may hedge against currency fluctuations, it is possible that a degree of currency exposure may remain even at the time a hedging transaction is implemented. As a result, changes in currency exchange rates may affect Fund returns even when the hedge works as intended. The effectiveness of the Fund's currency hedging strategy will also generally be affected by the volatility of both the securities that the Fund holds, and the volatility of the U.S. dollar relative to the currencies to be hedged. Increased volatility may reduce the effectiveness of the Fund's currency hedging strategy and may impact the costs associated with hedging transactions. The effectiveness of the Fund's currency hedging strategy and the costs associated with hedging transactions may also in general be affected by interest rates. Significant differences between U.S. dollar interest rates and foreign currency interest rates may further impact the effectiveness of the Fund's currency hedging strategy. There can be no assurance that the Fund's hedging transactions will be effective. The Fund's currency hedging activities will potentially increase or accelerate dis-

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tributions to shareholders, increase distributions taxed to shareholders as ordinary income, result in the re-characterization of prior ordinary income distributions as return of capital, or generate losses that cannot be used to offset income or capital gain in subsequent years. The Fund will bear the costs associated with any such hedging transaction, regardless of any gain or loss experienced on the hedging transaction.

Depositary Receipts Risk . American Depositary Receipts (“ADRs”) are typically trust receipts issued by a U.S. bank or trust company that evidence an indirect interest in underlying securities issued by a foreign entity. Global Depositary Receipts (“GDRs”), European Depositary Receipts (“EDRs”), and other types of depositary receipts are typically issued by non-U.S. banks or financial institutions to evidence an interest in underlying securities issued by either a U.S. or a non-U.S. entity. Investments in non-U.S. issuers through ADRs, GDRs, EDRs, and other types of depositary receipts generally involve risks applicable to other types of investments in non-U.S. issuers. Investments in depositary receipts may be less liquid and more volatile than the underlying securities in their primary trading market. If a depositary receipt is denominated in a different currency than its underlying securities, the Portfolio and, therefore, the Fund will be subject to the currency risk of both the investment in the depositary receipt and the underlying security. There may be less publicly available information regarding the issuer of the securities underlying a depositary receipt than if those securities were traded directly in U.S. securities markets. Depositary receipts may or may not be sponsored by the issuers of the underlying securities, and information regarding issuers of securities underlying unsponsored depositary receipts may be more limited than for sponsored depositary receipts. The values of depositary receipts may decline for a number of reasons relating to the issuers or sponsors of the depositary receipts, including, but not limited to, insolvency of the issuer or sponsor. Holders of depositary receipts may have limited or no rights to take action with respect to the underlying securities or to compel the issuer of the receipts to take action. The prices of depositary receipts may differ from the prices of securities upon which they are based.

Derivatives Risk. A derivative is a financial contract the value of which depends on, or is derived from, the value of an underlying asset, interest rate, or index. Derivative transactions typically involve leverage and may have significant volatility. It is possible that a derivative transaction will result in a loss greater than the principal amount invested, and the Fund may not be able to close out a derivative transaction at a favorable time or price. Risks associated with derivative instruments include potential changes in value in response to interest rate changes or other market developments or as a result of the counterparty's credit quality; the potential for the derivative transaction not to have the effect the Adviser anticipated or a different or less favorable effect than the Adviser anticipated; the failure of the counterparty to the derivative transaction to perform its obligations under the transaction or to settle a trade; possible mispricing or improper valuation of the derivative instrument; imperfect correlation in the value of a derivative with the asset, rate, or index underlying the derivative; the risk that the Fund may be required to post collateral or margin with its counterparty, and will not be able to recover the collateral or margin in the event of the counterparty's insolvency or bankruptcy; the risk that the Fund will experience losses on its derivatives investments and on its other portfolio investments, even when the derivatives investments may be intended in part or entirely to hedge those portfolio investments; the risks specific to the asset underlying the derivative instrument; lack of liquidity for the derivative instrument, including without limitation absence of a secondary trading market; the potential for reduced returns to the Fund due to losses on the transaction and an increase in volatility; the potential for the derivative transaction to have the effect of accelerating the recognition of gain; and legal risks arising from the documentation relating to the derivative transaction.

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Forward Currency Contracts Risk . In a forward currency contract, the Fund agrees to buy in the future an amount in one currency in return for another currency, at an exchange rate determined at the time the contract is entered into. If currency exchange rates move against the Fund's position during the term of the contract, the Fund will lose money on the contract. There is no limit on the extent to which exchange rates may move against the Fund's position. The markets for certain currencies may at times become illiquid, and the Fund may be unable to enter into new forward contracts or to close out existing contracts. Forward currency contracts are entered into in the over-the-counter market, and the Fund's ability to profit from a contract will depend on the willingness and ability of its counterparty to perform its obligations under the contract. Use by the Fund of foreign currency forward contracts may give rise to investment leverage.

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Growth Stock Risk. The prices of growth stocks may be based largely on expectations of future earnings, and their prices can decline rapidly and significantly in reaction to negative news about such factors as earnings, revenues, the economy, political developments, or other news. Growth stocks may underperform value stocks and stocks in other broad style categories (and the stock market as a whole) over any period of time and may shift in and out of favor with investors generally, sometimes rapidly, depending on changes in market, economic, and other factors. As a result, at times when it holds substantial investments in growth stocks, the Fund may underperform other investment funds that invest more broadly or that favor different investment styles. Because growth companies typically reinvest their earnings, growth stocks typically do not pay dividends at levels associated with other types of stocks, if at all.

IPO Risk . The Fund may at times have the opportunity to invest in securities offered in initial public offerings (“IPOs”). IPOs involve companies that have no public operating history and therefore entail more risk than established public companies. The prices of securities offered in IPOs can have significant volatility and the Fund may lose money on an investment in such securities. IPOs may not be available to the Fund at all times, and the Fund may not always invest in IPOs offered to it. Investments in IPOs may have a substantial beneficial effect on the Fund's investment performance. The Fund's investment return earned during a period of substantial investment in IPOs may not be sustained during other periods when the Fund makes more limited, or no, investments in IPOs. There can be no assurance that the Fund will have the opportunity to invest in IPOs that are made available to other clients of the Adviser.

Leveraging Risk . Borrowing transactions, reverse repurchase agreements, certain derivatives transactions, securities lending transactions and other investment transactions such as when-issued, delayed-delivery, or forward commitment transactions may create investment leverage. If the Fund engages in transactions that have a leveraging effect on the Fund's investment portfolio, the value of the Fund will be potentially more volatile and all other risks will tend to be compounded. This is because leverage generally creates investment risk with respect to a larger base of assets than the Fund would otherwise have and so magnifies the effect of any increase or decrease in the value of the Fund's underlying assets. The use of leverage is considered to be a speculative investment practice and may result in losses to the Fund. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. The use of leverage may cause the Fund to liquidate positions when it may not be advantageous to do so to satisfy repayment, interest payment, or margin obligations or to meet asset segregation or coverage requirements.

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Management Risk . The Fund is actively managed. The Adviser's judgments about the attractiveness, relative value, or potential appreciation of a particular sector, security, commodity or investment strategy may prove to be incorrect, and may cause the Fund to incur losses. There can be no assurance that the Adviser's investment techniques and decisions will produce the desired results.

Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject the Fund to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and the Fund's investment program in particular can be uncertain. In recent periods, governmental and non-governmental issuers have defaulted on, or have been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including, without limitation, in Europe or Asia. Defaults or restructurings by governments or others of their debts could have substantial adverse effects on economies, financial markets, and asset valuations around the world. Further Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, or investor perception that these efforts are not succeeding, could negatively affect financial markets generally as well as the values and liquidity of certain securities.

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tion activities of other investors in the master fund. The ability of the Fund to meet redemption requests will depend on its ability to redeem its interest in the master fund. The Adviser or an affiliate serves as investment adviser to the master fund, leading to potential conflicts of interest. For example, the Adviser or its affiliates will receive fees based on the amount of assets invested in the master fund. Investment by the Fund in the master fund may be beneficial in the management of the master fund, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest the Fund's assets in a master fund sponsored or managed by the Adviser or its affiliates in lieu of investments by the Fund directly in portfolio securities, or may have an incentive to invest in such master fund over a master fund sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by the Fund in a master fund sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a master fund sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which the Fund does so. The Fund will bear its pro rata portion of the expenses incurred by the master fund.

Modeling Risk . The Adviser uses quantitative models in an effort to enhance returns and manage risk. Any imperfections, errors or limitations in these models could limit any benefit to the Fund from the use of the models, or could result in incorrect outputs or in investment outcomes different from or opposite to those expected or desired by the Adviser. These models may make simplifying assumptions that limit their effectiveness and may draw from historical data that does not adequately identify or reflect factors necessary to an appropriate or useful output. There can be no assurance that the models will behave as expected in all market conditions. In addition, computer programming used to create quantitative models, or the data on which such models operate, might contain one or more errors. Such errors might never be detected, or might be detected only after the Fund has sustained a loss (or reduced performance) related to such errors.

Preferred Securities Risk . Generally, preferred security holders have no or limited voting rights with respect to the issuing company. In addition, preferred securities are subordinated to bonds and other debt instruments in a company's capital structure and therefore will be subject to greater credit risk than those debt instruments. Unlike debt securities, dividend payments on a preferred security typically must be declared by the issuer's board of directors. An issuer's board of directors is generally not under any obligation to pay a dividend (even if such dividends have accrued), and may suspend payment of dividends on preferred securities at any time. Therefore, in the event an issuer of preferred securities experiences economic difficulties, the issuer's preferred securities may lose substantial value due to the reduced likelihood that the issuer's board of directors will declare a dividend and the fact that the preferred security may be subordinated to other securities of the same issuer. Further, because many preferred securities pay dividends at a fixed rate, their market price can be sensitive to changes in interest rates in a manner similar to bonds - that is, as interest rates rise, the value of the preferred securities held by the Fund are likely to decline. Therefore, to the extent that the Fund invests a substantial portion of its assets in fixed rate preferred securities, rising interest rates may cause the value of the Fund's investments to decline significantly. In addition, because many preferred securities allow holders to convert the preferred securities into common stock of the issuer, their market price can be sensitive to changes in the value of the issuer's common stock and, therefore, declining common stock values may also cause the value of the Fund's investments to decline. Preferred securities often have call features which allow the issuer to redeem the security at its discretion. The redemption of a preferred security having a higher than average yield may cause a decrease in the Fund's yield.

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Rights or Warrants Risk . A warrant gives the holder a right to purchase, at any time during a specified period, a predetermined number of shares of common stock at a fixed price. Rights are similar to warrants but typically have a shorter duration and are issued by a company to existing stockholders to provide those holders the right to purchase additional shares of stock at a later date. Unlike a convertible debt security or preferred stock, a warrant or right does not pay fixed dividends. Warrants and rights may lack a liquid secondary market for resale. The prices of warrants and rights may fluctuate as a result of changes in the value of the underlying security or obligation or due to speculation in the market for the warrants or rights or other factors. Prices of warrants and rights do not necessarily move in tandem with the prices of their underlying securities; their prices may have significant volatility and it is possible that the Fund will lose its entire investment in a warrant or right. The Fund's failure to exercise a warrant or subscription right to purchase common shares in an issuer might result in the dilution of the Fund's interest in the issuing company.

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of the Fund's shares in response to factors affecting or expected to affect an industry, market, or economic sector in which the Fund focuses its investments, resulting in extreme inflows or outflows of cash into and out of the Fund. Such extreme cash inflows or outflows might affect management of the Fund adversely. The Fund may establish or terminate a focus in an industry or sector at any time in the Adviser's discretion and without notice to investors.

Volatility Risk. Because the Fund seeks to exhibit relative low volatility and excess returns as compared to the Index over the long term, both its portfolio investments and its returns may differ, potentially greatly, from those of the Index. There can be no assurance that the Fund will in fact experience lower volatility than the Index nor can there be any assurance that the Fund will produce returns in excess of the benchmark. The application of the Adviser's active stock selection model may lead to a degree of added risk in exchange for the potential outperformance relative to the Index. Because the Fund is managed to limit volatility, it is likely that in periods of rapidly rising markets the Fund will experience less favorable returns than the Index.

Additional Information About Non-Principal Investment Strategies and Risks

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Fund. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for the Fund and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by the Fund. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Fund) or otherwise using such information for the benefit of its clients or itself.

Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Fund) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, the Fund, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect the Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect the Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject the Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of the Fund inaccessible or inaccurate or incomplete. The Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. The Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. The Fund relies on third-party service providers for many of its day-to-day opera-

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tions, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Fund. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which the Fund invests, which could result in material adverse consequences for such issuers, and may cause the Fund's investment in such securities to lose value.

Temporary Defensive Positions . In response to actual or perceived adverse market, economic, political, or other conditions, the Fund may (but will not necessarily), without notice, depart from its principal investment strategies by temporarily investing for defensive purposes. Temporary defensive positions may include, but are not limited to, cash, cash equivalents, U.S. government securities, repurchase agreements collateralized by such securities, money market funds, and high-quality debt investments. If the Fund invests for defensive purposes, it may not achieve its investment objective. In addition, the defensive strategy may not work as intended.

Portfolio Holdings Disclosure

The Fund's portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

Investment Adviser

The Fund invests as part of a “master-feeder” structure. The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the Portfolio, a separate mutual fund, that has substantially identical investment policies, strategies and risks and a substantially identical investment objective as the Fund. Descriptions of the investment activities of the Fund also generally describe the expected investment activities of the Portfolio. The Fund can withdraw its investment in the Portfolio if, at any time, the Fund's Board of Trustees determines that it would be in the best interests of the Fund's shareholders, or if the investment objectives of the Portfolio changed so that they were inconsistent with the objectives of the Fund. If the Fund withdraws its investment from the Portfolio, the Fund may invest all of its assets in another mutual fund that has substantially similar investment strategies as the Fund, the Adviser may directly manage the Fund's assets, or the Board may take such other action it deems appropriate and in the best interests of shareholders of the Fund, which may include liquidation of the Fund.

Total Annual Fund Operating Expense Waiver . SSGA FM, as the investment adviser to the Fund, is contractually obligated, through April 30, 2020, (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees and distribution, shareholder servicing and sub-transfer agency fees) exceed average daily net assets on an annual basis of 0.75% for the Fund. These waiver and/or reimbursement arrangements may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

A discussion regarding the Board's consideration of the Fund's Investment Advisory Agreement is provided in the Fund's Semi-Annual Report to shareholders for the period ended June 30, 2018.

The Adviser manages the Fund using a team of investment professionals. The team approach is used to create an environment that encourages the flow of investment ideas. The portfolio managers within the team work together in a cohesive manner to develop and enhance techniques that drive the investment process for the investment strategy. This approach requires portfolio managers to share a variety of responsibilities including investment strategy and analysis while retaining responsibility for the implementation of the strategy within any particular portfolio. The approach also enables the team to draw upon the resources of other groups within SSGA. The portfolio management team is overseen by the SSGA Investment Committee.

The professionals primarily responsible for the day-to-day management of the Fund are Adel Daghmouri and Chee Ooi.

Adel Daghmouri is a Vice President of SSGA and the Adviser and a Senior Portfolio Manager in the Active Quantitative Equity Group. He focuses on managing global investment strategies, product development and quantitative research within developed markets. Prior to this, he was a founding member of the Quantitative Canadian Active Equity Team responsible for portfolio management across active, enhanced and market-neutral strategies. Since joining SSGA in 1998, Mr. Daghmouri has also worked as a portfolio manager in the Global Structured Products Group focusing on a broad range of international and domestic strategies. Mr. Daghmouri holds a Bachelor of Business Administration from Laval University and a Master of Science degree in Finance from HEC Montreal.

Chee Ooi is a Managing Director of SSGA and the Adviser and a Senior Portfolio Manager in the Active Quantitative Equity Group. His responsibilities include research and portfolio management across the quantitative international active equity strategies. Mr. Ooi has over twenty years of experience in quantitative equity research and investment management. Prior to joining SSGA in 2008, he

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was a director and senior quantitative analyst in Citigroup's Global Quantitative Research Group in New York and started his career in finance at Salomon Brothers as an equity derivatives research analyst. He has published papers in the Journal of Portfolio Management on his pioneering work on classification and regression tree model in stock selection and has presented at industry conferences. Mr. Ooi holds a Bachelor of Science in Electrical Engineering and Computer Science from the Massachusetts Institute of Technology.

Additional information about the portfolio managers' compensation, other accounts managed by the portfolio managers, and the portfolio managers' ownership of the Fund is available in the SAI.

Other Fund Services

The Administrator, Sub-Administrator and Custodian

The Adviser serves as administrator of the Fund. The amount of the fee paid to the Adviser for administrative services may vary by share class. The Fund currently pays the Adviser an administrative fee at the annual rate of 0.05% with respect to each of its share classes. State Street Bank and Trust Company (“State Street”), a subsidiary of State Street Corporation, serves as sub-administrator for the Fund for a fee that is paid by the Adviser. State Street also serves as custodian of the Fund for a separate fee that is paid by the Fund. SSGA FM serves as administrator of the Portfolio and State Street serves as sub-administrator and custodian of the Portfolio.

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Fund's transfer agent and dividend disbursing agent (the “Transfer Agent”).

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Fund's distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

Additional Information

Shareholder Information

Determination of Net Asset Value

The Fund determines its net asset value (“NAV”) per share once each business day as of the scheduled close of regular trading on the New York Stock Exchange (the “NYSE”). Pricing does not occur on NYSE holidays. A business day is one on which the NYSE is open for regular trading. The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. In unusual circumstances, such as an emergency or an unscheduled close or halt of trading on the NYSE, the time at which share prices are determined may be changed. The NAV per share is based on the market value of the investments held in the Fund. The NAV of each class of the Fund's Shares is calculated by dividing the value of the assets of the Fund attributable to that class less the liabilities of the Fund attributable to that class by the number of shares in the class outstanding. As noted in this Prospectus, the Fund may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when the Fund does not price its shares. Consequently, the NAV of the Fund's Shares may change on days when shareholders are not able to purchase or redeem the Fund's Shares. The Fund values each security or other investment pursuant to guidelines adopted by the Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Fund's Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii) a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by the Fund occurs after the close of a related exchange

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but before the determination of the Fund's NAV. Attempts to determine the fair value of securities or other investments introduce an element of subjectivity to the pricing of securities or other investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the price the Fund would have received had it sold the investment. To the extent that the Fund invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the funds. The prospectuses of these funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

Investing in State Street Institutional Investment Trust Shares

Purchasing Shares

Choosing a Share Class

The Fund offers three classes of shares through this Prospectus: Class A, Class I and Class K, available to you subject to the eligibility requirements set forth below.

When you buy Class A shares, the initial sales load is deducted from the amount you invest, unless you qualify for an initial sales load waiver. This means that less money will be invested in the Fund immediately. Class A shares have a Rule 12b-1 fee of 0.25% per year. A contingent deferred sales charge (“CDSC”) of 1.00% may be assessed on redemptions of Class A shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase as part of an investment of $1,000,000 or more.

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	Class A	Class I	Class K
Availability	Available to the general public through certain Financial Intermediaries.	Limited to certain investors, including: • Certain banks, broker-dealers and other Financial Intermediaries. • Certain employer- sponsored retirement plans. • Certain employees or affiliates of State Street Corporation or its affiliates	Limited to certain investors, including certain qualified recordkeepers and employer-sponsored retirement plans.
Minimum Initial Investment	$2,000. The investment minimum may be modified, waived or reduced for certain types of investors ( e.g ., 401(k) or 403(b) plans) and investments as well as for certain fee-based programs where an agreement is in place.	$1,000,000. The investment minimum may be modified, waived or reduced for certain types of investors (e.g., 401(k) or 403(b) plans) and investments as well as for certain fee- based programs where an agreement is in place.	$10,000,000. The investment minimum may be modified, waived or reduced for certain types of investors ( e.g ., 401(k) or 403(b) plans) and investments as well as for certain fee- based programs where an agreement is in place.
Maximum Investment	None.	None.	None.
Initial (Front-End) Sales Charge	Yes. 5.25%, payable at time of purchase. Lower sales charges are available for larger investments. See the chart under “Class A” section of this Prospectus.	No. Entire purchase price is invested in shares of the Fund.	No. Entire purchase price is invested in shares of the Fund.
Deferred (CDSC) Sales Charge	No, except for purchases of $1,000,000 or more that are redeemed within 18 months after purchase.	No.	No.
Distribution and Service (Rule 12b-1) Fees	0.25% annual fee.	No.	No.
Redemption Fees	No.	No.	No.

Class A

Class A shares are available to the general public for investment through qualified recordkeepers with a distribution and/or fund servicing agreement maintained with SSGA FD.

When you buy Class A shares, you pay an initial (or front-end) sales charge at the time of your investment, which is included in the offering price, unless you qualify for a sales charge reduction or waiver. This fee is deducted from the amount you invest, and the remainder of your money is used to buy shares in the Fund. The table below shows the amount of sales charge you would pay at different levels of investment and the commissions paid to Financial Intermediaries at each level of investment. The actual sales charge you pay may vary slightly from the rates disclosed due to rounding.

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Amount of Purchase Payment	Sales Charge as a % of Offering Price	Sales Charge as a % of Net Amount Invested	Financial Intermediary Compensation as a % of Offering Price
Less than $50,000	5.25%	5.54%	4.75%
$50,000-$99,999	4.50%	4.71%	4.00%
$100,000-$249,999	3.50%	3.63%	3.25%
$250,000-$499,999	2.50%	2.56%	2.25%
$500,000-$999,999	2.00%	2.04%	1.75%
$1,000,000 or more	None	None	Advanced Commission ^{1, 2}

¹	Class A advanced commission for purchases over $1 million:

1.00%	First $3 million
Plus 0.50%	Next $12 million
Plus 0.25%	Over $15 million

Reducing Your Class A Sales Charge

1.	Your account(s);
2.	Account(s) of your spouse or domestic partner;
3.	Account(s) of children under the age of 21 who share your residential address;
4.	Trust accounts established by any of the individuals in items (1) through (3) above. If the person(s) who established the trust is deceased, the trust account may be aggregated with the account(s) of the primary beneficiary of the trust;
5.	Solely controlled business accounts; and
6.	Single-participant retirement plans of any of the individuals in items (1) through (3) above.

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Gifting of Shares . If you make a gift of shares, upon your request, you may combine purchases, if made at the same time, under right of accumulation of Class A, Class I and Class N shares of a State Street Fund (other than any shares of money market funds) at the sales charge discount allowed for the combined purchase. The receiver of the gift may also be entitled to a prospective reduction in sales charges in accordance with the Fund's right of accumulation or other provisions. You or the receiver of the gift must provide certain account information to State Street or their agents at the time of purchase to exercise this right.

Letter of Intent. In order to immediately reduce your Class A sales charge, you may sign a Letter of Intent stating your intention to buy a specified amount of Class A shares of one or more State Street Funds within a 13-month period at the reduced sales charge rates applicable to the aggregate amount of the intended purchases stated in the Letter. Purchases of Class A shares of one or more State Street Funds you make over the 13- month period will be combined and you will pay the same sales charge on the new Class A shares that you would have paid if all shares were purchased at once. The 13-month Letter of Intent period commences on the day that the Letter of Intent is received by the Fund or your Financial Intermediary. Purchases submitted not more than three months prior to the date the Letter of Intent is received are considered in determining the level of sales charge that will be paid pursuant to the Letter of Intent; however, the Letter of Intent will not result in any reduction in the amount of any previously paid sales charge. In addition, investors do not receive credit for shares purchased by the reinvestment of distributions.

Waiver Of The Class A Sales Charge

A sales charge (“load”) may not be imposed on Class A shares of the Fund if the shares were:

1.	Acquired through the reinvestment of dividends and capital gain distributions.
2.	Acquired in exchange for shares of another Class A State Street Fund that were previously assessed a sales charge. However, if your shares are subject to CDSC, the CDSC will continue to apply to your new shares at the same CDSC rate.
3.	Bought in State Street Funds that do not offer Class N (no load) shares ¹ by officers, directors or trustees, retirees and employees and their immediate family members (i.e., spouses, domestic partners, children, grandchildren, parents, grandparents, and any dependent of the person, as defined in Section 152 of the Internal Revenue Code of 1986 (the “Code”)) of:

•	The State Street Funds
•	State Street Corporation and its subsidiaries and affiliates

4.	Bought by employees of:

•

DST Asset Manager Solutions, Inc. and its subsidiaries and affiliates.

•

5.	Bought by:

•	Authorized retirement plans serviced or sponsored by a Financial Intermediary, provided that such Financial Intermediary has entered into an agreement with SSGA FD or with the Fund with respect to such purchases at NAV.
•	Investors who are directly rolling over or transferring shares from an established State Street Fund or State Street qualified retirement plan. Rolling over or transferring shares involves the transferring of shares (in-kind); there is no cash movement associated with the transaction.

¹	State Street Funds that offer Class N Shares include: State Street Dynamic Small Cap Fund (SVSCX), State Street Defensive Emerging Markets Equity Fund (SSEMX), State Street International Stock Selection Fund (SSAIX) and State Street S&P 500 Index Fund (SVSPX).

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•	Clients of Financial Intermediaries that (i) charge an ongoing fee for advisory, management, consulting or similar services, or (ii) have entered into an agreement with SSGA FD to offer Class A shares through a no-load network or platform, or self-directed brokerage accounts that may or may not charge transaction fees to customers.
•	Insurance company separate accounts.
•	Tuition Programs that qualify under Section 529 of the Code.

6.	Bought with proceeds from the sale of Class A shares of a State Street Fund, but only if the purchase is made within 90 days of the sale or distribution. Appropriate documentation may be required. Please refer to Class A Account Reinstatement Privileges below.

7.	Bought in connection with plans of reorganization of a State Street Fund, such as mergers, asset acquisitions and exchange offers to which the Fund is a party. However, you may pay a CDSC when you sell the Fund Shares you received in connection with the plan of reorganization.

Additional Sales Charge Waiver Disclosure

How the CDSC is Calculated

The State Street Funds calculate the CDSC by treating all purchases made in a given month as though they were made on the first day of the month.

You should retain any records necessary to substantiate historical costs because SSGA FD, the Fund, the transfer agent and your Financial Intermediary may not maintain such information.

Waiver of the CDSC

In the following situations, no CDSC is imposed on redemptions of Class A shares of the Fund:

1.	If you participate in the Automatic Withdrawal Plan (AWP). Redemptions made on a regular periodic basis ( e.g . monthly) will not be subject to any applicable CDSC if they are, in the aggregate, less than or equal to 10% annually of the current market value of the account balance. Redemptions made as part of a required minimum distribution are also included in calculating amounts eligible for this waiver. For information on the Automatic Withdrawal Plan, please see Service Options.
2.	If you are a registered participant or beneficial owner of an account and you die or become disabled (as defined in Section 72(m)(7) of the Code). This waiver is only available for accounts open prior to the shareholder's or beneficiary's death or disability, and the redemption must be made within one year of such event. Subsequent purchases into such account are not eligible for the CDSC waiver. In order to qualify for this waiver, SSGA FD must be notified of such death or disability at the time of the redemption order and be provided with satisfactory evidence of such death or disability.
3.	Redemptions that represent a required minimum distribution from your IRA Account or other qualifying retirement plan but only if you are at least age 70 1/2. If you maintain more than one IRA, only the assets credited to the IRA that is invested in one or more of the State Street Funds are considered when calculating that portion of your minimum required distribution that qualifies for the waiver.
4.	A distribution from a qualified retirement plan by reason of the participant's retirement.

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5.	Redemptions that are involuntary and result from a failure to maintain the required minimum balance in an account.

6.	Exchanges in connection with plans of reorganization of a State Street Fund, such as mergers, asset acquisitions and exchange offers to which the Fund is a party. However, you may pay a sales charge when you redeem the Fund Shares you receive in connection with the plan of reorganization.

7.	Exchanges for shares of the same class of another State Street Fund. However, if your shares are subject to CDSC, the CDSC will continue to apply to your new shares. For purposes of the CDSC, shares will continue to age from the date of the original purchase of the Fund Shares.
8.	Redemption of shares purchased through employer sponsored retirement plans and deferred compensation plans. The CDSC, however, will not be waived if the plan redeems all of the shares that it owns on behalf of participants prior to the applicable CDSC period, as defined above.
9.	Redemptions as part of annual IRA custodial fees.
10.	Acquired through the reinvestment of dividends and capital gains distributions.

Appropriate documentation may be required. Please refer to Class A Account Reinstatement Privileges below.

Class A Account Reinstatement Privileges

Class I

Class I shares are available to the following categories of investors and/or investments:

1.	Banks, broker-dealers and other financial institutions (including registered investment advisers and financial planners) purchasing shares on behalf of their clients in:

•	discretionary and non-discretionary advisory programs;
•	fund supermarkets;
•	asset allocation programs;
•	other programs in which the client pays an asset-based fee for advice or for executing transactions in Fund Shares or for otherwise participating in the program; or
•	certain other investment programs that do not charge an asset-based fee;

2.	Qualified state tuition plans described in Section 529 of the Code and donor-advised charitable gift funds (subject to all applicable terms and conditions);
3.	Defined contribution, defined benefit and other employer-sponsored employee benefit plans, whether or not qualified under the Code;
4.	Certain other registered open-end investment companies whose shares are distributed by SSGA FD;

5.	Certain retirement and deferred compensation programs established by State Street Corporation or its affiliates for their employees or the Fund's Trustees;

6.	Current or retired Directors or Trustees of the State Street Funds, officers and employees of SSGA, and any of its subsidiaries, such persons' spouses, and children under the age of 21, and trust accounts for which any of such person is a beneficiary;
7.	Investments made in connection with certain mergers and/or reorganizations as approved by the Adviser;

8.	The reinvestment of dividends from Class I shares in additional Class I shares of the Fund; and

9.	Qualified recordkeepers with a distribution and/or fund servicing agreement maintained with SSGA FD.

The minimum investment for Class I shares is $1,000,000.

Class K

Class K shares are available to the following categories of investors:

1.	Qualified recordkeepers with an applicable agreement maintained with SSGA FD;

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2.	Defined benefit plans, defined contribution plans, endowments and foundations with greater than $10,000,000 in a qualified tax-exempt plan;
3.	Employers with greater than $10,000,000 in the aggregate between qualified and non-qualified plans that they sponsor; and
4.	Defined contribution, defined benefit and other employer-sponsored employee benefit plans, whether or not qualified under the Code.

The minimum investment for Class K shares is $10,000,000.

How to Initiate a Purchase Request

Investing in the State Street Funds Through a Financial Intermediary

Please be sure to check Exchanging Shares and Frequent-Trading Limits below.

How to Pay for a Purchase

By Check . You may send a check to make initial or additional purchases to your fund account. Make your check payable to “State Street Funds” and include the appropriate fund name and account number ( e.g ., “State Street Defensive Global Equity Fund—a/c #xxx”) in the memo section of the check.

Trade Dates-Purchases

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If your purchase request is not in good order, it may be rejected.

For further information about purchase transactions, consult our website at www.ssgafunds.com or see Contacting the State Street Funds.

Other Purchase Policies You Should Know

Redeeming Shares

By Telephone. You may call the State Street Funds to request a redemption of shares. See Contacting the State Street Funds .

By Mail. You may send a written request to the State Street Funds to redeem from the Fund account or to make an exchange. See Contacting the State Street Funds .

Please be sure to check Exchanging Shares and Frequent-Trading Limits below.

Trade Date-Redemptions

The trade date for any redemption request received in good order will depend on the day and time the State Street Funds receive your request in good order and the manner in which you are redeeming.

How to Receive Redemption Proceeds

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treasurer's check. The State Street Funds reserve the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Fund. The State Street Funds reserve the right to suspend the right of shareholder redemption or postpone the date of payment for more than seven days to the extent permitted by the 1940 Act.

Other Redemption Policies that You Should Know

Address Changes. If your address of record has been changed within thirty (30) days of the redemption request, the request must be in writing and bear a medallion guarantee.

Significant/Unusual Economic or Market Activity. During periods of significant or unusual economic or market activity, you may encounter delays attempting to give instructions by phone.

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Large Redemptions. Requests for redemptions over $50,000 must be in writing and bear a medallion guarantee.

Exchanging Shares

Share Class Conversions

You may be able to convert your shares to a different share class of the same Fund that has a lower expense ratio provided that you are eligible to buy that share class and that certain conditions are met. This conversion feature is intended for shares held through a Financial Intermediary offering a fee-based or wrap fee program that has an agreement with SSGA FD specific for this purpose. In such instance, your shares may be automatically converted under certain circumstances. Class N shares of a State Street Fund may be converted to Class I shares of the same State Street Fund. Not all share classes are available through all Financial Intermediaries. If your shares of the Fund are converted to a different share class of the same Fund, the transaction will be based on the respective net asset value of each class as of the trade date of the conversion. Consequently, you may receive fewer shares or more shares than originally owned, depending on that day's net asset values. The total value of the initially held shares, however, will equal the total value of the converted shares at the time of conversion. The conversion of shares of one class of the Fund into shares of another class of the same Fund is not taxable for federal income tax purposes and no gain or loss will be reported on the transaction. See the applicable prospectus for share class information. Please contact your Financial Intermediary regarding the tax consequences of any conversion and for additional information.

Frequent-Trading Limits

Frequent, short-term trading, abusive trading practices and market timing (together, “Excessive Trading”), often in response to short-term fluctuations in the market, are not knowingly permitted by the State Street Funds. The State Street Funds do not accommodate frequent purchases and redemptions of Fund Shares by Fund shareholders. Excessive Trading into and out of a State Street Fund may harm the Fund's performance by disrupting portfolio management strategies and by increasing expenses. These expenses are borne by all Fund shareholders, including long-term investors who do not generate such costs.

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As a means to protect each State Street Fund and its shareholders from Excessive Trading:

•	The State Street Funds' transfer agent compiles, monitors and reports account-level information on omnibus and underlying shareholder/participant activity. Depending on the account type, monitoring will be performed on a daily, monthly, quarterly and/or annual basis;

•

The State Street Funds' distributor has obtained information from each Financial Intermediary holding shares in an omnibus account with the State Street Funds regarding whether the Financial Intermediary has adopted and maintains procedures that are reasonably designed to protect the Fund against harmful short-term trading; and

•	With respect to State Street Funds that invest in securities that trade on foreign markets, pursuant to the State Street Funds' fair valuation procedures, pricing adjustments may be made based on information received from a third-party, multi-factor fair valuation pricing service.

The State Street Funds' distributor has detailed procedures that document the transparency oversight and monitoring processes performed by the State Street Funds' transfer agent.

Service Options

Dividend and Capital Gain Distribution Option

Please refer to Dividends, Distributions and Tax Considerations below for additional information.

Automatic Withdrawal Plan

Telephone Redemptions and Exchanges

Automatic Investment Plan

Once the initial investment has been accepted, you may make subsequent investments of $100 or more monthly, quarterly or annually by direct deposit by debiting your bank checking or savings account. Once this option has been established, you may call the State Street Funds to make additional automatic purchases, to change the amount of the existing automatic purchase, or to stop it. The State Street Fund reserves the right to cancel your automatic investment plan if any correspondence sent by the Fund is returned by the postal or other delivery service as “undeliverable.”

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Additional Shareholder Information

Account Transfers

Responsibility for Fraud

Right to Change Policies

In addition to the rights expressly stated elsewhere in this Prospectus, the State Street Funds reserve the right, in the future, to:

1.	Alter, add, or discontinue any conditions of purchase (including eligibility requirements), redemption, exchange, service, or privilege at any time;
2.	Accept initial purchases by telephone;
3.	Freeze any account and/or suspend account services if the State Street Funds has received reasonable notice of a dispute regarding the assets in an account, including notice of a dispute between the registered or beneficial account owners, or if we reasonably believe a fraudulent transaction may occur or has occurred;
4.	Temporarily freeze any account and/or suspend account services upon initial notification to the State Street Funds of the death of the shareholder until the State Street Funds receive required documentation in good order;
5.	Alter, impose, discontinue, or waive any redemption fee, account service fee, or other fees charged to a group of shareholders; and
6.	Redeem an account or suspend account privileges, without the owner's permission to do so, in cases of threatening conduct or activity the State Street Funds believe to be suspicious, fraudulent, or illegal.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If the Fund's transfer agent identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

Dividends, Distributions and Tax Considerations

Distribution Options. You can choose from four different distribution options as indicated on the application:

•	Reinvestment Option—Dividends and capital gain distributions will be automatically reinvested in additional shares of the Fund. If you do not indicate a choice on the application, this option will be automatically assigned.

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•	Income-Earned Option—Capital gain distributions will be automatically reinvested, but a check, direct deposit or wire will be sent for each dividend distribution.
•	Cash Option—A check, wire or direct deposit will be sent for each dividend and capital gain distribution.
•	Direct Dividends Option—Dividends and capital gain distributions will be automatically invested in another identically registered State Street Fund of the same share class.

Delivery of Documents to Accounts Sharing an Address

Tax Considerations

The Fund invests substantially all of its assets in the Portfolio, which is expected to be treated as a regulated investment company for federal income tax purposes, and so substantially all of the Fund's income will result from distributions or deemed distributions from the Portfolio. Therefore, as applicable, and except as otherwise stated, references in this section to the assets owned or income earned by the Fund will include such assets and income of the Portfolio. The Fund generally expects to satisfy the requirements to qualify and be eligible to be treated as regulated investment companies, provided that the Portfolio also meets these requirements; the Fund currently expects that the Portfolio will meet these requirements. Because the Fund will invest substantially all its assets in the Portfolio, if the Portfolio were to fail to satisfy the diversification, 90% gross income, or distribution requirement and were not to cure that failure, the Fund itself would be unable to satisfy the diversification requirement. Such a failure to qualify and be eligible for treatment as a regulated investment company could subject the Fund or the Portfolio to regular corporate income taxes.

For U.S. federal income tax purposes, distributions of investment income generally are taxable to you as ordinary income. Taxes on distributions of capital gains generally are determined by how long the Fund or the Portfolio owned (or is deemed to have owned) the investments that generated them, rather than how long you have owned your Fund Shares. Distributions of net capital gains (that is, the excess of net long-term capital gains over net short-term capital losses) from the sale of investments that the Fund or the Portfolio, owned (or is deemed to have owned) for more than one year that are properly reported by the Fund, or the Portfolio and the Fund as capital gain dividends generally will be treated as long-term capital gain includible in your net capital gain and taxed to individuals at reduced rates. Distributions of gains from investments that a Fund or the Portfolio, owned (or is deemed to have owned) for one year or less generally will be taxable to you as ordinary income when distributed to you by the Fund. Distributions of investment income properly reported by the Fund, or the Portfolio and the Fund as derived from “qualified dividend income,” which will not include income from the Fund's or the Portfolio's, securities on loan, are taxed to individuals at the rates applicable to net capital gain, provided holding period and other requirements are met by both the shareholder and the Fund and the Portfolio. Distributions are taxable to you even if they are paid from income or gains earned by a Fund or the Portfolio before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares.

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An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by the Fund, including any capital gain dividends, and net gains recognized on the redemption of shares of the Fund.

The Fund's or the Portfolio's income from or the proceeds of dispositions of its investments in non-U.S. assets may be subject to non-U.S. withholding or other taxes, which will reduce the yield on those investments. In certain instances, the Fund or the Portfolio, and, in turn, the Fund, may be entitled to elect to pass through to its shareholders a credit (or deduction, for a shareholder that itemizes deductions and so chooses) for foreign taxes (if any) borne with respect to foreign securities income earned by the Fund or the Portfolio. If the Fund so elects, shareholders will include in gross income from foreign sources their pro rata shares of such taxes, if any, treated as paid by the Fund or the Portfolio. There can be no assurance that the Fund or the Portfolio will make such election, even if it is eligible to do so. If the Fund, or the Portfolio, does not qualify for or does not make such election, shareholders will not be entitled separately to claim a credit or deduction with respect to foreign taxes paid by the Fund or the Portfolio; in that case the foreign tax will nonetheless reduce the Fund's or the Portfolio's taxable income. Even if the Fund and the Portfolio, elect to pass through to shareholders foreign tax credits or deductions, tax-exempt shareholders and those who invest in the Fund through tax-advantaged accounts such as IRAs will not benefit from any such tax credit or deduction.

Certain of the Fund's or the Portfolio's investment practices, including derivative transactions and investments in debt obligations issued or purchased at a discount, will be subject to special and complex U.S. federal income tax provisions. These special rules may affect the timing, character, and/or amount of the Fund's distributions, or the Portfolio's distributions to the Fund and, in turn, the Fund's distributions to shareholders, and may require the Fund or, as applicable, the Portfolio to sell its investments at a time when it is not advantageous to do so.

The Fund's investment in the Portfolio may cause the tax treatment of the Fund's gains, losses and distributions to differ at times from the tax treatment that would apply if the Fund invested directly in the types of securities held by the Portfolio. As a result, investors may receive taxable distributions earlier and recognize higher amounts of capital gain or ordinary income than they otherwise would.

Cost Basis Reporting . Department of the Treasury regulations mandate cost basis reporting to shareholders and the IRS for redemptions of Fund Shares acquired on or after January 1, 2012 (“Post Effective Date Shares”). If you acquire and hold shares directly through the Fund and not through a Financial Intermediary, DST Asset Manager Solutions, Inc. will use a default average cost basis methodology for tracking and reporting your cost basis on Post Effective Date Shares, unless you request, in writing, another cost basis reporting methodology.

Financial Intermediary Arrangements

Distribution Arrangements and Rule 12b-1 Fees

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The Fund may pay distribution fees and other amounts described in this Prospectus at a time when shares of the Fund are unavailable for purchase.

Other Payments to Financial Intermediaries

The Financial Intermediary is often compensated by SSGA FD or its affiliates for the services it performs and in such cases is typically paid continually over time, during the period when the Financial Intermediary's clients hold investments in the Fund. The amount of continuing compensation paid by SSGA FD or its affiliates to different Financial Intermediaries for distribution and/or shareholder services varies. Any compensation is typically a percentage of the value of the Financial Intermediary's clients' investments in the Fund or a per account fee. The variation in compensation may, but will not necessarily, reflect enhanced or additional services provided by the Financial Intermediary.

If you invest through a Financial Intermediary and meet the eligibility criteria for more than one share class, you should discuss with your Financial Intermediary which share class is appropriate for you. Your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend one share class over another, when you are eligible to invest in more than one share class. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by the Fund or its affiliates with respect to the different share classes offered by the Fund.

SSGA FD and its affiliates (including SSGA FM), at their own expense and out of their own assets, may also provide other compensation to Financial Intermediaries in connection with sales of the Fund's shares or the servicing of shareholders or shareholder accounts. Such compensation may include, but is not limited to, financial assistance to Financial Intermediaries in connection with conferences, sales, or training programs for their employees; seminars for the public; advertising or sales campaigns; or other Financial Intermediary-sponsored special events. In some instances, this compensation may be made available only to certain Financial Intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the Fund's shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as Financial Industry Regulatory Authority, Inc.

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Financial Highlights

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET DEFENSIVE GLOBAL EQUITY FUND FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout the period

	Class I
	Year Ended 12/31/18	Year Ended 12/31/17	For the Period 02/19/2016* - 12/31/16
Net asset value, beginning of period	$12.48	$10.65	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.23	0.32	0.21
Net realized and unrealized gain (loss)	(1.02)	1.94	0.77
Total from investment operations	(0.79)	2.26	0.98
Distributions to shareholders from:
Net investment income	(0.50)	(0.39)	(0.31)
Net realized gains	(0.48)	(0.04)	(0.02)
Total distributions	(0.98)	(0.43)	(0.33)
Net asset value, end of period	$ 10.71	$ 12.48	$ 10.65
Total return (b)	(6.27)%	21.26%	9.85%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$2,001	$4,953	$3,194
Ratios to Average Net Assets:
Total expenses	3.43%	4.48%	5.37%(c)
Net expenses	0.76%	0.76%	0.75%(c)
Net investment income (loss)	1.80%	2.72%	2.26%(c)
Portfolio turnover rate (d)	64%	39%	38%(e)

*	Commencement of operations.
(a)	Per share numbers have been calculated using average shares outstanding, which more appropriately presents the per share data for the period.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates of the Fund. Total return for periods less than one year are not annualized. Broker commission charges are not included in this calculation.
(c)	Annualized.
(d)	Portfolio turnover rate is from the State Street Disciplined Global Equity Portfolio.
(e)	Not annualized.

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Contacting the State Street Funds

Online:	www.ssgafunds.com	24 hours a day, 7 days a week
Phone:	(800) 647-7327	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Overnight/ Registered, Express, Certified Mail
State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737	State Street Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407

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For more information about the Fund:

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

SSITSTATPRO3

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street International Value Spotlight Fund

Class A (-----) Class I (-----) Class K (SIVSX)

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with the Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling (800) 647-7327. Your election to receive reports in paper will apply to all funds held in your account.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in the Fund offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

The Fund may offer multiple classes of shares. This Prospectus covers only the Class A, Class I and Class K Shares of the Fund.

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Fund Summary	1
State Street International Value Spotlight Fund	1
Additional Information About Investment Objective, Principal Strategies and Risks	8
Additional Information About Non-Principal Investment Strategies and Risks	16
Portfolio Holdings Disclosure	18
Management and Organization	19
Shareholder Information	20
Dividends, Distributions and Tax Considerations	33
Financial Intermediary Arrangements	34
Financial Highlights	36

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State Street International Value Spotlight Fund

Investment Objective

The State Street International Value Spotlight Fund (the “International Value Spotlight Fund” or sometimes referred to in context as the “Fund”) seeks to provide long-term growth of capital.

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment)

	Class A	Class I	Class K
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	5.25%	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None ¹	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class A	Class I	Class K
Management Fee	0.75%	0.75%	0.75%
Distribution and/or Shareholder Service (12b-1) Fees	0.25%	0.00%	0.00%
Other Expenses ²	7.03%	7.03%	6.83%
Total Annual Fund Operating Expenses	8.03%	7.78%	7.58%
Less Fee Waivers and/or Expense Reimbursements ³	(6.83%)	(6.83%)	(6.83%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	1.20%	0.95%	0.75%

¹	A contingent deferred sales charge (“CDSC”) of 1.00% may be assessed on redemptions of Class A shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase as part of an investment of $1,000,000 or more.
²	Other expenses are based on estimates for the current fiscal year for Class A and Class I shares.

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2020 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.70% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

Example:

	1 year	3 years	5 years	10 years
Class A	$641	$2,173	$3,613	$6,850
Class I	$ 97	$1,671	$3,159	$6,532

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	1 year		3 years		5 years		10 years
Class K	$77		$1,617		$3,078		$6,414

Portfolio Turnover:

Principal Investment Strategies

The International Value Spotlight Fund invests principally in a portfolio of equity securities of non-U.S. issuers from around the world that State Street Global Advisors Ireland Limited (“SSGA Ireland” or the “Sub-Adviser”) believes are undervalued. SSGA Ireland uses a proprietary fundamental research-based process to identify companies where it believes there is a dislocation between the value of a company and the price of its equity securities, utilizing a proprietary integrated suite of security-specific financial analyses and valuation tools to analyze and model relevant aspects of a company's operational and financial performance in order to arrive at an estimate of the intrinsic value of a security. After identifying a universe of such companies, SSGA Ireland selects for investment those companies within such universe that it believes represent the optimal combination of long-term value and quality. The Fund expects typically to invest most of its assets in equity securities of issuers in the MSCI ACWI ex USA Index, but may invest any portion of its assets in other issuers. The Fund is a non-diversified investment company.

Under normal circumstances, the Fund will invest at least 80% of its net assets (plus borrowings, if any, for investment purposes) in securities of non-U.S. issuers, which may include issuers from both developed and emerging markets countries. SSGA Ireland considers a company to be a non-U.S. issuer if a company meets one of the following criteria: (i) it is organized outside the United States or maintains a principal place of business outside the United States; (ii) its securities are traded principally outside the United States; or (iii) during its most recent fiscal year, it derived at least 50% of its revenues or profits from goods produced or sold, investments made, or services performed outside the United States or it has at least 50% of its assets outside the United States.

Under normal circumstances, at least 90% of the Fund's net assets will be invested in publicly traded securities. The Fund expects to invest primarily in common stocks, but may also invest in preferred stocks, securities convertible into common or preferred stocks, and depositary receipts. The Fund may purchase securities in their initial public offerings, and may hold securities that are restricted as to resale. Equity securities held by the Fund may be denominated in non-U.S. currencies and may be held outside the United States, which may include both developed and emerging markets countries. The Fund also may invest in the securities of Chinese companies, normally restricted to residents of the People's Republic of China (commonly known as “A Shares” or “China A Shares”), through the Stock Connect program or other channels. The Fund may invest in other investment companies, including exchange-traded funds, to the extent permitted by applicable law (including those advised by SSGA Funds Management, Inc., the Fund's investment adviser). The Fund may hold a portion of its assets in cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by SSGA Funds Management, Inc. or an affiliate). While the Fund may invest in companies of any market capitalization, it expects to primarily invest in large capitalization companies. The Fund may invest in derivatives, such as futures contracts, in order to gain broad equity market exposures pending investments of cash, or to reduce market exposures pending the sales of securities. The Fund may enter into foreign currency futures and forward contracts to hedge currency risk, although the Adviser does not currently anticipate that such transactions will play any significant role in the Fund's investment process.

Principal Risks

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In addition, the Fund is subject to the following risks:

Derivatives Risk: Derivative transactions can create investment leverage and may have significant volatility. It is possible that a derivative transaction will result in a much greater loss than the principal amount invested, and the Fund may not be able to close out a derivative transaction at a favorable time or price. The counterparty to a derivatives contract may be unable or unwilling to make timely settlement payments, return the Fund's margin, or otherwise honor its obligations. A derivatives transaction may not behave in the manner anticipated by the Sub-Adviser or may not have the effect on the Fund anticipated by the Sub-Adviser.

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Management Risk: The Fund is actively managed. The Sub-Adviser's judgments about the attractiveness, relative value, or potential appreciation of a particular sector, security, commodity or investment strategy may prove to be incorrect, and may cause the Fund to incur losses. There can be no assurance that the Sub-Adviser's investment techniques and decisions will produce the desired results.

Modeling Risk: The Sub-Adviser uses quantitative models in an effort to enhance returns and manage risk. Any imperfections, errors or limitations in these models could limit any benefit to the Fund from the use of the models, or could result in incorrect outputs or in investment outcomes different from or opposite to those expected or desired by the Sub-Adviser. There can be no assurance that the models will behave as expected in all market conditions. In addition, computer programming used to create quantitative models, or the data on which such models operate, might contain one or more errors.

Non-Diversification Risk: As a “non-diversified” mutual fund, the Fund may hold a smaller number of portfolio securities than many other funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.

Risk of Investment in Other Pools: If the Fund invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected and is exposed indirectly to all of the risks applicable to an investment in such other pool. The investment policies of the other pool may not be the same as those of the Fund; as a result, an investment in the other pool may be subject to additional or different risks than those to which the Fund is typically subject. The Fund bears its proportionate share of the fees and expenses of any pool in which it invests. The Sub-Adviser or an affiliate may serve as investment adviser to a pool in which the Fund may invest, leading to potential conflicts of interest. It is possible that other clients of the Sub-Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Sub-Adviser or its affiliates at prices and at times more favorable than those at which the Fund does so.

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Stock Connect Investing Risk: The Fund's ability to achieve its investment objective may depend on its continued ability to invest in China “A Shares.” A Shares are equity securities of issuers incorporated in mainland China that are denominated and currently traded in Renminbi (“RMB”) on the Shanghai or Shenzhen Stock Exchanges. The Fund may invest in A Shares listed and traded on the Shanghai Stock Exchange or Shenzhen Stock Exchange through the Stock Connect program, or on such other stock exchanges in China which participate in the Stock Connect program from time to time. The Fund's investments in Stock Connect A Shares are generally subject to Chinese securities regulations and listing rules, among other restrictions that may affect the Fund's investments and returns, including daily limits on net purchases and transfer restrictions. Such investments are also subject to heightened tax and settlement risk and the risk of price fluctuations of A Shares during times when the Stock Connect program is not trading. The Stock Connect program is a relatively new program. Further developments are likely and there can be no assurance as to the program's continued existence or whether future developments regarding the program may restrict or adversely affect the Fund's investments or returns.

Value Stock Risk: A “value” style of investing is subject to the risk that the returns on “value” equity securities are less than returns on other styles of investing or the overall stock market. Value stocks present the risk that they may decline in price or never reach their expected full market value, either because the market fails to recognize a stock's intrinsic worth or the Sub-Adviser overestimates the stock's expected value.

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Performance

The bar chart and table below provide some indication of the risks of investing in the International Value Spotlight Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of the Index. The bar chart shows how the Class K shares' returns have varied for each full calendar year shown. Except for differences in returns resulting from differences in fees and expenses, all share classes would have substantially similar returns because all share classes invest in the same portfolio of securities. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at www.ssgafunds.com.

Annual Total Return (years ended 12/31)

Highest Quarterly Return: 8.80% (Q1, 2017)
Lowest Quarterly Return: -15.70% (Q4, 2018)

Average Annual Total Returns (for periods ended 12/31/18)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. After-tax returns depend on an investor's tax situation and may differ from those shown below, and after-tax returns are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts (IRAs). Except for differences in returns resulting from differences in fees, expenses, and sales charges (as applicable), all share classes would have substantially similar returns because all share classes invest in the same portfolio of securities.

	One Year	Since Inception	Inception Date
Class K			7/13/2016
Return Before Taxes	-19.32%	6.04%
Return After Taxes on Distributions	-23.90%	1.38%
Return After Taxes on Distributions and Sale of Fund Shares	-9.40%	3.47%
MSCI ACWI ex USA Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)	-14.20%	2.47%

The Fund will make updated performance information, including its current net asset value, available at the Fund's website: www.ssgafunds.com.

Investment Adviser and Sub-Adviser

SSGA Funds Management, Inc. (“SSGA FM” or the “Adviser”), serves as the investment adviser to the Fund. SSGA Ireland, an affiliate of the Adviser, serves as investment sub-adviser to the Fund, subject to supervision by the Adviser and the Trust's Board of Trustees. To the extent that a reference in this Prospectus refers to the Adviser, with respect to the Fund, such reference should also be read to refer to SSGA Ireland, where the context requires.

The professional primarily responsible for the day-to-day management of the Fund is Barry Glavin who has been portfolio manager for the Fund since inception in 2016.

Barry Glavin, CFA, is a Senior Managing Director of SSGA Ireland and Chief Investment Officer of SSGA Ireland's Dublin-based Fundamental Value Team. He joined SSGA Ireland in 2006.

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Purchase and Sale of Fund Shares

Purchase Minimums

Class A
To establish an account	$2,000
To add to an existing account	None
Class I
To establish an account	$1,000,000
To add to an existing account	None
Class K
To establish an account	$10,000,000
To add to an existing account	None

You may purchase or redeem Fund Shares on any day the Fund is open for business.

Written Requests and Wire Transfers . You may purchase or redeem Fund Shares by written request or wire transfer.

Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight/Registered, Express, Certified Mail:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Intermediary:

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objective, Principal Strategies and Risks

Investment Objective

Principal Investment Strategies

Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure.

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ment or transaction, resulting in a loss to the Fund. The Fund may experience significant delays in obtaining any recovery in an insolvency, bankruptcy, or other reorganization proceeding involving its counterparty (including recovery of any collateral posted by it) and may obtain only a limited recovery or may obtain no recovery in such circumstances. If the Fund holds collateral posted by its counterparty, it may be delayed or prevented from realizing on the collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty. Under applicable law or contractual provisions, including if the Fund enters into an investment or transaction with a financial institution and such financial institution (or an affiliate of the financial institution) experiences financial difficulties, then the Fund may in certain situations be prevented or delayed from exercising its rights to terminate the investment or transaction, or to realize on any collateral and may result in the suspension of payment and delivery obligations of the parties under such investment or transactions or in another institution being substituted for that financial institution without the consent of the Fund. Further, the Fund may be subject to “bail-in” risk under applicable law whereby, if required by the financial institution's authority, the financial institution's liabilities could be written down, eliminated or converted into equity or an alternative instrument of ownership. A bail-in of a financial institution may result in a reduction in value of some or all of its securities and, if the Fund holds such securities or has entered into a transaction with such a financial security when a bail-in occurs, the Fund may also be similarly impacted.

Currency Hedging Risk . If a derivative is used as a hedge against a position that the Fund holds, any gain generated by the derivative generally should be substantially offset by losses on the hedged investment, and vice versa. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. Hedges are sometimes subject to imperfect matching between a derivative and its reference asset. Furthermore, while the Fund may hedge against currency fluctuations, it is possible that a degree of currency exposure may remain even at the time a hedging transaction is implemented. As a result, changes in currency exchange rates may affect Fund returns even when the hedge works as intended. The effectiveness of the Fund's currency hedging strategy will also generally be affected by the volatility of both the securities included in the Index, and the volatility of the U.S. dollar relative to the currencies to be hedged. Increased volatility may reduce the effectiveness of the Fund's currency hedging strategy and may impact the costs associated with hedging transactions. The effectiveness of the Fund's currency hedging strategy and the costs associated with hedging transactions may also in general be affected by interest rates. Significant differences between U.S. dollar interest rates and foreign currency interest rates may further impact the effectiveness of the Fund's currency hedging strategy. There can be no assurance that the Fund's hedging transactions will be effective. The Fund's currency hedging activities will potentially increase or accelerate distributions to shareholders, increase distributions taxed to individuals as ordinary income, result in the re-characterization of prior ordinary income distributions as return of capital, or generate losses that cannot be used to offset income or capital gain in subsequent years. The Fund will bear the costs associated with any such hedging transaction, regardless of any gain or loss experienced on the hedging transaction.

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depositary receipts, including, but not limited to, insolvency of the issuer or sponsor. Holders of depositary receipts may have limited or no rights to take action with respect to the underlying securities or to compel the issuer of the receipts to take action. The prices of depositary receipts may differ from the prices of securities upon which they are based.

Derivatives Risk. A derivative is a financial contract the value of which depends on, or is derived from, the value of an underlying asset, interest rate, or index. Derivative transactions typically involve leverage and may have significant volatility. It is possible that a derivative transaction will result in a loss greater than the principal amount invested, and the Fund may not be able to close out a derivative transaction at a favorable time or price. Risks associated with derivative instruments include potential changes in value in response to interest rate changes or other market developments or as a result of the counterparty's credit quality; the potential for the derivative transaction not to have the effect the Adviser anticipated or a different or less favorable effect than the Adviser anticipated; the failure of the counterparty to the derivative transaction to perform its obligations under the transaction or to settle a trade; possible mispricing or improper valuation of the derivative instrument; imperfect correlation in the value of a derivative with the asset, rate, or index underlying the derivative; the risk that the Fund may be required to post collateral or margin with its counterparty, and will not be able to recover the collateral or margin in the event of the counterparty's insolvency or bankruptcy; the risk that the Fund will experience losses on its derivatives investments and on its other portfolio investments, even when the derivatives investments may be intended in part or entirely to hedge those portfolio investments; the risks specific to the asset underlying the derivative instrument; lack of liquidity for the derivative instrument, including without limitation absence of a secondary trading market; the potential for reduced returns to the Fund due to losses on the transaction and an increase in volatility; the potential for the derivative transaction to have the effect of accelerating the recognition of gain; and legal risks arising from the documentation relating to the derivative transaction.

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Large Shareholder Risk . To the extent a large proportion of the shares of the Fund are highly concentrated or held by a small number of shareholders (or a single shareholder), including funds or accounts over which the Adviser has investment discretion, the Fund is subject to the risk that these shareholders will purchase or redeem Fund shares in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of the Fund to conduct its investment program. For example, they could require the Fund to sell portfolio securities or purchase portfolio securities unexpectedly and incur substantial transaction costs and/or accelerate the realization of taxable income and/or gains to shareholders, or the Fund may be required to sell its more liquid portfolio investments to meet a large redemption, in which case the Fund's remaining assets may be less liquid, more volatile, and more difficult to price. The Fund may hold a relatively large proportion of its assets in cash in anticipation of large redemptions, diluting its investment returns.

Leveraging Risk . Borrowing transactions, reverse repurchase agreements, certain derivatives transactions, securities lending transactions and other investment transactions such as when-issued, delayed-delivery, or forward commitment transactions may create investment leverage. If the Fund engages in transactions that have a leveraging effect on the Fund's investment portfolio, the value of the Fund will be potentially more volatile and all other risks will tend to be compounded. This is because leverage generally creates investment risk with respect to a larger base of assets than the Fund would otherwise have and so magnifies the effect of any increase or decrease in the value of the Fund's underlying assets. The use of leverage is considered to be a speculative investment practice and may result in losses to the Fund. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. The use of leverage may cause the Fund to liquidate positions when it may not be advantageous to do so to satisfy repayment, interest payment, or margin obligations or to meet asset segregation or coverage requirements.

Management Risk . The Fund is actively managed. The Adviser's and Sub-Adviser's judgments about the attractiveness, relative value, or potential appreciation of a particular sector, security, commodity or investment strategy may prove to be incorrect, and may cause the Fund to incur losses. There can be no assurance that the Adviser's and Sub-Adviser's investment techniques and decisions will produce the desired results.

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Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject the Fund to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and the Fund's investment program in particular can be uncertain. In recent periods, governmental and non-governmental issuers have defaulted on, or have been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including, without limitation, in Europe or Asia. Defaults or restructurings by governments or others of their debts could have substantial adverse effects on economies, financial markets, and asset valuations around the world. Further Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, or investor perception that these efforts are not succeeding, could negatively affect financial markets generally as well as the values and liquidity of certain securities.

Modeling Risk . The Adviser uses quantitative models in an effort to enhance returns and manage risk. Any imperfections, errors or limitations in these models could limit any benefit to the Fund from the use of the models, or could result in incorrect outputs or in investment outcomes different from or opposite to those expected or desired by the Adviser. These models may make simplifying assumptions that limit their effectiveness and may draw from historical data that does not adequately identify or reflect factors necessary to an appropriate or useful output. There can be no assurance that the models will behave as expected in all market conditions. In addition, computer programming used to create quantitative models, or the data on which such models operate, might contain one or more errors. Such errors might never be detected, or might be detected only after the Fund has sustained a loss (or reduced performance) related to such errors.

Non-Diversification Risk . As a “non-diversified” fund, the Fund may hold a smaller number of portfolio securities than many other mutual funds. To the extent the Fund invests in a relatively small number of issuers, a decline in the market value of a particular security held by the Fund may affect its value more than if it invested in a larger number of issuers. The value of Fund Shares may be more volatile than the values of shares of more diversified funds.

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repatriation of non-U.S. currencies. Income and gains with respect to investments in certain countries may be subject to withholding and other taxes. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, and financial reporting standards, regulatory framework and practices comparable to those in the United States. The securities of some non-U.S. entities are less liquid and at times more volatile than securities of comparable U.S. entities, and could become subject to sanctions or embargoes that adversely affect the Fund's investment. Non-U.S. transaction costs, such as brokerage commissions and custody costs may be higher than in the U.S. In addition, there may be a possibility of nationalization or expropriation of assets, imposition of currency exchange controls, confiscatory taxation, and diplomatic developments that could adversely affect the values of the Fund's investments in certain non-U.S. countries. Investments in securities of non-U.S. issuers also are subject to foreign political and economic risk not associated with U.S. investments, meaning that political events (civil unrest, national elections, changes in political conditions and foreign relations, imposition of exchange controls and repatriation restrictions), social and economic events (labor strikes, rising inflation) and natural disasters occurring in a country where the Fund invests could cause the Fund's investments in that country to experience gains or losses.

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managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by the Fund in a pool sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which the Fund does so.

Special Risk Considerations of Investing in China . Investing in securities of Chinese issuers, including by investing in A Shares, involves certain risks and considerations not typically associated with investing in securities of U.S. issuers, including, among others, (i) more frequent (and potentially widespread) trading suspensions and government interventions with respect to Chinese issuers, resulting in a lack of liquidity and in price volatility, (ii) currency revaluations and other currency exchange rate fluctuations or blockage, (iii) the nature and extent of intervention by the Chinese government in the Chinese securities markets, whether such intervention will continue and the impact of such intervention or its discontinuation, (iv) the risk of nationalization or expropriation of assets, (v) the risk that the Chinese government may decide not to continue to support economic reform programs, (vi) limitations on the use of brokers, (vii) potentially higher rates of inflation, (viii) the unavailability of consistently-reliable economic data, (ix) the relatively small size and absence of operating history of many Chinese companies, (x) accounting, auditing and financial reporting standards in China are different from U.S. standards and, therefore, disclosure of certain material information may not be available, (xi) greater political, economic, social, legal and tax-related uncertainty, (xii) higher market volatility caused by any potential regional territorial conflicts or natural disasters, (xiii) higher dependence on exports and international trade, (xiv) the risk of increased trade tariffs, embargoes and other trade limitations, (xv) restrictions on foreign ownership, and (xvi) custody risks associated with investing through programs to access Chinese securities. Significant portions of the Chinese securities markets may become rapidly illiquid, as Chinese issuers have the ability to suspend the trading of their equity securities, and have shown a willingness to exercise that option in response to market volatility and other events. The liquidity of Chinese securities may shrink or disappear suddenly and without warning as a result of adverse economic, market or political events, or adverse investor perceptions, whether or not accurate.

Stock Connect Investing Risk . The Fund's ability to achieve its investment objective may depend on its continued ability to invest in China “A Shares.” A Shares are equity securities of issuers incorporated in mainland China that are denominated and currently traded in RMB on the Shanghai or Shenzhen Stock Exchanges. Subject to minor exceptions, under current regulations in China, foreign investors, such as the Fund, can invest in A Shares only (i) through certain institutional investors that have obtained a license and quota from the Chinese regulators or (ii) through the Hong Kong-Shanghai Stock Connect or Shenzhen-Hong Kong Stock Connect programs. The Fund may invest in A Shares listed and traded on the Shanghai Stock Exchange or Shenzhen Stock Exchange through the Stock Connect program, or on such other stock exchanges in China which participate in the Stock Connect program from time to time. The Fund's investments in Stock Connect A Shares are generally subject to Chinese securities regulations and listing rules, among other restrictions that may affect the Fund's investments and returns, including daily limits on net purchases and transfer restrictions. In addition, the Stock Connect program's trading, clearance and settlement procedures are relatively untested in China, which could pose risks to the Fund. While overseas investors currently are exempt from paying capital gains or value added taxes on income and gains from investments in Stock Connect A Shares, these Chinese tax rules could be changed, which could result in unexpected tax liabilities for the Fund.

The Stock Connect program will only operate on days when both the Chinese and Hong Kong markets are open for trading and when banks in both markets are open on the corresponding settlement days. There may be occasions when the Fund may be subject to the risk of price fluctuations of A Shares during the time when the Stock Connect program is not trading. Because of the way in which China A shares are held in Stock Connect, the Fund may not be able to exercise the rights of a shareholder and may be limited in its ability to pursue claims against the issuer of a security, and may suffer losses in the event the depository of the Shanghai or Shenzhen Stock Exchanges becomes insolvent. Only certain China A shares are eligible to be accessed through the Stock Connect program. Such securities may lose their eligibility at any time, in which case they presumably could be sold but could no longer be purchased through the Stock Connect program. The Stock Connect program is a relatively new program.

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Further developments are likely and there can be no assurance as to the program's continued existence or whether future developments regarding the program may restrict or adversely affect the Fund's investments or returns. In addition, the application and interpretation of the laws and regulations of Hong Kong and China, and the rules, policies or guidelines published or applied by relevant regulators and exchanges in respect of the Stock Connect program are uncertain, and they may have a detrimental effect on the Fund's investments and returns.

Value Stock Risk . Value stocks present the risk that they may decline in price or never reach their expected full market value, either because the market fails to recognize the stock's intrinsic worth or the Sub-Adviser overestimates the stock's expected value. Value stocks may underperform growth stocks and stocks in other broad style categories (and the stock market as a whole) over any period of time and may shift in and out of favor with investors generally, sometimes rapidly, depending on changes in market, economic, and other factors. As a result, at times when it holds substantial investments in value stocks the Fund may underperform other investment portfolios that invest more broadly or that favor different investment styles.

Additional Information About Non-Principal Investment Strategies and Risks

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Fund. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for the Fund and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned

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by the Fund. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Fund) or otherwise using such information for the benefit of its clients or itself.

Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Fund) and their service providers (including the Sub-Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, the Fund, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect the Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect the Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject the Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of the Fund inaccessible or inaccurate or incomplete. The Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. The Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. The Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Fund. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which the Fund invests, which could result in material adverse consequences for such issuers, and may cause the Fund's investment in such securities to lose value.

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ket value of the securities loaned by the Fund, marked to market each trading day. In a loan transaction, as compensation for lending its securities, the Fund will receive a portion of the dividends or interest accrued on the securities held as collateral or, in the case of cash collateral, a portion of the income from the investment of such cash. In addition, the Fund will receive the amount of all dividends, interest and other distributions on the loaned securities. However, the borrower has the right to vote the loaned securities. The Fund will call loans to vote proxies if a material issue affecting the investment is to be voted upon. Efforts to recall such securities promptly may be unsuccessful, especially for foreign securities or thinly traded securities, and may involve expenses to the Fund. Securities lending involves the risk that the Fund may lose money because the borrower of the loaned securities fails to return the securities in a timely manner or at all. Should the borrower of the securities fail financially, the Fund may experience delays in recovering the securities or exercising its rights in the collateral. Loans are made only to borrowers that are deemed by the securities lending agent to be of good financial standing. In a loan transaction, the Fund will also bear the risk of any decline in value of securities acquired with cash collateral. The Fund expects to invest cash collateral in a pooled investment vehicle advised by the Adviser. With respect to index funds, to the extent the collateral provided or investments made with cash collateral differ from securities included in the relevant Index, such collateral or investments may have a greater risk of loss than the securities included in the Index. In addition, the Fund will be subject to the risk that any income generated by reinvesting cash collateral is lower than any fees the Fund has agreed to pay a borrower.

Temporary Defensive Positions . In response to actual or perceived adverse market, economic, political, or other conditions, the Fund may (but will not necessarily), without notice, depart from its principal investment strategies by temporarily investing for defensive purposes. Temporary defensive positions may include, but are not limited to, cash, cash equivalents, U.S. government securities, repurchase agreements collateralized by such securities, money market funds, and high-quality debt investments. If the Fund invests for defensive purposes, it may not achieve its investment objective. In addition, the defensive strategy may not work as intended.

Portfolio Holdings Disclosure

The Fund's portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

The Fund is a separate, non-diversified series of the State Street Institutional Investment Trust (the “Trust”), which is an open-end management investment company organized as a business trust under the laws of The Commonwealth of Massachusetts.

Investment Adviser

Investment Sub-Adviser . SSGA Ireland, 78 Sir John Rogerson's Quay, Dublin 2, Ireland, a wholly-owned subsidiary of State Street Corporation, serves as the investment sub-adviser to SSGA FM with respect to the Fund. As of December 31, 2018, SSGA Ireland managed approximately $23.97 billion in assets with differing investment objectives across a variety of investment strategies and product types.

The Fund has entered into an investment advisory agreement with the Adviser, pursuant to which the Adviser will manage the Fund's assets, for compensation paid at an annual rate of 0.75% of the International Value Spotlight Fund's average daily net assets. The Adviser has entered into a sub-advisory agreement with the Sub-Adviser pursuant to which the Sub-Adviser will be responsible for the day-to-day management of any assets of the Fund. The Sub-Adviser receives fees from the Adviser for its services provided to the Fund.

Total Annual Fund Operating Expense Waiver . SSGA FM, as the investment adviser to the Fund, is contractually obligated, through April 30, 2020, (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed average daily net assets on an annual basis of 0.70% for the Fund. These waiver and/or reimbursement arrangements may not be terminated prior to April 30, 2020 except with approval of the Fund's Board of Trustees.

A discussion regarding the Board's consideration of the Fund's Investment Advisory Agreement and Sub-Advisory Agreement is provided in the Fund's Annual Report to Shareholders for the period ended December 31, 2018.

SSGA FM, as the investment adviser for the Fund, may hire one or more sub-advisers to oversee the day-to-day investment activities of the Fund. The sub-advisers are subject to oversight by the Adviser. The Adviser and the Trust have received an exemptive order from the SEC that permits the Adviser, with the approval of the Independent Trustees of the Trust to retain, and to amend contractual arrangements with unaffiliated investment sub-advisers for the Fund without a vote of the Fund's shareholders. The Trust will notify shareholders in the event of any change in the identity of a sub-adviser or sub-advisers of any Fund. The Adviser is not required to disclose fees paid to any individual sub-adviser retained pursuant to the order. The Sub-Adviser places all orders for purchases and sales of the Fund's investments.

Portfolio Management

The Adviser and Sub-Adviser manage the fund using one portfolio manager, who is responsible for its performance. The `buy discipline' for portfolio manager is to select stocks from the pool which they believe have the most upside to our estimate of intrinsic value, in which they share the Adviser and Sub-Adviser's conviction that the assumptions are robust, and which the portfolio manager believes will help construct a well-balanced, diversified portfolio. The portfolio manager is overseen by the SSGA Investment Committee.

The professional primarily responsible for the day-to-day management of the Fund is Barry Glavin.

Barry Glavin, CFA, is the Chief Investment Officer of SSGA Ireland's Dublin-based Fundamental Value Team and the Portfolio Manager responsible for the International Value Spotlight Strategy. He joined the business in November 2006 as Head of Industrials Research and led the Research Team for six years until his appointment as CIO in July 2013. Prior to joining SSGA Ireland, Mr.

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Glavin spent seven years with the HSBC group in London, as Head of Industrials Research with HSBC Halbis Partners, and in Paris, as a Portfolio Manager with the Multi Asset Class team. Barry began his financial career as a derivatives broker with Cargill Investor Services in Paris. Barry holds a Bachelor of Arts in Politics and Philosophy from University College Dublin and earned the Chartered Financial Analyst (CFA) designation in 2003.

Additional information about the portfolio manager's compensation, other accounts managed by the portfolio manager, and the portfolio manager's ownership of the Fund is available in the SAI.

Other Fund Services

The Administrator, Sub-Administrator and Custodian

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Fund's transfer agent and dividend disbursing agent (the “Transfer Agent”).

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Fund's distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

Additional Information

Shareholder Information

Determination of Net Asset Value

The Fund determines its net asset value (“NAV”) per share once each business day as of the scheduled close of regular trading on the New York Stock Exchange (the “NYSE”). Pricing does not occur on NYSE holidays. A business day is one on which the NYSE is open for regular trading. The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. In unusual circumstances, such as an emergency or an unscheduled close or halt of trading on the NYSE, the time at which share prices are determined may be changed. The NAV per share is based on the market value of the investments held in the Fund. The NAV of each class of the Fund's Shares is calculated by dividing the value of the assets of the Fund attributable to that class less the liabilities of the Fund attributable to that class by the number of shares in the class outstanding. As noted in this Prospectus, the Fund may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when the Fund does not price its shares. Consequently, the NAV of the Fund's Shares may change on days when shareholders are not able to purchase or redeem the Fund's Shares. Purchase and redemption orders for Fund Shares are processed, respectively, at the NAV next determined after the Fund accepts a purchase order or receives a redemption request in good form. The Fund values each security or other investment pursuant to guidelines adopted by the Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Fund's Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii) a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by the Fund occurs after the close of a related exchange but before the determination of the Fund's NAV. Attempts to determine the fair value of securities or other investments introduce an element of subjectivity to the pricing of securities or other

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investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the price the Fund would have received had it sold the investment. To the extent that the Fund invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the funds. The prospectuses of these funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

Investing in State Street Institutional Investment Trust Shares

Purchasing Shares

Choosing a Share Class

The Fund offers three classes of shares through this Prospectus: Class A, Class I and Class K, available to you subject to the eligibility requirements set forth below.

When you buy Class A shares, the initial sales load is deducted from the amount you invest, unless you qualify for an initial sales load waiver. This means that less money will be invested in the Fund immediately. Class A shares have a Rule 12b-1 fee of 0.25% per year. A contingent deferred sales charge (“CDSC”) of 1.00% may be assessed on redemptions of Class A shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase as part of an investment of $1,000,000 or more.

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	Class A	Class I	Class K
Availability	Available to the general public through certain Financial Intermediaries.	Limited to certain investors, including: • Certain banks, broker-dealers and other Financial Intermediaries. • Certain employer- sponsored retirement plans. • Certain employees or affiliates of State Street Corporation or its affiliates	Limited to certain investors, including certain qualified recordkeepers and employer-sponsored retirement plans.
Minimum Initial Investment	$2,000. The investment minimum may be modified, waived or reduced for certain types of investors ( e.g ., 401(k) or 403(b) plans) and investments as well as for certain fee-based programs where an agreement is in place.	$1,000,000. The investment minimum may be modified, waived or reduced for certain types of investors (e.g., 401(k) or 403(b) plans) and investments as well as for certain fee- based programs where an agreement is in place.	$10,000,000. The investment minimum may be modified, waived or reduced for certain types of investors ( e.g ., 401(k) or 403(b) plans) and investments as well as for certain fee- based programs where an agreement is in place.
Maximum Investment	None.	None.	None.
Initial (Front-End) Sales Charge	Yes. 5.25% for Equity Funds and 3.75% for Fixed Income Funds, payable at time of purchase. Lower sales charges are available for larger investments. See the chart under “Class A” section of this Prospectus.	No. Entire purchase price is invested in shares of the Fund.	No. Entire purchase price is invested in shares of the Fund.
Deferred (CDSC) Sales Charge	No, except for purchases of $1,000,000 or more that are redeemed within 18 months after purchase.	No.	No.
Distribution and Service (12b-1) Fees	0.25% annual fee.	No.	No.
Redemption Fees	No.	No.	No.

Class A

Class A shares are available to the general public for investment through qualified recordkeepers with a distribution and/or fund servicing agreement maintained with SSGA FD.

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When you buy Class A shares, you pay an initial (or front-end) sales charge at the time of your investment, which is included in the offering price, unless you qualify for a sales charge reduction or waiver. This fee is deducted from the amount you invest, and the remainder of your money is used to buy shares in the Fund. The table below shows the amount of sales charge you would pay at different levels of investment and the commissions paid to Financial Intermediaries at each level of investment. The actual sales charge you pay may vary slightly from the rates disclosed due to rounding.

Amount of Purchase Payment	Sales Charge as a % of Offering Price	Sales Charge as a % of Net Amount Invested	Financial Intermediary Compensation as a % of Offering Price
Less than $50,000	5.25%	5.54%	4.75%
$50,000-$99,999	4.50%	4.71%	4.00%
$100,000-$249,999	3.50%	3.63%	3.25%
$250,000-$499,999	2.50%	2.56%	2.25%
$500,000-$999,999	2.00%	2.04%	1.75%
$1,000,000 or more	None	None	Advanced Commission ^{1, 2}

¹	Class A advanced commission for purchases over $1 million:

1.00%	First $3 million
Plus 0.50%	Next $12 million
Plus 0.25%	Over $15 million

Reducing Your Class A Sales Charge

1.	Your account(s);
2.	Account(s) of your spouse or domestic partner;
3.	Account(s) of children under the age of 21 who share your residential address;
4.	Trust accounts established by any of the individuals in items (1) through (3) above. If the person(s) who established the trust is deceased, the trust account may be aggregated with the account(s) of the primary beneficiary of the trust;
5.	Solely controlled business accounts; and
6.	Single-participant retirement plans of any of the individuals in items (1) through (3) above.

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with State Street Funds, (2) the number of shares of the State Street Funds held in your account(s) with a Financial Intermediary, and (3) the number of shares of the State Street Funds held in an account with a Financial Intermediary owned by your spouse or domestic partner and by children under the age of 21 who share your residential address.

Gifting of Shares . If you make a gift of shares, upon your request, you may combine purchases, if made at the same time, under right of accumulation of Class A, Class I and Class N shares of a State Street Fund (other than any shares of money market funds) at the sales charge discount allowed for the combined purchase. The receiver of the gift may also be entitled to a prospective reduction in sales charges in accordance with the Fund's right of accumulation or other provisions. You or the receiver of the gift must provide certain account information to State Street or their agents at the time of purchase to exercise this right.

Letter of Intent. In order to immediately reduce your Class A sales charge, you may sign a Letter of Intent stating your intention to buy a specified amount of Class A shares of one or more State Street Funds within a 13-month period at the reduced sales charge rates applicable to the aggregate amount of the intended purchases stated in the Letter. Purchases of Class A shares of one or more State Street Funds you make over the 13- month period will be combined and you will pay the same sales charge on the new Class A shares that you would have paid if all shares were purchased at once. The 13-month Letter of Intent period commences on the day that the Letter of Intent is received by the Fund or your Financial Intermediary. Purchases submitted not more than three months prior to the date the Letter of Intent is received are considered in determining the level of sales charge that will be paid pursuant to the Letter of Intent; however, the Letter of Intent will not result in any reduction in the amount of any previously paid sales charge. In addition, investors do not receive credit for shares purchased by the reinvestment of distributions.

Waiver Of The Class A Sales Charge

A sales charge (“load”) may not be imposed on Class A shares of the Fund if the shares were:

1.	Acquired through the reinvestment of dividends and capital gain distributions.
2.	Acquired in exchange for shares of another Class A State Street Fund that were previously assessed a sales charge. However, if your shares are subject to CDSC, the CDSC will continue to apply to your new shares at the same CDSC rate.
3.	Bought in State Street Funds that do not offer Class N (no load) shares ¹ by officers, directors or trustees, retirees and employees and their immediate family members (i.e., spouses, domestic partners, children, grandchildren, parents, grandparents, and any dependent of the person, as defined in Section 152 of the Internal Revenue Code of 1986 (the “Code”)) of:

•	The State Street Funds
•	State Street Corporation and its subsidiaries and affiliates

4.	Bought by employees of:

•

DST Asset Manager Solutions, Inc. and its subsidiaries and affiliates.

•

¹	State Street Funds that offer Class N Shares include: State Street Dynamic Small Cap Fund (SVSCX), State Street Defensive Emerging Markets Equity Fund (SSEMX), State Street International Stock Selection Fund (SSAIX) and State Street S&P 500 Index Fund (SVSPX).

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5.	Bought by:

•	Authorized retirement plans serviced or sponsored by a Financial Intermediary, provided that such Financial Intermediary has entered into an agreement with SSGA FD or with the Fund with respect to such purchases at NAV.
•	Investors who are directly rolling over or transferring shares from an established State Street Fund or State Street qualified retirement plan. Rolling over or transferring shares involves the transferring of shares (in-kind); there is no cash movement associated with the transaction.
•	Clients of Financial Intermediaries that (i) charge an ongoing fee for advisory, management, consulting or similar services, or (ii) have entered into an agreement with SSGA FD to offer Class A shares through a no-load network or platform, or self-directed brokerage accounts that may or may not charge transaction fees to customers.
•	Insurance company separate accounts.
•	Tuition Programs that qualify under Section 529 of the Code.

6.	Bought with proceeds from the sale of Class A shares of a State Street Fund, but only if the purchase is made within 90 days of the sale or distribution. Appropriate documentation may be required. Please refer to Class A Account Reinstatement Privileges below.

7.	Bought in connection with plans of reorganization of a State Street Fund, such as mergers, asset acquisitions and exchange offers to which the Fund is a party. However, you may pay a CDSC when you sell the Fund Shares you received in connection with the plan of reorganization.

Additional Sales Charge Waiver Disclosure

How the CDSC is Calculated

The State Street Funds calculate the CDSC by treating all purchases made in a given month as though they were made on the first day of the month.

You should retain any records necessary to substantiate historical costs because SSGA FD, the Fund, the transfer agent and your Financial Intermediary may not maintain such information.

Waiver of the CDSC

In the following situations, no CDSC is imposed on redemptions of Class A shares of the Fund:

If you participate in the Automatic Withdrawal Plan (AWP). Redemptions made on a regular periodic basis ( e.g . monthly) will not be subject to any applicable CDSC if they are, in the aggregate, less than or equal to 10% annually of the current market value of the account balance. Redemptions made as part of a required minimum distribution are also included in calculating amounts eligible for this waiver. For information on the Automatic Withdrawal Plan, please see Service Options.

If you are a registered participant or beneficial owner of an account and you die or become disabled (as defined in Section 72(m)(7) of the Code). This waiver is only available for accounts open prior to the shareholder's or beneficiary's death or disability, and the redemption must be made within one year of such event. Subsequent purchases into such account are not eligible for the CDSC

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	waiver. In order to qualify for this waiver, SSGA FD must be notified of such death or disability at the time of the redemption order and be provided with satisfactory evidence of such death or disability.
3.	Redemptions that represent a required minimum distribution from your IRA Account or other qualifying retirement plan but only if you are at least age 70 1/2. If you maintain more than one IRA, only the assets credited to the IRA that is invested in one or more of the State Street Funds are considered when calculating that portion of your minimum required distribution that qualifies for the waiver.
4.	A distribution from a qualified retirement plan by reason of the participant's retirement.
5.	Redemptions that are involuntary and result from a failure to maintain the required minimum balance in an account.

6.	Exchanges in connection with plans of reorganization of a State Street Fund, such as mergers, asset acquisitions and exchange offers to which the Fund is a party. However, you may pay a sales charge when you redeem the Fund Shares you receive in connection with the plan of reorganization.

7.	Exchanges for shares of the same class of another State Street Fund. However, if your shares are subject to CDSC, the CDSC will continue to apply to your new shares. For purposes of the CDSC, shares will continue to age from the date of the original purchase of the Fund Shares.
8.	Redemption of shares purchased through employer sponsored retirement plans and deferred compensation plans. The CDSC, however, will not be waived if the plan redeems all of the shares that it owns on behalf of participants prior to the applicable CDSC period, as defined above.
9.	Redemptions as part of annual IRA custodial fees.
10.	Acquired through the reinvestment of dividends and capital gains distributions.

Appropriate documentation may be required. Please refer to Class A Account Reinstatement Privileges below.

Class A Account Reinstatement Privileges

Class I

Class I shares are available to the following categories of investors and/or investments:

1.	Banks, broker-dealers and other financial institutions (including registered investment advisers and financial planners) purchasing shares on behalf of their clients in:

•	discretionary and non-discretionary advisory programs;
•	fund supermarkets;
•	asset allocation programs;
•	other programs in which the client pays an asset-based fee for advice or for executing transactions in Fund Shares or for otherwise participating in the program; or
•	certain other investment programs that do not charge an asset-based fee;

2.	Qualified state tuition plans described in Section 529 of the Code and donor-advised charitable gift funds (subject to all applicable terms and conditions);
3.	Defined contribution, defined benefit and other employer-sponsored employee benefit plans, whether or not qualified under the Code;
4.	Certain other registered open-end investment companies whose shares are distributed by SSGA FD;

5.	Certain retirement and deferred compensation programs established by State Street Corporation or its affiliates for their employees or the Fund's Trustees;

6.	Current or retired Directors or Trustees of the State Street Funds, officers and employees of SSGA, and any of its subsidiaries, such persons' spouses, and children under the age of 21, and trust accounts for which any of such person is a beneficiary;
7.	Investments made in connection with certain mergers and/or reorganizations as approved by the Adviser;

8.	The reinvestment of dividends from Class I shares in additional Class I shares of the Fund; and

9.	Qualified recordkeepers with a distribution and/or fund servicing agreement maintained with SSGA FD.

The minimum investment for Class I shares is $1,000,000.

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Class K

Class K shares are available to the following categories of investors:

1.	Qualified recordkeepers with an applicable agreement maintained with SSGA FD;
2.	Defined benefit plans, defined contribution plans, endowments and foundations with greater than $10,000,000 in a qualified tax-exempt plan;
3.	Employers with greater than $10,000,000 in the aggregate between qualified and non-qualified plans that they sponsor; and
4.	Defined contribution, defined benefit and other employer-sponsored employee benefit plans, whether or not qualified under the Code.

The minimum investment for Class K shares is $10,000,000.

How to Initiate a Purchase Request

Investing in the State Street Funds Through a Financial Intermediary

Please be sure to check Exchanging Shares and Frequent-Trading Limits below.

How to Pay for a Purchase

By Check . You may send a check to make initial or additional purchases to your fund account. Make your check payable to “State Street Funds” and include the appropriate fund name and account number ( e.g ., “State Street Global Value Spotlight Fund—a/c #xxx”) in the memo section of the check.

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Trade Dates-Purchases

If your purchase request is not in good order, it may be rejected.

For further information about purchase transactions, consult our website at www.ssgafunds.com or see Contacting the State Street Funds.

Other Purchase Policies You Should Know

Redeeming Shares

By Telephone. You may call the State Street Funds to request a redemption of shares. See Contacting the State Street Funds .

By Mail. You may send a written request to the State Street Funds to redeem from the Fund account or to make an exchange. See Contacting the State Street Funds .

Please be sure to check Exchanging Shares and Frequent-Trading Limits below.

Trade Date-Redemptions

The trade date for any redemption request received in good order will depend on the day and time the State Street Funds receive your request in good order and the manner in which you are redeeming.

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How to Receive Redemption Proceeds

Regardless of the method the Fund use to make a redemption payment, the Fund typically expect to pay out redemption proceeds on the next business day after a redemption request is received in good order. If you purchased State Street Fund Shares by check or an automatic investment program and you elect to redeem shares within 15 days of the purchase, you may experience delays in receiving redemption proceeds. In this case, the State Street Funds generally will postpone sending redemption proceeds until it can verify that the check or automatic investment program investment has been collected, but in no event will this delay exceed 15 days. There will be no such delay for redemptions following purchases paid by federal funds wire or by bank cashier's check, certified check or treasurer's check. The State Street Funds reserve the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Fund. The State Street Funds reserve the right to suspend the right of shareholder redemption or postpone the date of payment for more than seven days to the extent permitted by the 1940 Act.

Other Redemption Policies that You Should Know

Address Changes. If your address of record has been changed within thirty (30) days of the redemption request, the request must be in writing and bear a medallion guarantee.

Significant/Unusual Economic or Market Activity. During periods of significant or unusual economic or market activity, you may encounter delays attempting to give instructions by phone.

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Large Redemptions. Requests for redemptions over $50,000 must be in writing and bear a medallion guarantee.

Exchanging Shares

Share Class Conversions

You may be able to convert your shares to a different share class of the same Fund that has a lower expense ratio provided that you are eligible to buy that share class and that certain conditions are met. This conversion feature is intended for shares held through a Financial Intermediary offering a fee-based or wrap fee program that has an agreement with SSGA FD specific for this purpose. In such instance, your shares may be automatically converted under certain circumstances. Class N shares of a State Street Fund may be converted to Class I shares of the same State Street Fund. Not all share classes are available through all Financial Intermediaries. If your shares of the Fund are converted to a different share class of the same Fund, the transaction will be based on the respective net asset value of each class as of the trade date of the conversion. Consequently, you may receive fewer shares or more shares than originally owned, depending on that day's net asset values. The total value of the initially held shares, however, will equal the total value of the converted shares at the time of conversion. The conversion of shares of one class of the Fund into shares of another class of the same Fund is not taxable for federal income tax purposes and no gain or loss will be reported on the transaction. See the applicable prospectus for share class information. Please contact your Financial Intermediary regarding the tax consequences of any conversion and for additional information.

Frequent-Trading Limits

Frequent, short-term trading, abusive trading practices and market timing (together, “Excessive Trading”), often in response to short-term fluctuations in the market, are not knowingly permitted by the State Street Funds. The State Street Funds do not accommodate frequent purchases and redemptions of Fund Shares by Fund shareholders. Excessive Trading into and out of a State Street Fund may harm the Fund's performance by disrupting portfolio management strategies and by increasing expenses. These expenses are borne by all Fund shareholders, including long-term investors who do not generate such costs.

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As a means to protect each State Street Fund and its shareholders from Excessive Trading:

•	The State Street Funds' transfer agent compiles, monitors and reports account-level information on omnibus and underlying shareholder/participant activity. Depending on the account type, monitoring will be performed on a daily, monthly, quarterly and/or annual basis;

•

•	With respect to State Street Funds that invest in securities that trade on foreign markets, pursuant to the State Street Funds' fair valuation procedures, pricing adjustments may be made based on information received from a third-party, multi-factor fair valuation pricing service.

The State Street Funds' distributor has detailed procedures that document the transparency oversight and monitoring processes performed by the State Street Funds' transfer agent.

Service Options

Dividend and Capital Gain Distribution Option

Please refer to Dividends, Distributions and Tax Considerations below for additional information.

Automatic Withdrawal Plan

Telephone Redemptions and Exchanges

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Automatic Investment Plan

Once the initial investment has been accepted, you may make subsequent investments of $100 or more monthly, quarterly or annually by direct deposit by debiting your bank checking or savings account. Once this option has been established, you may call the State Street Funds to make additional automatic purchases, to change the amount of the existing automatic purchase, or to stop it. The State Street Fund reserves the right to cancel your automatic investment plan if any correspondence sent by the Fund is returned by the postal or other delivery service as “undeliverable.”

Additional Shareholder Information

Account Transfers

Responsibility for Fraud

Right to Change Policies

In addition to the rights expressly stated elsewhere in this Prospectus, the State Street Funds reserve the right, in the future, to:

1.	Alter, add, or discontinue any conditions of purchase (including eligibility requirements), redemption, exchange, service, or privilege at any time;
2.	Accept initial purchases by telephone;
3.	Freeze any account and/or suspend account services if the State Street Funds has received reasonable notice of a dispute regarding the assets in an account, including notice of a dispute between the registered or beneficial account owners, or if we reasonably believe a fraudulent transaction may occur or has occurred;
4.	Temporarily freeze any account and/or suspend account services upon initial notification to the State Street Funds of the death of the shareholder until the State Street Funds receive required documentation in good order;
5.	Alter, impose, discontinue, or waive any redemption fee, account service fee, or other fees charged to a group of shareholders; and
6.	Redeem an account or suspend account privileges, without the owner's permission to do so, in cases of threatening conduct or activity the State Street Funds believe to be suspicious, fraudulent, or illegal.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If the Fund's transfer agent identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

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Dividends, Distributions and Tax Considerations

Distribution Options. You can choose from four different distribution options as indicated on the application:

•	Reinvestment Option—Dividends and capital gain distributions will be automatically reinvested in additional shares of the Fund. If you do not indicate a choice on the application, this option will be automatically assigned.

•	Income-Earned Option—Capital gain distributions will be automatically reinvested, but a check, direct deposit or wire will be sent for each dividend distribution.
•	Cash Option—A check, wire or direct deposit will be sent for each dividend and capital gain distribution.
•	Direct Dividends Option—Dividends and capital gain distributions will be automatically invested in another identically registered State Street Fund of the same share class.

Delivery of Documents to Accounts Sharing an Address

Tax Considerations

The Fund intends to elect to be treated as a regulated investment company and intends each year to qualify and to be eligible to be treated as such. A regulated investment company generally is not subject to tax at the corporate level on income and gains that are timely distributed to shareholders. In order to qualify and be eligible for treatment as a regulated investment company, the Fund must, among other things, satisfy diversification, 90% gross income and distribution requirements. The Fund's failure to qualify and be eligible for treatment as a regulated investment company would result in corporate level taxation, and consequently, a reduction in income available for distribution to shareholders.

For U.S. federal income tax purposes, distributions of investment income generally are taxable to you as ordinary income. Taxes on distributions of capital gains generally are determined by how long the Fund owned (or is deemed to have owned) the investments that generated them, rather than how long you have owned your Fund Shares. Distributions of net capital gains (that is, the excess of net long-term capital gains over net short-term capital losses) from the sale of investments that the Fund owned (or is deemed to have owned) for more than one year that are properly reported by the Fund as capital gain dividends generally will be treated as long-term capital gain includible in your net capital gain and taxed to individuals at reduced rates. Distributions of gains from investments that the Fund owned (or is deemed to have owned) for one year or less generally will be taxable to you as ordinary income. Distributions of investment income properly reported by the Fund as derived from “qualified dividend income,” which will not include income from the Fund's portfolio securities on loan, are taxed to individuals at the rates applicable to net capital gain, provided holding period and other requirements are met by both the shareholder and the Fund. Distributions are taxable to you even if they are paid from income or gains earned by the Fund before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares.

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An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by the Fund, including any capital gain dividends, and net gains recognized on the redemption of shares of the Fund.

The Fund's income from or proceeds of dispositions of its investments in non-U.S. assets may be subject to non-U.S. withholding or other taxes, which will reduce the yield on those investments. In certain instances, the Fund may be entitled to elect to pass through to its shareholders a credit (or deduction, for a shareholder that itemizes deductions and so chooses) for foreign taxes (if any) borne with respect to foreign securities income earned by the Fund. If the Fund so elects, shareholders will include in gross income from foreign sources their pro rata shares of such taxes, if any, treated as paid by the Fund. There can be no assurance that the Fund will make such election, even if it is eligible to do so. If the Fund does not qualify for or does not make such election, shareholders will not be entitled separately to claim a credit or deduction with respect to foreign taxes paid by the Fund; in that case the foreign tax will nonetheless reduce the Fund's taxable income. Shareholders that are not subject to U.S. federal income tax, and those who invest in the Fund through tax-advantaged accounts (including those who invest through individual retirement accounts or other tax-advantaged retirement plans), generally will receive no benefit from any tax credit or deduction passed through by the Fund.

Certain of the Fund's investment practices, including derivative transactions and investments in debt obligations issued or purchased at a discount, will be subject to special and complex U.S. federal income tax provisions. These special rules may affect the timing, character, and/or amount of the Fund's distributions, and may require the Fund to sell its investments at a time when it is not advantageous to do so.

Cost Basis Reporting . Department of the Treasury regulations mandate cost basis reporting to shareholders and the IRS for redemptions of Fund Shares acquired on or after January 1, 2012 (“Post Effective Date Shares”). If you acquire and hold shares directly through the Fund and not through a Financial Intermediary, DST Asset Manager Solutions, Inc. will use a default average cost basis methodology for tracking and reporting your cost basis on Post Effective Date Shares, unless you request, in writing, another cost basis reporting methodology.

Financial Intermediary Arrangements

Distribution Arrangements and Rule 12b-1 Fees

The Fund may pay distribution fees and other amounts described in this Prospectus at a time when shares of the Fund are unavailable for purchase.

Other Payments to Financial Intermediaries

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The Financial Intermediary is often compensated by SSGA FD or its affiliates for the services it performs and in such cases is typically paid continually over time, during the period when the Financial Intermediary's clients hold investments in the Fund. The amount of continuing compensation paid by SSGA FD or its affiliates to different Financial Intermediaries for distribution and/or shareholder services varies. Any compensation is typically a percentage of the value of the Financial Intermediary's clients' investments in the Fund or a per account fee. The variation in compensation may, but will not necessarily, reflect enhanced or additional services provided by the Financial Intermediary.

If you invest through a Financial Intermediary and meet the eligibility criteria for more than one share class, you should discuss with your Financial Intermediary which share class is appropriate for you. Your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend one share class over another, when you are eligible to invest in more than one share class. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by the Fund or its affiliates with respect to the different share classes offered by the Fund.

SSGA FD and its affiliates (including SSGA FM), at their own expense and out of their own assets, may also provide other compensation to Financial Intermediaries in connection with sales of the Fund's shares or the servicing of shareholders or shareholder accounts. Such compensation may include, but is not limited to, financial assistance to Financial Intermediaries in connection with conferences, sales, or training programs for their employees; seminars for the public; advertising or sales campaigns; or other Financial Intermediary-sponsored special events. In some instances, this compensation may be made available only to certain Financial Intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the Fund's shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as Financial Industry Regulatory Authority, Inc.

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Financial Highlights

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INTERNATIONAL VALUE SPOTLIGHT FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Class K
	Year Ended 12/31/18	Year Ended 12/31/17	For the Period 7/14/16* - 12/31/16
Net asset value, beginning of period	$ 12.56	$11.25	$10.00
Income (loss) from investment operations:
Net investment income (loss) (a)	0.21	0.24	0.02
Net realized and unrealized gain (loss)	(2.66)	2.56	1.44
Total from investment operations	(2.45)	2.80	1.46
Distributions to shareholders from:
Net investment income	(0.22)	(0.24)	(0.02)
Net realized gains	(1.81)	(1.25)	(0.19)
Total distributions	(2.03)	(1.49)	(0.21)
Net asset value, end of period	$ 8.08	$ 12.56	$ 11.25
Total return (b)	(19.32)%	25.03%	14.57%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 1,617	$2,512	$2,250
Ratios to average net assets:
Total expenses	7.58%	7.26%	7.76%(c)
Net expenses	0.75%	0.75%	0.75%(c)
Net investment income (loss)	1.76%	1.86%	0.44%(c)
Portfolio turnover rate	63%	45%	26%(d)

*	Commencement of operations.
(a)	Net investment income per share is calculated using the average shares method.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates of the Fund. Total return for periods less than one year are not annualized. Results represent past performance and are not indicative of future results.
(c)	Annualized.
(d)	Not annualized.

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Contacting the State Street Funds

Online:	www.ssgafunds.com	24 hours a day, 7 days a week
Phone:	(800) 647-7327	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Overnight/ Registered, Express, Certified Mail
State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737	State Street Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407

The Funds do not consider the U.S. Postal Service or other independent delivery services to be their agents. Therefore, deposits in the mail or with such services, or receipt at the Fund's post office box, of purchase orders or redemption requests, do not constitute receipt by the Fund or Transfer Agent.

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For more information about the Fund:

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

SSITVSLSTATPRO

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Institutional Liquid Reserves Fund

Trust Class (TILXX)

State Street Institutional Treasury Plus Money Market Fund

Trust Class (TPLXX)

Beginning on January 1, 2021, as permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of the Fund's annual and semi- annual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Fund (or from your financial intermediary, such as a broker-dealer or bank). Instead, the reports will be made available on the Fund's website (www.ssga.com/cash), and you will be notified by mail each time a report is posted, and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Funds electronically by calling (866) 392-0869.

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with a Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling (866) 392-0869. Your election to receive reports in paper will apply to all funds held in your account, if you invest through your financial intermediary or all funds held with the fund complex if you invest directly with a Fund.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in any of the Funds offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Each Fund may offer multiple classes of shares. This Prospectus covers only the Trust Class Shares of the applicable Funds.

State Street Institutional Liquid Reserves Fund is a “floating net asset value” money market fund. The share price of this Fund will fluctuate.

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Fund Summaries	1
State Street Institutional Liquid Reserves Fund	1
State Street Institutional Treasury Plus Money Market Fund	6
Additional Information About Investment Objectives, Principal Strategies and Risks	11
Additional Information About Non-Principal Investment Strategies and Risks	18
Portfolio Holdings Disclosure	20
Management and Organization	21
Shareholder Information	22
Dividends, Distributions and Tax Considerations	28
Financial Intermediary Arrangements	29
Financial Highlights	31

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State Street Institutional Liquid Reserves Fund

Investment Objective

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%
Other Expenses	0.13%
Total Annual Fund Operating Expenses	0.18%

Example:

1 year		3 years		5 years		10 years
$18		$58		$101		$230

Principal Investment Strategies

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high quality obligations of U.S. or foreign companies; asset-backed securities, including asset-backed commercial paper; mortgage-related securities; and repurchase agreements. These instruments may bear fixed, variable or floating rates of interest or may be zero-coupon securities. The Fund also may invest in shares of other money market funds, including funds advised by the Adviser. Under normal market conditions, the Fund intends to invest more than 25% of its total assets in bank obligations. A substantial portion of the Fund may be invested in securities that are issued or traded pursuant to exemptions from registration under the federal securities laws.

Principal Risks

In addition, the Fund is subject to the following principal risks:

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Performance

The bar chart and table below provide some indication of the risks of investing in the ILR Fund by illustrating the variability of the Fund's returns for Trust Class Shares from year-to-year. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.57% (Q4, 2018)
Lowest Quarterly Return: 0.19% (Q1, 2017)

Average Annual Total Returns (for periods ended 12/31/18)

		One Year		Since Inception		Inception Date
Trust Class		1.96%		1.31%		8/29/2016

To obtain the Fund's current yield, please call (877) 521-4083.

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Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Purchase and Sale of Fund Shares

Trust Class shares of the Fund are only available for purchase by shareholders of the Fund who owned Trust Class shares on August 29, 2016.

Purchase Minimums

Trust Class
To establish an account	$15,000,000
To add to an existing account	No minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone:

By Intermediary:

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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State Street Institutional Treasury Plus Money Market Fund

Investment Objective

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%
Other Expenses	0.13%
Total Annual Fund Operating Expenses	0.18%

Example:

1 year		3 years		5 years		10 years
$18		$58		$101		$230

Principal Investment Strategies

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Principal Risks

In addition, the Fund is subject to the following principal risks:

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Performance

The bar chart and table below provide some indication of the risks of investing in the Treasury Plus Fund by illustrating the variability of the Fund's returns for Trust Class Shares from year-to-year. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.53% (Q4, 2018)
Lowest Quarterly Return: 0.10% (Q1, 2017)

Average Annual Total Returns (for periods ended 12/31/18)

		One Year		Since Inception		Inception Date
Trust Class		1.69%		1.05%		8/29/2016

To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Purchase and Sale of Fund Shares

Trust Class shares of the Fund are only available for purchase by shareholders of the Fund who owned Trust Class shares on August 29, 2016.

Purchase Minimums

Trust Class
To establish an account	$15,000,000
To add to an existing account	No minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone:

By Intermediary:

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Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objectives, Principal Strategies and Risks

Investment Objective

The investment objective of each of the ILR Fund and the Treasury Plus Fund, as stated in each Fund's Summary, may be changed without shareholder approval.

ILR Fund

Principal Investment Strategies

Treasury Plus Fund

Principal Investment Strategies

The Treasury Plus Fund is a government money market fund and attempts to meet its investment objective by investing only in U.S. Treasury bills, notes and bonds (which are direct obligations of the U.S. government) and repurchase agreements collateralized by these obligations. The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

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Additional Information About Risks

Risk information is applicable to both Funds unless otherwise noted. The risks are described in alphabetical order and not in the order of importance or potential exposure.

Call/Prepayment Risk (principal risk for the ILR Fund) . Call/prepayment risk is the risk that an issuer will exercise its right to pay principal on an obligation held by a Fund earlier than expected or required. This may occur, for example, when there is a decline in interest rates, and an issuer of bonds or preferred stock redeems the bonds or stock in order to replace them with obligations on which it is required to pay a lower interest or dividend rate. It may also occur when there is an unanticipated increase in the rate at which mortgages or other receivables underlying mortgage- or asset-backed securities held by a Fund are prepaid. In any such case, a Fund may be forced to invest the prepaid amounts in lower-yielding investments, resulting in a decline in the Fund's income.

Counterparty Risk . A Fund will be subject to credit risk with respect to the counterparties with which a Fund enters into repurchase agreements and other transactions. If a counterparty fails to meet its contractual obligations, a Fund may be unable to terminate the transaction, and it may be delayed or prevented from realizing on any collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty.

Credit Risk . Credit risk is the risk that an issuer, guarantor or liquidity provider of a fixed-income security held by a Fund may be unable or unwilling, or may be perceived (whether by market participants, ratings agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. It includes the risk that the security will be downgraded by a credit rating agency; generally, lower credit quality issuers present higher credit risks. An actual or perceived decline in creditworthiness of an issuer of a fixed-income security held by a Fund may result in a decrease in the value of the security. It is possible that the ability of an issuer to meet its obligations will decline substantially during the period when a Fund owns securities of the issuer or that the issuer will default on its obligations or that the obligations of the issuer will be limited or restructured.

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Extension Risk (principal risk for the ILR Fund). During periods of rising interest rates, the average life of certain types of securities may be extended because of slower-than-expected principal payments. This may increase the period of time during which an investment earns a below-market interest rate, increase the security's duration and reduce the value of the security. Extension risk may be heightened during periods of adverse economic conditions generally, as payment rates decline due to higher unemployment levels and other factors.

Liquidity Risk (principal risk for the ILR Fund) . Liquidity risk is the risk that a Fund may not be able to dispose of securities readily at a favorable time or prices (or at all) or at prices approximating those at which a Fund currently values them. For example, certain investments may be subject to restrictions on resale, may trade in the over-the-counter market or in limited volume, or may not have an active trading market. Illiquid securities may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value. It may be difficult for a Fund to value illiquid securities accurately. The market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. Disposal of illiquid securities may entail registration expenses and other transaction costs that are higher

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than those for liquid securities. A Fund may seek to borrow money to meet its obligations (including among other things redemption obligations) if it is unable to dispose of illiquid investments, resulting in borrowing expenses and possible leveraging of the Fund. In some cases, due to unanticipated levels of illiquidity a Fund may choose to meet its redemption obligations wholly or in part by distributions of assets in-kind.

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ties, or may have an incentive to invest in such master fund over a master fund sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by a Fund in a master fund sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a master fund sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Fund does so. A Fund will bear its pro rata portion of the expenses incurred by the master fund.

Money Market Risk (principal risk for the Treasury Plus Fund) . An investment in a money market fund is not a deposit of any bank and is not insured or guaranteed by the FDIC or any other government agency. Although a money market fund generally seeks to preserve the value of its shares at $1.00 per share, there can be no assurance that it will do so, and it is possible to lose money by investing in a money market fund. A major or unexpected increase in interest rates or a decline in the credit quality of an issuer or entity providing credit support, an inactive trading market for money market instruments, or adverse market, economic, industry, political, regulatory, geopolitical, and other conditions could cause a money market fund's share price to fall below $1.00. It is possible that a money market fund will issue and redeem shares at $1.00 per share at times when the fair value of the money market fund's portfolio per share is more or less than $1.00. A money market fund may be permitted or required to impose redemption fees or to impose limitations on redemptions during periods of high illiquidity in the markets for the investments held by it. None of State Street Corporation, State Street, State Street Global Advisors, SSGA FM or their affiliates (collectively, the “State Street Entities”) guarantee the value of an investment in a money market fund at $1.00 per share. Investors should have no expectation of capital support to a money market fund from the State Street Entities.

Mortgage-Related and Other Asset-Backed Securities Risk (principal risk for the ILR Fund) . Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed income investments. The liquidity of mortgage-related and asset-backed securities may change over time. Mortgage-related securities represent a participation in, or are secured by, mortgage loans. Other asset-backed securities are typically structured like mortgage-related securities, but instead of mortgage loans or interests in mortgage loans, the underlying assets may include, for example, items such as motor vehicle installment sales or installment loan contracts, leases on various types of real and personal property, and receivables from credit card agreements. During periods of falling interest rates, mortgage-related and other asset-backed securities, which typically provide the issuer with the right to prepay the security prior to maturity, may be prepaid, which may result in a Fund having to reinvest the proceeds in other investments at lower interest rates. During periods of rising interest rates, the average life of mortgage-related and other asset-backed securities may extend because of slower-than expected principal payments. This may lock in a below market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. As a result, mortgage-related and other asset-backed securities may have less potential for capital appreciation during periods of declining interest rates than other debt securities of comparable maturities, although they may have a similar risk of decline in market values during periods of rising interest rates. Prepayment rates are difficult to predict and the potential impact of prepayments on the value of a mortgage-related or other asset-backed security depends on the terms of the instrument and can result in significant volatility. The price of a mortgage-related or other asset-backed security also depends on the credit quality and adequacy of the underlying assets or collateral. Mortgage-related or other asset-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) will generally entail greater credit risk than obligations guaranteed by the U.S. Government. Defaults on the underlying assets, if any, may impair the value of a mortgage-related or other asset-backed security. For some asset-backed securities in which a Fund invests, such as those backed by credit card receivables, the underlying cash flows may not be supported by a security interest in a related asset. Moreover, the values of mortgage-related and other asset-backed securities may be substantially dependent on the servicing of the underlying asset pools, and are therefore subject to risks associated with the negligence or malfeasance by their servicers and to the credit risk of their servicers. In certain situations, the mishandling of related documentation may also affect the rights of securities holders in and to the underlying collateral. There may be legal and practical limitations on the enforceability of any security interest granted with respect to underlying assets, or the value of the underlying assets, if any, may be insufficient if the issuer defaults.

Non-U.S. Securities Risk (principal risk for the ILR Fund) . Investments in securities of non-U.S. issuers (including depositary receipts) entail risks not typically associated with investing in securities of U.S. issuers. Similar risks may apply to securities traded on a U.S. securities exchange that are issued by entities with significant exposure to non-U.S. countries. In certain countries, legal remedies available to investors may be more limited than those available with regard to U.S. investments. Income and gains with respect to investments in certain countries may be subject to withholding and other taxes. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, and financial

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reporting standards, regulatory framework and practices comparable to those in the United States. The securities of some non-U.S. entities are less liquid and at times more volatile than securities of comparable U.S. entities, and could become subject to sanctions or embargoes that adversely affect a Fund's investment. Non-U.S. transaction costs, such as brokerage commissions and custody costs may be higher than in the U.S. In addition, there may be a possibility of nationalization or expropriation of assets, imposition of currency exchange controls, confiscatory taxation, and diplomatic developments that could adversely affect the values of a Fund's investments in certain non-U.S. countries. Investments in securities of non-U.S. issuers also are subject to foreign political and economic risk not associated with U.S. investments, meaning that political events (civil unrest, national elections, changes in political conditions and foreign relations, imposition of exchange controls and repatriation restrictions), social and economic events (labor strikes, rising inflation) and natural disasters occurring in a country where a Fund invests could cause the Fund's investments in that country to experience gains or losses.

Rapid Changes in Interest Rates . The values of most instruments held by a Fund are adversely affected by changes in interest rates generally, especially increases in interest rates. Rapid changes in interest rates may cause significant requests to redeem Fund Shares, and possibly cause a Fund to sell portfolio securities at a loss to satisfy those requests. Significant losses would negatively affect the NAV per share of the ILR Fund and, in the case of the Treasury Plus Fund, could impair the Fund's ability to maintain a stable share price of $1.00.

Reinvestment Risk (principal risk for the ILR Fund). Income from a Fund's portfolio may decline when the Fund invests the proceeds from investment income, sales of portfolio securities or matured, traded or called debt obligations. For instance, during periods of declining interest rates, an issuer of debt obligations may exercise an option to redeem securities prior to maturity, forcing a Fund to reinvest the proceeds in lower-yielding securities. A decline in income received by a Fund from its investments is likely to have a negative effect on the yield and total return of the Fund Shares.

Repurchase Agreement Risk . A repurchase agreement is an agreement to buy a security from a seller at one price and a simultaneous agreement to sell it back to the original seller at an agreed-upon price, typically representing the purchase price plus interest. Repurchase agreements may be viewed as loans made by a Fund which are collateralized by the securities subject to repurchase. A Fund's investment return on such transactions will depend on the counterparty's willingness and ability to perform its obligations under a repurchase agreement. If a Fund's counterparty should default on its obligations and a Fund is delayed or prevented from recovering the collateral, or if the value of the collateral is insufficient, a Fund may realize a loss.

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a pool sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by a Fund in a pool sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Fund does so.

Stable Share Price Risk (principal risk for the Treasury Plus Fund) . If the market value of one or more of the Fund's investments changes substantially, the Fund may not be able to maintain a stable share price of $1.00. This risk typically is higher during periods of rapidly changing interest rates or when issuer credit quality generally is falling, and is made worse when the Fund experiences significant redemption requests.

U.S. Government Securities Risk (principal risk for the ILR Fund) . U.S. government securities, such as Treasury bills, notes and bonds and mortgage-backed securities guaranteed by the Government National Mortgage Association (“Ginnie Mae”), are supported by the full faith and credit of the United States; others are supported by the right of the issuer to borrow from the U.S. Treasury; others are supported by the discretionary authority of the U.S. government to purchase the agency's obligations; and still others are supported only by the credit of the issuing agency, instrumentality, or enterprise. Although U.S. government-sponsored enterprises such as the Federal Home Loan Mortgage Corporation (“Freddie Mac”) and the Federal National Mortgage Association (“Fannie Mae”) may be chartered or sponsored by Congress, they are not funded by Congressional appropriations, and their securities are not issued by the U.S. Treasury nor supported by the full faith and credit of the U.S. government. There is no assurance that the U.S. government would provide financial support to its agencies and instrumentalities if not required to do so. In addition, certain governmental entities have been subject to regulatory scrutiny regarding their accounting policies and practices and other concerns that may result in legislation, changes in regulatory oversight and/or other consequences that could adversely affect the credit quality, availability, or investment character of securities issued by these entities. The value and liquidity of U.S. government securities may be affected adversely by changes in the ratings of those securities. Securities issued by the U.S. Treasury historically have been considered to present minimal credit risk. The downgrade in the long-term U.S. credit rating by at least one major rating agency has introduced greater uncertainty about the ability of the U.S. to repay its obligations. A further credit rating downgrade or a U.S. credit default could decrease the value and increase the volatility of a Fund's investments.

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tion of greater policymaking uncertainty. A downgrade of the ratings of U.S. government debt obligations, which are often used as a benchmark for other borrowing arrangements, could result in higher interest rates for individual and corporate borrowers, cause disruptions in the international bond markets and have a substantial negative effect on the U.S. economy. A downgrade of U.S. Treasury securities from another ratings agency or a further downgrade below AA+ rating by Standard & Poor's Ratings Services may cause the value of the Fund's U.S. Treasury obligations to decline. In recent years, impasses in Congress regarding the federal budget have caused repeated temporary Federal government shutdowns. While Congress has temporarily suspended the debt limit from time to time, the risks that the U.S. government will not adopt a long-term budget or deficit reduction plan, of one or more additional Federal government shutdowns or of future failures to not increase the Federal government's debt limit, may affect investor and consumer confidence and may adversely impact financial markets and the broader economy, perhaps suddenly and to a significant degree.

Additional Information About Non-Principal Investment Strategies and Risks

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Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Funds) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, a Fund, a Portfolio, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect a Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect a Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject a Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of a Fund inaccessible or inaccurate or incomplete. A Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. A Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. Each Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Funds. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which each Fund invests, which could result in material adverse consequences for such issuers, and may cause a Fund's investment in such securities to lose value.

Risk of Investment in Other Pools (risk for the Treasury Plus Fund) . If a Fund invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected. A Fund is exposed indirectly to all of the risks applicable to an investment in such other pool. In addition, lack of liquidity in the underlying pool could result in its value being more volatile than the underlying portfolio of securities, and may limit the ability of a Fund to sell or redeem its interest in the pool at a time or at a price it might consider desirable. The investment policies and limitations of the other pool may not be the same as those of the Fund; as a result, the Fund may be subject to additional or different risks, or may achieve a reduced investment return, as a result of its investment in another pool. If a pool is an exchange-traded fund or other product traded on a securities exchange or otherwise actively traded, its shares may trade at a premium or discount to their NAV, an effect that might be more pronounced in less liquid markets. A Fund bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Fund may invest, leading to potential conflicts of interest. For example, the Adviser or its affiliates may receive fees based on the amount of assets invested in the pool. Investment by a Fund in the pool may be beneficial to the Adviser or an affiliate in the management of the pool, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest a Fund's assets in a pool sponsored or managed by the Adviser or its affiliates in lieu of investments by the Fund directly in portfolio securities, or may have an incentive to invest in the pool over a pool sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by a Fund in a pool sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Fund does so.

Trust Class Closure . The Trust Class of the ILR Fund and the Treasury Plus Fund is currently closed to new investors, except as noted below.

Shareholders who owned Trust Class shares on August 29, 2016, may continue to purchase shares of the class. Fund management may, in its discretion, reopen the share class to certain investors in the future. The Fund reserves the right to modify this policy at any time.

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Portfolio Holdings Disclosure

The Funds' portfolio holdings disclosure policy is described in the SAI.

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Management and Organization

Investment Adviser

SSGA FM serves as the investment adviser to each Fund and corresponding Portfolio and, subject to the oversight of the Board, is responsible for the investment management of each Fund. The Adviser provides an investment management program for each Fund and manages the investment of each Fund's assets. The Adviser is a wholly-owned subsidiary of State Street Global Advisors, Inc., which itself is a wholly-owned subsidiary of State Street Corporation. The Adviser is registered with the SEC under the Investment Advisers Act of 1940, as amended. The Adviser and certain other affiliates of State Street Corporation make up SSGA. SSGA is one of the world's largest institutional money managers and the investment management arm of State Street Corporation. As of December 31, 2018, the Adviser managed approximately $452.10 billion in assets and SSGA managed approximately $2.51 trillion in assets. The Adviser's principal business address is One Iron Street, Boston, Massachusetts 02210.

Total Annual Fund Operating Expense Waivers . SSGA FM, as the investment adviser to each Fund, is contractually obligated, through April 30, 2020, (i) to waive up to the full amount of the advisory fee payable by each Fund, and/or (ii) to reimburse a Fund for expenses to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.07% of average daily net assets on an annual basis. These waiver and/or reimbursement arrangements may not be terminated prior to April 30, 2020 except with approval of the Funds' Board of Trustees.

A discussion regarding the Board's consideration of the Funds' Investment Advisory Agreement is provided in the Funds' Semi-Annual Report to Shareholders for the period ended June 30, 2018.

The Administrator, Sub-Administrator and Custodian

The Adviser serves as administrator of each Fund. The amount of the fee paid to the Adviser for administrative services may vary by share class. Each Fund currently pays the Adviser an administrative fee at the annual rate of 0.05% in respect of the class of shares in this Prospectus. State Street Bank and Trust Company (“State Street”), a subsidiary of State Street Corporation, serves as the sub-administrator for the Funds for a fee that is paid by the Adviser. State Street also serves as custodian of the Funds for a separate fee that is paid by the Funds. SSGA FM serves as administrator of the Portfolios and State Street serves as sub-administrator and custodian of the Portfolios.

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Funds' transfer agent and dividend disbursing agent (the “Transfer Agent”).

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The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Funds' distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

The Shareholder Servicing Agent

Additional Information

Shareholder Information

Determination of Net Asset Value

For the ILR Fund

The Fund determines its NAV per share three times each business day at 8:00 a.m., 12:00 p.m. and 3:00 p.m. ET except for days when the NYSE's regular closing is prior to 3:00 p.m. ET, in which event the Fund will determine its final NAV for the day at the earlier closing time. The Fund calculates its NAV to four decimal places.

For the Treasury Plus Fund

The Treasury Plus Fund determines its NAV per share once each business day at 5:00 p.m. ET except for days when the NYSE closes earlier than its regular closing time, in which event the Treasury Plus Fund will determine its NAV at the earlier closing time (the time when the Treasury Plus Fund determines its NAV per share is referred to herein as the “Valuation Time”). The Fund seeks to maintain a $1.00 per share NAV and, accordingly, uses the amortized cost valuation method, in compliance with the risk limiting conditions of Rule 2a-7 under the Investment Company Act of 1940, as amended (the “1940 Act”), to value its portfolio instruments. The amortized cost valuation method initially prices an instrument at its cost and thereafter assumes a constant amortization to maturity of any discount or premium, regardless of the impact of fluctuating interest rates on the market value of the instrument.

For all Funds

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Pricing does not occur on NYSE holidays. A business day is one on which the NYSE is open for regular trading. The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. The Funds reserve the right to accept orders to purchase or redeem shares, or to continue to accept such orders following the close of the NYSE, on any day that is not a business day or any day on which the NYSE closes early, provided the Federal Reserve remains open. As noted in this Prospectus, certain Funds may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when a Fund does not price its shares. Consequently, the NAV of a Fund's shares may change on days when shareholders are not able to purchase or redeem the Fund's shares. The Funds also may establish special hours on those days to determine each Fund's NAV. In the event that the Funds invoke the right to accept orders to purchase or redeem shares on any day that is not a business day or adopt special hours of operation, the Fund will post advance notice of these events at:www.ssga.com/cash.

Investing in State Street Institutional Investment Trust Shares

Purchasing Shares

Subject to the restrictions described above under “Trust Class Closure,” investors pay no sales load to invest in the Trust Class Shares of the Fund. The price for Fund Shares is the NAV per share. Purchase requests received by a Fund in good order (a purchase request is in good order if it meets the requirements implemented from time to time by the Transfer Agent or authorized agent of the Fund, and for new accounts includes submission of a completed and signed application and all documentation necessary to open an account) on a business day will, if payment is received by FedWire, be priced at the NAV next determined after the order is accepted by the Fund. Payments received by FedWire prior to the last Valuation Times (for the ILR Fund generally, 3:00 p.m. ET, unless the Fund closes earlier), will earn dividend accrual for that purchase.

All purchases that are made by check will begin earning dividends the following Business Day after the day the order is accepted. (If you purchase shares by check, your order will not be in good form until the Transfer Agent receives federal funds for the check.) All purchase orders are subject to acceptance by the Funds. The Funds intend to be as fully invested as is practicable; therefore, investments must be made in Federal Funds (i.e., monies credited to the account of the Funds' custodian bank by a Federal Reserve Bank).

The minimum initial investment in Trust Class of the Funds is $15 million, although the Adviser may waive the minimum in its discretion. Holdings of related customer accounts may be aggregated for purposes of determining the minimum investment amount. “Related customer accounts” may include, but are not limited to, accounts held by the same investment or retirement plan, financial institution, broker, dealer or intermediary. The Funds and the Adviser reserve the right to increase or decrease the minimum amount required to open or maintain an account. There is no minimum subsequent investment, except in relation to maintaining certain minimum account balances (See “Redeeming Shares” below).The Funds require prior notification of subsequent investments in excess of $50 million. The Funds reserve the right to cease accepting investments at any time or to reject any investment order. The Treasury Plus Fund may limit the amount of a purchase order received after 3:00 p.m. ET.

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The ILR Fund determines its NAV at 8:00 a.m., 12:00 p.m. and 3:00 p.m. ET. The 8:00 a.m., 12:00 p.m. and 3:00 p.m. NAV calculation times are intended to facilitate same day settlement.

How to Purchase Shares

Please see “Trust Class Closure” above regarding restrictions on purchasing shares of the Trust Class.

By Mail:

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone/Fax:

For your initial investment, send the original, signed Institutional Account Application Form to the address above.

Wire Instructions:

Instruct your bank to transfer money by Federal Funds wire to:
State Street Bank and Trust Company
1 Iron Street
Boston, MA 02110

ABA# 011000028
DDA# 9904-631-0
State Street Institutional Investment Trust
Fund Name
Class Name
Account Number
Account Registration

Redeeming Shares

An investor may redeem all or any portion of its investment. Redemption orders are processed at the NAV next determined after a Fund receives a redemption order in good form.

For the Treasury Plus Fund

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If the Fund receives a redemption order in good form prior to 5:00 p.m. ET on a business day, the Fund typically expects to pay out redemption proceeds on that day, but no later than the next business day if redemption proceeds are sent by wire or ACH. If redemption proceeds are sent by check, the Fund typically expects to pay out redemption proceeds on the next business day. No dividends will be paid on shares that are redeemed and wired the same day. If a redemption order is placed after 5:00 p.m. ET, the Fund typically expects to pay out redemption proceeds on the next business day (and dividends will accrue up to, but not including, the day that redemption proceeds are sent). The Fund reserves the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Fund.

For the ILR Fund

If the Fund receives a redemption order in good form prior to its last valuation time (generally, 3:00 p.m. ET, unless the Fund closes earlier) on a business day, the Fund typically sends payment for redeemed shares on that day, but no later than the next business day if redemption proceeds are sent by wire or ACH. If redemption proceeds are sent by check, the Fund typically expects to pay out redemption proceeds on the next business day. If a full redemption order is requested, no dividends will accrue with respect to shares on the day the redemption proceeds are sent. If a redemption order is placed after the last valuation time (generally, 3:00 p.m. ET, unless the Fund closes earlier) the Fund typically expects to pay out redemption proceeds on the next business day (and dividends will accrue up to, but not including, the day that redemption proceeds are sent). The Fund reserves the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Fund.

Certain special limitations affecting redemptions . The SEC has implemented a number of requirements, including liquidity fees and redemption gates, for money market funds based on the amount of fund assets in “weekly liquid assets,” which generally includes cash, direct obligations of the U.S. government, certain other U.S. government or agency securities, and securities that will mature or are subject to a demand feature that is exercisable and payable within five business days. The ILR Fund will pass through to its investors any liquidity fee or suspension of redemptions imposed by the Money Market Portfolio on the same terms and conditions as imposed by the Money Market Portfolio on the ILR Fund.

If the Money Market Portfolio's weekly liquid assets fall below 30% of its total assets and the Portfolio's Board of Trustees determines it is in the best interests of the Portfolio, the Portfolio may immediately impose a liquidity fee of no more than 2% and/or temporarily suspend redemptions for up to 10 business days in any 90 day period. If the Portfolio's weekly liquid assets fall below 10% of its total assets at the end of any business day, the Portfolio will impose a liquidity fee of 1% on all redemptions beginning on the next business day, unless the Portfolio's Board determines that imposing such a fee would not be in the best interests of the Portfolio or determines that a lower or higher fee (not to exceed 2%) would be in the best interests of the Portfolio, which would remain in effect until weekly liquid assets return to 30% or the Portfolio's Board determines that the fee is no longer in the best interests of the Portfolio. All liquidity fees payable by the ILR Fund would be passed through to its shareholders, would be payable to the Portfolio and could offset any losses realized by the Portfolio when seeking to honor redemption requests. If liquidity fees are imposed or redemptions are suspended by the Portfolio, the ILR Fund will notify shareholders on the ILR Fund's website. The ILR Fund expects to treat such liquidity fees paid to the Portfolio as reducing proceeds paid to shareholders in redemption of ILR Fund shares, and not constituting income to the Portfolio or the Fund. There may be circumstances under which the ILR Fund may impose its own liquidity fees and/or suspend redemptions based on the level of the ILR Fund's own weekly liquid assets, in which case the ILR Fund will also provide notice to shareholders.

If the Money Market Portfolio's weekly liquid assets fall below 10% of its assets on a business day, the Portfolio may cease honoring redemptions and liquidate in the discretion of the Portfolio's Board. If the ILR Fund is notified that its Portfolio's weekly liquid assets fall below 10% of the Portfolio's assets and the Portfolio has suspended redemptions and intends to liquidate, the ILR Fund may also do so in the discretion of the ILR Fund's Board. There may be circumstances under which the ILR Fund may cease honoring redemptions and liquidate in the discretion of its Board based on the level of the ILR Fund's own weekly liquid assets. If the ILR Fund ceases honoring redemptions and determines to liquidate, the ILR Fund expects that it would notify shareholders on the ILR Fund's website. Distributions to shareholders of liquidation proceeds may occur in one or more disbursements.

For All Funds :

The Treasury Plus Fund is a government money market fund that has not elected to be subject to the fees and gates provisions of Rule 2a-7. The right of any investor to receive payment with respect to any redemption may be suspended or the payment of the redemption proceeds postponed in accordance with Section 22(e) of the 1940 Act and the rules thereunder, including during any period in which the NYSE is closed (other than weekends or holidays) or trading on the NYSE is restricted or if an emergency exists as a result of which disposal by the Fund of securities owned by it is not reasonably practicable or it is not reasonably practicable for

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the Fund fairly to determine the value of its net assets. In addition, the SEC may by order permit suspension of redemptions for the protection of shareholders of the Fund. Although the Treasury Plus Fund attempts to maintain its NAV at $1.00 per share, there can be no assurance that it will be successful, and there can be no assurance that a shareholder will receive $1.00 per share upon any redemption.

How to Redeem Shares


By Mail:	Send a signed letter to: State Street Institutional Investment Trust Funds P.O. Box 219737 Kansas City, MO 64121-9737
	The letter should include information necessary to process your request as described below. The Fund may require a medallion guarantee in certain circumstances. See “Medallion Guarantees” below.
By Overnight:	State Street Institutional Investment Trust Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407
By Telephone:	Please call (866) 392-0869 between the hours of 7:00 a.m. and 5:00 p.m. ET.
The Funds will need the following information to process your redemption request:
➣ name(s) of account owners; ➣ account number(s); ➣ the name of the Fund; ➣ your daytime telephone number; and ➣ the dollar amount or number of shares being redeemed.

On any day that the Funds calculate their NAVs earlier than normal, the Funds reserve the right to adjust the times noted above for purchasing and redeeming shares.

Medallion Guarantees . Certain redemption requests must include a medallion guarantee for each registered account owner if any of the following apply:

•	Your account address has changed within the last 10 business days.
•	Redemption proceeds are being transferred to an account with a different registration.
•	A wire is being sent to a financial institution other than the one that has been established on your Fund account.

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•	Other unusual situations as determined by the Transfer Agent.

All redemption requests regarding shares of the Treasury Plus Fund after 4:00 p.m. ET may only be placed by telephone or pre-established other means such as a transmission. The Treasury Plus Fund reserves the right to postpone payments for redemption requests received after 4:00 p.m. ET until the next business day.

Same day settlement of redemption proceeds will only be available for redemption requests accepted prior to the ILR Fund's last Valuation Time of the day (generally, 3:00 p.m. ET unless the Fund closes earlier).

The Funds reserve the right to waive medallion guarantee requirements, require a medallion guarantee under other circumstances or reject or delay redemption if the medallion guarantee is not in good form. Medallion guarantees may be provided by an eligible financial institution such as a commercial bank, a FINRA member firm such as a stock broker, a savings association or a national securities exchange. A notary public cannot provide a medallion guarantee. The Funds reserve the right to reject a medallion guarantee if it is not provided by a STAMP Medallion guarantor.

The Funds may terminate the receipt of redemption orders by telephone at any time, in which case you may redeem shares by other means.

If you choose to purchase or redeem shares by sending instructions by regular mail, they will not be deemed received in good order until they are released by the post office and redelivered to the Transfer Agent's physical location at 430 W 7th Street Suite 219737 in Kansas City, MO 64105-1407. There will be a time lag, which may be one or more days, between regular mail receipt at the post office box and redelivery to such physical location in Kansas City, and a Fund's NAV may change over those days. You might consider using express rather than regular mail if you believe the time of receipt of your transaction request to be sensitive.

Exchanging Shares

An exchange occurs when you use the proceeds from the redemption of shares of a Fund in the State Street Institutional Investment Trust to simultaneously purchase shares of a different Fund in the State Street Institutional Investment Trust. Currently, exchanging shares is allowed from/to the Treasury Plus Fund, State Street Institutional U.S. Government Money Market Fund, and State Street Institutional Treasury Money Market Fund. Effective October 12, 2016, exchanges from/to the ILR Fund is not permitted.Exchanges may be made within the same class ( i.e . Trust Class shares for Trust Class shares). The account holding the original shares must be registered in the same name as the account holding the new shares received in the exchange. You may make exchange requests by telephone, or by mail. See Purchasing Shares and Redeeming Shares. Exchanges are subject to the terms applicable to the purchases of the fund into which you are exchanging. Exchange privileges may not be available for mutual funds advised by SSGA FM (the “State Street Funds”) and may be suspended or rejected.

Excessive Trading

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Delivery of Documents to Accounts Sharing an Address

To reduce expenses, we may mail only one copy of the Funds' Prospectus and each annual and semi-annual report to those addresses shared by two or more accounts. If you wish to receive individual copies of these documents, please call us at (877) 521-4083, or contact your financial institution. We will begin sending you individual copies thirty (30) days after receiving your request.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a State Street Fund identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Fund (if you hold shares directly with the Fund) or to your financial intermediary (if you do not hold shares directly with the Fund).

Dividends, Distributions and Tax Considerations

Each Fund invests substantially all of its investible assets in a corresponding Portfolio that is treated as a partnership for U.S. federal income tax purposes. The nature and character of each Fund's income, gains, losses and deductions generally will be determined at the Portfolio level, and each Fund will be allocated its share of the corresponding Portfolio's income, gains, losses and deductions. As applicable, references in this discussion to income, gains and losses of a Fund will be to income, gains and losses recognized and deductions accruing at the Portfolio level and allocated to or otherwise taken into account by the Fund, and references to assets of a Fund will be to the Fund's allocable share of the assets of the corresponding Portfolio.

Distributions are taxable to you even if they are paid from income or gains earned by the Fund before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares.

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An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by a Fund and net gains recognized on the redemption of shares of a Fund.

Financial Intermediary Arrangements

Payments to Financial Intermediaries

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Third-Party Transactions . The State Street Funds have authorized certain Financial Intermediaries to accept purchase, redemption and exchange orders on the State Street Funds' behalf. Orders received for a State Street Fund by a Financial Intermediary that has been authorized to accept orders on the Fund's behalf (or other Financial Intermediaries designated by the Financial Intermediary) will be deemed accepted by the Fund at the time they are received by the Financial Intermediary and will be priced based on the Fund's next NAV determination as long as the Financial Intermediary transmits the order in good form and in a timely manner to the applicable State Street Fund(s). For the ILR Fund, the State Street Funds will be the sole party to determine if a trade is received in good order. The Financial Intermediary is responsible for transmitting your orders and associated funds in good form and in a timely manner to the applicable State Street Fund(s). The State Street Funds will not be responsible for delays by the Financial Intermediary in transmitting your orders, including timely transfer of payment, to a Fund.

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Financial Highlights

The financial highlight tables are intended to help you understand each Fund's Trust Class shares financial performance since the inception date of the Trust Class shares. Certain information reflects the performance results for a single Fund Share. The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in each Fund (assuming reinvestment of all dividends and distributions). This information has been audited by Ernst & Young LLP, the Trust's independent registered public accounting firm, whose report, along with each Fund's financial highlights and financial statements, is included in the annual report to shareholders, which is available upon request. Any references to Notes in these financial highlight tables refer to the “Notes to Financial Statements” section of each Fund's financial statements, and the financial information included in these tables should be read in conjunction with the financial statements incorporated by reference in the SAI.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL LIQUID RESERVES FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Trust Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	For the Period 8/29/16* - 12/31/16
Net asset value, beginning of period	$ 0.9999	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0193	0.0099	0.0015
Net realized and unrealized gain (loss)	0.0001	(0.0001)	0.0000(b)
Total from investment operations	0.0194	0.0098	0.0015
Distributions to shareholders from:
Net investment income	(0.0193)	(0.0099)	(0.0015)
Net realized gains	—	(0.0000)(b)	—
Total distributions	(0.0193)	(0.0099)	(0.0015)
Net asset value, end of period	$ 1.0000	$ 0.9999	$ 1.0000
Total return (c)	1.96%	0.99%	0.15%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$704,123	$764,391	$1,211,202
Ratios to Average Net Assets:
Total expenses	0.18%	0.18%	0.19%(d)
Net expenses	0.18%	0.18%	0.19%(d)
Net investment income (loss)	1.91%	0.97%	0.39%(d)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Annualized.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL TREASURY PLUS MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Trust Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	For the Period 8/29/16* - 12/31/16
Net asset value, beginning of period	$ 1.0000	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0168	0.0071	0.0007
Net realized gain (loss)	—	0.0000(b)	0.0000(b)
Total from investment operations	0.0168	0.0071	0.0007
Distributions to shareholders from:
Net investment income	(0.0168)	(0.0071)	(0.0007)
Net realized gains	—	(0.0000)(b)	—
Total distributions	(0.0168)	(0.0071)	(0.0007)
Net asset value, end of period	$ 1.0000	$ 1.0000	$ 1.0000
Total return (c)	1.69%	0.71%	0.07%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$4,481,410	$6,903,267	$7,962,822
Ratios to Average Net Assets:
Total expenses	0.18%	0.18%	0.18%(d)
Net expenses	0.18%	0.18%	0.18%(d)
Net investment income (loss)	1.64%	0.70%	0.19%(d)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Annualized.

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Contacting the State Street Funds

Online:	www.ssga.com/cash	24 hours a day, 7 days a week
Phone:	(877) 521-4083	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Overnight/ Registered, Express, Certified Mail
State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737	State Street Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407

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For more information about the Funds:

The Funds' SAI includes additional information about the Funds and is incorporated by reference into this document. Additional information about the Funds' investments is available in the Funds' most recent annual and semi-annual reports to shareholders. The Funds' SAI is available, without charge, upon request. The Funds' annual and semi-annual reports are available, without charge, upon request. Shareholders in the Funds may make inquiries to the Funds to receive such information by calling (877) 521-4083 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. Each Fund's Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, free of charge, on the Funds' website at www.ssga.com/cash.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

ILRTRCLSTATPRO

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Institutional U.S. Government Money Market Fund Class M (GOMXX)

Beginning on January 1, 2021, as permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of the Fund's annual and semi- annual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Fund (or from your financial intermediary, such as a broker-dealer or bank). Instead, the reports will be made available on the Fund's website (www.ssga.com/cash), and you will be notified by mail each time a report is posted, and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Fund electronically by calling (866) 392-0869.

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with the Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling (866) 392-0869. Your election to receive reports in paper will apply to all funds held in your account, if you invest through your financial intermediary or all funds held with the fund complex if you invest directly with a Fund.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in the Fund offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

The Fund offers multiple classes of shares. This Prospectus covers only the Class M share class.

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Fund Summary	1
State Street Institutional U.S. Government Money Market Fund	1
Additional Information About Investment Objective, Principal Strategies and Risks	6
Additional Information About Non-Principal Investment Strategies and Risks	11
Portfolio Holdings Disclosure	12
Management and Organization	13
Shareholder Information	14
Dividends, Distributions and Tax Considerations	19
Financial Intermediary Arrangements	20
Financial Highlights	21

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State Street Institutional U.S. Government Money Market Fund

Investment Objective

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%
Other Expenses	0.05%
Total Annual Fund Operating Expenses	0.10%

Example:

1 year		3 years		5 years		10 years
$10		$32		$56		$128

Principal Investment Strategies

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The Fund attempts to meet its investment objective by investing in:

•

•	Obligations issued or guaranteed by the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association, and U.S. government-sponsored entities such as the Federal Home Loan Bank, and the Federal Farm Credit Banks Funding Corporation, which are not backed by the full faith and credit of the United States; and
•	Repurchase agreements collateralized by U.S. government securities.

Principal Risks

In addition, the Fund is subject to the following principal risks:

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Performance

On September 28, 2018, Class M Shares of the U.S. Government Fund were liquidated and investment operations ceased at that time. Class M shares of the Fund have not re-commenced investment operations as of the date of this Prospectus. The bar chart and table below provide some indication of the risks of investing in the U.S. Government Fund by illustrating the variability of the Fund's returns for Premier Class shares from year-to-year. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash. Returns of Class M shares could have been similar to the returns shown for Premier Class shares because the shares are invested in the same portfolio of securities. Returns would differ only to the extent that Class M shares do not have the same expenses as Premier Class shares. The Fund's past performance does not necessarily indicate how the Fund will perform in the future.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.54% (Q4, 2018)
Lowest Quarterly Return: 0.00% (Q4, 2011)

Average Annual Total Returns (for periods ended 12/31/18)

		One Year		Five Years		Ten Years		Inception Date
Premier Class		1.76%		0.56%		0.32%		10/25/2007

To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Purchase and Sale of Fund Shares

Purchase Minimums

To establish an account	$750,000,000
To add to an existing account	No Minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

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By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone:

By Intermediary:

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objective, Principal Strategies and Risks

Investment Objective

The investment objective of the U.S. Government Fund, as stated in the Fund Summary, may be changed without shareholder approval.

U.S. Government Fund

Principal Investment Strategies

The U.S. Government Fund is a government money market fund and invests only in obligations issued or guaranteed as to principal and/or interest, as applicable, by the U.S. government or its agencies and instrumentalities, as well as repurchase agreements secured by such instruments. The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

The Fund follows a disciplined investment process that attempts to provide stability of principal, liquidity and current income, by investing in U.S. government securities. Among other things, SSGA FM conducts its own credit analyses of potential investments and portfolio holdings, and relies substantially on a dedicated short-term credit research team. The Fund invests in accordance with regulatory requirements applicable to money market funds. Regulations require, among other things, a money market fund to invest only in short-term, high quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity. All securities held by the Fund are U.S. dollar-denominated, and they may have fixed, variable or floating interest rates.

The Fund attempts to meet its investment objective by investing in:

•

•	Obligations issued or guaranteed by the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association, and U.S. government-sponsored entities such as the Federal Home Loan Bank, and the Federal Farm Credit Banks Funding Corporation, which are not backed by the full faith and credit of the United States; and
•	Repurchase agreements collateralized by U.S. government securities.

Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure.

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The credit rating assigned to any particular investment does not necessarily reflect the issuer's current financial condition and does not reflect an assessment of an investment's volatility or liquidity. Securities rated in the lowest category of investment-grade are considered to have speculative characteristics. If a security held by the Fund loses its rating or its rating is downgraded, the Fund may nonetheless continue to hold the security in the discretion of the Adviser. In the case of asset-backed or mortgage-related securities, changes in the actual or perceived ability of the obligors on the underlying assets or mortgages to make payments of interest and/or principal may affect the values of those securities.

Debt Securities Risk . The values of debt securities may increase or decrease as a result of the following: market fluctuations, increases in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments or illiquidity in debt securities markets; the risk of low rates of return due to reinvestment of securities during periods of falling interest rates or repayment by issuers with higher coupon or interest rates; and/or the risk of low income due to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of the Fund's fixed income securities to decrease, an adverse impact on the liquidity of the Fund's fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Fund may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

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Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject the Fund to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and the Fund's investment program in particular can be uncertain. In recent periods, governmental and non-governmental issuers have defaulted on, or have been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including, without limitation, in Europe or Asia. Defaults or restructurings

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Mortgage-Related and Other Asset-Backed Securities Risk . Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed income investments. The liquidity of mortgage-related and asset-backed securities may change over time. Mortgage-related securities represent a participation in, or are secured by, mortgage loans. Other asset-backed securities are typically structured like mortgage-related securities, but instead of mortgage loans or interests in mortgage loans, the underlying assets may include, for example, items such as motor vehicle installment sales or installment loan contracts, leases on various types of real and personal property, and receivables from credit card agreements. During periods of falling interest rates, mortgage-related and other asset-backed securities, which typically provide the issuer with the right to prepay the security prior to maturity, may be prepaid, which may result in the Fund having to reinvest the proceeds in other investments at lower interest rates. During periods of rising interest rates, the average life of mortgage-related and other asset-backed securities may extend because of slower-than expected principal payments. This may lock in a below market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. As a result, mortgage-related and other asset-backed securities may have less potential for capital appreciation during periods of declining interest rates than other debt securities of comparable maturities, although they may have a similar risk of decline in market values during periods of rising interest rates. Prepayment rates are difficult to predict and the potential impact of prepayments on the value of a mortgage-related or other asset-backed security depends on the terms of the instrument and can result in significant volatility. The price of a mortgage-related or other asset-backed security also depends on the credit quality and adequacy of the underlying assets or collateral. Mortgage-related or other asset-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) will generally entail greater credit risk than obligations guaranteed by the U.S. Government. Defaults on the underlying assets, if any, may impair the value of a mortgage-related or other asset-backed security. For some asset-backed securities in which the Fund invests, such as those backed by credit card receivables, the underlying cash flows may not be supported by a security interest in a related asset. Moreover, the values of mortgage-related and other asset-backed securities may be substantially dependent on the servicing of the underlying asset pools, and are therefore subject to risks associated with the negligence or malfeasance by their servicers and to

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Additional Information About Non-Principal Investment Strategies and Risks

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Fund. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for the Fund and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by the Fund. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Fund) or otherwise using such information for the benefit of its clients or itself.

Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Fund) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, the Fund, the Portfolio, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect the Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect the Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject the Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of the Fund inaccessible or inaccurate or incomplete. The Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. The Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. The Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put

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Portfolio Holdings Disclosure

The Fund's portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

Investment Adviser

A discussion regarding the Board's consideration of the Fund's Investment Advisory Agreement is provided in the Fund's Semi-Annual Report to Shareholders for the period ended June 30, 2018.

The Administrator, Sub-Administrator and Custodian

The Adviser serves as administrator of the Fund. The amount of the fee paid to the Adviser for administrative services may vary by share class. The Fund currently pays the Adviser an administrative fee at the annual rate of 0.03% in respect of the class of shares in this Prospectus. State Street Bank and Trust Company (“State Street”), a subsidiary of State Street Corporation, serves as the sub-administrator for the Fund for a fee that is paid by the Adviser. State Street also serves as custodian of the Fund for a separate fee that is paid by the Fund. SSGA FM serves as administrator of the Portfolio and State Street serves as sub-administrator and custodian of the Portfolio.

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Fund's transfer agent and dividend disbursing agent (the “Transfer Agent”).

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The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Fund's distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

The Shareholder Servicing Agent

Additional Information

Shareholder Information

Determination of Net Asset Value

Investing in State Street Institutional Investment Trust Shares

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Purchasing Shares

The Fund offers one class of shares through this Prospectus: Class M shares, available to you subject to the eligibility requirements set forth below.

Investors pay no sales load to invest in the Class M shares of the Fund. The price for Fund shares is the NAV per share. Purchase requests received by the Fund in good order (a purchase request is in good order if it meets the requirements implemented from time to time by the Transfer Agent or authorized agent of the Fund, and for new accounts includes submission of a completed and signed application and all documentation necessary to open an account) on a business day will, if payment is received by FedWire, be priced at the NAV next determined after the order is accepted by the Fund. Payments received by FedWire prior to the last Valuation Time will earn dividend accrual for that purchase. All purchases that are made by check will be priced with the last valuation price and begin earning dividends the following business day after the day the order is accepted. (If you purchase shares by check, your order will not be in good form until the Transfer Agent receives federal funds for the check.) All purchase orders are subject to acceptance by the Fund. The Fund intends to be as fully invested as is practicable; therefore, investments must be made in Federal Funds (i.e., monies credited to the account of the Fund's custodian bank by a Federal Reserve Bank).

The minimum initial investment in Class M shares of the Fund is $750,000,000, although the Adviser may waive the minimum in its discretion. Holdings of related customer accounts may be aggregated for purposes of determining the minimum investment amount. “Related customer accounts” may include, but are not limited to, accounts held by the same investment or retirement plan, financial institution, broker, dealer or intermediary. The Fund and the Adviser reserve the right to increase or decrease the minimum amount required to open or maintain an account. There is no minimum subsequent investment, except in relation to maintaining certain minimum account balances (See “Redeeming Shares” below).The Fund requires prior notification of subsequent investments in excess of $50,000,000.

The Fund reserves the right to cease accepting investments at any time or to reject any investment order. In addition, the Fund may limit the amount of a purchase order received after 3:00 p.m. ET.

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How to Purchase Shares

By Mail:

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone/Fax:

For your initial investment, send the original, signed Institutional Account Application Form to the address above.

Wire Instructions:

Instruct your bank to transfer money by Federal Funds wire to:
State Street Bank and Trust Company
1 Iron Street
Boston, MA 02110

ABA# 011000028
DDA# 9904-631-0
State Street Institutional Investment Trust
Fund Name
Class Name
Account Number
Account Registration

Redeeming Shares

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How to Redeem Shares


By Mail:	Send a signed letter to: State Street Institutional Investment Trust Funds P.O. Box 219737 Kansas City, MO 64121-9737
	The letter should include information necessary to process your request as described below. The Fund may require a medallion guarantee in certain circumstances. See “Medallion Guarantees” below.
By Overnight:	State Street Institutional Investment Trust Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407
By Telephone:	Please call (866) 392-0869 between the hours of 7:00 a.m. and 5:00 p.m. ET.
The Fund will need the following information to process your redemption request:
➣ name(s) of account owners; ➣ account number(s); ➣ the name of the Fund; ➣ your daytime telephone number; and ➣ the dollar amount or number of shares being redeemed.

On any day that the Fund calculates its NAV earlier than normal, the Fund reserves the right to adjust the times noted above for purchasing and redeeming shares.

Medallion Guarantees . Certain redemption requests must include a medallion guarantee for each registered account owner if any of the following apply:

•	Your account address has changed within the last 10 Business Days.

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•	Redemption proceeds are being transferred to an account with a different registration.
•	A wire is being sent to a financial institution other than the one that has been established on your Fund account.
•	Other unusual situations as determined by the Transfer Agent.

The Fund may terminate the receipt of redemption orders by telephone at any time, in which case you may redeem shares by other means.

If you choose to purchase or redeem shares by sending instructions by regular mail, they will not be deemed received in good order until they are released by the post office and redelivered to the Transfer Agent's physical location at 430 W 7th Street Suite 219737 in Kansas City, MO 64105-1407. There will be a time lag, which may be one or more days, between regular mail receipt at the post office box and redelivery to such physical location in Kansas City, and the Fund's NAV may change over those days. You might consider using express rather than regular mail if you believe the time of receipt of your transaction request to be sensitive.

Excessive Trading

Delivery of Documents to Accounts Sharing an Address

To reduce expenses, we may mail only one copy of the Fund's Prospectus and the annual and semi-annual report to those addresses shared by two or more accounts. If you wish to receive individual copies of these documents, please call us at (877) 521-4083, or contact your financial institution. We will begin sending you individual copies thirty (30) days after receiving your request.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a State Street Fund identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Fund (if you hold shares directly with the Fund) or to your financial intermediary (if you do not hold shares directly with the Fund).

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Dividends, Distributions and Tax Considerations

An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by the Fund and net gains recognized on the redemption of shares of the Fund.

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Financial Intermediary Arrangements

Payments to Financial Intermediaries

The Financial Intermediary is often compensated by SSGA FD or its affiliates for the services it performs and in such cases is typically paid continually over time, during the period when the Financial Intermediary's clients hold investments in the Fund. The amount of continuing compensation paid by SSGA FD or its affiliates to different Financial Intermediaries for distribution and/or shareholder services varies. Any compensation is typically a percentage of the value of the Financial Intermediary's clients' investments in the Fund or a per account fee. The variation in compensation may, but will not necessarily, reflect enhanced or additional services provided by the Financial Intermediary.

If you invest through a Financial Intermediary and meet the eligibility criteria for more than one share class, you should discuss with your Financial Intermediary which share class is appropriate for you. Your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend one share class over another, when you are eligible to invest in more than one share class. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by the Fund or its affiliates with respect to the different share classes offered by the Fund.

SSGA FD and its affiliates (including SSGA FM), at their own expense and out of their own assets, may also provide other compensation to Financial Intermediaries in connection with sales of the Fund's shares or the servicing of shareholders or shareholder accounts. Such compensation may include, but is not limited to, financial assistance to Financial Intermediaries in connection with conferences, sales, or training programs for their employees; seminars for the public; advertising or sales campaigns; or other Financial Intermediary-sponsored special events. In some instances, this compensation may be made available only to certain Financial Intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the Fund's shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as FINRA.

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Financial Highlights

The Class M shares of the Fund were not operational as of December 31, 2018 and therefore do not have financial information.

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Contacting the State Street Funds

Online:	www.ssga.com/cash	24 hours a day, 7 days a week
Phone:	(877) 521-4083	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Overnight/ Registered, Express, Certified Mail
State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737	State Street Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407

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For more information about the Fund:

The Fund's SAI includes additional information about the Fund and is incorporated by reference into this document. Additional information about the Fund's investments is available in the Fund's most recent annual and semi-annual reports to shareholders. The Fund's SAI is available, without charge, upon request. The Fund's annual and semi-annual reports are available, without charge, upon request. Shareholders in the Fund may make inquiries to the Fund to receive such information by calling (877) 521-4083 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. The Fund's Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, free of charge, on the Fund's website at www.ssga.com/cash.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

SSITMSTATPRO

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Institutional U.S. Government Money Market Fund Administration Class (SALXX)

Beginning on January 1, 2021, as permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of the Fund's annual and semi- annual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Fund (or from your financial intermediary, such as a broker-dealer or bank). Instead, the reports will be made available on the Fund's website (www.ssga.com/cash), and you will be notified by mail each time a report is posted, and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Fund electronically by calling (866) 392-0869.

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with the Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling (866) 392-0869. Your election to receive reports in paper will apply to all funds held in your account, if you invest through your financial intermediary or all funds held with the fund complex if you invest directly with a Fund.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in the Fund offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

The Fund offers multiple classes of shares. This Prospectus covers only the Administration Class Shares.

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Fund Summary	1
State Street Institutional U.S. Government Money Market Fund	1
Additional Information About Investment Objective, Principal Strategies and Risks	6
Additional Information About Non-Principal Investment Strategies and Risks	11
Portfolio Holdings Disclosure	12
Management and Organization	13
Shareholder Information	14
Dividends, Distributions and Tax Considerations	19
Financial Intermediary Arrangements	20
Financial Highlights	23

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State Street Institutional U.S. Government Money Market Fund

Investment Objective

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.05%
Other Expenses	0.27%
Total Annual Fund Operating Expenses	0.37%

Example:

1 year		3 years		5 years		10 years
$38		$119		$208		$468

Principal Investment Strategies

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The Fund attempts to meet its investment objective by investing in:

•

•	Obligations issued or guaranteed by the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association, and U.S. government-sponsored entities such as the Federal Home Loan Bank, and the Federal Farm Credit Banks Funding Corporation, which are not backed by the full faith and credit of the United States; and
•	Repurchase agreements collateralized by U.S. government securities.

Principal Risks

In addition, the Fund is subject to the following principal risks:

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Performance

The bar chart and table below provide some indication of the risks of investing in the U.S. Government Fund by illustrating the variability of the Fund's returns for Administration Class shares from year-to-year. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.48% (Q4, 2018)
Lowest Quarterly Return: 0.06% (Q1, 2017)

Average Annual Total Returns (for periods ended 12/31/18)

		One Year		Since Inception		Inception Date
Administration Class		1.51%		0.42%		8/23/2016

To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Purchase and Sale of Fund Shares

Purchase Minimums

Administration Class
To establish an account	$1,000
To add to an existing account	No Minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

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By Telephone:

By Intermediary:

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objective, Principal Strategies and Risks

Investment Objective

The investment objective of the U.S. Government Fund, as stated in the Fund Summary, may be changed without shareholder approval.

U.S. Government Fund

Principal Investment Strategies

The U.S. Government Fund is a government money market fund and invests only in obligations issued or guaranteed as to principal and/or interest, as applicable, by the U.S. government or its agencies and instrumentalities, as well as repurchase agreements secured by such instruments. The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

The Fund follows a disciplined investment process that attempts to provide stability of principal, liquidity and current income, by investing in U.S. government securities. Among other things, SSGA FM conducts its own credit analyses of potential investments and portfolio holdings, and relies substantially on a dedicated short-term credit research team. The Fund invests in accordance with regulatory requirements applicable to money market funds. Regulations require, among other things, a money market fund to invest only in short-term, high quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity. All securities held by the Fund are U.S. dollar-denominated, and they may have fixed, variable or floating interest rates.

The Fund attempts to meet its investment objective by investing in:

•

•	Obligations issued or guaranteed by the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association, and U.S. government-sponsored entities such as the Federal Home Loan Bank, and the Federal Farm Credit Banks Funding Corporation, which are not backed by the full faith and credit of the United States; and
•	Repurchase agreements collateralized by U.S. government securities.

Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure.

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The credit rating assigned to any particular investment does not necessarily reflect the issuer's current financial condition and does not reflect an assessment of an investment's volatility or liquidity. Securities rated in the lowest category of investment-grade are considered to have speculative characteristics. If a security held by the Fund loses its rating or its rating is downgraded, the Fund may nonetheless continue to hold the security in the discretion of the Adviser. In the case of asset-backed or mortgage-related securities, changes in the actual or perceived ability of the obligors on the underlying assets or mortgages to make payments of interest and/or principal may affect the values of those securities.

Debt Securities Risk . The values of debt securities may increase or decrease as a result of the following: market fluctuations, increases in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments or illiquidity in debt securities markets; the risk of low rates of return due to reinvestment of securities during periods of falling interest rates or repayment by issuers with higher coupon or interest rates; and/or the risk of low income due to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of the Fund's fixed income securities to decrease, an adverse impact on the liquidity of the Fund's fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Fund may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

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Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject the Fund to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and the Fund's investment program in particular can be uncertain. In recent periods, governmental and non-governmental issuers have defaulted on, or have been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including, without limitation, in Europe or Asia. Defaults or restructurings

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Mortgage-Related and Other Asset-Backed Securities Risk . Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed income investments. The liquidity of mortgage-related and asset-backed securities may change over time. Mortgage-related securities represent a participation in, or are secured by, mortgage loans. Other asset-backed securities are typically structured like mortgage-related securities, but instead of mortgage loans or interests in mortgage loans, the underlying assets may include, for example, items such as motor vehicle installment sales or installment loan contracts, leases on various types of real and personal property, and receivables from credit card agreements. During periods of falling interest rates, mortgage-related and other asset-backed securities, which typically provide the issuer with the right to prepay the security prior to maturity, may be prepaid, which may result in the Fund having to reinvest the proceeds in other investments at lower interest rates. During periods of rising interest rates, the average life of mortgage-related and other asset-backed securities may extend because of slower-than expected principal payments. This may lock in a below market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. As a result, mortgage-related and other asset-backed securities may have less potential for capital appreciation during periods of declining interest rates than other debt securities of comparable maturities, although they may have a similar risk of decline in market values during periods of rising interest rates. Prepayment rates are difficult to predict and the potential impact of prepayments on the value of a mortgage-related or other asset-backed security depends on the terms of the instrument and can result in significant volatility. The price of a mortgage-related or other asset-backed security also depends on the credit quality and adequacy of the underlying assets or collateral. Mortgage-related or other asset-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) will generally entail greater credit risk than obligations guaranteed by the U.S. Government. Defaults on the underlying assets, if any, may impair the value of a mortgage-related or other asset-backed security. For some asset-backed securities in which the Fund invests, such as those backed by credit card receivables, the underlying cash flows may not be supported by a security interest in a related asset. Moreover, the values of mortgage-related and other asset-backed securities may be substantially dependent on the servicing of the underlying asset pools, and are therefore subject to risks associated with the negligence or malfeasance by their servicers and to

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Additional Information About Non-Principal Investment Strategies and Risks

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Fund. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for the Fund and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by the Fund. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Fund) or otherwise using such information for the benefit of its clients or itself.

Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Fund) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, the Fund, the Portfolio, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect the Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect the Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject the Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of the Fund inaccessible or inaccurate or incomplete. The Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. The Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. The Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put

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Portfolio Holdings Disclosure

The Fund's portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

Investment Adviser

A discussion regarding the Board's consideration of the Fund's Investment Advisory Agreement is provided in the Fund's Semi-Annual Report to Shareholders for the period ended June 30, 2018.

The Administrator, Sub-Administrator and Custodian

The Adviser serves as administrator of the Fund. The amount of the fee paid to the Adviser for administrative services may vary by share class. The Fund currently pays the Adviser an administrative fee at the annual rate of 0.05% in respect of the class of shares in this Prospectus. State Street Bank and Trust Company (“State Street”), a subsidiary of State Street Corporation, serves as the sub-administrator for the Fund for a fee that is paid by the Adviser. State Street also serves as custodian of the Fund for a separate fee that is paid by the Fund. SSGA FM serves as administrator of the Portfolio and State Street serves as sub-administrator and custodian of the Portfolio.

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Fund's transfer agent and dividend disbursing agent (the “Transfer Agent”).

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The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Fund's distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

The Shareholder Servicing Agent

Additional Information

Shareholder Information

Determination of Net Asset Value

Investing in State Street Institutional Investment Trust Shares

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Purchasing Shares

The Fund offers one class of shares through this Prospectus: Administration Class shares available to you subject to the eligibility requirements set forth below. All classes of the Fund share the same investment objective and investments, but the different share classes have different expense structures and eligibility requirements. You should choose the class with the expense structure that best meets your needs for which you are eligible. In choosing a share class, you should consider the amount you plan to invest. Your investment professional can help you choose the share class that best suits your investment needs.

The chart below summarizes the features of the Administration Class. This chart is only a general summary, and you should read the description of the Fund's expenses in the Fund Summary in this Prospectus.

The minimum purchase amount may be waived for specific investors or types of investors, including, without limitation, retirement plans, employees of State Street Corporation and its affiliates and their family. In the case of shareholders purchasing shares through a Financial Intermediary, the minimum purchase amount may be applied at the level of the Financial Intermediary.

Minimum Initial Investment	$5,000,000
Maximum Investment	None.
Initial Sales Charge	No. Entire purchase price is invested in shares of the Fund.
Deferred (CDSC) Sales Charge	No.
Distribution and Service (12b-1) Fees	0.05% annual fee.
Redemption Fees	No.

Investors pay no sales load to invest in Administration Class shares of the Fund. The price for Fund Shares is the NAV per share. Purchase requests received by a Fund in good order (a purchase request is in good order if it meets the requirements implemented from time to time by the Transfer Agent or authorized agent of the Fund, and for new accounts includes submission of a completed and signed application and all documentation necessary to open an account) on a business day will, if payment is received by FedWire, be priced at the NAV next determined after the order is accepted by the Fund. Payments received by FedWire prior to the last Valuation Time will earn dividend accrual for that purchase. All purchases that are made by check will be priced with the last valuation price and will begin earning dividends the following business day after the day the order is accepted. (If you purchase shares by check, your order will not be in good form until the Transfer Agent receives federal funds for the check.) All purchase orders are subject to acceptance by the Fund. The Fund intends to be as fully invested as is practicable; therefore, investments must be made in Federal Funds (i.e., monies credited to the account of the Fund's custodian bank by a Federal Reserve Bank).

The minimum initial investment in Administration Class shares of the Fund is $5,000,000 although the Adviser may waive the minimum in its discretion. Holdings of related customer accounts may be aggregated for purposes of determining the minimum investment amount. “Related customer accounts” may include, but are not limited to, accounts held by the same investment or retirement plan, financial institution, broker, dealer or intermediary. The Fund and the Adviser reserve the right to increase or decrease the minimum amount required to open or maintain an account. There is no minimum subsequent investment, except in relation to maintaining certain minimum account balances (See “Redeeming Shares” below). The Fund requires prior notification of subsequent investments in excess of $50,000,000. The Fund reserves the right to cease accepting investments at any time or to reject any investment order. In addition, the Fund may limit the amount of a purchase order received after 3:00 p.m. ET.

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How to Purchase Shares

By Mail:

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone/Fax:

For your initial investment, send the original, signed Institutional Account Application Form to the address above.

Wire Instructions:

Instruct your bank to transfer money by Federal Funds wire to:
State Street Bank and Trust Company
1 Iron Street
Boston, MA 02110

ABA# 011000028
DDA# 9904-631-0
State Street Institutional Investment Trust
Fund Name
Class Name
Account Number
Account Registration

Automatic Investment Plan . An Automatic Investment Plan is available for all operational State Street Funds that offer the Administration Class shares. Once an initial investment has been accepted, you may elect to make automatic subsequent investments of $100 or more on a periodic basis (i.e., monthly, quarterly, semi-annually, or annually) by authorizing the Fund to debit your bank checking or savings account through Automated Clearing House (ACH). Once this option has been established, you may call the State Street Funds to make additional automatic purchases, to change the amount of the existing automatic purchase, or to discontinue the service. The Fund reserves the right to cancel your Automatic Investment Plan if any correspondence sent by the Fund to your address of record is returned by the postal service or other delivery service as “undeliverable.” Ask your financial adviser or financial intermediary for details.

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Redeeming Shares

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How to Redeem Shares


By Mail:	Send a signed letter to: State Street Institutional Investment Trust Funds P.O. Box 219737 Kansas City, MO 64121-9737
	The letter should include information necessary to process your request as described below. The Fund may require a medallion guarantee in certain circumstances. See “Medallion Guarantees” below.
By Overnight:	State Street Institutional Investment Trust Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407
By Telephone:	Please call (866) 392-0869 between the hours of 7:00 a.m. and 5:00 p.m. ET.
The Fund will need the following information to process your redemption request:
➣ name(s) of account owners; ➣ account number(s); ➣ the name of the Fund; ➣ your daytime telephone number; and ➣ the dollar amount or number of shares being redeemed.

On any day that the Fund calculates its NAV earlier than normal, the Fund reserves the right to adjust the times noted above for purchasing and redeeming shares.

Medallion Guarantees . Certain redemption requests must include a medallion guarantee for each registered account owner if any of the following apply:

•	Your account address has changed within the last 10 Business Days.

•	Redemption proceeds are being transferred to an account with a different registration.
•	A wire is being sent to a financial institution other than the one that has been established on your Fund account.
•	Other unusual situations as determined by the Transfer Agent.

The Fund may terminate the receipt of redemption orders by telephone at any time, in which case you may redeem shares by other means.

If you choose to purchase or redeem shares by sending instructions by regular mail, they will not be deemed received in good order until they are released by the post office and redelivered to the Transfer Agent's physical location at 430 W 7th Street Suite 219737 in Kansas City, MO 64105-1407. There will be a time lag, which may be one or more days, between regular mail receipt at the post office box and redelivery to such physical location in Kansas City, and the Fund's NAV may change over those days. You might consider using express rather than regular mail if you believe the time of receipt of your transaction request to be sensitive.

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Exchanging Shares

An exchange occurs when you use the proceeds from the redemption of shares of the Fund in the State Street Institutional Investment Trust to simultaneously purchase shares of a different Fund in the State Street Institutional Investment Trust. Exchanges may be made within the same class ( i.e . Administration Class shares for Administration Class shares). The account holding the original shares must be registered in the same name as the account holding the new shares received in the exchange. You may make exchange requests by telephone, or by mail. See Purchasing Shares and Redeeming Shares. Exchanges are subject to the terms applicable to the purchases of the fund into which you are exchanging. Exchange privileges may not be available for mutual funds advised by SSGA FM (the “State Street Funds”) and may be suspended or rejected. Effective October 12, 2016, exchanges into or from any share of the State Street Institutional Liquid Reserves Fund will not be permitted.

Excessive Trading

Delivery of Documents to Accounts Sharing an Address

To reduce expenses, we may mail only one copy of the Fund's Prospectus and the annual and semi-annual report to those addresses shared by two or more accounts. If you wish to receive individual copies of these documents, please call us at (877) 521-4083, or contact your financial institution. We will begin sending you individual copies thirty (30) days after receiving your request.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a State Street Fund identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Fund (if you hold shares directly with the Fund) or to your financial intermediary (if you do not hold shares directly with the Fund).

Dividends, Distributions and Tax Considerations

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An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by the Fund and net gains recognized on the redemption of shares of the Fund.

Financial Intermediary Arrangements

Distribution Arrangements and Rule 12b-1 Fees

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attributable to its Administration Class shares. Because these fees are paid out of the assets of the Fund attributable to its shares on an ongoing basis, they will increase the cost of your investment and may cost you more over time than paying other types of sales charges. Long-term shareholders of the Fund may pay more in Rule 12b-1 fees than the economic equivalent of the maximum front-end sales charge permitted by the FINRA.

Because the Fund pays distribution and other fees for the sale of its shares and for services provided to shareholders out of the Fund's assets on an ongoing basis, over time those fees will increase the cost of your investment and may cost you more than paying other types of sales loads.

The Fund may pay distribution fees and other amounts described in this Prospectus at a time when shares of the Fund are unavailable for purchase.

Other Payments to Financial Intermediaries

The Financial Intermediary is often compensated by SSGA FD or its affiliates for the services it performs and in such cases is typically paid continually over time, during the period when the Financial Intermediary's clients hold investments in the Fund. The amount of continuing compensation paid by SSGA FD or its affiliates to different Financial Intermediaries for distribution and/or shareholder services varies. Any compensation is typically a percentage of the value of the Financial Intermediary's clients' investments in the Fund or a per account fee. The variation in compensation may, but will not necessarily, reflect enhanced or additional services provided by the Financial Intermediary.

If you invest through a Financial Intermediary and meet the eligibility criteria for more than one share class, you should discuss with your Financial Intermediary which share class is appropriate for you. Your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend one share class over another, when you are eligible to invest in more than one share class. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by the Fund or its affiliates with respect to the different share classes offered by the Fund.

SSGA FD and its affiliates (including SSGA FM), at their own expense and out of their own assets, may also provide other compensation to Financial Intermediaries in connection with sales of the Fund's shares or the servicing of shareholders or shareholder accounts. Such compensation may include, but is not limited to, financial assistance to Financial Intermediaries in connection with conferences, sales, or training programs for their employees; seminars for the public; advertising or sales campaigns; or other Financial Intermediary-sponsored special events. In some instances, this compensation may be made available only to certain Financial Intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the Fund's shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as FINRA.

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Financial Highlights

The financial highlight tables are intended to help you understand the Fund's Administration Class Shares financial performance since the inception date of the Administration Class shares. Certain information reflects the performance results for a single Fund Share. The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in the Fund (assuming reinvestment of all dividends and distributions). This information has been audited by Ernst & Young LLP, the Trust's independent registered public accounting firm, whose report, along with the Fund's financial highlights and financial statements, is included in the annual report to shareholders, which is available upon request. Any references to Notes in these financial highlight tables refer to the “Notes to Financial Statements” section of the Fund's financial statements, and the financial information included in these tables should be read in conjunction with the financial statements incorporated by reference in the SAI.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL U.S. GOVERNMENT MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Administration Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	For the Period 8/23/16* - 12/31/16
Net asset value, beginning of period	$ 1.0000	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0150	0.0054	0.0001
Net realized gain (loss)	—	0.0000(b)	(0.0000)(b)
Total from investment operations	0.0150	0.0054	0.0001
Distributions to shareholders from:
Net investment income	(0.0150)	(0.0054)	(0.0001)
Net realized gains	—	(0.0000)(b)	—
Total distributions	(0.0150)	(0.0054)	(0.0001)
Net asset value, end of period	$ 1.0000	$ 1.0000	$ 1.0000
Total return (c)	1.51%	0.54%	0.01%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$1,686,105	$1,909,670	$3,423,655
Ratios to Average Net Assets:
Total expenses	0.37%	0.37%	0.37%(d)
Net investment income (loss)	1.47%	0.50%	0.04%(d)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(d)	Annualized.

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Contacting the State Street Funds

Online:	www.ssga.com/cash	24 hours a day, 7 days a week
Phone:	(877) 521-4083	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Overnight/ Registered, Express, Certified Mail
State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737	State Street Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407

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For more information about the Fund:

The Fund's SAI includes additional information about the Fund and is incorporated by reference into this document. Additional information about the Fund's investments is available in the Fund's most recent annual and semi-annual reports to shareholders. The Fund's SAI is available, without charge, upon request. The Fund's annual and semi-annual reports are available, without charge, upon request. Shareholders in the Fund may make inquiries to the Fund to receive such information by calling (877) 521-4083 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. The Fund's Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, free of charge, on the Fund's website at www.ssga.com/cash.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

SALXXARIPRO

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

Neuberger Berman Money Fund

A Private Label of the Investment Class Shares of the

State Street Institutional U.S. Government Money Market Fund (GVVXX)

State Street Institutional Treasury Plus Money Market Fund (TPVXX)

Advised by SSGA Funds Management, Inc.,

a subsidiary of State Street Corporation

Beginning on January 1, 2021, as permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of a Fund's annual and semi- annual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Fund (or from your financial intermediary, such as a broker-dealer or bank). Instead, the reports will be made available on the Fund's website (www.ssga.com/cash), and you will be notified by mail each time a report is posted, and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Funds electronically by calling (800) 877-9700.

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with a Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling (800) 877-9700. Your election to receive reports in paper will apply to all funds held in your account, if you invest through your financial intermediary or all funds held with the fund complex if you invest directly with a Fund.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in any of the Funds offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Each Fund offers multiple classes of shares. This Prospectus covers only the Investment Class.

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Fund Summaries	1
State Street Institutional U.S. Government Money Market Fund	1
State Street Institutional Treasury Plus Money Market Fund	6
Additional Information About Investment Objectives, Principal Strategies and Risks	11
Additional Information About Non-Principal Investment Strategies and Risks	17
Portfolio Holdings Disclosure	18
Management and Organization	19
Shareholder Information	20
Dividends, Distributions and Tax Considerations	25
Financial Intermediary Arrangements	26
Financial Highlights	29

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State Street Institutional U.S. Government Money Market Fund

Investment Objective

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.10%
Other Expenses	0.32%
Total Annual Fund Operating Expenses	0.47%

Example:

1 year		3 years		5 years		10 years
$48		$151		$263		$591

Principal Investment Strategies

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The Fund attempts to meet its investment objective by investing in:

•

•	Obligations issued or guaranteed by the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association, and U.S. government-sponsored entities such as the Federal Home Loan Bank, and the Federal Farm Credit Banks Funding Corporation, which are not backed by the full faith and credit of the United States; and
•	Repurchase agreements collateralized by U.S. government securities.

Principal Risks

In addition, the Fund is subject to the following principal risks:

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Performance

The bar chart and table below provide some indication of the risks of investing in the U.S. Government Fund by illustrating the variability of the Fund's returns from year-to-year. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.45% (Q4, 2018)
Lowest Quarterly Return: 0.00% (Q2, 2009)

Average Annual Total Returns (for periods ended 12/31/18)

		One Year		Five Years		Ten Years		Inception Date
Investment Class		1.40%		0.37%		0.19%		10/17/2007

To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Purchase and Sale of Fund Shares

Purchase Minimums

To establish an account	$2,000.00
To add to an existing account	$100.00

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

Send a signed letter to:
Neuberger Berman Funds
State Street Global Advisors
P.O. Box 219737
Kansas City, MO 64121-9737

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By Overnight:

Send a signed letter to:
Neuberger Berman Funds
c/o State Street Institutional Trust Funds
State Street Global Advisors
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone:

For wire transfer instructions, please call (800)-877-9700 between 9:00 a.m. and 6 p.m. Eastern time. Redemptions by telephone are permitted only if you previously have been authorized for these transactions.

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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State Street Institutional Treasury Plus Money Market Fund

Investment Objective

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.10%
Other Expenses	0.32%
Total Annual Fund Operating Expenses	0.47%

Example:

1 year		3 years		5 years		10 years
$48		$151		$263		$591

Principal Investment Strategies

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Principal Risks

In addition, the Fund is subject to the following principal risks:

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Performance

The bar chart and table below provide some indication of the risks of investing in the Treasury Plus Fund by illustrating the variability of the Fund's returns from year-to-year. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash.

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.45% (Q4, 2018)
Lowest Quarterly Return: 0.00% (Q1, 2009)

Average Annual Total Returns (for periods ended 12/31/18)

		One Year		Five Years		Ten Years		Inception Date
Investment Class		1.40%		0.36%		0.18%		10/24/2007

To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Purchase and Sale of Fund Shares

Purchase Minimums

To establish an account	$2,000.00
To add to an existing account	$100.00

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

Send a signed letter to:
Neuberger Berman Funds
State Street Global Advisors
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight:

Send a signed letter to:
Neuberger Berman Funds
c/o State Street Institutional Trust Funds
State Street Global Advisors
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone:

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Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objectives, Principal Strategies and Risks

Investment Objective

The investment objective of each of the U.S. Government Fund and the Treasury Plus Fund, as stated in each Fund's Summary, may be changed without shareholder approval.

U.S. Government Fund

Principal Investment Strategies

The U.S. Government Fund is a government money market fund and invests only in obligations issued or guaranteed as to principal and/or interest, as applicable, by the U.S. government or its agencies and instrumentalities, as well as repurchase agreements secured by such instruments. The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

The Fund follows a disciplined investment process that attempts to provide stability of principal, liquidity and current income, by investing in U.S. government securities. Among other things, SSGA FM conducts its own credit analyses of potential investments and portfolio holdings, and relies substantially on a dedicated short-term credit research team. The Fund invests in accordance with regulatory requirements applicable to money market funds. Regulations require, among other things, a money market fund to invest only in short-term, high quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity. All securities held by the Fund are U.S. dollar-denominated, and they may have fixed, variable or floating interest rates.

The Fund attempts to meet its investment objective by investing in:

•

•	Obligations issued or guaranteed by the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association, and U.S. government-sponsored entities such as the Federal Home Loan Bank, and the Federal Farm Credit Banks Funding Corporation, which are not backed by the full faith and credit of the United States; and
•	Repurchase agreements collateralized by U.S. government securities.

Treasury Plus Fund

Principal Investment Strategies

The Treasury Plus Fund is a government money market fund and attempts to meet its investment objective by investing only in U.S. Treasury bills, notes and bonds (which are direct obligations of the U.S. government) and repurchase agreements collateralized by these obligations. The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

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Additional Information About Risks

Risk information is applicable to all Funds unless otherwise noted. The risks are described in alphabetical order and not in the order of importance or potential exposure.

Call/Prepayment Risk (principal risk for the U.S. Government Fund) . Call/prepayment risk is the risk that an issuer will exercise its right to pay principal on an obligation held by a Fund earlier than expected or required. This may occur, for example, when there is a decline in interest rates, and an issuer of bonds or preferred stock redeems the bonds or stock in order to replace them with obligations on which it is required to pay a lower interest or dividend rate. It may also occur when there is an unanticipated increase in the rate at which mortgages or other receivables underlying mortgage- or asset-backed securities held by a Fund are prepaid. In any such case, a Fund may be forced to invest the prepaid amounts in lower-yielding investments, resulting in a decline in the Fund's income.

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Extension Risk (principal risk for the U.S. Government Fund). During periods of rising interest rates, the average life of certain types of securities may be extended because of slower-than-expected principal payments. This may increase the period of time during which an investment earns a below-market interest rate, increase the security's duration and reduce the value of the security. Extension risk may be heightened during periods of adverse economic conditions generally, as payment rates decline due to higher unemployment levels and other factors.

Liquidity Risk . Liquidity risk is the risk that a Fund may not be able to dispose of securities readily at a favorable time or prices (or at all) or at prices approximating those at which a Fund currently values them. For example, certain investments may be subject to restrictions on resale, may trade in the over-the-counter market or in limited volume, or may not have an active trading market. Illiquid securities may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value. It may be difficult for a Fund to value illiquid securities accurately. The market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. Disposal of illiquid securities may entail registration expenses and other transaction costs that are higher than those for liquid securities. A Fund may seek to borrow money to meet its obligations (including among other things redemption obligations) if it is unable to dispose of illiquid investments, resulting in borrowing expenses and possible leveraging of the Fund. In some cases, due to unanticipated levels of illiquidity a Fund may choose to meet its redemption obligations wholly or in part by distributions of assets in-kind.

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individual issuers or related groups of issuers, securities markets, interest rates, credit ratings, inflation, investor sentiment, and other factors affecting the value of a Fund's investments. Given the increasing interdependence among global economies and markets, conditions in one country, market, or region might adversely affect markets, issuers, and/or foreign exchange rates in other countries, including the U.S. Any partial or complete dissolution of the Economic and Monetary Union of the European Union, or any increased uncertainty as to its status, could have significant adverse effects on currency and financial markets, and on the values of a Fund's investments. Securities and financial markets may be susceptible to market manipulation or other fraudulent trade practices, which could disrupt the orderly functioning of these markets or adversely affect the values of investments traded in these markets, including investments held by a Fund. To the extent a Fund has focused its investments in the market or index of a particular region, adverse geopolitical and other events could have a disproportionate impact on the Fund.

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of high illiquidity in the markets for the investments held by it. None of State Street Corporation, State Street, State Street Global Advisors, SSGA FM or their affiliates (collectively, the “State Street Entities”) guarantee the value of an investment in a money market fund at $1.00 per share. Investors should have no expectation of capital support to a money market fund from the State Street Entities.

Mortgage-Related and Other Asset-Backed Securities Risk (principal risk for the U.S. Government Fund) . Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed income investments. The liquidity of mortgage-related and asset-backed securities may change over time. Mortgage-related securities represent a participation in, or are secured by, mortgage loans. Other asset-backed securities are typically structured like mortgage-related securities, but instead of mortgage loans or interests in mortgage loans, the underlying assets may include, for example, items such as motor vehicle installment sales or installment loan contracts, leases on various types of real and personal property, and receivables from credit card agreements. During periods of falling interest rates, mortgage-related and other asset-backed securities, which typically provide the issuer with the right to prepay the security prior to maturity, may be prepaid, which may result in a Fund having to reinvest the proceeds in other investments at lower interest rates. During periods of rising interest rates, the average life of mortgage-related and other asset-backed securities may extend because of slower-than expected principal payments. This may lock in a below market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. As a result, mortgage-related and other asset-backed securities may have less potential for capital appreciation during periods of declining interest rates than other debt securities of comparable maturities, although they may have a similar risk of decline in market values during periods of rising interest rates. Prepayment rates are difficult to predict and the potential impact of prepayments on the value of a mortgage-related or other asset-backed security depends on the terms of the instrument and can result in significant volatility. The price of a mortgage-related or other asset-backed security also depends on the credit quality and adequacy of the underlying assets or collateral. Mortgage-related or other asset-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) will generally entail greater credit risk than obligations guaranteed by the U.S. Government. Defaults on the underlying assets, if any, may impair the value of a mortgage-related or other asset-backed security. For some asset-backed securities in which a Fund invests, such as those backed by credit card receivables, the underlying cash flows may not be supported by a security interest in a related asset. Moreover, the values of mortgage-related and other asset-backed securities may be substantially dependent on the servicing of the underlying asset pools, and are therefore subject to risks associated with the negligence or malfeasance by their servicers and to the credit risk of their servicers. In certain situations, the mishandling of related documentation may also affect the rights of securities holders in and to the underlying collateral. There may be legal and practical limitations on the enforceability of any security interest granted with respect to underlying assets, or the value of the underlying assets, if any, may be insufficient if the issuer defaults.

Rapid Changes in Interest Rates . The values of most instruments held by a Fund are adversely affected by changes in interest rates generally, especially increases in interest rates. Rapid changes in interest rates may cause significant requests to redeem Fund Shares, and possibly cause a Fund to sell portfolio securities at a loss to satisfy those requests. Significant losses could impair a Fund's ability to maintain a stable share price of $1.00.

Reinvestment Risk (principal risk for the U.S. Government Fund). Income from a Fund's portfolio may decline when the Fund invests the proceeds from investment income, sales of portfolio securities or matured, traded or called debt obligations. For instance, during periods of declining interest rates, an issuer of debt obligations may exercise an option to redeem securities prior to maturity, forcing a Fund to reinvest the proceeds in lower-yielding securities. A decline in income received by a Fund from its investments is likely to have a negative effect on the yield and total return of the Fund Shares.

Repurchase Agreement Risk . A repurchase agreement is an agreement to buy a security from a seller at one price and a simultaneous agreement to sell it back to the original seller at an agreed-upon price, typically representing the purchase price plus interest. Repurchase agreements may be viewed as loans made by a Fund which are collateralized by the securities subject to repurchase. A Fund's investment return on such transactions will depend on the counterparty's willingness and ability to perform its obligations under a repurchase agreement. If a Fund's counterparty should default on its obligations and a Fund is delayed or prevented from recovering the collateral, or if the value of the collateral is insufficient, a Fund may realize a loss.

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U.S. Government Securities Risk (principal risk for the U.S. Government Fund) . U.S. government securities, such as Treasury bills, notes and bonds and mortgage-backed securities guaranteed by the Government National Mortgage Association (“Ginnie Mae”), are supported by the full faith and credit of the United States; others are supported by the right of the issuer to borrow from the U.S. Treasury; others are supported by the discretionary authority of the U.S. government to purchase the agency's obligations; and still others are supported only by the credit of the issuing agency, instrumentality, or enterprise. Although U.S. government-sponsored enterprises such as the Federal Home Loan Mortgage Corporation (“Freddie Mac”) and the Federal National Mortgage Association (“Fannie Mae”) may be chartered or sponsored by Congress, they are not funded by Congressional appropriations, and their securities are not issued by the U.S. Treasury nor supported by the full faith and credit of the U.S. government. There is no assurance that the U.S. government would provide financial support to its agencies and instrumentalities if not required to do so. In addition, certain governmental entities have been subject to regulatory scrutiny regarding their accounting policies and practices and other concerns that may result in legislation, changes in regulatory oversight and/or other consequences that could adversely affect the credit quality, availability, or investment character of securities issued by these entities. The value and liquidity of U.S. government securities may be affected adversely by changes in the ratings of those securities. Securities issued by the U.S. Treasury historically have been considered to present minimal credit risk. The downgrade in the long-term U.S. credit rating by at least one major rating agency has introduced greater uncertainty about the ability of the U.S. to repay its obligations. A further credit rating downgrade or a U.S. credit default could decrease the value and increase the volatility of a Fund's investments.

U.S. Treasury Obligations Risk (principal risk for the Treasury Plus Fund) . U.S. Treasury obligations may differ from other securities in their interest rates, maturities, times of issuance and other characteristics. Similar to other issuers, changes to the financial condition or credit rating of the U.S. government may cause the value of a Fund's U.S. Treasury obligations to decline. The total public debt of the United States as a percent of gross domestic product grew rapidly after the financial crisis of 2008 and has remained at a historically high level. Although high debt levels do not necessarily indicate or cause economic problems, they may create certain systemic risks if sound debt management practices are not implemented. A high national debt level may increase market pressures to meet government funding needs, which may drive debt cost higher and cause a country to sell additional debt, thereby increasing refinancing risk. A high national debt also raises concerns that a government will not be able to make principal or interest payments when they are due. In the worst case, unsustainable debt levels can cause a decline in the value of the dollar (which may lead to inflation), and can prevent the U.S. government from implementing effective counter-cyclical fiscal policy in economic downturns. On August 5, 2011, Standard & Poor's Ratings Services downgraded U.S. Treasury securities from AAA rating to AA+ rating. Standard & Poor's Ratings Services stated that its decision was prompted by its view on the rising public debt burden and its perception of greater policymaking uncertainty. A downgrade of the ratings of U.S. government debt obligations, which are often used as a benchmark for other borrowing arrangements, could result in higher interest rates for individual and corporate borrowers, cause disruptions in the international bond markets and have a substantial negative effect on the U.S. economy. A downgrade of U.S. Treasury securities from another ratings agency or a further downgrade below AA+ rating by Standard & Poor's Ratings Services may cause the value of the Fund's U.S. Treasury obligations to decline. In recent years, impasses in Congress regarding the federal budget have caused repeated temporary Federal government shutdowns. While Congress has temporarily suspended the debt limit from time to time, the risks that the U.S. government will not adopt a long-term budget or deficit reduction plan, of one or more additional Federal government shutdowns or of future failures to not increase the Federal government's debt limit, may affect investor and consumer confidence and may adversely impact financial markets and the broader economy, perhaps suddenly and to a significant degree.

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Additional Information About Non-Principal Investment Strategies and Risks

Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Funds) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, a Fund, a Portfolio, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect a Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect a Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject a Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of a Fund inaccessible or inaccurate or incomplete. A Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. A Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. Each Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Funds. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which each Fund invests, which could result in material adverse consequences for such issuers, and may cause a Fund's investment in such securities to lose value.

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Portfolio Holdings Disclosure

The Funds' portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

Investment Adviser

SSGA FM serves as the investment adviser to each Fund and corresponding Portfolio and, subject to the oversight of the Board, is responsible for the investment management of each Fund. The Adviser provides an investment management program for each Fund and manages the investment of each Fund's assets. The Adviser is a wholly-owned subsidiary of State Street Global Advisors, Inc., which itself is a wholly-owned subsidiary of State Street Corporation. The Adviser is registered with the SEC under the Investment Advisers Act of 1940, as amended. The Adviser and certain other affiliates of State Street Corporation make up SSGA. SSGA is one of the world's largest institutional money managers and the investment management arm of State Street Corporation. As of December 31, 2018, the Adviser managed approximately $452.10 billion in assets and SSGA managed approximately $2.51 trillion in assets. The Adviser's principal business address is One Iron Street, Boston, Massachusetts 02210.

Each Fund has entered into an investment advisory agreement with the Adviser pursuant to which the Adviser will manage the Fund's assets directly, for compensation paid at an annual rate of 0.05% of the Fund's average daily net assets, in the event that the Fund were to cease investing substantially all of its assets in its corresponding Portfolio or another investment company with essentially the same investment objectives and policies as the Fund. The Adviser does not receive any management fees from a Fund under that agreement so long as the Fund continues to invest substantially all of its assets in the corresponding Portfolio or in another investment company with essentially the same investment objectives and policies as the Fund. The Adviser places all orders for purchases and sales of the Portfolios' investments. For the year ended December 31, 2018, the effective management fee paid, reflecting certain fee waivers and expense reimbursements of the Adviser, was 0.05% for U.S. Government Portfolio and 0.05% for Treasury Plus Portfolio.

Total Annual Fund Operating Expense Waivers . SSGA FM, as the investment adviser to each Fund, is contractually obligated, through April 30, 2020, (i) to waive up to the full amount of the advisory fee payable by each Fund, and/or (ii) to reimburse a Fund for expenses to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.07% of average daily net assets on an annual basis. These waiver and/or reimbursement arrangements may not be terminated prior to April 30, 2020 except with approval of the Funds' Board of Trustees.

A discussion regarding the Board's consideration of the Funds' Investment Advisory Agreement is provided in the Funds' Semi-Annual Report to Shareholders for the period ended June 30, 2018.

The Administrator, Sub-Administrator and Custodian

The Adviser serves as administrator of each Fund. The amount of the fee paid to the Adviser for administrative services may vary by share class. Each Fund currently pays the Adviser an administrative fee at the annual rate of 0.05% in respect of the class of shares in this Prospectus. State Street Bank and Trust Company (“State Street”), a subsidiary of State Street Corporation, serves as the sub-administrator for the Funds for a fee that is paid by the Adviser. State Street also serves as custodian of the Funds for a separate fee that is paid by the Funds. SSGA FM serves as administrator of the Portfolios and State Street serves as sub-administrator and custodian of the Portfolios.

The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Funds' transfer agent and dividend disbursing agent (the “Transfer Agent”).

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The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Funds' distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

The Shareholder Servicing Agent

The “Servicing Agent”

Neuberger Berman Management LLC (“Neuberger Berman”) serves as the servicing agent for shareholders of mutual funds distributed and advised by Neuberger Berman (a “Neuberger Berman Fund”) that are also shareholders of a Fund.

Additional Information

Shareholder Information

Note : This prospectus is intended to relate principally to purchases of shares through Neuberger Berman. Information appearing below assumes that shares are purchased and redeemed through Neuberger Berman and is based on information previously provided by Neuberger Berman to the Funds.

Determination of Net Asset Value

Each of the Funds determines its NAV per share once each day on which the New York Stock Exchange (the “NYSE”), the Federal Reserve banks and State Street are open for business (a “Business Day”) at 5:00 p.m. ET except for days when the NYSE closes earlier than its regular closing time, in which event the Fund will determine its NAV at the earlier closing time (the time when the Fund determines its NAV per share is referred to herein as the “Valuation Time”). Pricing does not occur on NYSE holidays.

The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. The Funds reserve the right to accept orders to purchase or redeem shares, or to continue to accept such orders following the close of the NYSE, on any day that is not a Business Day or any day on which the NYSE closes early, provided the Federal Reserve remains open. The Funds also may establish special hours on those days to determine each Fund's NAV. In the event that the Funds invoke the right to accept orders to purchase or redeem shares on any day that is not a Business Day or adopt special hours of operation, the Funds will post advance notice of these events at: www.ssga.com/cash.

Each Fund seeks to maintain a $1.00 per share NAV and, accordingly, uses the amortized cost valuation method, in compliance with the risk limiting conditions of Rule 2a-7 under the Investment Company Act of 1940, as amended (the “1940 Act”), to value its portfolio instruments. The amortized cost valuation method initially prices an instrument at its cost and thereafter assumes a constant amortization to maturity of any discount or premium, regardless of the impact of fluctuating interest rates on the market value of the instrument.

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Investing in State Street Institutional Investment Trust Shares

Requests for transactions in the State Street Funds will be processed when they are received in “good order.” “Good order” means that the request is in an accurate and complete form, and all applicable documents have been received in such accurate and complete form (including typically, a signed application and medallion-guaranteed documents), and, for a purchase request, the check or wired funds have cleared.

Purchasing Shares

Investors pay no sales load to invest in shares of the Funds. The price for Fund Shares is the NAV per share. Purchase requests received by a Fund in good order (a purchase request is in good order if it meets the requirements implemented from time to time by the Transfer Agent or authorized agent of the Fund, and for new accounts includes submission of a completed and signed application and all documentation necessary to open an account) on a business day will, if payment is received by FedWire, be priced at the NAV next determined after the order is accepted by the Fund. Payments received by FedWire prior to the last Valuation Time will earn dividend accrual for that purchase.

All purchases that are made by check will begin earning dividends the following Business Day after the day the order is accepted.(If you purchase shares by check, your order will not be in good form until the Transfer Agent receives federal funds for the check.) All purchase orders are subject to acceptance by the Funds. The Funds intend to be as fully invested as is practicable; therefore, investments must be made in Federal Funds (i.e., monies credited to the account of the Funds' custodian bank by a Federal Reserve Bank).

Neuberger Berman is responsible for transmitting your purchase request and funds in good form and in a timely manner to the applicable Fund(s). A Fund will not be responsible for delays by Neuberger Berman in transmitting your purchase request, including timely transfer of payment, to the Fund.

The Funds reserve the right to cease accepting investments at any time or to reject any investment order. In addition, the Funds may limit the amount of a purchase order received after 3:00 p.m. ET.

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How to Purchase Shares

By Mail:

An initial investment in the Funds must be preceded or accompanied by a completed, signed Neuberger Berman Fund Application Form, sent to:

Neuberger Berman Funds
c/o State Street Institutional Trust Funds
State Street Global Advisors
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

Your first investment must be at least $2,000. Additional investments can be as little as $100. All checks must be made out to “Neuberger Berman Funds”. Neuberger Berman will not accept checks made out to you or other parties and signed over to it. Neuberger Berman cannot accept cash, money orders, starter checks, cashier's checks, traveler's checks or other cash equivalents. You will be responsible for any losses or fees resulting from a bad check. If necessary, Neuberger Berman may effect sales of Fund shares belonging to you in order to cover these losses.

By Telephone:

An initial investment in the Funds must be preceded or accompanied by a completed, signed Neuberger Berman Fund Application Form. Neuberger Berman does not accept phone orders for a first investment. To add shares to an existing account using FUNDfone», call (800) 335-9366.

Additional shares will be purchased when your order is accepted by the Funds. Additional investments must be for at least $100.

For your initial investment, send the original, signed Neuberger Berman Account Application Form to the address above.

Wire Instructions:

Before wiring any money, call (800) 877-9700 for an order confirmation. Please have your financial institution send your wire to Neuberger Berman's account at State Street Bank and Trust Company and include your name, the Fund name, your account number and other information as requested.

State Street Bank/Boston
ABA# 011-000028
Attn: NB Deposit Account
DDA#9904-199-8

By Internet:

You may place an order with Neuberger Berman to purchase shares for your account by placing an order online at www.nb.com.

In accordance with certain federal regulations, Neuberger Berman is required to obtain, verify and record information that identifies each entity that applies to open an account. For this reason, when you open (or change ownership of) an account, Neuberger Berman will request certain information, including your name, residential/business address, date of birth (for individuals) and taxpayer identification number or other government identification number and other information that will allow us to identify you which will be used to verify your identity. Neuberger Berman may also request to review other identification documents such as driver license, passport or documents showing the existence of the business entity. If you do not provide sufficient information to verify your identity, Neuberger Berman will not open an account for you. As required by law, Neuberger Berman may employ various procedures, such as comparing your information to fraud databases or requesting additional information and documentation from you, to ensure that the information supplied by you is correct. Neuberger Berman reserves the right to reject any purchase for any reason, including failure to provide the Trust with information necessary to confirm your identity as required by law.

Redeeming Shares

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An investor may redeem all or any portion of its investment. Redemption orders are processed at the NAV next determined after a Fund receives a redemption order in good form to Neuberger Berman.

For the Treasury Plus Fund

If Neuberger Berman receives a redemption order prior to 5:00 p.m. Eastern Time on a Business Day, Neuberger Berman typically expects to pay out redemption proceeds on that day, but no later than the next Business Day if redemption proceeds are sent by wire or ACH. If redemption proceeds are sent by check, Neuberger Berman typically expects to pay out redemption proceeds on the next Business Day. No dividends will be paid on shares that are redeemed and wired the same day. The Treasury Plus Fund reserves the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Fund.

For the U.S. Government Fund

If Neuberger Berman receives a redemption order in good form prior to 5:00 p.m. Eastern Time on a Business Day, shares are redeemed and the Neuberger Berman typically sends payment for redeemed shares on that day, but no later than next Business Day if redemption proceeds are sent by wire or ACH. If redemption proceeds are sent by check, Neuberger Berman typically expects to pay out redemption proceeds on the next Business Day. If a full redemption order is requested, no dividends will accrue with respect to shares on the day the redemption proceeds are sent. If a redemption order is placed after 5:00 p.m. Eastern Time, Neuberger Berman typically expects to pay out the redemption proceeds for the shares will be sent next Business Day (and dividends will accrue up to, but not including, the day that redemption proceeds are sent).

For All Funds

Each Fund is a government money market fund that has not elected to be subject to the fees and gates provisions of Rule 2a-7. The right of any investor to receive payment with respect to any redemption may be suspended or the payment of the redemption proceeds postponed in accordance with Section 22(e) of the 1940 Act and the rules thereunder, including during any period in which the NYSE is closed (other than weekends or holidays) or trading on the NYSE is restricted or if an emergency exists as a result of which disposal by the Fund of securities owned by it is not reasonably practicable or it is not reasonably practicable for the Fund fairly to determine the value of its net assets. In addition, the SEC may by order permit suspension of redemptions for the protection of shareholders of the Fund. Although each Fund attempts to maintain its NAV at $1.00 per share, there can be no assurance that it will be successful, and there can be no assurance that a shareholder will receive $1.00 per share upon any redemption.

When selling shares in an account that you do not intend to close, remember to leave at least $2,000 worth of shares in the account. Otherwise, Neuberger Berman has the right to request that you bring the balance back up to the minimum level. If you have not done so within 60 days, Neuberger Berman may close your account and redeem the proceeds. Neuberger Berman is responsible for transmitting your redemption request in good form and in a timely manner to the applicable Fund(s). A Fund will not be responsible for delays by Neuberger Berman in transmitting your redemption request to the Fund.

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How to Redeem Shares


By Mail:	Send a signed letter to: Neuberger Berman Funds c/o State Street Bank & Trust Co. 430 West 7th Street Suite 219189 Kansas City, MO 64105-1407
	The letter should include information necessary to process your request as described below. The Fund may require a medallion guarantee in certain circumstances. See “Medallion Guarantees” below.
By Telephone:	Please call Neuberger Berman at (800) 877-9700 between the hours of 8:00 a.m. and 6:00 p.m. ET.
You must provide the following information: ➣ name(s) of account owners; ➣ account number(s); ➣ the name of the Fund; ➣ the dollar amount, percentage or number of shares being redeemed; and ➣ any other instructions. To place an order using FUNDfone», call (800) 335-9366.
By Internet:	You may instruct Neuberger Berman to redeem shares by placing an order online at www.nb.com.

On any day that the Funds calculate NAV earlier than normal, the Funds reserve the right to adjust the times noted above for purchasing and redeeming shares.

Medallion Guarantees . You may need a Medallion signature guarantee when you sell shares of a Fund. A Medallion signature guarantee is a guarantee that your signature is authentic. Most banks, brokers and other financial institutions can provide you with one. Some may charge a fee; others may not, particularly if you are a customer of theirs.

Medallion signature guarantees are required for a variety of transactions including requests for changes to your account or to the instructions for distribution of proceeds. Neuberger Berman reserves the right to require a Medallion signature guarantee on any transaction at our discretion.

A notarized signature from a notary public is not a Medallion signature guarantee.

Exchanging Shares . You can move an investment from a Fund to a comparable class of another Neuberger Berman Fund in the Fund family through an exchange of shares, or by electing to use your cash distributions from a Fund to purchase shares of the other Fund. There are three things to remember when making an exchange:

•	both accounts must have the same registration;
•	you will need to observe the minimum account balance requirements for the fund accounts involved; and
•	because an exchange is treated as a sale for tax purposes, consider any tax consequences before placing your order.

Privileges and Services . You have access to a range of Neuberger Berman services to make investing easier:

Systematic Withdrawals . This plan lets you arrange withdrawals of at least $100 from a Fund on a periodic schedule. You can also set up payments to distribute the full value of an account over a given time.

Electronic Bank Transfers . When you sell Fund shares, you can have the money sent to your bank account electronically rather than mailed to you as a check. Please note that your bank must be a member of the Automated Clearing House, or ACH, system.

Internet Access . At www.nb.com, you can initiate transactions, check your account and access a wealth of information.

FUNDfone ^® . Get up-to-date performance and account information through our 24-hour automated service by calling (800) 335-9366. If you already have a Neuberger Berman fund account, you can place orders to buy, sell or exchange fund shares.

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Checkwriting . If you would like to write checks against your Institutional U.S. Government Money Market Fund account, please call (800) 877-9700. Withdrawals must be for at least $250.

About Mail Transactions . If you choose to purchase, exchange or redeem shares by sending instructions by regular mail, they will not be deemed received in good order until they are released by the post office and redelivered to the Transfer Agent's physical location at 430 West 7th Street, Suite 219189 in Kansas City, MO 64105. There will be a time lag, which may be one or more days, between regular mail receipt at the post office box and redelivery to such physical location in Kansas City, and a Fund's NAV may change over those days. You might consider using express rather than regular mail if you believe the time of receipt of your transaction request to be sensitive.

Other Policies . Under certain circumstances, Neuberger Berman reserves the right to:

•	reject any exchange or purchase order;
•	suspend or reject any future purchase order from any investor who does not provide payment to settle a purchase order;
•	change, suspend or revoke the exchange privilege; and
•	suspend the telephone order privilege.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a the Fund identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Fund (if you hold shares directly with the Fund) or to your financial intermediary (if you do not hold shares directly with the Fund).

Excessive Trading

Dividends, Distributions and Tax Considerations

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For U.S. federal income tax purposes, distributions of investment income are generally taxable to you as ordinary income. Taxes on distributions of capital gains generally are determined by how long the Portfolio owned (or is deemed to have owned) the investments that generated them, rather than how long you have owned your Fund Shares. Any net short-term gains the Fund distributes will be taxable to you as ordinary income. The Funds generally does not expect to make distributions that are eligible for taxation as long-term capital gains. Distributions are taxable to you even if they are paid from income or gains earned by the Fund before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares. If the NAV of Fund Shares were to vary from $1.0000 per share, shareholders generally would realize a gain or loss upon the redemption or other taxable disposition of such Fund Shares. Any such gains generally would be taxable to you as either short-term or long-term capital gain, depending upon how long you have held such Fund Shares.

An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by a Fund and net gains recognized on the redemption of shares of a Fund.

Financial Intermediary Arrangements

Distribution Arrangements and Rule 12b-1 Fees

The Funds have adopted a distribution plan pursuant to Rule 12b-1 under the 1940 Act under which a Fund may compensate SSGA FD (or others) for services in connection with the distribution of a Fund's Investment Shares and for services provided to Fund shareholders (the “Plan”). The Plan calls for payments at an annual rate (based on average daily net assets) of 0.10% of the Fund's net assets attributable to its Investment Shares. Because these fees are paid out of the assets of a Fund attributable to its Investment Shares on an ongoing basis, they will increase the cost of your investment and may cost you more over time than paying other types of sales charges. Long-term shareholders of the Fund may pay more in Rule 12b-1 fees than the economic equivalent of the maximum front-end sales charge permitted by the FINRA.

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A Fund may pay distribution fees and other amounts described in this Prospectus at a time when shares of that Fund are unavailable for purchase.

Other Payments to Financial Intermediaries

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This Page Intentionally Left Blank

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Financial Highlights

The financial highlight tables are intended to help you understand each Fund's Investment Class Shares financial performance for the past five fiscal years. Certain information reflects the performance results for a single Fund Share. The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in each Fund (assuming reinvestment of all dividends and distributions). This information has been audited by Ernst & Young LLP, the Trust's independent registered public accounting firm, whose report, along with each Fund's financial highlights and financial statements, is included in the annual report to shareholders, which is available upon request. Any references to Notes in these financial highlight tables refer to the “Notes to Financial Statements” section of each Fund's financial statements, and the financial information included in these tables should be read in conjunction with the financial statements incorporated by reference in the SAI.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL U.S. GOVERNMENT MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Investment Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	Year Ended 12/31/14
Net asset value, beginning of period	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0140	0.0044	0.0000(b)	0.0000(b)(c)	(0.0000)(b)(c)
Net realized gain (loss)	—	0.0000(b)	0.0000(b)	—	—
Total from investment operations	0.0140	0.0044	0.0000(b)	0.0000(b)	(0.0000)(b)
Distributions to shareholders from:
Net investment income	(0.0140)	(0.0044)	(0.0000)(b)	—	—
Net realized gains	—	(0.0000)(b)	—	—	—
Total distributions	(0.0140)	(0.0044)	(0.0000)(b)	—	—
Net asset value, end of period	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Total return (d)	1.40%	0.44%	0.00%(e)	0.00%(e)	0.00%(e)
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$380,085	$432,488	$903,050	$971,551	$615,706
Ratios to Average Net Assets:
Total expenses	0.47%	0.47%	0.47%	0.47%	0.47%
Net expenses	0.47%	0.47%	0.37%	0.10%	0.07%
Net investment income (loss)	1.42%	0.40%	0.00%(e)	0.00%(e)	0.00%(e)

(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Per share numbers have been calculated using average shares outstanding, which more appropriately presents the per share data for the period.
(d)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(e)	Amount is less than 0.005%.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL TREASURY PLUS MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Investment Class(a)
	Year Ended 12/31/18	Year Ended 12/31/17	Year Ended 12/31/16	Year Ended 12/31/15	Year Ended 12/31/14
Net asset value, beginning of period	$ 1.0000	$ 1.0000	$ 1.0000	$1.0000	$1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0139	0.0042	0.0000(b)	0.0000(b)(c)	0.0000(b)(c)
Net realized gain (loss)	—	0.0000(b)	0.0000(b)	0.0000(b)	0.0000(b)
Total from investment operations	0.0139	0.0042	0.0000(b)	0.0000(b)	0.0000(b)
Distributions to shareholders from:
Net investment income	(0.0139)	(0.0042)	(0.0000)(b)	—	—
Net realized gains	—	(0.0000)(b)	—	—	—
Total distributions	(0.0139)	(0.0042)	(0.0000)(b)	—	—
Net asset value, end of period	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000	$ 1.0000
Total return (d)	1.40%	0.42%	0.00%(e)	0.00%(e)	0.00%(e)
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$ 69,812	$ 19,242	$ 48,170	$60,041	$74,781
Ratios to Average Net Assets:
Total expenses	0.47%	0.47%	0.49%	0.49%	0.48%
Net expenses	0.47%	0.47%	0.31%	0.06%	0.05%
Net investment income (loss)	1.54%	0.36%	0.00%(e)	0.00%(e)	0.00%(e)

(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Per share numbers have been calculated using average shares outstanding, which more appropriately presents the per share data for the period.
(d)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(e)	Amount is less than 0.005%.

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For more information about the Funds:

The Funds' SAI includes additional information about the Funds and is incorporated by reference into this document. Additional information about the Funds' investments is available in the Funds' most recent annual and semi-annual reports to shareholders. The Funds' SAI is available, without charge, upon request. The Funds' annual and semi-annual reports are available, without charge, upon request. Shareholders in the Funds may make inquiries to the Funds to receive such information by calling (877) 521-4083 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

00228673

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

Prospectus

Dated April 30, 2019

State Street Institutional
Investment Trust

State Street Treasury Obligations Money Market Fund (TAQXX)

Beginning on January 1, 2021, as permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of the Fund's annual and semi- annual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Fund (or from your financial intermediary, such as a broker-dealer or bank). Instead, the reports will be made available on the Fund's website (www.ssga.com/cash), and you will be notified by mail each time a report is posted, and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Fund electronically by calling (866) 392-0869.

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with the Fund, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling (866) 392-0869. Your election to receive reports in paper will apply to all funds held in your account, if you invest through your financial intermediary or all funds held with the fund complex if you invest directly with a Fund.

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in the Fund offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

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Fund Summary	1
State Street Treasury Obligations Money Market Fund	1
Additional Information About Investment Objective, Principal Strategies and Risks	5
Additional Information About Non-Principal Investment Strategies and Risks	9
Portfolio Holdings Disclosure	10
Management and Organization	11
Shareholder Information	12
Dividends, Distributions and Tax Considerations	17
Financial Intermediary Arrangements	18
Financial Highlights	21

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State Street Treasury Obligations Money Market Fund

Investment Objective

The investment objective of State Street Treasury Obligations Money Market Fund (the “Treasury Obligations Fund” or sometimes referred to in context as the “Fund”) is to seek a high level of current income consistent with preserving principal and liquidity and the maintenance of a stable $1.00 per share net asset value (“NAV”).

Fees and Expenses of the Fund

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Treasury Obligations Fund (“Fund Shares”). The expenses shown in the table and the Example reflect the expenses of the Fund and the Fund's proportionate share of the expenses of the State Street Treasury Plus Money Market Portfolio (the “Treasury Plus Portfolio” or sometimes referred to in context as the “Portfolio”).

Shareholder Fees (fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%
Other Expenses	0.08%
Total Annual Fund Operating Expenses	0.13%
Less Fee Waivers and/or Expense Reimbursements ¹	(0.03%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.10%

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), is contractually obligated until April 30, 2021 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, and extraordinary expenses) exceed 0.10% of average daily net assets on an annual basis. This waiver and/or reimbursement may not be terminated prior to April 30, 2021 except with approval of the Fund's Board of Trustees.

Example:

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated, and then sell all of your Fund Shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The calculation of costs for the one-year and three-year periods takes into account the effect of the current contractual fee waivers and/or reimbursements. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

1 year		3 years		5 years		10 years
$10		$39		$70		$163

Principal Investment Strategies

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among other things, the Fund to invest only in short-term securities (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity.

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the Treasury Plus Portfolio, which has substantially identical investment policies to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Treasury Plus Portfolio, and it participates in the investment returns achieved by the Treasury Plus Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Treasury Plus Portfolio.

Principal Risks

In addition, the Fund is subject to the following principal risks:

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Performance

The bar chart and table below provide some indication of the risks of investing in the Treasury Obligations Fund by illustrating the variability of the Fund's returns from year-to-year. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (877) 521-4083 or by visiting our website at www.ssga.com/cash or call 1-877-521-4083.

Highest Quarterly Return: 0.55% (Q4, 2018)
Lowest Quarterly Return: 0.33% (Q1, 2018)

Annual Total Returns (years ended 12/31)

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Average Annual Total Returns (for periods ended 12/31/18)

		One Year		Since Inception		Inception Date
State Street Treasury Obligations Money Market Fund		1.79%		1.64%		10/5/2017

To obtain the Fund's current yield, please call (877) 521-4083.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund.

Purchase and Sale of Fund Shares

Purchase Minimums

To establish an account	$1,000,000,000
To add to an existing account	No minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

By Mail:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone:

By Intermediary:

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

Tax Information

Payments to Broker-Dealers and Other Financial Intermediaries

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Additional Information About Investment Objective, Principal Strategies and Risks

Investment Objective

The Board of Trustees may change the Fund's investment objective without shareholder approval.

Principal Investment Strategies

The Fund is a government money market fund and attempts to meet its investment objective by investing only in U.S. Treasury bills, notes and bonds (which are direct obligations of the U.S. government) and repurchase agreements collateralized by these obligations. The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs. The Fund invests in accordance with regulatory requirements applicable to money market funds, which require, among other things, the Fund to invest only in short-term securities (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity.

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the Treasury Plus Portfolio, which has substantially identical investment policies to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Treasury Plus Portfolio, and it participates in the investment returns achieved by the Treasury Plus Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Treasury Plus Portfolio.

Additional Information About Risks

Additional information about risks is described below. The risks are described in alphabetical order and not in the order of importance or potential exposure.

The credit rating assigned to any particular investment does not necessarily reflect the issuer's current financial condition and does not reflect an assessment of an investment's volatility or liquidity. Securities rated in the lowest category of investment-grade are considered to have speculative characteristics. If a security held by the Fund loses its rating or its rating is downgraded, the Fund may nonetheless continue to hold the security in the discretion of the Adviser. In the case of asset-backed or mortgage-related securities, changes in the actual or perceived ability of the obligors on the underlying assets or mortgages to make payments of interest and/or principal may affect the values of those securities.

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to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of the Fund's fixed income securities to decrease, an adverse impact on the liquidity of the Fund's fixed income securities, and increased volatility of the fixed income markets. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Fund may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

Large Shareholder Risk . To the extent a large proportion of the interests of the Portfolio are highly concentrated or held by a small number of investors (or a single investor), including funds or accounts over which the Adviser has investment discretion, the Portfolio is subject to the risk that these investors will purchase or redeem Portfolio interests in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of the Portfolio to conduct its investment program. For example, they could require the Portfolio to sell portfolio securities or purchase portfolio securities unexpectedly and incur substantial transaction costs and/or accelerate the realization of taxable income and/or gains to investors, or the Portfolio may be required to sell its more liquid portfolio investments to meet a large redemption, in which case the Portfolio's remaining assets may be less liquid, more volatile, and more difficult to price. The Portfolio may hold a relatively large proportion of its assets in cash in anticipation of large redemptions, diluting its investment returns.

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Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject the Fund to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and the Fund's investment program in particular can be uncertain. In recent periods, governmental and non-governmental issuers have defaulted on, or have been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including, without limitation, in Europe or Asia. Defaults or restructurings by governments or others of their debts could have substantial adverse effects on economies, financial markets, and asset valuations around the world. Further Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, or investor perception that these efforts are not succeeding, could negatively affect financial markets generally as well as the values and liquidity of certain securities.

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could cause a money market fund's share price to fall below $1.00. It is possible that a money market fund will issue and redeem shares at $1.00 per share at times when the fair value of the money market fund's portfolio per share is more or less than $1.00. A money market fund may be permitted or required to impose redemption fees or to impose limitations on redemptions during periods of high illiquidity in the markets for the investments held by it. None of State Street Corporation, State Street, State Street Global Advisors, SSGA FM or their affiliates (collectively, the “State Street Entities”) guarantee the value of an investment in a money market fund at $1.00 per share. Investors should have no expectation of capital support to a money market fund from the State Street Entities.

Variable and Floating Rate Securities Risk . Variable or floating rate securities are debt securities with variable or floating interest rates payments. Variable or floating rate securities bear rates of interest that are adjusted periodically according to formulae intended generally to reflect market rates of interest and allow the Fund to participate (determined in accordance with the terms of the securities) in increases in interest rates through upward adjustments of the coupon rates on the securities. However, during periods of increasing interest rates, changes in the coupon rates may lag behind the changes in market rates or may have limits on the maximum increases in coupon rates. Alternatively, during periods of declining interest rates, the coupon rates on such securities will typically readjust downward resulting in a lower yield. The Fund may also invest in variable or floating rate equity securities, whose dividend payments vary based on changes in market rates of interest or other factors.

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Additional Information About Non-Principal Investment Strategies and Risks

The investments described below reflect the Fund's and the Treasury Plus Portfolio's current practices. In addition to the principal risks described above, other risks are described in some of the descriptions of the investments below:

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Fund. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issuers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for the Fund and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by the Fund. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Fund) or otherwise using such information for the benefit of its clients or itself.

Cybersecurity Risk . With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Fund) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, the Fund, the Portfolio, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect the Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect the Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject the Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of the Fund inaccessible or inaccurate or incomplete. The Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. The Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified given the evolving nature of this threat. The Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Fund. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which the Fund invests, which could result in material adverse consequences for such issuers, and may cause the Fund's investment in such securities to lose value.

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Portfolio Holdings Disclosure

The Fund's portfolio holdings disclosure policy is described in the SAI.

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Management and Organization

The Fund invests as part of a “master/feeder” structure. The Fund currently seeks to achieve its investment objective by investing substantially all of its investable assets in the Treasury Plus Portfolio, a separate mutual fund, that has substantially identical investment objective, investment policies, and risks as the Fund. All discussions about the Fund's investment objective, policies and risks should be understood to refer also to the investment objectives, policies and risks of the Treasury Plus Portfolio.

The Fund can withdraw its investment in the Portfolio if, at any time, the Fund's Board of Trustees determines that it would be in the best interests of the Fund's shareholders, or if the investment objectives of the Treasury Plus Portfolio changed so that they were inconsistent with the objectives of the Fund. If the Fund withdraws its investment from the Portfolio, the Fund may invest all of its assets in another mutual fund that has the same investment objective as the Fund, the Adviser may directly manage the Fund's assets, or the Board may take such other action it deems appropriate and in the best interests of shareholders of the Fund, which may include liquidation of the Fund.

Investment Adviser

SSGA FM serves as the investment adviser to the Fund and the Treasury Plus Portfolio and, subject to the oversight of the Board, is responsible for the investment management of the Fund. The Adviser provides an investment management program for the Fund and manages the investment of the Fund's assets. The Adviser is a wholly-owned subsidiary of State Street Global Advisors, Inc., which itself is a wholly-owned subsidiary of State Street Corporation. The Adviser is registered with the SEC under the Investment Advisers Act of 1940, as amended. The Adviser and certain other affiliates of State Street Corporation make up SSGA. SSGA is one of the world's largest institutional money managers and the investment management arm of State Street Corporation. As of December 31, 2018, the Adviser managed approximately $452.10 billion in assets and SSGA managed approximately $2.51 trillion in assets. The Adviser's principal business address is One Iron Street, Boston, Massachusetts 02210.

The Fund has entered into an investment advisory agreement with the Adviser pursuant to which the Adviser will manage the Fund's assets directly, for compensation paid at an annual rate of 0.05% of the Fund's average daily net assets, in the event that the Fund were to cease investing substantially all of its assets in the Treasury Plus Portfolio or another investment company with essentially the same investment objectives and policies as the Fund. The Adviser does not receive any management fees from the Fund under that agreement so long as the Fund continues to invest substantially all of its assets in the Treasury Plus Portfolio or in another investment company with essentially the same investment objectives and policies as the Fund. The Adviser places all orders for purchases and sales of the Portfolio's investments. For the year ended December 31, 2018, the effective management fee paid, reflecting certain fee waivers and expense reimbursements of the Adviser, was 0.05% for Treasury Plus Portfolio.

Total Annual Fund Operating Expense Waivers . SSGA FM, as the investment adviser to the Fund, is contractually obligated until April 30, 2021 (i) to waive up to the full amount of the advisory fee payable by the Fund and/or (ii) to reimburse the Fund to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, and extraordinary expenses) exceed 0.10% of average daily net assets on an annual basis. This reimbursement may not be terminated prior to April 30, 2021 except with approval of the Fund's Board of Trustees.

Voluntary Expense Waiver . Additionally, the Adviser has voluntarily agreed to waive its advisory fee and/or to reimburse the Fund for expenses to the extent that the Fund's total annual operating expenses exceed 0.08% of average daily net assets on an annual basis (the “Voluntary Expense Waiver”). The Adviser may discontinue the voluntary fee waiver and/or expense limitation arrangement at any time, in its sole discretion.

A discussion regarding the Board's consideration of the Fund's Investment Advisory Agreement is provided in the Fund's Semi-Annual Report to Shareholders for the period ended June 30, 2018.

The Administrator, Sub-Administrator and Custodian

The Adviser serves as administrator of the Fund. The amount of the fee paid to the Adviser for administrative services may vary by share class. The Fund currently pays the Adviser an administrative fee at the annual rate of 0.05%. State Street Bank and Trust Company (“State Street”), a subsidiary of State Street Corporation, serves as the sub-administrator for the Fund for a fee that is paid by the Adviser. State Street also serves as custodian of the Fund for a separate fee that is paid by the Fund. SSGA FM serves as administrator of the Portfolio and State Street serves as sub-administrator and custodian of the Portfolio.

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The Transfer Agent and Dividend Disbursing Agent

DST Asset Manager Solutions, Inc. is the Fund's transfer agent and dividend disbursing agent (the “Transfer Agent”).

The Distributor

State Street Global Advisors Funds Distributors, LLC serves as the Fund's distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

Additional Information

Shareholder Information

Determination of Net Asset Value

The Fund determines its NAV per share once each day on which the NYSE, the Federal Reserve banks and State Street are open for business (a “Business Day”) at 5:00 p.m. ET except for days when the NYSE closes earlier than its regular closing time, in which event the Fund will determine its NAV at the earlier closing time (the time when the Fund determines its NAV per share is referred to herein as the “Valuation Time”). Pricing does not occur on NYSE holidays.

The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. The Fund reserves the right to accept orders to purchase or redeem shares, or to continue to accept such orders following the close of the NYSE, on any day that is not a Business Day or any day on which the NYSE closes early, provided the Federal Reserve remains open. As noted in this Prospectus, the Fund may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when the Fund does not price its shares. Consequently, the NAV of the Fund's shares may change on days when shareholders are not able to purchase or redeem the Fund's shares. The Fund also may establish special hours on those days to determine the Fund's NAV. In the event that the Fund invoke the right to accept orders to purchase or redeem shares on any day that is not a Business Day or adopt special hours of operation, the Fund will post advance notice of these events at: www.ssga.com/cash.

Investing in State Street Institutional Investment Trust Shares

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Purchasing Shares

Investors pay no sales load to invest in the Fund Shares. The price for Fund Shares is the NAV per share. Purchase requests received by the Fund in good order (a purchase request is in good order if it meets the requirements implemented from time to time by the Transfer Agent or authorized agent of the Fund, and for new accounts includes submission of a completed and signed application and all documentation necessary to open an account) on a Business Day will, if payment is received by FedWire, be priced at the NAV next determined after the order is accepted by the Fund. Payments received by FedWire prior to the last Valuation Times will earn dividend accrual for that purchase.

All purchases that are made by check will begin earning dividends the following Business Day after the day the order is accepted. (If you purchase shares by check, your order will not be in good form until the Transfer Agent receives federal funds for the check.) All purchase orders are subject to acceptance by the Fund. The Fund intends to be as fully invested as is practicable; therefore, investments must be made in Federal Funds (i.e., monies credited to the account of the Fund's custodian bank by a Federal Reserve Bank).

The minimum initial investment in the Fund is $1 billion, although the Adviser may waive the minimum in its discretion. Holdings of related customer accounts may be aggregated for purposes of determining the minimum investment amount. “Related customer accounts” may include, but are not limited to, accounts held by the same investment or retirement plan, financial institution, broker, dealer or intermediary. The Fund and the Adviser reserve the right to increase or decrease the minimum amount required to open or maintain an account. There is no minimum subsequent investment, except in relation to maintaining certain minimum account balances (See “Redeeming Shares” below).The Fund requires prior notification of subsequent investments in excess of $50 million. The Fund reserves the right to cease accepting investments at any time or to reject any investment order. The Fund may limit the amount of a purchase order received after 3:00 p.m. ET.

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How to Purchase Shares

By Mail:

By Overnight:

State Street Funds
430 W 7 ^th Street Suite 219737
Kansas City, MO 64105-1407

By Telephone/Fax:

For your initial investment, send the original, signed Institutional Account Application Form to the address above.

Wire Instructions:

Instruct your bank to transfer money by Federal Funds wire to:
State Street Bank and Trust Company
1 Iron Street
Boston, MA 02110

ABA# 011000028
DDA# 9904-631-0
State Street Institutional Investment Trust
Fund Name
Account Number
Account Registration

Redeeming Shares

An investor may redeem all or any portion of its investment. Redemption orders are processed at the NAV next determined after the Fund receives a redemption order in good form.

If the Fund receives a redemption order in good form prior to 5:00 p.m. ET on a Business Day, the Fund typically expects to pay out redemption proceeds on that day, but no later than next Business Day if redemption proceeds are sent by wire or ACH. If redemption proceeds are sent by check, the Fund typically expects to pay out redemption proceeds on the next Business Day. If a redemption order is placed after 5:00 p.m. ET, the Fund typically expects to pay out redemption proceeds on the next Business Day (and dividends will accrue up to, but not including, the day that redemption proceeds are sent). The Fund reserves the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Fund.

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A request for a partial redemption by an investor whose account balance is below the minimum amount or a request for partial redemption by an investor that would bring the account below the minimum amount may be treated as a request for a complete redemption of the account. These minimums may be different for investments made through certain financial intermediaries as determined by their policies and may be waived in the Adviser's discretion. The Fund reserves the right to modify minimum account requirements at any time with or without prior notice. The Fund also reserves the right to involuntarily redeem an investor's account if the investor's account balance falls below the applicable minimum amount due to transaction activity.

How to Redeem Shares


By Mail:	Send a signed letter to: State Street Institutional Investment Trust Funds P.O. Box 219737 Kansas City, MO 64121-9737
	The letter should include information necessary to process your request as described below. The Fund may require a medallion guarantee in certain circumstances. See “Medallion Guarantees” below.
By Overnight:	State Street Institutional Investment Trust Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407
By Telephone:	Please call (866) 392-0869 between the hours of 7:00 a.m. and 5:00 p.m. ET.
The Fund will need the following information to process your redemption request:
➣ name(s) of account owners; ➣ account number(s); ➣ the name of the Fund; ➣ your daytime telephone number; and ➣ the dollar amount or number of shares being redeemed.

On any day that the Fund calculates its NAV earlier than normal, the Fund reserves the right to adjust the times noted above for purchasing and redeeming shares.

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Medallion Guarantees . Certain redemption requests must include a medallion guarantee for each registered account owner if any of the following apply:

•	Your account address has changed within the last 10 business days.
•	Redemption proceeds are being transferred to an account with a different registration.
•	A wire is being sent to a financial institution other than the one that has been established on your Fund account.
•	Other unusual situations as determined by the Transfer Agent.

The Fund reserves the right to waive medallion guarantee requirements, require a medallion guarantee under other circumstances or reject or delay redemption if the medallion guarantee is not in good form. Medallion guarantees may be provided by an eligible financial institution such as a commercial bank, a FINRA member firm such as a stock broker, a savings association or a national securities exchange. A notary public cannot provide a medallion guarantee. The Fund reserves the right to reject a medallion guarantee if it is not provided by a STAMP Medallion guarantor.

The Fund may terminate the receipt of redemption orders by telephone at any time, in which case you may redeem shares by other means.

If you choose to purchase or redeem shares by sending instructions by regular mail, they will not be deemed received in good order until they are released by the post office and redelivered to the Transfer Agent's physical location at 430 W 7th Street Suite 219737 in Kansas City, MO 64105-1407. There will be a time lag, which may be one or more days, between regular mail receipt at the post office box and redelivery to such physical location in Kansas City, and the Fund's NAV may change over those days. You might consider using express rather than regular mail if you believe the time of receipt of your transaction request to be sensitive.

Exchanging Shares

Currently, exchanging shares from/to this Fund to any other State Street Fund is not permitted.

Excessive Trading

Delivery of Documents to Accounts Sharing an Address

To reduce expenses, we may mail only one copy of the Fund's Prospectus and the annual and semi-annual report to those addresses shared by two or more accounts. If you wish to receive individual copies of these documents, please call us at (877) 521-4083, or contact your financial institution. We will begin sending you individual copies thirty (30) days after receiving your request.

Unclaimed Property

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a State Street Fund identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

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If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the representative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Fund (if you hold shares directly with the Fund) or to your financial intermediary (if you do not hold shares directly with the Fund).

Dividends, Distributions and Tax Considerations

The Fund invests substantially all of its investible assets in a corresponding Portfolio that is treated as a partnership for U.S. federal income tax purposes. The nature and character of the Fund's income, gains, losses and deductions generally will be determined at the Portfolio level, and each Fund will be allocated its share of the corresponding Portfolio's income, gains, losses and deductions. As applicable, references in this discussion to income, gains and losses of the Fund will be to income, gains and losses recognized and deductions accruing at the Portfolio level and allocated to or otherwise taken into account by the Fund, and references to assets of the Fund will be to the Fund's allocable share of the assets of the corresponding Portfolio.

The Fund's income from or proceeds of investments in non-U.S. assets may be subject to non- U.S. withholding and other taxes. This will decrease the Fund's return on securities subject to such taxes. Tax treaties between certain countries and the U.S. may reduce or eliminate such taxes. Although such taxes will reduce the Fund's taxable income, shareholders generally will not be entitled separately to claim a credit or deduction with respect to foreign taxes incurred by the Fund.

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An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by the Fund and net gains recognized on the redemption of shares of the Fund.

Financial Intermediary Arrangements

Payments to Financial Intermediaries

The Financial Intermediary is often compensated by SSGA FD or its affiliates for the services it performs and in such cases is typically paid continually over time, during the period when the Financial Intermediary's clients hold investments in the Fund. The amount of continuing compensation paid by SSGA FD or its affiliates to different Financial Intermediaries for distribution and/or shareholder services varies. Any compensation is typically a percentage of the value of the Financial Intermediary's clients' investments in the Fund or a per account fee. The variation in compensation may, but will not necessarily, reflect enhanced or additional services provided by the Financial Intermediary.

If you invest through a Financial Intermediary and meet the eligibility criteria for more than one share class, you should discuss with your Financial Intermediary which share class is appropriate for you. Your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend one share class over another, when you are eligible to invest in more than one share class. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by the Fund or its affiliates with respect to the different share classes offered by the Fund.

SSGA FD and its affiliates (including SSGA FM), at their own expense and out of their own assets, may also provide other compensation to Financial Intermediaries in connection with sales of the Fund's shares or the servicing of shareholders or shareholder accounts. Such compensation may include, but is not limited to, financial assistance to Financial Intermediaries in connection with conferences, sales, or training programs for their employees; seminars for the public; advertising or sales campaigns; or other Financial Intermediary-sponsored special events. In some instances, this compensation may be made available only to certain Financial Intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the Fund's shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as FINRA.

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Financial Highlights

The financial highlight tables are intended to help you understand the Fund's financial performance since the Treasury Obligations Money Market Fund's inception. Certain information reflects the performance results for a single Fund Share. The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in the Fund (assuming reinvestment of all dividends and distributions). This information has been audited by Ernst & Young LLP, the Trust's independent registered public accounting firm, whose report, along with the Fund's financial highlights and financial statements, is included in the annual report to shareholders, which is available upon request. Any references to Notes in these financial highlight tables refer to the “Notes to Financial Statements” section of the Fund's financial statements, and the financial information included in these tables should be read in conjunction with the financial statements incorporated by reference in the SAI.

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STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET TREASURY OBLIGATIONS MONEY MARKET FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period


	Year Ended 12/31/18(a)	For the Period 10/5/17* - 12/31/17(a)
Net asset value, beginning of period	$ 1.0000	$ 1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0178	0.0025
Total from investment operations	0.0178	0.0025
Distributions to shareholders from:
Net investment income	(0.0178)	(0.0025)
Total distributions	(0.0178)	(0.0025)
Net asset value, end of period	$ 1.0000	$ 1.0000
Total return (b)	1.79%	0.25%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$3,620,569	$2,926,362
Ratios to average net assets:
Total expenses	0.13%	0.16%(c)
Net expenses	0.08%	0.08%(c)
Net investment income (loss)	1.77%	1.08%(c)

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates. Total return for periods of less than one year is not annualized. Results represent past performance and are not indicative of future results.
(c)	Annualized.

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Contacting the State Street Funds

Online:	www.ssga.com/cash	24 hours a day, 7 days a week
Phone:	(877) 521-4083	Monday – Friday 7:00 am – 5:00 pm EST

Written requests should be sent to:

Regular mail	Overnight/ Registered, Express, Certified Mail
State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737	State Street Funds 430 W 7 ^th Street Suite 219737 Kansas City, MO 64105-1407

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For more information about the Fund:

The Fund's SAI includes additional information about the Fund and is incorporated by reference into this document. Additional information about the Fund's investments is available or will be available, in the Fund's most recent annual and semi-annual reports to shareholders. The Fund's SAI is available, without charge, upon request. The Fund's annual and semi-annual reports are available, or will be available, without charge, upon request. Shareholders in the Fund may make inquiries to the Fund to receive such information by calling (877) 521-4083 or the customer service center at the telephone number shown in the accompanying contract prospectus, if applicable. The Fund's Prospectus and SAI are available, and the annual and semi-annual reports to shareholders are available, free of charge, on the Funds' website at www.ssga.com/cash.

SSGA Funds Management, Inc .

ONE IRON STREET

BOSTON, MASSACHUSETTS 02210

TAQXXSTATPRO

The State Street Institutional Investment Trust's Investment Company Act File Number is 811-09819.

STATE STREET INSTITUTIONAL INVESTMENT TRUST

(the “Trust”)

One Iron Street

Boston, Massachusetts 02210

STATEMENT OF ADDITIONAL INFORMATION

April 30, 2019

STATE STREET INSTITUTIONAL LIQUID RESERVES FUND

Premier Class (SSIXX)

Investment Class (SSVXX)

Service Class (LRSXX)

Institutional Class (SSHXX)

Investor Class (SSZXX)

Administration Class (SSYXX)

Trust Class (TILXX)

STATE STREET INSTITUTIONAL U.S. GOVERNMENT MONEY MARKET FUND

Premier Class (GVMXX)

Investment Class (GVVXX)

Service Class (GVSXX)

Institutional Class (SAHXX)

Investor Class (SAMXX)

Administration Class (SALXX)

Class G (SSOXX)

Class M (GOMXX)

STATE STREET INSTITUTIONAL TREASURY MONEY MARKET FUND

Premier Class ( TRIXX)

Investment Class (TRVXX)

Service Class (TYSXX)

Institutional Class (SSJXX)

Investor Class (SSNXX)

Administration Class (SSKXX)

STATE STREET INSTITUTIONAL TREASURY PLUS MONEY MARKET FUND

Premier Class (TPIXX)

Investment Class (TPVXX)

Service Class (TPSXX)

Institutional Class (SAJXX)

Investor Class (SAEXX)

Administration Class (SSQXX)

Trust Class (TPLXX)

STATE STREET TREASURY OBLIGATIONS MONEY MARKET FUND (TAQXX)

STATE STREET ULTRA SHORT TERM BOND FUND

Institutional Class (SSTUX)

Investment Class (SSUTX)

This Statement of Additional Information (“SAI”) relates to the prospectuses dated April 30, 2019 as may be revised and/or supplemented from time to time thereafter for each of the Funds listed above (each, a “Prospectus” and collectively, the “Prospectuses”).

The SAI is not a prospectus and should be read in conjunction with the Prospectuses. A copy of each Prospectus can be obtained free of charge by calling (877) 521-4083 or by written request to the Trust at the address listed above.

The Trust’s audited financial statements for the fiscal year ended December 31, 2018, including the independent registered public accounting firm reports thereon, are included in the Trust’s annual reports and are incorporated into this SAI by reference. Copies of the Trust’s annual reports and semiannual reports are available, without charge, upon request, by calling (877) 521-4083 or by written request to the Trust at the address above.

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General			3
Description of the Funds and Their Investments and Risks			4
Additional Investments and Risks			4
Management of the Trust and State Street Master Funds			16
Proxy Voting Procedures			26
Control Persons and Principal Holders of Securities			26
Investment Advisory and Other Services			32
Portfolio Managers			40
Brokerage Allocation and Other Practices			41
Declaration of Trust, Capital Stock and Other Information			43
Pricing of Shares			44
Taxation of the Funds			45
Underwriter			55
Financial Statements			55
Appendix A – Ratings of Debt Instruments			A-1
Appendix B – Trust’s Proxy Voting Procedures			B-1
Appendix C – Adviser’s Proxy Voting Procedures and Guidelines			C-1

GENERAL

The Trust was organized as a business trust under the laws of The Commonwealth of Massachusetts on February 16, 2000.

The Trust is an open-end management investment company. The Trust includes the following diversified series:

•

State Street Equity 500 Index Fund;

•

State Street Aggregate Bond Index Fund;

•

State Street Institutional Liquid Reserves Fund (the “ILR Fund”);

•

State Street Institutional U.S. Government Money Market Fund (the “U.S. Government Fund”);

•

State Street Institutional Treasury Money Market Fund (the “Treasury Fund”);

•

State Street Institutional Treasury Plus Money Market Fund (the “Treasury Plus Fund”);

•

State Street Treasury Obligations Money Market Fund (the “Treasury Obligations Fund”);

•

State Street Target Retirement Fund;

•

State Street Target Retirement 2015 Fund;

•

State Street Target Retirement 2020 Fund;

•

State Street Target Retirement 2025 Fund;

•

State Street Target Retirement 2030 Fund;

•

State Street Target Retirement 2035 Fund;

•

State Street Target Retirement 2040 Fund;

•

State Street Target Retirement 2045 Fund;

•

State Street Target Retirement 2050 Fund;

•

State Street Target Retirement 2055 Fund;

•

State Street Target Retirement 2060 Fund;

•

State Street Global Equity ex-U.S. Index Fund;

•

State Street Equity 500 Index II Portfolio;

•

State Street Aggregate Bond Index Portfolio;

•

State Street Global Equity ex-U.S. Index Portfolio;

•

State Street Emerging Markets Equity Index Fund;

•

State Street Hedged International Developed Equity Index Fund;

•

State Street International Developed Equity Index Fund;

•

State Street Small/Mid Cap Equity Index Fund;

•

State Street Small/Mid Cap Equity Index Portfolio;

•

State Street Cash Reserves Fund

•

State Street Cash Reserves Portfolio

•

State Street Ultra Short Term Bond Fund (the “Ultra Short Bond Fund”);

•

State Street Ultra Short Term Bond Portfolio (the “Ultra Short Bond Portfolio”);

•

State Street Defensive Global Equity Fund;

The Trust includes the following non-diversified series:

•

State Street International Value Spotlight Fund;

•

State Street China Equity Select Fund

The ILR Fund, Treasury Fund, Treasury Plus Fund, and U.S. Government Fund are referred to in this SAI as the “Money Funds,” “Money Market Funds,” or the “Funds.” The Treasury Fund, Treasury Plus Fund and the Treasury Obligations Fund are also sometimes separately referred to in this SAI as the “Treasury Funds.” Each of the Money Market Funds and the Ultra Short Bond Fund may be referred to in context as the “Fund” as appropriate.

Each Fund listed below as a feeder fund (each a “Feeder Fund” and collectively the “Feeder Funds”) seeks to achieve its investment objective by investing substantially all of its investable assets in a corresponding master portfolio in the Trust or, as indicated below, the State Street Master Funds that has substantially similar investment strategies to those of the Feeder Fund. The table below shows the respective Portfolio in which each Feeder Fund invests. All Portfolios together are referred to in this SAI as the “Portfolios” and each Portfolio may be referred to in context as the “Portfolio” as appropriate.


Feeder Fund		Master Portfolio
ILR Fund		State Street Money Market Portfolio (“Money Market Portfolio”)*
U.S. Government Fund		State Street U.S. Government Money Market Portfolio (“U.S. Government Portfolio”)*
Treasury Fund		State Street Treasury Money Market Portfolio (“Treasury Portfolio”)*
Treasury Plus Fund		State Street Treasury Plus Money Market Portfolio (“Treasury Plus Portfolio”)*
Treasury Obligations Fund		Treasury Plus Portfolio*
Ultra Short Bond Fund		Ultra Short Bond Portfolio

*	This Portfolio is in the State Street Master Funds.

The Money Market Portfolio, Treasury Portfolio, Treasury Plus Portfolio and U.S. Government Portfolio are referred to in this SAI as the “Money Portfolios,” or “Money Market Portfolios.” The Treasury Portfolio and Treasury Plus Portfolio are also sometimes separately referred to in this SAI as the “Treasury Portfolios.”

Trust Class shares of the ILR Fund are issued only to former shareholders of SSGA Prime Money Market Fund and SSGA Money Market Fund, each a series of SSGA Funds. Trust Class shares of the Treasury Plus Fund are issued only to former shareholders of SSGA U.S. Treasury Money Market Fund, a series of SSGA Funds.

DESCRIPTION OF THE FUNDS AND THEIR INVESTMENTS AND RISKS

Each Fund’s Prospectus contains information about the investment objective and policies of that Fund. This SAI should only be read in conjunction with the Prospectus of the Fund or Funds in which you intend to invest.

In addition to the principal investment strategies and the principal risks of the Funds and Portfolios described in each Fund’s Prospectus, a Fund or Portfolio may employ other investment practices and may be subject to additional risks, which are described below. In reviewing these practices of the Feeder Funds, you should assume that the practices of the corresponding Portfolio are the same in all material respects.

ADDITIONAL INVESTMENTS AND RISKS

To the extent consistent with its investment objective and restrictions, each Fund or Portfolio may invest in the following instruments and use the following techniques, and is subject to the following additional risks.

Auction Rate Securities.

Auction rate municipal securities permit the holder to sell the securities in an auction at par value at specified intervals. The dividend or interest is typically reset by “Dutch” auction in which bids are made by broker-dealers and other institutions for a certain amount of securities at a specified minimum yield. The rate set by the auction is the lowest interest or dividend rate that covers all securities offered for sale. While this process is designed to permit auction rate securities to be traded at par value, there is the risk that an auction will fail due to insufficient demand for the securities. A Portfolio will take the time remaining until the next scheduled auction date into account for purposes of determining the securities’ duration.

Cash Reserves

A Fund may hold portions of its assets in cash or short-term debt instruments with remaining maturities of 397 days or less pending investment or to meet anticipated redemptions and day-to-day operating expenses. Short-term debt instruments consist of: (i) short-term obligations of the U.S. Government, its agencies, instrumentalities, authorities or political subdivisions; (ii) other short-term debt securities rated at the time of purchase Aa or higher by Moody’s Investors Service, Inc. (“Moody’s”) or AA or higher by Standard & Poor’s Rating Group (“S&P”) or, if unrated, of comparable quality in the opinion of SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”); (iii) commercial paper; (iv) bank obligations, including negotiable certificates of deposit, time deposits and bankers’ acceptances; and (v) repurchase agreements.

Cleared Derivatives Transactions

Transactions in some types of swaps are required to be centrally cleared. In a cleared derivatives transaction, a Portfolio’s counterparty to the transaction is a central derivatives clearing organization, or clearing house, rather than a bank or broker. Because the Portfolios are not members of a clearing house, and only members of a clearing house can participate directly in the clearing house, the Portfolios hold cleared derivatives through accounts at clearing members. In cleared derivatives transactions, a Portfolio will make payments (including margin payments) to and receive payments from a clearing house through its accounts at clearing members. Clearing members guarantee performance of their clients’ obligations to the clearing house. Centrally cleared derivative arrangements may be less favorable to a Portfolio than bilateral (non-cleared) arrangements. For example, a Portfolio may be required to provide greater amounts of margin for cleared derivatives transactions than for bilateral derivatives transactions. Also, in contrast to bilateral derivatives transactions, in some cases following a period of notice to a Portfolio, a clearing member generally can require termination of existing cleared derivatives transactions at any time or an increase in margin requirements above the margin that the clearing member required at the beginning of a transaction. Clearing houses also have broad rights to increase margin requirements for existing transactions or to terminate transactions at any time. Each Portfolio is subject to risk if it enters into a derivatives transaction that is required to be cleared (or which the Adviser expects to be cleared), and no clearing member is willing or able to clear the transaction on the Portfolio’s behalf. In that case, the transaction might have to be terminated, and the Portfolio could lose some or all of the benefit of the transaction, including loss of an increase in the value of the transaction and loss of hedging protection. In addition, the documentation governing the relationship between the Portfolios and clearing members is drafted by the clearing members and generally is less favorable to the Portfolios than typical bilateral derivatives documentation. For example, documentation relating to cleared derivatives generally includes a one-way indemnity by the Portfolio in favor of the clearing member for losses the clearing member incurs as the Portfolio’s clearing member. Also, such documentation typically does not provide the Portfolio any remedies if the clearing member defaults or becomes insolvent.

Counterparty risk with respect to derivatives has been and will continue to be affected by new rules and regulations relating to the derivatives market. With respect to a centrally cleared transaction, a party is subject to the credit risk of the clearing house and the clearing member through which it holds its cleared position. Credit risk of market participants with respect to centrally cleared derivatives is concentrated in a few clearing houses, and it is not clear how an insolvency proceeding of a clearing house would be conducted and what impact an insolvency of a clearing house would have on the financial system. A clearing member is obligated by contract and regulation to segregate all funds received from customers with respect to cleared derivatives positions from the clearing member’s proprietary assets. However, all funds and other property received by a clearing member from its customers with respect to cleared derivatives are generally held by the clearing member on a commingled basis in an omnibus account (which can be invested in instruments permitted under the regulations). Therefore, a Portfolio might not be fully protected in the event of the bankruptcy of the Portfolio’s clearing member because the Portfolio would be limited to recovering only a pro rata share of the funds held by the clearing member on behalf of customers, with a claim against the clearing member for any deficiency. Also, the clearing member is required to transfer to the clearing house the amount of margin required by the clearing house for cleared derivatives, which amount is generally held in an omnibus account at the clearing house for all customers of the clearing member. Regulations promulgated by the CFTC require that the clearing member notify the clearing house of the initial margin provided by the clearing member to the clearing house that is attributable to each customer. However, if the clearing member does not accurately report the Portfolio’s initial margin, the Portfolio is subject to the risk that a clearing house will use the assets attributable to it in the clearing house’s omnibus account to satisfy payment obligations a defaulting customer of the clearing member has to the clearing house. In addition, clearing members generally provide the clearing house the net amount of variation margin required for cleared swaps for all of its customers, rather than individually for each customer. A Portfolio is therefore subject to the risk that a clearing house will not make variation margin payments owed to the Portfolio if another customer of the clearing member has suffered a loss and is in default, and the risk that the Portfolio will be required to provide additional variation margin to the clearing house before the clearing house will move the Portfolio’s cleared derivatives positions to another clearing member. In addition, if a clearing member does not comply with the applicable regulations or its agreement with the Portfolio, or in the event of fraud or misappropriation of customer assets by a clearing member, the Portfolio could have only an unsecured creditor claim in an insolvency of the clearing member with respect to the margin held by the clearing member.

Swap Execution Facilities

losses or costs that may be incurred as a result of the Portfolio’s transactions on the SEF. In addition, a Portfolio may be subject to execution risk if it enters into a derivatives transaction that is required to be cleared, and no clearing member is willing to clear the transaction on the Portfolio’s behalf. In that case, the transaction might have to be terminated, and the Portfolio could lose some or all of the benefit of any increase in the value of the transaction after the time of the trade.

Risks Associated with Derivatives Regulation

The U.S. government has enacted legislation that provides for new regulation of the derivatives market, including clearing, margin, reporting, and registration requirements. The European Union and some other countries are implementing similar requirements, which will affect a Portfolio when it enters into a derivatives transaction with a counterparty organized in that country or otherwise subject to that country’s derivatives regulations. Clearing rules and other new rules and regulations could, among other things, restrict a Portfolio’s ability to engage in, or increase the cost to the Portfolio of, derivatives transactions, for example, by making some types of derivatives no longer available to the Portfolio, increasing margin or capital requirements, or otherwise limiting liquidity or increasing transaction costs. While the new rules and regulations and central clearing of some derivatives transactions are designed to reduce systemic risk (i.e., the risk that the interdependence of large derivatives dealers could cause them to suffer liquidity, solvency or other challenges simultaneously), there is no assurance that they will achieve that result, and in the meantime, as noted above, central clearing and related requirements expose the Portfolios to new kinds of costs and risks.

For example, in the event of a counterparty’s (or its affiliate’s) insolvency, a Portfolio’s ability to exercise remedies, such as the termination of transactions, netting of obligations and realization on collateral, could be stayed or eliminated under new special resolution regimes adopted in the United States, the European Union and various other jurisdictions. Such regimes provide government authorities with broad authority to intervene when a financial institution is experiencing financial difficulty. In particular, with respect to counterparties who are subject to such proceedings in the European Union, the liabilities of such counterparties to the Portfolios could be reduced, eliminated, or converted to equity in such counterparties (sometimes referred to as a “bail in”).

Additionally, U.S. regulators, the EU and certain other jurisdictions have adopted minimum margin and capital requirements for uncleared derivatives transactions. These rules impose minimum margin requirements on derivatives transactions between a Portfolio and its counterparties. They impose regulatory requirements on the timing of transferring margin and the types of collateral that parties are permitted to exchange.

These and other regulations are new and evolving, so their potential impact on the Portfolios and the financial system are not yet known.

Custodial Risk

There are risks involved in dealing with the custodians or brokers who hold a Portfolio’s investments or settle a Portfolio’s trades. It is possible that, in the event of the insolvency or bankruptcy of a custodian or broker, a Portfolio would be delayed or prevented from recovering its assets from the custodian or broker, or its estate, and may have only a general unsecured claim against the custodian or broker for those assets. In recent insolvencies of brokers or other financial institutions, the ability of certain customers to recover their assets from the insolvent’s estate has been delayed, limited, or prevented, often unpredictably, and there is no assurance that any assets held by a Portfolio with a custodian or broker will be readily recoverable by the Portfolio. In addition, there may be limited recourse against non-U.S. sub-custodians in those situations in which a Portfolio invests in markets where custodial and/or settlement systems and regulations are not fully developed, including emerging markets, and the assets of the Portfolio have been entrusted to such sub-custodians. SSGA FM or an affiliate may serve as the custodian of the Portfolios.

Eurodollar Certificates of Deposit (“ECDs”), Eurodollar Time Deposits (“ETDs”) and Yankee Certificates of Deposit (“YCDs”)

The Money Market Portfolios may invest in ECDs, ETDs and YCDs. ECDs and ETDs are U.S. dollar denominated certificates of deposit and time deposits, respectively, issued by non-U.S. branches of domestic banks and non-U.S. banks. YCDs are U.S. dollar denominated certificates of deposit issued by U.S. branches of non-U.S. banks.

Different risks than those associated with the obligations of domestic banks may exist for ECDs, ETDs and YCDs because the banks issuing these instruments, or their domestic or non-U.S. branches, are not necessarily subject to the same regulatory requirements that apply to domestic banks, such as loan limitations, examinations, and reserve, accounting, auditing, recordkeeping and public reporting requirements. Obligations of non-U.S. issuers also involve risks such as future unfavorable political and economic developments, withholding tax, seizures of non-U.S. deposits, currency controls, interest limitations, and other governmental restrictions that might affect repayment of principal or payment of interest, or the ability to honor a credit commitment.

Forward Commitments

Each Fund may invest in forward commitments. Each Fund may contract to purchase securities for a fixed price at a future date beyond customary settlement time consistent with the Fund’s ability to manage its investment portfolio and meet redemption requests. A Fund may dispose of a commitment prior to settlement if it is appropriate to do so and realize short-term profits or losses upon such sale. When effecting such transactions, cash or other liquid assets (such as liquid high quality debt obligations) held by a Fund of a dollar amount sufficient to make payment for the portfolio securities to be purchased will be segregated on the Fund’s records at the trade date and maintained until the transaction is settled. Such segregated assets will be marked to market on a daily basis, and if the market value of such assets declines, additional cash or assets will be segregated so that the market value of the segregated assets will equal the amount of such Fund’s obligations. Forward commitments involve a risk of loss if the value of the security to be purchased declines prior to the settlement date, or if the other party fails to complete the transaction.

Government Mortgage-Related Securities

The Government National Mortgage Association (“GNMA” or “Ginnie Mae”) is the principal federal government guarantor of mortgage-related securities. GNMA is a wholly owned U.S. Government corporation within the Department of Housing and Urban Development. It guarantees, with the full faith and credit of the United States, full and timely payment of all monthly principal and interest on its mortgage-related securities. GNMA pass-through securities are considered to have a relatively low risk of default in that (1) the underlying mortgage loan portfolio is comprised entirely of government-backed loans and (2) the timely payment of both principal and interest on the securities is guaranteed by the full faith and credit of the U.S. Government, regardless of whether they have been collected. GNMA pass-through securities are, however, subject to the same interest rate risk as comparable privately issued mortgage-related securities. Therefore, the effective maturity and market value of a Portfolio’s GNMA securities can be expected to fluctuate in response to changes in interest rate levels.

Residential mortgage loans are also pooled by the Federal Home Loan Mortgage Corporation (“FHLMC” or “Freddie Mac”), a corporate instrumentality of the U.S. Government. The mortgage loans in FHLMC’s portfolio are not government backed; FHLMC, not the U.S. Government, guarantees the timely payment of interest and ultimate collection of principal on FHLMC securities. FHLMC also issues guaranteed mortgage certificates, on which it guarantees semiannual interest payments and a specified minimum annual payment of principal.

The Federal National Mortgage Association (“FNMA” or “Fannie Mae”) is a government-sponsored corporation owned entirely by private stockholders. It is subject to general regulation by the Secretary of Housing and Urban Development. FNMA purchases residential mortgages from a list of approved seller/servicers, which include savings and loan associations, savings banks, commercial banks, credit unions and mortgage bankers. Pass-through securities issued by FNMA are guaranteed as to timely payment of principal and interest only by FNMA, not the U.S. Government.

Illiquid Securities

Each Portfolio, except for the Treasury Portfolio, may invest in illiquid securities. The absence of a regular trading market for illiquid securities imposes additional risks on investments in these securities. Illiquid securities may be difficult to value and may often be disposed of only after considerable expense and delay.

Each Money Market Portfolio (and Money Market Fund) is managed in accordance with Rule 2a-7 under the Investment Company Act of 1940, as amended (the “1940 Act”). As a result, each Money Market Portfolio (and Money Market Fund) has adopted the following liquidity policies (except as noted):

The Portfolio/Fund may not purchase an illiquid security if, immediately after purchase, the Portfolio/Fund would have invested more than 5% of its total assets in illiquid securities (securities that cannot be sold or disposed of in the ordinary course of business within seven days at approximately the market value ascribed to them by the Portfolio/Fund);

The Portfolio/Fund may not purchase a security other than a security offering daily liquidity if, immediately after purchase, the Portfolio/Fund would have invested less than 10% of its total assets in securities offering daily liquidity (includes securities that mature or are subject to demand within one business day, cash, direct U.S. Government obligations or amounts receivable and due unconditionally within one business day on pending sales of portfolio securities); and

The Portfolio/Fund may not purchase a security other than a security offering weekly liquidity if, immediately after purchase, the Portfolio/Fund would have invested less than 30% of its total assets in securities offering weekly liquidity (includes securities that mature or are subject to demand within five business days, cash, direct U.S. Government obligations, Government agency discount notes with remaining maturities of 60 days or less or amounts receivable and due unconditionally within five business days on pending sales of portfolio securities).

Under Rule 2a-7, “illiquid security” means a security that cannot be sold or disposed of in the ordinary course of business within seven calendar days at approximately the value ascribed to it by the seller.

The Ultra Short Bond Portfolio (and its corresponding Fund) will not acquire any illiquid investment if, immediately after the acquisition, the Portfolio/Fund would have invested more than 15% of its net assets in illiquid investments that are assets. For purposes of this restriction, an “illiquid investment” is any investment that the Portfolio/Fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment.

Industrial Development and Private Activity Bonds

Industrial development bonds are issued to finance a wide variety of capital projects including: electric, gas, water and sewer systems; ports and airport facilities; colleges and universities; and hospitals. The principal security for these bonds is generally the net revenues derived from a particular facility, group of facilities, or in some cases, the proceeds of a special excise tax or other specific revenue sources. Although the principal security behind these bonds may vary, many provide additional security in the form of a debt service reserve fund whose money may be used to make principal and interest payments on the issuer’s obligations. Some authorities provide further security in the form of a state’s ability without obligation to make up deficiencies in the debt service reserve fund.

Private activity bonds are considered municipal securities if the interest paid thereon is exempt from federal income tax and they are issued by or on behalf of public authorities to raise money to finance various privately operated facilities for business and manufacturing, housing, sports, and pollution control. These bonds are also used to finance public facilities such as airports, mass transit systems, ports and parking. The payment of the principal and interest on such bonds is dependent solely on the ability of the facility’s user to meet its financial obligations and the value of any real or personal property pledged as security for such payment. Interest income on these bonds may be an item of tax preference subject to federal alternative minimum tax for individuals and corporations.

Insured Municipal Securities

Insured municipal securities are those for which scheduled payments of interest and principal are guaranteed by a private (non-governmental) insurance company. The insurance entitles a fund to receive only the face or par value of the securities held by the fund, but the ability to be paid is limited to the claims paying ability of the insurer. The insurance does not guarantee the market value of the municipal securities or the net asset value of a Portfolio’s shares. Insurers are selected based upon the diversification of their portfolios and the strength of the management team which contributes to the claims paying ability of the entity. However, the Adviser selects securities based upon the underlying credit, with bond insurance viewed as an enhancement only. The Adviser’s objective is to have an enhancement that provides additional liquidity to insulate against volatility in changing markets.

Investment-Grade Bonds

The Money Market Portfolio may invest in corporate notes and bonds that are rated investment-grade by a nationally recognized statistical rating organization (“NRSRO”) (and, in the case of the Money Market Portfolio, rated in one of the two short-term highest rating categories by at least two NRSROs or by one NRSRO if only one NRSRO has rated the security) or, if unrated, are of comparable quality to the rated securities described above, as determined by the Adviser, in accordance with procedures established by the Board of Trustees. Investment-grade securities include securities rated Baa by Moody’s or BBB- by S&P (and securities of comparable quality); securities rated Baa by Moody’s or BBB by S&P may have speculative characteristics.

Market Disruption and Geopolitical Risk

The Portfolios are subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets. War, terrorism, and related geopolitical events have led, and in the future may lead, to increased short-term market volatility and may have adverse long-term effects on U.S. and world economies and markets generally. Likewise, natural and environmental disasters and systemic market dislocations may be highly disruptive to economies and markets. Those events as well as other changes in non-U.S. and domestic economic and political conditions also could adversely affect individual issuers or related groups of issuers, securities markets, interest rates, credit ratings, inflation, investor sentiment, and other factors affecting the value of a Portfolio’s investments. Given the increasing interdependence between global economies and markets, conditions in one country, market, or region might adversely impact markets, issuers and/or foreign exchange rates in other countries, including the U.S. Continuing uncertainty as to the status of the Euro and the European Monetary Union (the “EMU”) has created significant volatility in currency and financial markets generally. Any partial or complete dissolution of the EMU, or any continued uncertainty as to its status, could have significant adverse effects on currency and financial markets, and on the values of a Portfolio’s investments.

Mortgage-Related Securities

The Portfolios, except for the Treasury Portfolios, may invest in mortgage-related securities. Mortgage-related securities represent an interest in a pool of, or are secured by, mortgage loans. Mortgage-related securities may be issued or guaranteed by (i) U.S. Government agencies or instrumentalities such as GNMA, FNMA and FHLMC or (ii) other issuers, including private companies.

Many mortgage-related securities provide regular payments which consist of interest and, in most cases, principal. In contrast, other forms of debt securities normally provide for periodic payment of interest in fixed amounts with principal payments at maturity or specified call dates. In effect, payments on many mortgage-related securities are a “pass-through” of the payments made by the individual borrowers on their mortgage loans, net of any fees paid to the issuer or guarantor of such securities.

Because of the possibility of prepayments (and due to scheduled repayments of principal), mortgage-related securities are less effective than other types of securities as a means of “locking in” attractive long-term interest rates. Prepayments would have to be reinvested at lower rates. As a result, these securities may have less potential for capital appreciation during periods of declining interest rates than other securities of comparable maturities, although they may have a similar risk of decline in market value during periods of rising interest rates. Prepayments may also significantly shorten the effective maturities of these securities, especially during periods of declining interest rates. Conversely, during periods of rising interest rates, a reduction in prepayments may increase the effective maturities of these securities, subjecting them to a greater risk of decline in market value in response to rising interest rates than traditional debt securities, and, therefore, potentially increasing the volatility of the Portfolios.

Collateralized mortgage obligations (“CMOs”) may be issued by a U.S. Government agency or instrumentality or by a private issuer. CMOs are typically structured with classes or series that have different maturities and are generally retired in sequence. Each class of obligations receives periodic interest payments according to its terms. However, monthly principal payments and any prepayments from the collateral pool are generally paid first to the holders of the most senior class. Thereafter, payments of principal are generally allocated to the next most senior class of obligations until that class of obligations has been fully repaid. Any or all classes of obligations of a CMO may be paid off sooner than expected because of an increase in the payoff speed of the pool. Changes in prepayment rates may have significant effects on the values and the volatility of the various classes and series of a CMO. Payment of interest or principal on some classes or series of a CMO may be subject to contingencies or some classes or series may bear some or all of the risk of default on the underlying mortgages. Stripped mortgage-related securities are usually structured with two classes that receive different portions of the interest and principal distributions on a pool of mortgage loans. The yield to maturity on an interest only or “IO” class of stripped mortgage-related securities is extremely sensitive not only to changes in prevailing interest rates but also to the rate of principal payments (including prepayments) on the underlying assets. A rapid rate of principal prepayments may have a measurable adverse effect on a Fund’s yield to maturity to the extent it invests in IOs. If the assets underlying the IO experience greater than anticipated prepayments of principal, the Fund may fail to recoup fully, or at all, its initial investment in these securities. Conversely, principal only securities or “POs” tend to increase in value if prepayments are greater than anticipated and decline if prepayments are slower than anticipated. The secondary market for stripped mortgage-related securities may be more volatile and less liquid than that for other mortgage-related securities, potentially limiting a Portfolio’s ability to buy or sell those securities at any particular time.

Municipal and Municipal-Related Securities

The Portfolios may invest in municipal and municipal-related securities. Municipal securities may bear fixed, floating or variable rates of interest or may be zero coupon securities. Municipal securities are generally of two types: general obligations and revenue obligations. General obligations are backed by the full faith and credit of the issuer. These securities include tax anticipation notes, bond anticipation notes, general obligation bonds and commercial paper. Revenue obligations are backed by the revenues generated from a specific project or facility and include industrial development bonds and private activity bonds. Tax anticipation notes are issued to finance working capital needs of municipalities and are generally issued in anticipation of future tax revenues. Bond anticipation notes are issued in expectation of the issuer obtaining longer-term financing.

Municipal obligations are affected by economic, business or political developments. These securities may be subject to provisions of litigation, bankruptcy and other laws affecting the rights and remedies of creditors, or may become subject to future laws extending the time for payment of principal and/or interest, or limiting the rights of municipalities to levy taxes. The Portfolio may be more adversely impacted by changes in tax rates and policies than other funds. Because interest income from municipal securities is normally not subject to regular federal income taxation, the attractiveness of municipal securities in relation to other investment alternatives is affected by changes in federal income tax rates applicable to, or the continuing federal income tax-exempt status of, such interest income. Any proposed or actual changes in such rates or exempt status, therefore, can significantly affect the demand for and supply, liquidity and marketability of municipal securities. This could in turn affect a Portfolio’s ability to acquire and dispose of municipal securities at desirable yield and price levels. Concentration of a Portfolio’s investments in these municipal obligations will subject the Portfolio, to a greater extent than if such investment was not so concentrated, to the risks of adverse economic, business or political developments affecting the particular state, industry or other area of concentration. Issuers, including governmental issuers, of municipal securities may be unable to pay their obligations as they become due. Recent declines in tax revenues, and increases in liabilities, such as pension and health care liabilities, may increase the actual or perceived risk of default on such securities.

Municipal Leases

The Portfolios may purchase participation interests in municipal obligations, including municipal lease/purchase agreements. Municipal leases are an undivided interest in a portion of an obligation in the form of a lease or installment purchase issued by a state or local government to acquire equipment or facilities. These instruments may have fixed, floating or variable rates of interest, with remaining maturities of 13 months or less. Certain participation interests may permit a Portfolio to demand payment on not more than seven days’ notice, for all or any part of the Portfolio’s interest, plus accrued interest.

Municipal leases frequently have special risks not normally associated with general obligation or revenue bonds. Some leases or contracts include “non-appropriation” clauses, which provide that the governmental issuer has no obligation to make future payments under the lease or contract unless money is appropriated for such purpose by the appropriate legislative body on a yearly or other periodic basis. To reduce these risks, the Portfolios will only purchase municipal leases subject to a non-appropriation clause when the payment of principal and accrued interest is backed by a letter of credit or guarantee of a bank.

Whether a municipal lease agreement will be considered illiquid for the purpose of a Portfolio’s restriction on investments in illiquid securities will be determined in accordance with procedures established by the Board of Trustees.

Other Asset-Backed Securities

In addition to the mortgage related securities discussed above, the Portfolios, except for the Treasury Portfolios and the U.S. Government Portfolio, may invest in asset-backed securities that are not mortgage-related. Asset-backed securities other than mortgage-related securities represent undivided fractional interests in pools of instruments, such as consumer loans, and are typically similar in structure to mortgage-related pass-through securities. Payments of principal and interest are passed through to holders of the securities and are typically supported by some form of credit enhancement, such as a letter of credit, surety bond, limited guarantee by another entity, or by priority to certain of the borrower’s other securities. The degree of credit-enhancement, if any, varies, applying only until exhausted and generally covering only a fraction of the security’s par value.

The value of such asset-backed securities is affected by changes in the market’s perception of the asset backing the security, changes in the creditworthiness of the servicing agent for the instrument pool, the originator of the instruments, or the financial institution providing any credit enhancement and the expenditure of any portion of any credit enhancement. The risks of investing in asset-backed securities are ultimately dependent upon payment of the underlying instruments by the obligors, and a Fund would generally have no recourse against the obligee of the instruments in the event of default by an obligor. The underlying instruments are subject to prepayments which shorten the duration of asset-backed securities and may lower their return, in generally the same manner as described above for prepayments of pools of mortgage loans underlying mortgage-related securities.

Pre-Refunded Municipal Securities

The interest and principal payments on pre-refunded municipal securities are typically paid from the cash flow generated from an escrow fund consisting of U.S. Government securities. These payments have been “pre-refunded” using the escrow fund.

Purchase of Other Investment Company Shares

Each Portfolio may, to the extent permitted under the 1940 Act and exemptive rules and orders thereunder, invest in shares of other investment companies, which include funds managed by SSGA FM, which invest exclusively in money market instruments or in investment companies with investment policies and objectives which are substantially similar to those of the Portfolios. These investments may be made temporarily, for example, to invest uncommitted cash balances or, in limited circumstances, to assist in meeting shareholder redemptions, or as long-term investments.

Repurchase Agreements

Each Portfolio, except for the Treasury Portfolio, may enter into repurchase agreements with banks, other financial institutions, such as broker-dealers, and other institutional counterparties. Under a repurchase agreement, the Portfolio purchases securities from a financial institution that agrees to repurchase the securities at the Portfolio’s original purchase price plus interest within a specified time. The Portfolio will limit repurchase transactions to those member banks of the Federal Reserve System, broker-dealers and other financial institutions whose creditworthiness the Adviser considers satisfactory. Should the counterparty to a transaction fail financially, the Portfolio may encounter delay and incur costs before being able to sell the securities, or may be prevented from realizing on the securities. Further, the amount realized upon the sale of the securities may be less than that necessary to fully compensate the Portfolio.

Reverse Repurchase Agreements

The Portfolios may enter into reverse repurchase agreements, which are a form of borrowing. Under reverse repurchase agreements, a Portfolio transfers possession of portfolio securities to financial institutions in return for cash in an amount equal to a percentage of the portfolio securities’ market value and agrees to repurchase the securities at a future date by repaying the cash with interest. Each Portfolio retains the right to receive interest and principal payments from the securities. Cash or liquid high quality debt obligations from a Portfolio’s portfolio equal in value to the repurchase price including any accrued interest will be segregated by the Custodian on the Portfolio’s records while a reverse repurchase agreement is in effect. Reverse repurchase agreements involve the risk that the market value of securities sold by a Portfolio may decline below the price at which it is obligated to repurchase the securities. Reverse repurchase agreements involve the risk that the buyer of the securities sold might be unable to deliver them when a Portfolio seeks to repurchase the securities. If the buyer files for bankruptcy or becomes insolvent, a Portfolio may be delayed or prevented from recovering the security that it sold.

Section 4(a)(2) Commercial Paper/Rule 144A Securities

Each Portfolio, except for the U.S. Government Portfolio and the Treasury Portfolios, may invest in commercial paper issued in reliance on the so called “private placement” exemption from registration afforded by Section 4(a)(2) of the Securities Act of 1933, as amended (“1933 Act”) (“Section 4(a)(2) paper”).

Section 4(a)(2) paper is restricted as to disposition under the federal securities laws and generally is sold to investors who agree that they are purchasing the paper for investment and not with a view to public distribution. Any resale by the purchaser must be a transaction exempt from the registration requirements of the 1933 Act. Section 4(a)(2) paper normally is resold to other institutional investors like the Portfolios through or with the assistance of the issuer or investment dealers that make a market in Section 4(a)(2) paper. Rule 144A securities generally must be sold only to other institutional investors.

There can be no assurance that a liquid trading market will exist at any time for any particular Section 4(a)(2) paper or Rule 144A securities.

Tax Exempt Commercial Paper

The Portfolios, may invest in tax exempt commercial paper. Tax exempt commercial paper is a short-term obligation with a stated maturity of 365 days or less. It is typically issued to finance seasonal working capital needs or as short-term financing in anticipation of longer term financing. Each instrument may be backed only by the credit of the issuer or may be backed by some form of credit enhancement, typically in the form of a guarantee by a commercial bank. Commercial paper backed by guarantees of foreign banks may involve additional risk due to the difficulty of obtaining and enforcing judgments against such banks and the generally less restrictive regulations to which such banks are subject. The Portfolios will only invest in commercial paper rated at the time of purchase not less than Prime-1 by Moody’s, A-1 by S&P or F-1 by Fitch Ratings. See Appendix A for more information on the ratings of debt instruments.

Tender Option Bonds

A tender option is a municipal obligation (generally held pursuant to a custodial arrangement) having a relatively long maturity and bearing interest at a fixed rate substantially higher than prevailing short-term tax exempt rates, that has been coupled with the agreement of a third party, such as a bank, broker-dealer or other financial institution, pursuant to which such institution grants the security holders the option, at periodic intervals, to tender their securities to the institution and receive the face value thereof. As consideration for providing the option, the financial institution receives periodic fees equal to the difference between the municipal obligation’s fixed coupon rate and the rate, as determined by a remarketing or similar agent at or near the commencement of such period, that would cause the securities, coupled with the tender option, to trade at par on the date of such determination. Thus, after payment of this fee, the security holder effectively holds a demand obligation that bears interest at the prevailing short-term tax exempt rate. Subject to applicable regulatory requirements, a Portfolio may buy tender option bonds if the agreement gives the Portfolio the right to tender the bond to its sponsor no less frequently than once every 397 days. The Adviser will consider on an ongoing basis the creditworthiness of the issuer of the underlying obligation, any custodian and the third party provider of the tender option. In certain instances and for certain tender option bonds, the option may be terminable in the event of a default in payment of principal or interest on the underlying municipal obligation and for other reasons.

Treasury Inflation-Protected Securities

The Portfolios may invest in Inflation-Protection Securities (“TIPSs”), a type of inflation-indexed Treasury security. TIPSs typically provide for semiannual payments of interest and a payment of principal at maturity. In general, each payment will be adjusted to take into account any inflation or deflation that occurs between the issue date of the security and the payment date based on the Consumer Price Index for All Urban Consumers (“CPI-U”).

Each semiannual payment of interest will be determined by multiplying a single fixed rate of interest by the inflation-adjusted principal amount of the security for the date of the interest payment. Thus, although the interest rate will be fixed, the amount of each interest payment will vary with changes in the principal of the security as adjusted for inflation and deflation.

TIPSs also provide for an additional payment (a “minimum guarantee payment”) at maturity if the security’s inflation-adjusted principal amount for the maturity date is less than the security’s principal amount at issuance. The amount of the additional payment will equal the excess of the security’s principal amount at issuance over the security’s inflation-adjusted principal amount for the maturity date.

U.S. Government Securities

Each Portfolio may purchase U.S. Government securities. With respect to U.S. Government securities, the Treasury Portfolio will invest exclusively in direct obligations of the U.S. Treasury, such as U.S. Treasury bills, notes and bonds generally maturing within 397 days, and other mutual funds, subject to regulatory limitations, that invest exclusively in such obligations. The Treasury Plus Portfolio will invest only in direct obligations of the U.S. Treasury (U.S. Treasury bills, notes and bonds) and repurchase agreements collateralized by these obligations. The types of U.S. Government obligations in which each other Portfolio may at times invest include: (1) U.S. Treasury obligations and (2) obligations issued or guaranteed by U.S. Government agencies and instrumentalities which are supported by any of the following: (a) the full faith and credit of the U.S. Treasury, (b) the right of the issuer to borrow an amount limited to a specific line of credit from the U.S. Treasury, (c) discretionary authority of the U.S. Government agency or instrumentality, or (d) the credit of the instrumentality (examples of agencies and instrumentalities are: Federal Land Banks, Federal Housing Administration, Federal Farm Credit Bank, Farmers Home Administration, Export-Import Bank of the United States, Central Bank for Cooperatives, Federal Intermediate Credit Banks, Federal Home Loan Banks, General Services Administration, Maritime Administration, Tennessee Development Bank, Asian-American Development Bank, International Bank for Reconstruction and Development and Federal National Mortgage Association (“Fannie Mae” or “FNMA”). No assurance can be given that in the future the U.S. Government will provide financial support to U.S. Government securities it is not obligated to support.

The Portfolios may purchase U.S. Government obligations on a forward commitment basis.

Variable Amount Master Demand Notes

The Portfolios, except for the Treasury Portfolios and the U.S. Government Portfolio, may invest in variable amount master demand notes which are unsecured obligations that are redeemable upon demand and are typically unrated. These instruments are issued pursuant to written agreements between their issuers and holders. The agreements permit the holders to increase (subject to an agreed maximum) and the holders and issuers to decrease the principal amount of the notes, and specify that the rate of interest payable on the principal fluctuates according to an agreed formula. Generally, changes in interest rates will have a smaller effect on the market value of these securities than on the market value of comparable fixed income obligations. Thus, investing in these securities generally allows less opportunity for capital appreciation and depreciation than investing in comparable fixed income securities. There may be no active secondary market with respect to a particular variable rate instrument.

Variable and Floating Rate Securities

The Portfolios may invest in variable and floating rate securities. In general, variable rate securities are instruments issued or guaranteed by entities such as (1) U.S. Government, or an agency or instrumentality thereof, (2) corporations, (3) financial institutions, (4) insurance companies or (5) trusts that have a rate of interest subject to adjustment at regular intervals. A variable rate security provides for the automatic establishment of a new interest rate on set dates. Interest rates on these securities are ordinarily tied to widely recognized market rates, which are typically set once a day. Generally, changes in interest rates will have a smaller effect on the market value of variable and floating rate securities than on the market value of comparable fixed income obligations. Thus, investing in variable and floating rate securities generally allows less opportunity for capital appreciation and depreciation than investing in comparable fixed income securities. Variable rate obligations will be deemed to have a maturity equal to the period remaining until the next readjustment of the interest rate.

Many financial instruments use or may use a floating rate based on LIBOR, which is the offered rate for short-term Eurodollar deposits between major international banks. On July 27, 2017, the head of the United Kingdom’s Financial Conduct Authority announced a desire to phase out the use of LIBOR by the end of 2021. There remains uncertainty regarding the future utilization of LIBOR and the nature of any replacement rate. As such, the potential effect of a transition away from LIBOR on a Fund or the financial instruments in which a Fund invests cannot yet be determined. The transition process might lead to increased volatility and illiquidity in markets that currently rely on LIBOR to determine interest rates. It could also lead to a reduction in the value of some LIBOR-based investments and reduce the effectiveness of new hedges placed against existing LIBOR-based instruments. Since the usefulness of LIBOR as a benchmark could deteriorate during the transition period, these effects could occur prior to the end of 2021.

When-Issued Securities

Each Portfolio may purchase securities on a when-issued basis. Delivery of and payment for these securities may take place as long as a month or more after the date of the purchase commitment. The value of these securities is subject to market fluctuation during this period, and no income accrues to the Portfolio until settlement takes place. When entering into a when-issued transaction, the Portfolio will rely on the other party to consummate the transaction; if the other party fails to do so, the Portfolio may be disadvantaged. The Portfolios will not invest more than 25% of their respective net assets in when-issued securities.

Securities purchased on a when-issued basis and held by a Portfolio are subject to changes in market value based upon actual or perceived changes in the level of interest rates. Generally, the value of such securities will fluctuate inversely to changes in interest rates — i.e., they will appreciate in value when interest rates decline and decrease in value when interest rates rise. Therefore, if in order to achieve higher interest income a Portfolio remains substantially fully invested at the same time that it has purchased securities on a “when-issued” basis, there will be a greater possibility of fluctuation in the Portfolio’s NAV.

Zero Coupon Securities

The Portfolios may invest in zero coupon securities. Zero coupon securities are notes, bonds and debentures that: (1) do not pay current interest and are issued at a substantial discount from par value; (2) have been stripped of their unmatured interest coupons and receipts; or (3) pay no interest until a stated date one or more years into the future. These securities also include certificates representing interests in such stripped coupons and receipts. Generally, changes in interest rates will have a greater impact on the market value of a zero coupon security than on the market value of the comparable securities that pay interest periodically during the life of the instrument. In the case of any zero-coupon debt obligations with a fixed maturity date of more than one year from the date of issuance that are treated as issued originally at a discount, a Portfolio will be required to accrue original issue discount (“OID”) for U.S. federal income tax purposes and, in the case of a Portfolio treated as a RIC, may as a result be required to pay out as an income distribution an amount which is greater than the total amount of cash interest the Portfolio actually received. To generate sufficient cash to make the requisite distributions to maintain its qualification for treatment as a “regulated investment company” (“RIC”) under the Internal Revenue Code of 1986, as amended (the “Code”), a Portfolio that is taxed as a RIC may be required to sell investments, including at a time when it may not be advantageous to do so.

The Portfolios may invest no more than 25% of their respective total assets in stripped securities that have been stripped by their holder, typically a custodian bank or investment brokerage firm. Privately-issued stripped securities are not themselves guaranteed by the U.S. Government, but the future payment of principal or interest on U.S. Treasury obligations which they represent is so guaranteed.

Asset Segregation and Coverage

A Portfolio may be required to earmark or otherwise segregate liquid assets in respect of its obligations under derivatives transactions that involve contractual obligations to pay in the future, or a Portfolio may engage in other measures to “cover” its obligations with respect to such transactions. The amounts that are earmarked or otherwise segregated may be based on the notional value of the derivative or on the daily mark-to-market obligation under the derivatives contract and may be reduced by amounts on deposit with the applicable broker or counterparty to the derivatives transaction. In certain circumstances, a Portfolio may enter into an offsetting position rather than earmarking or segregating liquid assets. A Portfolio may modify its asset segregation and coverage policies from time to time. Although earmarking or segregating may in certain cases have the effect of limiting a Portfolio’s ability to engage in derivatives transactions, the extent of any such limitation will depend on a variety of factors, including the method by which the Fund determines the nature and amount of assets to be earmarked or segregated.

Fundamental Investment Restrictions

The Portfolios in which the Funds invest each have substantially the same investment restrictions as their corresponding Funds. In reviewing the description of a Fund’s investment restrictions below, you should assume that the investment restrictions of the corresponding Portfolio are the same in all material respects as those of the Fund.

The Trust has adopted the following restrictions applicable to the Funds, which may not be changed without the affirmative vote of a “majority of the outstanding voting securities” of a Fund, which is defined in the 1940 Act to mean the affirmative vote of the lesser of (1) more than 50% of the outstanding shares of the Fund and (2) 67% or more of the shares present at a meeting if more than 50% of the outstanding shares are present at the meeting in person or by proxy.

A Fund may borrow money and issue senior securities to the extent consistent with applicable law from time to time.

A Fund may make loans, including to affiliated investment companies, to the extent consistent with applicable law from time to time.

A Fund may purchase or sell commodities to the extent consistent with applicable law from time to time.

A Fund may purchase, sell or hold real estate to the extent consistent with applicable law from time to time.

A Fund may underwrite securities to the extent consistent with applicable law from time to time.

For the Money Market Funds:

A Fund may not purchase any security if, as a result, 25% or more of the Fund’s total assets (taken at current value) would be invested in a particular industry (for purposes of this restriction, investment companies are not considered to constitute a particular industry or group of industries), except as is consistent with applicable law from time to time and as follows: each Fund is permitted to invest without limit in “government securities” (as defined in the 1940 Act), tax-exempt securities issued by a U.S. territory or possession, a state or local government, or a political subdivision of any of the foregoing and bankers’ acceptances, certificates of deposit and similar instruments issued by: (i) U.S. banks, (ii) U.S. branches of foreign banks (in circumstances in which the Adviser determines that the U.S. branches of foreign banks are subject to the same regulation as U.S. banks), (iii) foreign branches of U.S. banks (in circumstances in which the Adviser determines that the Fund will have recourse to the U.S. bank for the obligations of the foreign branch), and (iv) foreign branches of foreign banks (to the extent that the Adviser determines that the foreign branches of foreign banks are subject to the same or substantially similar regulations as U.S. banks).

With respect to investment policy on concentration (#6 above), a Money Market Fund may concentrate in bankers’ acceptances, certificates of deposit and similar instruments when, in the opinion of the Adviser, the yield, marketability and availability of investments meeting the Fund’s quality standards in the banking industry justify any additional risks associated with the concentration of the Fund’s assets in such industry.

For the Ultra Short Bond Fund:

The Fund may not purchase any security if, as a result, 25% or more of the Fund’s total assets (taken at current value) would be invested in a particular industry (for purposes of this restriction, investment companies are not considered to constitute a particular industry or group of industries), except as is consistent with applicable law from time to time and as follows: the Fund is permitted to invest without limit in “government securities” (as defined in the 1940 Act) and tax-exempt securities issued by a U.S. territory or possession, a state or local government, or a political subdivision of any of the foregoing.

For purposes of the above investment limitation number 6, in the case of a tax-exempt bond issued by a non-governmental user, where the tax-exempt bond is backed only by the assets and revenues of the non-governmental user, then such non-governmental user would be deemed to be the sole issuer. For each Fund, all percentage limitations (except the limitation to borrowings) on investments will apply at the time of the making of an investment and shall not be considered violated unless an excess or deficiency occurs or exists immediately after and as a result of such investment. Except for the investment restrictions expressly identified as fundamental, or to the extent designated as such in the Prospectus with respect to a Fund, the other investment policies described in this SAI or in the Prospectus are not fundamental and may be changed by approval of the Trustees without shareholder approval.

Non-Fundamental Investment Restrictions

Names Rule Policy

To the extent a Fund is subject to Rule 35d-1 under the 1940 Act, the Fund has an investment policy, described in the Fund’s prospectus, to, under normal circumstances, invest at least 80% of its assets in the particular types of investments suggested by the Fund’s name (a “Name Policy”). “Assets” for the purposes of a Name Policy are net assets plus the amount of any borrowings for investment purposes. The percentage limitation applies at the time of purchase of an investment. A Fund’s Name Policy may be changed by the Board of Trustees of the Trust without shareholder approval. However, to the extent required by SEC regulations, shareholders will be provided with at least sixty (60) days’ notice prior to any change in a Fund’s Name Policy.

Additional Information

Fundamental Investment Restrictions (1) through (5), as numbered above limit a Fund’s ability to engage in certain investment practices and purchase securities or other instruments to the extent consistent with applicable law as that law changes from time to time. Applicable law includes the 1940 Act, the rules or regulations thereunder and applicable orders of SEC as are currently in place. In addition, interpretations and guidance provided by the SEC staff may be taken into account, where deemed appropriate by a Fund, to determine if an investment practice or the purchase of securities or other instruments is permitted by applicable law. As such, the effects of these limitations will change as the statute, rules, regulations or orders (or, if applicable, interpretations) change, and no shareholder vote will be required or sought when such changes permit or require a resulting change in practice.

Disclosure of Portfolio Holdings

Introduction

The policies set forth below to be followed by State Street Bank and Trust Company (“State Street”) and SSGA FM ( collectively, the “Service Providers”) for the disclosure of information about the portfolio holdings of the SSGA Funds, State Street Master Funds, and State Street Institutional Investment Trust (each, a “Trust”). These disclosure policies are intended to ensure compliance by the Service Providers and the Trust with applicable regulations of the federal securities laws, including the 1940 Act and the Investment Advisers Act of 1940, as amended. The Board of Trustees of the Trust must approve all material amendments to the policy.

General Policy

It is the policy of the Service Providers to protect the confidentiality of client holdings and prevent the selective disclosure of non-public information concerning the Trust.

No information concerning the portfolio holdings of the Trust may be disclosed to any party (including shareholders) except as provided below. The Service Providers are not permitted to receive compensation or other consideration in connection with disclosing information about a Fund’s portfolio to third parties. In order to address potential conflicts between the interest of Fund shareholders, on the one hand, and those of the Service Providers or any affiliated person of those entities or of the Fund, on the other hand, the Fund’s policies require that non-public disclosures of information regarding the Fund’s portfolio may be made only if there is a legitimate business purpose consistent with fiduciary duties to all shareholders of the Fund.

The Board of Trustees of the Trust exercises continuing oversight over the disclosure of each Fund’s holdings by (i) overseeing the implementation and enforcement of the portfolio holding disclosure policy, Codes of Ethics and other relevant policies of each Fund and its service providers by the Trust’s Chief Compliance Officer (“CCO”) and (2) considering reports and recommendations by the Trust’s CCO concerning any material compliance matters (as defined in Rule 38a-1 under the 1940 Act). The Board reserves the right to amend the policy at any time without prior notice in its sole discretion.

Publicly Available Information. Any party may disclose portfolio holdings information after the holdings are publicly available.

For the Ultra Short Bond Fund: Disclosure of the complete holdings of the Fund is required to be made quarterly within 60 days of the end of the Fund’s fiscal quarter in the Annual Report and Semi-Annual Report to Fund shareholders and in the monthly holdings report on Form N-PORT, with every third month made available to the public by the SEC 60 days after the end of the Portfolios’ fiscal quarter. You can find SEC filings on the SEC’s website, www.sec.gov. The Fund will also make complete portfolio holdings available generally no later than 60 calendar days after the end of the Fund’s fiscal quarter or subsequent to periodic portfolio holdings disclosure in the Fund’s filings with the SEC or on the Fund’s website.

For Money Market Funds: Each Fund generally will post on its website (or, in the case of a Portfolio, on the corresponding Feeder Fund’s website) a full list of its portfolio holdings each Friday reflecting the portfolio holdings of the fund on the immediately preceding Wednesday. Each Fund will also post a full list of its portfolio holdings on its website (or, in the case of a Portfolio, on the corresponding Fund’s website) no later than the fifth business day of each month, reflecting its portfolio holdings as of the last business day of the previous month. Such monthly posting shall contain such information as required by Rule 2a-7(h)(10) under the 1940 Act and remain posted on the website for not less than six months. Each Fund is also required to file with the SEC its complete portfolio holdings in monthly reports on Form N-MFP, available on the SEC’s website at www.sec.gov.

Information about each Fund’s 10 largest holdings generally is posted on the Funds’ website at SSGAFUNDS.com within 30 days following the end of each month.

Press Interviews Brokers and Other Discussions

Portfolio managers and other senior officers or spokespersons of the Service Providers or the Trust may disclose or confirm the ownership of any individual portfolio holding position to reporters, brokers, shareholders, consultants or other interested persons only if such information has been previously publicly disclosed in accordance with these disclosure policies. For example, a portfolio manager discussing the Trust may indicate that he owns XYZ Company for the Trust only if the Trust’s ownership of such company has previously been publicly disclosed.

Trading Desk Reports

State Street Global Advisors’ (“SSGA”) trading desk may periodically distribute lists of investments held by its clients (including the Trust) for general analytical research purposes. In no case may such lists identify individual clients or individual client position sizes. Furthermore, in the case of equity securities, such lists shall not show aggregate client position sizes.

Miscellaneous

Confidentiality Agreement . No non-public disclosure of the Funds’ portfolio holdings will be made to any party unless such party has signed a written Confidentiality Agreement. For purposes of the disclosure policies, any Confidentiality Agreement must be in a form and substance acceptable to, and approved by, the Trust’s officers.

Evaluation Service Providers. There are numerous mutual fund evaluation services (such as Morningstar, Inc. and Broadridge Financial Solutions, Inc., formerly, Lipper, Inc.) and due diligence departments of broker-dealers and wirehouses that regularly analyze the portfolio holdings of mutual funds in order to monitor and report on various attributes. These services and departments then distribute the results of their analysis to the public, paid subscribers and/or in-house brokers. In order to facilitate the review of the Trust by these services and departments, the Trust may distribute (or authorize the Service Providers and the Trust’s custodian or fund accountants to distribute) month-end portfolio holdings to such services and departments only if such entity has executed a confidentiality agreement.

Additional Restrictions . Notwithstanding anything herein to the contrary, the Trust’s Board of Trustees, State Street and SSGA FM may, on a case-by-case basis, impose additional restrictions on the dissemination of portfolio information beyond those found in these disclosure policies.

Waivers of Restrictions. These disclosure policies may not be waived, or exceptions made, without the consent of the Trust’s officers. All waivers and exceptions involving the Trust will be disclosed to the Board of Trustees of the Trust no later than its next regularly scheduled quarterly meeting.

Disclosures Required by Law . Nothing contained herein is intended to prevent the disclosure of portfolio holdings information as may be required by applicable law. For example, SSGA FM, State Street, the Trust or any of its affiliates or service providers may file any report required by applicable law (such as Schedules 13D, 13G and 13F or Form N-MFP), respond to requests from regulators and comply with valid subpoenas.

MANAGEMENT OF THE TRUST AND STATE STREET MASTER FUNDS

The Board of Trustees is responsible for overseeing generally the management, activities and affairs of the Funds and has approved contracts with various organizations to provide, among other services, day-to-day management required by the Trust (see the section called “Investment Advisory and Other Services”). The Board has engaged the Adviser to manage the Funds on a day-to day basis. The Board is responsible for overseeing the Adviser and other service providers in the operation of the Trust in accordance with the provisions of the 1940 Act, applicable Massachusetts law and regulation, other applicable laws and regulations, and the Amended and Restated Declaration of Trust. The Trustees listed below are also Trustees of the SSGA Funds, the State Street Master Funds and the State Street Navigator Securities Lending Trust (the “Navigator Trust”) and their respective series. Except for Messrs. Ross and Taber, the Trustees listed below are also Trustees of State Street Institutional Funds, State Street Variable Insurance Series Funds, Inc., Elfun Diversified Fund, Elfun Government Money Market Fund, Elfun Tax-Exempt Income Fund, Elfun Income Fund, Elfun International Equity Fund and Elfun Trusts (collectively, the “Elfun Funds”). The following table provides information with respect to each Trustee, including those Trustees who are not considered to be “interested” as that term is defined in the 1940 Act (the “Independent Trustees”), and each officer of the Trusts.


NAME, ADDRESS, AND YEAR OF BIRTH	POSITION(S) HELD WITH TRUST	TERM OF OFFICE AND LENGTH OF TIME SERVED	PRINCIPAL OCCUPATION DURING PAST FIVE YEARS AND RELEVANT EXPERIENCE	NUMBER OF FUNDS IN FUND COMPLEX OVERSEEN BY TRUSTEE†	OTHER DIRECTORSHIPS HELD BY TRUSTEE DURING PAST FIVE YEARS
INDEPENDENT TRUSTEES

Michael F. Holland c/o SSGA Funds Management, Inc. One Iron Street Boston, MA 022101 YOB: 1944	Trustee and Co-Chairperson of the Board	Term: Indefinite Elected: 7/99	Chairman, Holland & Company L.L.C. (investment adviser) (1995- present).	71	Director, the Holland Series Fund, Inc.; Director, The China Fund, Inc.; Director, The Taiwan Fund, Inc. (2007-2017); Director, Reaves Utility Income Fund, Inc.; and Director, Blackstone/GSO Loans (and Real Estate) Funds.

Patrick J. Riley c/o SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1948	Trustee and Co-Chairperson of the Board	Term: Indefinite Elected: 1/14	2002 to May 2010, Associate Justice of the Superior Court, Commonwealth of Massachusetts; 1985 to 2002, Partner, Riley, Burke & Donahue, L.L.P. (law firm); 1998 to Present, Independent Director, State Street Global Advisers Ireland, Ltd. (investment company); 1998 to Present, Independent Director, SSGA Liquidity plc (formerly, SSGA Cash Management Fund plc); January 2009 to Present, Independent Director, SSGA Fixed Income plc; and January 2009-2019, Independent Director, SSGA Qualified Funds PLC.	71	Board Director and Chairman, SPDR Europe 1PLC Board (2011-Present); Board Director and Chairman, SPDR Europe II, PLC (2013- Present).

John R. Costantino c/o SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1946	Trustee and Co- Chairperson of the Qualified Legal Compliance Committee	Term: Indefinite Elected: 12/18	Managing General Partner, NGN Capital LLC (2006 – present); and Managing Director, Vice President of Walden Capital Management (1996 – present).	71	Director of Kleinfeld Bridal Corp. (March 2016 – present); Trustee of Neuroscience Research Institute (1986 – present); Trustee of Fordham University (1989 – 1995 and 2001 – 2007) and Trustee Emeritus (2007 – present); Trustee of GE Funds (1993 – February 2011); Director of Artes Medical (2006 – 2008); and Trustee of Gregorian University Foundation (1992 – 2007).

Donna M. Rapaccioli c/o SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1962	Trustee and Co-Chairperson of the Audit Committee	Term: Indefinite Elected: 12/18	Dean of the Gabelli School of Business (2007 – present) and Accounting Professor (1987 – present) at Fordham University.	71	Trustee of Emmanuel College (2010 – present); Director- Graduate Management Admissions Council (2015 – present);


NAME, ADDRESS, AND YEAR OF BIRTH	POSITION(S) HELD WITH TRUST	TERM OF OFFICE AND LENGTH OF TIME SERVED	PRINCIPAL OCCUPATION DURING PAST FIVE YEARS AND RELEVANT EXPERIENCE	NUMBER OF FUNDS IN FUND COMPLEX OVERSEEN BY TRUSTEE†	OTHER DIRECTORSHIPS HELD BY TRUSTEE DURING PAST FIVE YEARS
Richard D. Shirk c/o SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1945	Trustee and Co-Chairman of the Qualified Legal and Compliance Committee	Term: Indefinite Elected: 1/14	March 2001 to April 2002, Chairman (1996 to March 2001, President and Chief Executive Officer), Cerulean Companies, Inc. (holding company) (Retired); 1992 to March 2001, President and Chief Executive Officer, Blue Cross Blue Shield of Georgia (health insurer, managed healthcare).	71	1998 to December 2008, Chairman, Board Member and December 2008 to Present, Investment Committee Member, Healthcare Georgia Foundation (private foundation); September 2002 to 2012, Lead Director and Board Member, Amerigroup Corp. (managed health care); 1999 to 2013, Board Member and (since 2001) Investment Committee Member, Woodruff Arts Center; and 2003 to 2009, Trustee, Gettysburg College; Board member, Aerocare Holdings, Regenesis Biomedical Inc.

Rina K. Spence c/o SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1948	Trustee and Co- Chairperson of the Audit Committee, Co-Chairperson of the Nominating Committee and Co-Chairperson of the Governance Committee	Term: Indefinite Elected: 7/99	President of SpenceCare International LLC (international healthcare consulting) (1999 – present); Chief Executive Officer, IEmily.com (health internet company) (2000 – 2001); Chief Executive Officer of Consensus Pharmaceutical, Inc. (1998 – 1999); Founder, President and Chief Executive Officer of Spence Center for Women’s Health (1994 –1998); President and CEO, Emerson Hospital (1984 – 1994); Honorary Consul for Monaco in Boston (2015 – present).	71	Trustee, Eastern Enterprise (utilities) (1988 – 2000); Director, Berkshire Life Insurance Company of America (1993 – 2009).


NAME, ADDRESS, AND YEAR OF BIRTH	POSITION(S) HELD WITH TRUST	TERM OF OFFICE AND LENGTH OF TIME SERVED	PRINCIPAL OCCUPATION DURING PAST FIVE YEARS AND RELEVANT EXPERIENCE	NUMBER OF FUNDS IN FUND COMPLEX OVERSEEN BY TRUSTEE†	OTHER DIRECTORSHIPS HELD BY TRUSTEE DURING PAST FIVE YEARS
Bruce D. Taber c/o SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1943	Trustee and Co-Chairman of the Valuation Committee and Co- Chairman of the Governance Committee	Term: Indefinite Elected: 1/14	Retired; 1999 to 2016, Partner, Zenergy LLC (a technology company providing Computer Modeling and System Analysis to the General Electric Power Generation Division); Until December 2008, Independent Director, SSGA Cash Management Fund plc; Until December 2008, Independent Director, State Street Global Advisers Ireland, Ltd. (investment companies).	53

Michael A. Jessee c/o SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1946	Trustee and Co-Chairman of the Valuation Committee	Term: Indefinite Appointed: 7/16 Elected: 12/18	Retired; formerly, President and Chief Executive Officer of the Federal Home Loan Bank of Boston (1989 – 2009); Trustee, Randolph-Macon College (2004 – 2016).	71


NAME, ADDRESS, AND YEAR OF BIRTH	POSITION(S) HELD WITH TRUST	TERM OF OFFICE AND LENGTH OF TIME SERVED	PRINCIPAL OCCUPATION DURING PAST FIVE YEARS AND RELEVANT EXPERIENCE	NUMBER OF FUNDS IN FUND COMPLEX OVERSEEN BY TRUSTEE†	OTHER DIRECTORSHIPS HELD BY TRUSTEE DURING PAST FIVE YEARS
INTERESTED TRUSTEES ⁽¹⁾

Ellen M. Needham ⁽²⁾ SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1967	Trustee and President	Term: Indefinite Elected: 12/18	President and Director, SSGA Funds Management, Inc. (2001 – present); Senior Managing Director, State Street Global Advisors (1992 – present); Director, State Street Global Advisors Funds Distributors, LLC (May 2017 – present).*	71

James E. Ross ⁽³⁾ SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1965	Trustee	Term: Indefinite Appointed: 2/07 Elected: 12/18	Chairman and Director, SSGA Funds Management, Inc. (2005-present); Executive Vice President, State Street Global Advisors (2012-present); Chief Executive Officer and Director, State Street Global Advisors Funds Distributors, LLC (May 2017 – present); Director, State Street Global Markets, LLC (2013 – April 2017); President, SSGA Funds Management, Inc. (2005 – 2012); Principal, State Street Global Advisors (2000-2005).	189	SSGA SPDR ETFs Europe I plc (Director) (November 2016 – present); SSGA SPDR ETFs Europe II plc (Director) (November 2016 – present).

†	For the purpose of determining the number of portfolios overseen by the Trustees, “Fund Complex” comprises registered investment companies for which SSGA FM serves as investment adviser.

(1)	The individuals listed below are Trustees who are “interested persons,” as defined in the 1940 Act, of the Trusts (“Interested Trustees”).

(2)	Ms. Needham is an Interested Trustee because of her employment by SSGA FM, an affiliate of the Trust.

(3)	Mr. Ross is an Interested Trustee because of his employment by SSGA FM, an affiliate of the Trust.

*	Served in various capacities and/or with various affiliated entities during noted time period.

The following lists the principal officers for the Trust and State Street Master Funds, as well as their mailing addresses and ages, positions with the Trusts and length of time served, and present and principal occupations:


NAME, ADDRESS, AND YEAR OF BIRTH	POSITION(S) HELD WITH TRUST	TERM OF OFFICE AND LENGTH OF TIME SERVED	PRINCIPAL OCCUPATION DURING PAST FIVE YEARS
OFFICERS:
Ellen M. Needham SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1967	President, Trustee	Term: Indefinite Elected: 10/12	President and Director, SSGA Funds Management, Inc. (2001 – present); Senior Managing Director, State Street Global Advisors (1992 –present); Director, State Street Global Advisors Funds Distributors, LLC (May 2017 – present).

Bruce S. Rosenberg SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1961	Treasurer	Term: Indefinite Elected: 2/16	Managing Director, State Street Global Advisors and SSGA Funds Management, Inc. (July 2015 – present); Director, Credit Suisse (April 2008 – July 2015).


NAME, ADDRESS, AND YEAR OF BIRTH	POSITION(S) HELD WITH TRUST	TERM OF OFFICE AND LENGTH OF TIME SERVED	PRINCIPAL OCCUPATION DURING PAST FIVE YEARS
Ann M. Carpenter SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1966	Vice President and Deputy Treasurer	Term: Indefinite Elected: 10/12 Term: Indefinite Elected: 2/16	Chief Operating Officer, SSGA Funds Management, Inc. (April 2005 – present) ; Managing Director, State Street Global Advisors. (2005 –present).

Chad C. Hallett SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1969	Deputy Treasurer	Term: Indefinite Elected: 2/16	Vice President, State Street Global Advisors and SSGA Funds Management, Inc. (November 2014 – present); Vice President, State Street Bank and Trust Company (2001 –November 2014).*

Darlene Anderson-Vasquez SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1968	Deputy Treasurer	Term: Indefinite Elected: 11/16	Managing Director, State Street Global Advisors and SSGA Funds Management, Inc. (May 2016 – present); Senior Vice President, John Hancock Investments (September 2007 – May 2016).

Arthur A. Jensen SSGA Funds Management, Inc. 1600 Summer Street Stamford, CT 06905 YOB: 1966	Deputy Treasurer	Term: Indefinite Elected: 11/16	Vice President State Street Global Advisors Funds Management, Inc. (July 2016 – present); Deputy Treasurer of Elfun Funds (July 2016 – present); Treasurer of State Street Institutional Funds, State Street Variable Insurance Series Funds, Inc. and GE Retirement Savings Plan Funds (June 2011 – present); Treasurer of Elfun Funds (June 2011– July 2016); Mutual Funds Controller of GE Asset Management Incorporated (April 2011 – July 2016).


NAME, ADDRESS, AND YEAR OF BIRTH	POSITION(S) HELD WITH TRUST	TERM OF OFFICE AND LENGTH OF TIME SERVED	PRINCIPAL OCCUPATION DURING PAST FIVE YEARS
Sujata Upreti SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1974	Assistant Treasurer	Term: Indefinite Elected: 2/16	Vice President, State Street Global Advisors and SSGA Funds Management, Inc. (May 2015 – present); Assistant Director, Cambridge Associates, LLC (July 2014 – January 2015); Vice President, Bank of New York Mellon (July 2012 – August 2013); Manager, PricewaterhouseCoopers, LLP (September 2003 – July 2012).

Daniel Foley SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1972	Assistant Treasurer	Term: Indefinite Elected: 2/16	Vice President, State Street Global Advisors and SSGA Funds Management, Inc. (April 2007 – present).*

Daniel G. Plourde SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1980	Assistant Treasurer	Term: Indefinite Elected: 5/17	Vice President, State Street Global Advisors and SSGA Funds Management, Inc. (May 2015 – present); Officer, State Street Bank and Trust Company (March 2009 – May 2015).

Brian Harris SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1973	Chief Compliance Officer, Anti-Money Laundering Officer and Code of Ethics Compliance Officer	Term: Indefinite Elected: 11/13 Term: Indefinite Elected: 9/16	Managing Director, State Street Global Advisors and SSGA Funds Management, Inc. (June 2013 – Present); Senior Vice President and Global Head of Investment Compliance, BofA Global Capital Management (September 2010 – May 2013).


NAME, ADDRESS, AND YEAR OF BIRTH	POSITION(S) HELD WITH TRUST	TERM OF OFFICE AND LENGTH OF TIME SERVED	PRINCIPAL OCCUPATION DURING PAST FIVE YEARS
Joshua A. Weinberg SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1978	Chief Legal Officer	Term: Indefinite Elected: 2/15	Managing Director and Managing Counsel, State Street Global Advisors (2011 – present)*; Clerk, SSGA Funds Management, Inc. (2013 – present); Associate, Financial Services Group, Dechert LLP (2005 – 2011).

Jesse D. Hallee State Street Bank and Trust Company 100 Summer Street, 7 ^th Floor Boston, MA 02111 YOB: 1976	Secretary	Term: Indefinite Elected: 9/16	Vice President and Managing Counsel, State Street Bank and Trust Company (2013 – present); Vice President and Counsel, Brown Brothers Harriman & Co. (2007-2013).

Khimmara Greer State Street Bank and Trust Company 100 Summer Street, 7th Floor Boston, MA 02111 YOB: 1983	Assistant Secretary	Term: Indefinite Elected: 5/16	Vice President and Counsel, State Street Bank and Trust Company (2015- present); Regulatory Advisor, JPMorgan (2014 – 2015).

*	Served in various capacities and/or with various affiliated entities during noted time period.

The By-Laws of the Trust provide that the Trust shall indemnify each person who is or was a Trustee of the Trust against all expenses, judgments, fines, settlements and other amounts actually and reasonably incurred in connection with any proceedings if the person in good faith and reasonably believes that his or her conduct was in the Trust’s best interest. The Trust, at its expense, provides liability insurance for the benefit of its Trustees and officers.

Summary of Trustees’ Qualifications

Following is a summary of the experience, attributes and skills which qualify each Trustee to serve on the Boards of Trustees of the Trust and State Street Master Funds.

Michael F. Holland: Mr. Holland is an experienced business executive with over 48 years of experience in the financial services industry including 22 years as a portfolio manager of another registered mutual fund; his experience includes service as a trustee, director or officer of various investment companies. He has served on the Board of Trustees and related Committees of State Street Institutional Investment Trust and State Street Master Funds for 19 years (since the Trusts’ inception) and possesses significant experience regarding the operations and history of those Trusts. Mr. Holland serves as a Trustee of the Navigator Trust, SSGA Funds, Elfun Funds, State Street Institutional Funds and State Street Variable Insurance Funds, Inc.

John R. Costantino: In addition to his tenure as a board member of various other funds advised by SSGA FM, Mr. Costantino has over 30 years of private equity investing experience. He has also served as an officer or a board member of charitable organizations and public and private companies for over 30 years. Mr. Costantino is an attorney and a certified public accountant. He serves as a Trustee of the Navigator Trust, SSGA Funds, Elfun Funds, State Street Institutional Funds and State Street Variable Insurance Funds, Inc.

Ellen M. Needham: Ms. Needham is a Senior Managing Director of State Street Global Advisors; Head of Global Funds Management, and President of SSGA Funds Management, Inc. She serves as a director of SSGA Funds Management, Inc. and State Street Global Advisors Funds Distributors, LLC. In her role, Ms. Needham is responsible for managing firm-wide processes that focus on governance, fund structure, subadviser oversight, tax, product viability, distribution, ongoing monitoring and regulatory coordination across all products globally. She has been involved in the investment industry for over thirty years, beginning her career at State Street in 1989. Ms. Needham serves as a Trustee of the Navigator Trust, SSGA Funds, Elfun Funds, State Street Institutional Funds and State Street Variable Insurance Funds, Inc.

Rina K. Spence: Ms. Spence is an experienced business executive with over 37 years of experience in the health care industry; her experience includes service as a trustee, director or officer of various investment companies, charities and utility companies and chief executive positions for various health care companies. She has served on the Board of Trustees and related Committees of the State Street Institutional Investment Trust and the State Street Master Funds for 19 years (since the Trusts’ inception) and possesses significant experience regarding the operations and history of those Trusts. Ms. Spence serves as a Trustee of the Navigator Trust, SSGA Funds, Elfun Funds, State Street Institutional Funds and State Street Variable Insurance Funds, Inc.

Donna M. Rapaccioli: Ms. Rapaccioli has over 30 years of service as a full-time member of the business faculty at Fordham University, where she developed and taught undergraduate and graduate courses, including International Accounting and Financial Statement Analysis and has taught at the executive MBA level. She has served on Association to Advance Collegiate Schools of Business accreditation team visits, lectured on accounting and finance topics and consulted for numerous investment banks. Ms. Rapaccioli serves as a Trustee of the Navigator Trust, SSGA Funds, Elfun Funds, State Street Institutional Funds and State Street Variable Insurance Funds, Inc.

James E. Ross: Mr. Ross is an experienced business executive with over 29 years of experience in the financial services industry; his experience includes service as a trustee, director or officer of various investment companies. He has served on the Board of Trustees of the State Street Institutional Investment Trust and the State Street Master Funds for 11 years and as President of the Trusts for over 11 years and possesses significant experience regarding the Trusts’ operations and history. He serves as a Trustee of the Navigator Trust, SSGA Funds, State Street Institutional Funds and State Street Variable Insurance Series Funds, Inc., and additional trusts that include series for which SSGA FM serves as investment adviser. Mr. Ross is also a senior executive officer of State Street Global Advisors and Chief Executive Officer of State Street Global Advisors Funds Distributors, LLC. Mr. Ross is also on the Board of Governors of the Investment Company Institute.

Patrick J. Riley: Mr. Riley is an experienced business executive with over 42 years of experience in the legal and financial services industries; his experience includes service as a trustee or director of various investment companies and Associate Justice of the Superior Court of the Commonwealth of Massachusetts. He has served on the Board of Trustees and related Committees of SSGA Funds for 30 years and possesses significant experience regarding the operations and history of the Trust. Mr. Riley serves as a Trustee of the Navigator Trust, SSGA Funds, Elfun Funds, State Street Institutional Funds and State Street Variable Insurance Funds, Inc.

Richard D. Shirk: Mr. Shirk is an experienced business executive with over 50 years of experience in the health care and insurance industries and with investment matters; his experience includes service as a trustee, director or officer of various health care companies and nonprofit organizations. He has served on the Board of Trustees and related Committees of SSGA Funds for 30 years and possesses significant experience regarding the operations and history of the Trust. Mr. Shirk serves as a Trustee of the Navigator Trust, SSGA Funds, Elfun Funds, State Street Institutional Funds and State Street Variable Insurance Funds, Inc.

Bruce D. Taber: Mr. Taber is an experienced business executive with over 45 years of experience in the power generation, technology and engineering industries; his experience includes service as a trustee or director of various investment companies. He has served on the Board of Trustees and related Committees of SSGA Funds for 26 years and possesses significant experience regarding the operations and history of the Trust. Mr. Taber also serves as a Trustee of the Navigator Trust.

Michael A. Jessee: Mr. Jessee is an experienced business executive with approximately 42 years of experience in the banking industry. He previously served as President and Chief Executive Officer of the Federal Home Loan Bank of Boston as well as various senior executive positions of major banks. Mr. Jessee has served on the Navigator Trust’s Board of Trustees and related committees for 23 years and possesses significant experience regarding the Trust’s operations and history. He serves as a Trustee of the Navigator Trust, SSGA Funds, Elfun Funds, State Street Institutional Funds and State Street Variable Insurance Funds, Inc.

References to the experience, attributes and skills of Trustees above are pursuant to requirements of the SEC, do not constitute holding out of the Board or any Trustee as having any special expertise or experience, and shall not impose any greater responsibility or liability on any such person or on the Board by reason thereof.

Standing Committees

The Board of Trustees has established various committees to facilitate the timely and efficient consideration of various matters of importance to Independent Trustees, the Trust, and the Trust’s shareholders and to facilitate compliance with legal and regulatory requirements. Currently, the Board has created an Audit Committee, Governance Committee, Valuation Committee, Nominating Committee and Qualified Legal Compliance Committee.

The Audit Committee is composed of all of the Independent Trustees. The Audit Committee meets twice a year, or more often as required, in conjunction with meetings of the Board of Trustees. The Audit Committee oversees and monitors the Trust’s internal accounting and control structure, its auditing function and its financial reporting process. The Audit Committee is responsible for selecting and retaining the independent accountants for the Trust. The Audit Committee is responsible for approving the audit plans, fees and other material arrangements in respect of the engagement of the independent accountants, including non-audit services performed. The Audit Committee reviews the qualifications of the independent accountant’s key personnel involved in the foregoing activities and monitors the independent accountant’s independence. During the fiscal year ended December 31, 2018, the Audit Committee held four meetings.

Each of the Governance Committee and the Nominating Committee is composed of all the Independent Trustees. The primary functions of the Governance Committee and the Nominating Committee, are to review and evaluate the composition and performance of the Board; make nominations for membership on the Board and committees; review the responsibilities of each committee; and review governance procedures, compensation of Independent Trustees and independence of outside counsel to the Trustees. The Nominating Committee will consider nominees to the Board recommended by shareholders. Recommendations should be submitted in accordance with the procedures set forth in the Nominating Committee Charter and should be submitted in writing to the Trust, to the attention of the Trust’s Secretary, at the address of the principal executive offices of the Trust. Shareholder recommendations must be delivered to, or mailed and received at, the principal executive offices of the Trust not less than sixty (60) calendar days nor more than ninety (90) calendar days prior to the date of the Board or shareholder meeting at which the nominee candidate would be considered for election. The Governance Committee performs an annual self-evaluation of Board members. During the fiscal year ended December 31, 2018, the Governance Committee held one meeting and Nominating Committee held two meetings.

The Valuation Committee is composed of all the Independent Trustees. The Valuation Committee’s primary purpose is to review the actions and recommendations of the Adviser’s Oversight Committee no less often than quarterly. The Trust has established procedures and guidelines for valuing portfolio securities and making fair value determinations from time to time through the Valuation Committee, with the assistance of the Oversight Committee, State Street and SSGA FM. During the fiscal year ended December 31, 2018, the Valuation Committee held four meetings.

The Qualified Legal Compliance Committee (the “QLCC”) is composed of all the Independent Trustees. The primary functions of the QLCC are to receive quarterly reports from the CCO; to oversee generally the Trust’s responses to regulatory inquiries; and to investigate matters referred to it by the Chief Legal Officer and make recommendations to the Board regarding the implementation of an appropriate response to evidence of a material violation of the securities laws or breach of fiduciary duty or similar violation by the Trust, its officers or the Trustees. During the fiscal year ended December 31, 2018, the QLCC held four meetings.

Leadership Structure and Risk Management Oversight

Ms. Needham and Mr. Ross, who are employees of the Adviser, serve as Trustees of the Trust and Ms. Needham serves as President of the Trust. The Board believes that this leadership structure is appropriate, since Mr. Ross and Ms. Needham provide the Board with insight regarding the Trust’s day-to-day management, while Mr. Holland and Mr. Riley provide an independent perspective on the Trust’s overall operation and Ms. Rapaccioli and Ms. Spence provide a specialized perspective on audit matters.

The Board has delegated management of the Trust to service providers who are responsible for the day-to-day management of risks applicable to the Trust. The Board oversees risk management for the Trust in several ways. The Board receives regular reports from both the CCO and administrator for the Trust, detailing the results of the Trust’s compliance with its Board-adopted policies and procedures, the investment policies and limitations of the Funds, and applicable provisions of the federal securities laws and the Code. As needed, the Adviser discusses management issues regarding the Trust with the Board, soliciting the Board’s input on many aspects of management, including potential risks to the Funds. The Board’s Audit Committee also receives reports on various aspects of risk that might affect the Trust and offers advice to management, as appropriate. The Trustees also meet in executive session with the independent counsel to the Independent Trustees, the independent registered public accounting firm, counsel to the Trust, the CCO and representatives of management, as needed. Through these regular reports and interactions, the Board oversees the risk management parameters for the Trust, which are effected on a day-to-day basis by service providers to the Trust.

Trustee Ownership of Securities of the Trust, Adviser and Distributor

As of December 31, 2018, none of the Independent Trustees or their immediate family members had any ownership of securities of the Adviser, State Street Global Advisors Funds Distributors, LLC (“SSGA FD”), the Trust’s distributor, or any person directly or indirectly controlling, controlled by or under common control with the Adviser or SSGA FD.

The following table sets forth information describing the dollar range of the Trust’s equity securities beneficially owned by each Trustee as of December 31, 2018.


	Dollar Range Of Equity Securities In The Funds	Aggregate Dollar Range Of Equity Securities In All Registered Investment Companies Overseen By Trustees In Family of Investment Companies
Name of Independent Trustee
Michael F. Holland	None		None
John R Costantino ⁽¹⁾	None		None
Patrick J. Riley	None		Over $100,000
Richard D. Shirk	None		Over $100,000
Rina K. Spence	None		None
Bruce D. Taber	None		Over $100,000
Donna M. Rapaccioli ⁽¹⁾	None		None
Michael A. Jessee	None		None
Name of Interested Trustees
James E. Ross	None		Over $100,000
Ellen M. Needham ⁽¹⁾	None		None

⁽¹⁾	Mr. Costantino and Mses. Rapaccioli and Needham became Trustees effective December 18, 2018.

Trustee Compensation

As of January 1, 2019, except as noted below, each Independent Trustee receives for his or her services to the State Street Master Funds, the State Street Institutional Investment Trust, the SSGA Funds, the Elfun Funds, the Navigator Trust, State Street Institutional Funds and State Street Variable Insurance Series Funds, Inc. a $195,000 annual base retainer in addition to $22,500 for each in-person meeting, $6,000 for each special in-person meeting and $2,500 for each telephonic meeting from the Trusts. The Trust pays a fixed allocation of $18,000 per Fund. The Co-Chairpersons receive an additional $50,000 annual retainer. The annual base retainer paid to Mr. Taber is $164,000 in light of the fact that Mr. Taber does not serve as a member of the Board of Trustees of the Elfun Funds, and the Board of Directors of State Street Institutional Funds and State Street Variable Insurance Series Funds, Inc. The Independent Trustees are reimbursed for travel and other out-of pocket expenses in connection with meeting attendance. As of the date of this SAI, the Trustees are not paid pension or retirement benefits as part of the Trust’s expenses.

The Trust’s officers are compensated by the Adviser and its affiliates.

The following table sets forth the total remuneration of Trustees and officers of the Trust for the fiscal year ended December 31, 2018:


	AGGREGATE COMPENSATION FROM THE TRUST		PENSION OR RETIREMENT BENEFITS ACCRUED AS PART OF TRUST EXPENSES		ESTIMATED ANNUAL BENEFITS UPON RETIREMENT		TOTAL COMPENSATION FROM TRUST & FUND COMPLEX PAID TO TRUSTEES
NAME OF INDEPENDENT TRUSTEE
Michael F. Holland	$	109,882	$	0	$	0	$	330,500
William L. Marshall ⁽¹⁾	$	88,093	$	0	$	0	$	287,500
Patrick J. Riley	$	110,816	$	0	$	0	$	337,500
Richard D. Shirk	$	88,093	$	0	$	0	$	287,500
Rina K. Spence	$	88,093	$	0	$	0	$	287,500
Bruce D. Taber	$	87,202	$	0	$	0	$	281,500
Douglas T. Williams ⁽¹⁾	$	88,093	$	0	$	0	$	287,500
Michael A. Jessee	$	88,093	$	0	$	0	$	287,500


	AGGREGATE COMPENSATION FROM THE TRUST		PENSION OR RETIREMENT BENEFITS ACCRUED AS PART OF TRUST EXPENSES		ESTIMATED ANNUAL BENEFITS UPON RETIREMENT		TOTAL COMPENSATION FROM TRUST & FUND COMPLEX PAID TO TRUSTEES
John R. Costantino ⁽²⁾	$	0	$	0	$	0	$	170,000
Donna M. Rapaccioli ⁽²⁾	$	0	$	0	$	0	$	160,000
NAME OF INTERESTED TRUSTEES
James E. Ross	$	0	$	0	$	0	$	0
Ellen M. Needham ⁽²⁾	$	0	$	0	$	0	$	0

⁽¹⁾	Messrs. Marshall and Williams retired as Trustees effective as of the close of business on December 18, 2018.

⁽²⁾	Mr. Costantino and Mses. Rapaccioli and Needham became Trustees effective December 18, 2018.

PROXY VOTING PROCEDURES

The Trust has adopted proxy voting procedures pursuant to which the Trust delegates the responsibility for voting proxies relating to portfolio securities held by the Portfolios to the Adviser as part of the Adviser’s general management of the Portfolios, subject to the Board’s continuing oversight. A copy of the Trust’s proxy voting procedures is located in Appendix B and a copy of the Adviser’s proxy voting procedures is located in Appendix C.

Shareholders may receive information regarding how the Funds voted proxies relating to portfolio securities during the most recent 12-month period ending June 30 (i) by calling (877) 521-4083 or (ii) on the SEC’s website at www.sec.gov .

CONTROL PERSONS AND PRINCIPAL HOLDERS OF SECURITIES

As of April 18, 2019, the Trustees and officers of the Trust owned in the aggregate less than 1% of the shares of each class (if applicable) of each Fund.

Persons or organizations owning 25% or more of the outstanding shares of a Fund may be presumed to “control” (as that term is defined in the 1940 Act) a Fund. As a result, these persons or organizations could have the ability to approve or reject those matters submitted to the shareholders of such Fund for their approval.

As of April 18, 2019, to the knowledge of the Trust, the following persons held of record or beneficially through one or more accounts 25% or more of the outstanding shares of a Fund.


Name and Address	Percentage
State Street Institutional Liquid Reserves Fund – Investment Class
Saturn & Co C/O State Street Bank & Trust Attn: FCG 124 200 Clarendon Boston MA 02116-5021		67.22	%
Mass Abrop & Co State Treasurer & Receiver General Abandoned Property Division 1 Ashburton Place Boston MA 02108-1518		32.78	%
State Street Institutional Liquid Reserves Fund – Trust Class
GFAS Control Acct Mt01 State Street Bank PO Box 1992 Quincy MA 02171		75.50	%
State Street Institutional Liquid Reserves Fund – Premier Class


Name and Address	Percentage
State Street Bank And Trust FBO Cash Sweep Clients Attn : Cash Sweep Sup – Rick Letham 1200 Crown Colony DR CC13 Quincy MA 02169-0938		70.90	%
State Street Institutional Liquid Reserves Fund – Institutional Class
Citi Bank, NA As Agent for Client A 388 Greenwich St FL 4th New York NY 10013-2375		47.45	%
University Hospitals Health System INC Retirement Plan, 3605 Warrensville Center RD Beachwood OH 44122-9100		29.11	%
State Street Institutional Liquid Reserves Fund – Investor Class
State Street Bank & Trust FBO Cash Sweeps Clients Attn: Cash sweep SUP 1200 Crown Colony DR CC13 Quincy MA 02169-0938		82.67	%
State Street Institutional Treasury Plus Money Market Fund – Investor Class
State Street Bank And Trust FBO Cash Sweep Clients Attn : Cash Sweep Sup – Rick Letham 1200 Crown Colony DR CC13 Quincy MA 02169-0938		100.00	%
State Street Institutional Treasury Plus Money Market Fund – Premier Class
State Street Bank And Trust FBO Cash Sweep Clients Attn : Cash Sweep Sup – Rick Letham 1200 Crown Colony DR CC13 Quincy MA 02169-0938		71.44	%
State Street Institutional Treasury Plus Money Market Fund – Trust Class
GFAS Control Acct MT01 State Street Bank PO Box 1992 Quincy MA 02171		91.91	%
State Street Institutional Treasury Plus Money Market Fund – Institutional Class
Hare & Co 2 Attn: STIF 111 Sanders Creek PKWY East Syracuse NY 13057-1382		99.96	%


Name and Address	Percentage
State Street Institutional Treasury Plus Money Market Fund – Administration Class
SSGA Pvt Funds Attn : Fund Services Team 1 Lincoln St Boston MA 02111-2901		100.00	%
State Street Institutional Treasury Plus Money Market Fund – Investment Class
Saturn & Co C/O State Street Bank & Trust Attn: FCG 124 200 Clarendon		78.33	%
State Street Institutional Treasury Money Market Fund – Investor Class
State Street Bank And Trust FBO Cash Sweep Clients Attn : Cash Sweep Sup – Rick Letham 1200 Crown Colony DR CC13 Quincy MA 02169-0938		100.00	%
State Street Institutional Treasury Money Market Fund – Premier Class
State Street Bank And Trust FBO Cash Sweep Clients Attn : Cash Sweep Sup – Rick Letham 1200 Crown Colony DR CC13
Quincy MA 02169-0938		66.07	%
State Street Institutional Treasury Money Market Fund – Investment Class
Saturn & Co C/O State Street Bank & Trust Attn: FCG 124 200 Clarendon
Boston MA 02116-5021		100.00	%
State Street Institutional Treasury Money Market Fund – Administration Class
SSGA Private Funds LLC
Attn Fund Services Team 1 Lincoln St
Boston MA 02111-2901		100.00	%
State Street Institutional Treasury Money Market Fund –Institutional Class
SSGA Private Funds LLC
Attn Fund Services Team 1 Lincoln St
Boston MA 02111-2901		100.00	%


Name and Address	Percentage
State Street Institutional U.S. Government Money Market Fund- Institutional Class
Citi Bank Na As Agent For Various
388 Greenwich St FI 4th New York NY 10013-2375		25.41	%
State Street Institutional U.S. Government Money Market Fund – Institutional Class
Hare & Co 2 Attn: STIF 111 Sanders Creek PKWY
East Syracuse NY 13057-1382		68.09	%
State Street Institutional U.S. Government Money Market Fund – Investor Class
Stormcrew & Co Attn MF Sweep Processing 1200 Crown Colony DR FL 3
Quincy MA 02169-0938		48.83	%
State Street Bank And Trust FBO Cash Sweep Clients
Attn : Cash Sweep Sup – Rick Letham 1200 Crown Colony DR CC13
Quincy MA 02169-0938		32.49	%
State Street Institutional U.S. Government Money Market Fund – Investment Class
Saturn & Co C/O State Street Bank & Trust
Attn: FCG 124 200 Clarendon
Boston MA 02116-5021		79.88	%
State Street Institutional U.S. Government Money Market Fund – Premier Class
State Street Bank And Trust FBO Cash Sweep Clients
Attn : Cash Sweep Sup – Rick Letham 1200 Crown Colony DR CC13
Quincy MA 02169-0938		61.05	%
State Street Institutional U.S. Government Money Market Fund – Class G
State Street Bank And Trust FBO Cash Sweep Clients
Attn : Cash Sweep Sup – Rick Letham 1200 Crown Colony DR CC13
Quincy MA 02169-0938		100	%
State Street Treasury Obligations Money Market Fund
State Street Bank And Trust FBO Cash Sweep Clients
Attn : Cash Sweep Sup – Rick Letham 1200 Crown Colony DR CC13
Quincy MA 02169-0938		99.08	%

As of April 18, 2019, to the knowledge of the Trust, the following persons held of record or beneficially through one or more accounts 5% or more of the outstanding shares of a class of a Fund.


State Street Institutional U.S. Government Money Market Fund – Investment Class
Typhoonbass & Co 1200 Crown Colony Dr
Quincy MA 02169-0938	9.71	%
Neuberger Berman Mgmt LLC FBO Neuberger Berman Funds Shareholders
Attn Owen F Mcentee Jr 605 Third Ave Mail Drop 2-7
New York NY 10158	10.41	%
State Street Institutional U.S. Government Money Market Fund – Institutional Class
TD Prime Services LLC
31 W 52ND ST FL 9TH1
New York NY 10019-6118	6.37	%
State Street Institutional Liquid Reserves Fund – Administration Class
Swathnore College 9804 PO BOX 1992
Boston MA 02130	23.18	%
Phoebe Putney Health System IVZ1 471 Third Ave PO BOX 1828 Alnabgya 31702-1828	7.52	%
TVLB 845 VG4N 801 Pennsylvania Ave Kansas City MO 64105-1307	12.41	%
State Street Institutional Liquid Reserves Fund – Trust Class
Sei Private Trust Company C/O Evercore FBO Newport Trust
Attn: Mutual Fund Administrator
One Freedom Valley Drive
Oaks PA 19456-9989	24.49	%
State Street Institutional Liquid Reserves Fund – Institutional Class
University Hospitals Health System INC Retirement Plan, 3605 Warrensville Center RD Beachwood OH 44122-9100	15.03	%
University Hospitals Health System, Inc 3605 Warrensville Center RD Beachwood OH 44122-9100	8.35	%
State Street Institutional Liquid Reserves Fund – Premier Class
Hare & Co Attn : 111 Sanders Creek PKWY East Syracuse NY 13057-1382	5.35	%
State Street Institutional Liquid Reserves Fund - Investor State Street Global Advisors Funds Distributors LLC Attn Editha Tenorio 1 Lincoln St # SFC-13 Boston MA 02111-2901	17.33	%


State Street Institutional U.S. Government Money Market Fund – Investor Class
Hare & Co
Attn : 111 Sanders Creek PKWY East Syracuse NY 13057-1382	18.68	%
State Street Institutional U.S. Government Money Market Fund – Administration Class
Black And Gold Fund Ltd Sovd 1776 Heritage DR Quincy MA 02171-2119	5.12	%
State Street Institutional Treasury Plus Money Market Fund – Trust Class
Saturn & Co C/O State Street Bank & Trust 1200 Crown Colony DCC10312
Quincy MA 02169-0938	6.61	%
State Street Institutional Treasury Plus Money Market Fund – Premier Class
Bristol Myers Squibb Compnay
Attn Bms Corp Treasury – Will Chao 100 Nassau Park Blvd Princeton NJ 08540-5997	9.01	%
State Street Institutional Treasury Plus Money Market Fund – Investment Class
Neuberger Berman Mgmt LLC FBO Neuberger Berman Funds Shareholders
Attn Owen F Mcentee Jr 605 Third Ave Mail Drop 2-7 New York NY-10158	21.67	%
State Street Institutional Treasury Money Market Fund – Premier Class
Merrill Lynch Pierce Fenner & Smith Attn Money Market Fund 200 North College ST FL 3
Charlotte NC 28202-2191	11.58	%

As of April 18, 2019, to the knowledge of the Trust, no persons held of record or beneficially through one or more accounts 25% or more of the outstanding shares of the Ultra Short Bond Fund and Ultra Short Bond Portfolio or 5% or more of the outstanding shares of any class of any such Fund.

INVESTMENT ADVISORY AND OTHER SERVICES

Investment Advisory Agreement

The Adviser is responsible for the investment management of the Funds pursuant to the Amended and Restated Investment Advisory Agreement dated November 17, 2015 as amended from time to time (the “Advisory Agreement”), by and between the Adviser and the Trust. The Adviser is a wholly-owned subsidiary of State Street Global Advisors, Inc., which itself is a wholly-owned subsidiary of State Street Corporation, a publicly held financial holding company. State Street is a wholly-owned subsidiary of State Street Corporation.

The Advisory Agreement will continue from year to year provided that such continuance is specifically approved at least annually by (a) the Trustees or by the vote of a majority of the outstanding voting securities of a Fund, and (b) vote of a majority of the Independent Trustees, cast in person at a meeting called for the purpose of voting on such approval. The Advisory Agreement may be terminated by the Adviser or the Trust without penalty upon sixty days’ notice and will terminate automatically upon its assignment. The Adviser and its affiliates may have deposit, loan and other commercial banking relationships with the issuers of obligations that may be purchased on behalf of the Funds, including outstanding loans to such issuers that could be repaid in whole or in part with the proceeds of securities so purchased. Such affiliates deal, trade and invest for their own accounts in such obligations and are among the leading dealers of various types of such obligations. The Adviser has informed the Funds that, in making its investment decisions, it will not obtain or use material non-public information in its possession or in the possession of any of its affiliates. In making investment recommendations for a Fund, the Adviser will not inquire or take into consideration whether an issuer of securities proposed for purchase or sale by the Fund is a customer of the Adviser, its parent or its subsidiaries or affiliates and, in dealing with its customers, the Adviser, its parent, subsidiaries and affiliates will not inquire or take into consideration whether securities of such customers were held by any fund managed by the Adviser or any such affiliate.

In certain instances there may be securities that are suitable for a Fund as well as for one or more of the Adviser’s other clients. Investment decisions for the Trust and for the Adviser’s other clients are made with a view to achieving their respective investment objectives. It may develop that a particular security is bought or sold for only one client even though it might be held by, or bought or sold for, other clients. Likewise, a particular security may be bought for one or more clients when one or more clients are selling that same security. Some simultaneous transactions are inevitable when several clients receive investment advice from the same investment adviser, particularly when the same security is suitable for the investment objectives of more than one client. When two or more clients are simultaneously engaged in the purchase or sale of the same security, the securities are allocated among clients in a manner believed to be equitable to each. The Trust recognizes that in some cases this system could have a detrimental effect on the price or volume of the security as far as a Fund is concerned. However, it is believed that the ability of each Fund to participate in volume transactions will produce better executions for the Funds.

ILR Fund, U.S. Government Fund, Treasury Fund, Treasury Plus Fund and Treasury Obligations Fund : Each Fund currently invests all of its assets in a related Portfolio that has the same investment objectives and substantially the same investment policies as the relevant Fund. As long as a Fund remains completely invested in its related Portfolio (or any other investment company), the Adviser is not entitled to receive any investment advisory fee with respect to the Fund. A Fund may withdraw its investment from the related Portfolio at any time. The Trust has retained the Adviser as investment adviser to manage a Fund’s assets in the event that the Fund withdraws its investment from its related Portfolio.

The Adviser is also the investment adviser to each of the related Portfolios pursuant to an investment advisory agreement (the “Portfolio Advisory Agreement”) between the Adviser and State Street Master Funds, on behalf of the Portfolios. The Adviser receives an investment advisory fee with respect to each related Portfolio. The Portfolio Advisory Agreement is the same in all material respects as the Advisory Agreement between the Trust on behalf of the Funds and the Adviser. Each Fund that invests in a related Portfolio bears a proportionate part of the management fees paid by the Portfolio (based on the percentage of the Portfolio’s assets attributable to the Fund).

For the services provided under the Advisory Agreement and the Portfolio Advisory Agreement, each Fund pays the Adviser a fee at an annual rate set forth below of the Fund’s average daily net assets.


Fund	Fee Rate
ILR Fund		0.05	%
U.S. Government Fund		0.05	%
Treasury Fund		0.05	%
Treasury Plus Fund		0.05	%
Treasury Obligations Fund		0.05	%

Ultra Short Bond Fund: The Fund expects to invest substantially all of its assets in a related Portfolio, which has the same investment objectives and substantially similar investment policies as the relevant Fund. The Portfolio pays no investment advisory fees to SSGA FM. For the services provided under the Advisory Agreement, the Fund pays the Adviser a fee at an annual rate set forth below of the Fund’s average daily net assets.


Fund	Fee Rate
Ultra Short Bond Fund		0.25	%

The advisory fees paid by the Ultra Short Bond Fund to SSGA FM for the last three fiscal years have been omitted because the Funds had not commenced investment operations as of December 31, 2018.

Total Annual Fund Operating Expense Waivers . The Adviser has contractually agreed with the Trust (i) to waive up to the full amount of the advisory fee payable by certain Funds, and/or (ii) to reimburse a Fund for expenses to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, extraordinary expenses, acquired fund fees, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed the following percentage of average daily net assets on an annual basis with respect to the below-listed Funds:


Fund	Expense Limitation			Expiration Date
ILR Fund		0.07	%		4/30/2020
U.S. Government Fund		0.07	%		4/30/2020
Treasury Plus Fund		0.07	%		4/30/2020
Treasury Obligations Fund		0.10	%		4/30/2021
Ultra Short Bond Fund		0.30	%		4/30/2020

Voluntary Expense Waiver. The Adviser has voluntarily agreed to waive its advisory fee and/or to reimburse the Treasury Obligations Fund for expenses to the extent that the Fund’s total annual operating expenses exceed 0.08% of average daily net assets on an annual basis (the “Voluntary Expense Waiver”). The Adviser may discontinue the Voluntary Expense Waiver at any time, in its sole discretion.

Voluntary Yield Waivers . In addition to any contractual expense limitation for a Fund, the Adviser from time to time has historically reduced fees and reimbursed expenses for certain Funds to the extent necessary to avoid a negative yield (the “Voluntary Reduction”). Under an agreement with the Adviser relating to the Voluntary Reduction, the Funds and the Portfolios have agreed to reimburse the Adviser for the full dollar amount of any Voluntary Reduction beginning on October 1, 2012, subject to certain limitations. A Fund will not be obligated to reimburse the Adviser:

•

more than three years after the end of the fiscal year for the Fund in which the Adviser provided a Voluntary Reduction;

•

in respect of any business day for which the net annualized one-day yield is less than 0.00%;

•

to the extent that the amount of the reimbursement to the Adviser on any day exceeds fifty percent of the yield (net of all expenses, exclusive of the reimbursement) of a Fund on that day;

•

to the extent that the amount of such reimbursement would cause the Fund’s net yield to fall below the Fund’s minimum net yield as determined by the Adviser in its sole discretion; or

•

in respect of any fee waivers and/or expense reimbursements that are necessary to maintain a Fund’s contractual total expense limit which is effective at the time of such fee waivers and/or expense reimbursements.

A reimbursement to the Adviser would increase fund expenses and negatively impact a Fund’s future yield. There is no guarantee that the Voluntary Reduction will be in effect at any given time or that a Fund will be able to avoid a negative yield. Reimbursement payments by a Fund to the Adviser in connection with the Voluntary Reduction are considered “extraordinary expenses” and are not subject to any contractual expense limitation agreement in effect for the Fund at the time of such payment. The Adviser may, in its sole discretion, irrevocably waive receipt of any or all reimbursement amounts due from a Fund.


	Amount Voluntarily Waived for the Fiscal Year Ended December 31, 2018		Aggregate Amount Waived Since October 1, 2012		Amount Potentially Recoverable by the Adviser
ILR Fund	$	0	$	5,908,845	$	0
U.S. Government Fund	$	0	$	18,374,436	$	0
Treasury Fund	$	0	$	41,812,346	$	0
Treasury Plus Fund	$	0	$	6,580,096	$	0

Administrator

SSGA FM serves as the administrator for the Funds pursuant to an Amended and Restated Administration Agreement dated June 1, 2015. Under the Amended and Restated Administration Agreement, SSGA FM is obligated to continuously provide business management services to the Trust and each Fund and will generally, subject to the general oversight of the Trustees and except as otherwise provided in the Amended and Restated Administration Agreement, manage all of the business and affairs of the Trust. The nature and amount of services provided by SSGA FM under the Amended and Restated Administration Agreement may vary as between classes of shares of a Fund, and a Fund may pay fees to SSGA FM under that Agreement at different rates in respect of its different share classes. Except as noted below, as consideration for SSGA FM’s services as administrator to each Fund, SSGA FM receives an annual fee of 0.05% of the average daily net assets of such Fund, accrued daily at the rate of 1/365th and payable monthly on the first business day of each month. As consideration for SSGA FM’s services as administrator to Class G shares of the U.S. Government Fund, SSGA FM receives an annual fee of 0.01% of the average daily net assets of such class, accrued daily at the rate of 1/365th and payable monthly on the first business day of each month.

The administration fees paid to SSGA FM for the last three fiscal years are set forth in the table below.


Fund	Fiscal year ended December 31, 2016		Fiscal year ended December 31, 2017		Fiscal year ended December 31, 2018
State Street Institutional Liquid Reserves Fund	$	17,771,169	$	4,878,264	$	6,048,744
State Street Institutional U.S. Government Money Market Fund	$	12,564,109	$	21,975,985	$	22,874,871
State Street Institutional Treasury Money Market Fund	$	6,006,871	$	6,569,201	$	5,481,415
State Street Institutional Treasury Plus Money Market Fund	$	2,184,065	$	5,128,505	$	5,321,372
State Street Treasury Obligations Money Market Fund ⁽¹⁾	$	—	$	207,692	$	1,643,013

(1)	Commencement of Operations August 21, 2017.

The administration fees paid by the Ultra Short Bond Fund to SSGA FM for the last three fiscal years have been omitted because the Fund had not commenced investment operations as of December 31, 2018.

Sub-Administrator, Custody and Fund Accounting

State Street serves as the sub-administrator for the Trust, pursuant to a sub-administration agreement dated June 1, 2015 (the “Sub-Administration Agreement”). State Street serves as the custodian for the Trust, pursuant to a custody agreement dated April 11, 2012 (the “Custody Agreement”). Under the Sub-Administration Agreement, State Street is obligated to provide certain sub-administrative services to the Trust. Under the Custody Agreement, State Street is obligated to provide certain custody services to the Trust, as well as basic portfolio recordkeeping required by the Trust for regulatory and financial reporting purposes. State Street is a wholly owned subsidiary of State Street Corporation, a publicly held financial holding company, and is affiliated with the Adviser. State Street’s mailing address is State Street Financial Center, One Lincoln Street, Boston, Massachusetts 02111-2900.

The sub-administration and custodian fees paid to State Street for the last three fiscal years are set forth in the table below.


Fund	Fiscal year ended December 31, 2016		Fiscal year ended December 31, 2017		Fiscal year ended December 31, 2018
State Street Institutional Liquid Reserves Fund	$	44,741	$	52,159	$	98,370
State Street Institutional U.S. Government Money Market Fund	$	46,728	$	56,329	$	424,858
State Street Institutional Treasury Money Market Fund	$	45,988	$	51,319	$	37,349
State Street Institutional Treasury Plus Money Market Fund	$	46,029	$	52,986	$	408,857
State Street Treasury Obligations Money Market Fund ⁽¹⁾	$	—	$	16,554	$	142,823

(1)	Commencement of Operations August 21, 2017.

The sub-administration and custodian fees paid by the Ultra Short Bond Fund to SSGA FM for the last three fiscal years have been omitted because the Fund had not commenced investment operations as of December 31, 2018.

Transfer Agent and Dividend Paying Agent

DST Asset Manager Solutions, Inc. serves as the Transfer and Dividend Paying Agent. DST Asset Manager Solutions, Inc. is paid for the following annual account services and activities including but not limited to: establishment and maintenance of each shareholder’s account; closing an account; acceptance and processing of trade orders; preparation and transmission of payments for dividends and distributions declared by each Fund; customer service support including receipt of correspondence and responding to shareholder and financial intermediary inquiries; investigation services; tax related support; financial intermediary fee payment processing; and charges related to compliance and regulatory services.

Portfolio fees are allocated to each Fund based on the average net asset value of each Fund and are billable on a monthly basis at the rate of 1/12 of the annual fee. DST Asset Manager Solutions, Inc. is reimbursed by each Fund for supplying certain out-of-pocket expenses including confirmation statements, investor statements, banking fees, postage, forms, audio response, telephone, records retention, customized programming/enhancements, reports, transcripts, microfilm, microfiche, and expenses incurred at the specific direction of the Fund. DST Asset Manager Solutions, Inc. principal business address is 2000 Crown Colony Drive, Quincy, MA 02169.

The transfer agency fees paid to DST Asset Manager Solutions, Inc. for the last three fiscal years are set forth in the table below.


Fund	Fiscal year ended December 31, 2016		Fiscal year ended December 31, 2017		Fiscal year ended December 31, 2018
State Street Institutional Liquid Reserves Fund	$	2,358,605	$	217,476	$	344,152
State Street Institutional U.S. Government Money Market Fund	$	4,134,856	$	140,703	$	117,997
State Street Institutional Treasury Money Market Fund	$	1,725,623	$	41,588	$	34,662
State Street Institutional Treasury Plus Money Market Fund	$	1,671,425	$	56,634	$	40,679
State Street Treasury Obligations Money Market Fund ⁽¹⁾	$	—	$	15,000	$	144

(1)	Commencement of Operations August 21, 2017.

The transfer agency fees paid by the Ultra Short Bond Fund to DST for the last three fiscal years have been omitted because the Fund had not commenced investment operations as of December 31, 2018.

Codes of Ethics

The Trust, the Adviser and SSGA FD have each adopted a code of ethics (together, the “Codes of Ethics”) pursuant to Rule 17j-1 under the 1940 Act as required by applicable law, which is designed to prevent affiliated persons of the Trust, the Adviser and SSGA FD from engaging in deceptive, manipulative or fraudulent activities in connection with securities held or to be acquired by the Funds (which may also be held by persons subject to the Codes of Ethics). The Codes of Ethics permit personnel, subject to the Codes of Ethics and their provisions, to invest in securities for their personal investment accounts, subject to certain limitations, including securities that may be purchased or held by the Trust, Adviser, State Street or SSGA FD.

Distributor

SSGA FD serves as the distributor of the Funds pursuant to the Distribution Agreement by and between SSGA FD and the Trust. Pursuant to the Distribution Agreement, the Funds, except for the Treasury Obligations Fund, pay SSGA FD fees under the Rule 12b-1 Plan in effect for the Funds. For a description of the fees paid to SSGA FD under the Rule 12b-1 Plan, see “Distribution Plans,” below. SSGA FD is an indirect wholly-owned subsidiary of State Street Corporation. SSGA FD’s mailing address is One Iron Street, Boston, MA 02210.

Distribution Plans

To compensate SSGA FD for the services it provides and for the expenses it bears in connection with the distribution of shares of the Funds, SSGA FD will be entitled to receive any front-end sales load applicable to the sale of shares of the Fund. Each Fund, except for the Treasury Obligations Fund, may make payments (“Rule 12b-1 Fees”) from the assets attributable to certain classes of its shares to SSGA FD under a distribution plan adopted pursuant to Rule 12b-1 under the 1940 Act (the “Distribution Plan”). The Distribution Plan is a compensation plan that provides for payments at annual rates (based on average daily net assets) set out below. Because Rule 12b-1 Fees are paid on an ongoing basis, they will increase the cost of your investment and may cost you more than paying other types of sales loads. The principal business address of SSGA FD is One Iron Street, Boston, MA 02210.

The Board, including all of the Trustees who are not interested persons (as defined in the 1940 Act) of the Trust (the “Independent Trustees”) and who have no direct or indirect financial interest in the Distribution Plan or any related agreements, (the “Qualified Distribution Plan Trustees”) approved the Distribution Plan. The Distribution Plan will continue in effect with respect to a class of shares of a Fund only if such continuance is specifically approved at least annually by a vote of both a majority of the Board of Trustees of the Trust and a majority of the Qualified Distribution Plan Trustees. The Distribution Plan may not be amended to increase materially the amount of a Fund’s permitted expenses thereunder without the approval of a majority of the outstanding shares of the affected share class and may not be materially amended in any case without a vote of the majority of both the Trustees and the Qualified Distribution Plan Trustees. As of December 31, 2018 none of the Independent Trustees had a direct or indirect financial interest in the operation of the Distribution Plan. The Distribution Plan calls for payments at an annual rate (based on each Fund’s average net assets) as follows:


Premier Class*	0.00	%
Service Class**	0.00	%
Investment Class	0.10	%
Institutional Class	0.00	%
Investor Class	0.00	%
Administration Class	0.05	%
Class M†	0.00	%
Class G††	0.00	%
Trust Class†††	0.00	%

*	All Funds except for Ultra Short Bond Fund and Treasury Obligations Fund.

**	ILR Fund, U.S. Government Fund, Treasury Fund and Treasury Plus Fund only.

†	U.S. Government Fund only.

††	U.S. Government Fund only.

†††	ILR Fund and Treasury Plus Fund only.

For the fiscal year ended December 31, 2018, the total Rule 12b-1 fees paid to SSGA FD and Intermediaries are reflected in the chart below:


Fund	SSGA FD Fiscal Year Ended December 31, 2018 ¹		Intermediaries Fiscal Year Ended December 31, 2018 ²
ILR Fund:
Investment Class	$	1,052	$	1,047
Administration Class	$	484,000	$	492,097
U.S. Government Fund:
Investment Class	$	468,754	$	425,352
Administration Class	$	983,058	$	983,941


Fund	SSGA FD Fiscal Year Ended December 31, 2018 ¹		Intermediaries Fiscal Year Ended December 31, 2018 ²
Treasury Fund:
Investment Class	$	340,667	$	340,653
Administration Class	$	11		—
Treasury Plus Fund:
Investment Class	$	34,706	$	24,721
Administration Class	$	11		—

¹	Amounts shown represent amounts retained by SSGA FD and are net of payments made by SSGA FD to other intermediaries.

²	Amounts shown represent amounts paid by SSGA FD to intermediaries out of payments it receives from the Funds under the Rule 12b-1 Distribution Plan.

The Distribution Plan may benefit the Funds by increasing sales of shares and reducing redemptions of shares, resulting potentially, for example, in economies of scale and more predictable flows of cash into and out of the Funds. Because Rule 12b-1 fees are paid out of a Fund’s assets, all shareholders share in that expense; however, because shareholders hold their shares through varying arrangements (for example, directly or through financial intermediaries), they may not share equally in the benefits of the Distribution Plan.

Shareholder Servicing Agent

SSGA FD serves as a shareholder servicing agent of the ILR Fund, the U.S. Government Fund, the Treasury Fund, and the Treasury Plus Fund pursuant to a Shareholder Servicing Agreement between SSGA FD and the Trust (the “Shareholder Servicing Agreement”). Pursuant to the Shareholder Servicing Agreement, SSGA FD provides or arranges for the provision of various administrative, sub-accounting and personal services to investors in the Institutional Class, Trust Class, Investor Class, Administration Class and Investment Class shares of such Funds. Services provided by SSGA FD or that SSGA FD arranges to be provided by a financial intermediary pursuant to the Shareholder Servicing Agreement include, among other things: establishing and maintaining shareholder account registrations; sub-accounting with respect to shares held in omnibus accounts; receiving and processing purchase and redemption orders, including aggregated orders, and delivering orders to the Fund’s transfer agent; processing and delivering trade confirmations, periodic statements, prospectuses, annual reports, semi-annual reports, shareholder notices, and other SEC-required communications; processing dividend and distribution payments and issuing related documentation; providing shareholder tax reporting and processing tax data; receiving, tabulating, and transmitting proxies for proxy solicitations; and responding to inquiries from shareholders. Shareholder servicing fees paid for the last fiscal year included amounts paid to affiliates of the Adviser and SSGA FD including State Street Global Markets, LLC and the Wealth Management Services and Global Services divisions of State Street Bank and Trust Company. These affiliates of the Adviser are also among the financial intermediaries that may receive fees from the Distribution Plan.

The Shareholder Servicing Agreement calls for payments by the ILR Fund, U.S. Government Fund, Treasury Fund and Treasury Plus Fund at an annual rate (based on average net assets) as follows:


Premier Class	None
Institutional Class	0.03	%
Service Class	0.05	%
Trust Class (Treasury Plus Fund)	0.056	%
Trust Class (ILR Fund)	0.058	%
Investor	0.08	%
Administration	0.20	%
Investment	0.25	%

The total shareholder servicing fees paid to SSGA FD pursuant to the Shareholder Servicing Agreement by the ILR Fund, the U.S. Government Fund, the Treasury Fund, and the Treasury Plus Fund for the last three fiscal years are reflected in the chart below :


Fund	Fiscal year ended December 31, 2016 ¹		Fiscal year ended December 31, 2017		Fiscal year ended December 31, 2018
State Street Institutional Liquid Reserves Fund	$	1,990,234	$	2,558,171	$	2,381,664
State Street Institutional U.S. Government Money Market Fund	$	2,070,091	$	7,556,858	$	6,131,521
State Street Institutional Treasury Money Market Fund	$	1,666,257	$	1,266,547	$	943,755
State Street Institutional Treasury Plus Money Market Fund	$	1,616,463	$	4,205,817	$	3,188,124

¹	Amounts reflect payments made for shareholder servicing pursuant to the Shareholder Servicing Agreement from the effective date of the agreement as well as payments made pursuant to a prior arrangement between the Funds and SSGA FD.

Payments to Financial Intermediaries

Financial intermediaries are firms that sell shares of mutual funds, including the Funds, and/or provide certain administrative and account maintenance services to mutual fund shareholders. Financial intermediaries may include, among others, brokers, financial planners or advisors, banks, retirement plan recordkeepers, and insurance companies. In some cases, a financial intermediary may hold its clients’ Fund shares in nominee or street name and may utilize omnibus accounts. Shareholder services provided by a financial intermediary may (though they will not necessarily) include, among other things: establishing and maintaining shareholder account registrations; sub-accounting with respect to shares held in omnibus accounts; receiving and processing purchase and redemption orders, including aggregated orders, and delivering orders to the Fund’s transfer agent; processing and delivering trade confirmations, periodic statements, prospectuses, annual reports, semi-annual reports, shareholder notices, and other SEC-required communications; processing dividend and distribution payments and issuing related documentation; providing shareholder tax reporting and processing tax data; receiving, tabulating, and transmitting proxies for proxy solicitations; and responding to inquiries from shareholders.

Some portion of SSGA FD’s payments to financial intermediaries will be made out of amounts received by SSGA FD under the Distribution Plans and pursuant to the Shareholder Servicing Agreement. In addition, the Funds may reimburse SSGA FD for payments SSGA FD makes to financial intermediaries that provide recordkeeping, shareholder servicing, sub-transfer agency, administrative and/or account maintenance services (collectively, “servicing”). The amount of the reimbursement for servicing compensation and the manner in which it is calculated are reviewed by the Trustees periodically.

A financial intermediary is often compensated by SSGA FD or its affiliates for the services the financial intermediary performs and in such cases it is typically paid continually over time, during the period when the intermediary’s clients hold investments in the Funds. The compensation to financial intermediaries may include networking fees and account-based fees. The amount of continuing compensation paid by SSGA FD to different financial intermediaries varies. In the case of most financial intermediaries, compensation for servicing in excess of any amount covered by payments under a Distribution Plan is generally paid at an annual rate of 0.03% – 0.25% of the aggregate average daily net asset value of Fund shares held by that financial intermediary’s customers, although in some cases the compensation may be paid at higher annual rates (which may, but will not necessarily, reflect enhanced or additional services provided by the financial intermediary). The amount paid by a Fund may vary by share class.

If you invest through a Financial Intermediary and meet the eligibility criteria for more than one share class, you should discuss with your Financial Intermediary which share class is appropriate for you. Your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend one share class over another, when you are eligible to invest in more than one share class. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by the Fund or its affiliates with respect to the different share classes offered by the Fund.

SSGA FD and its affiliates (including SSGA FM), at their own expense and out of their own assets, may also provide compensation to financial intermediaries in connection with sales of the Funds’ shares or servicing of shareholders or shareholder accounts by financial intermediaries. Such compensation may include, but is not limited to, ongoing payments, financial assistance to financial intermediaries in connection with conferences, sales, or training programs for their employees, seminars for the public, advertising or sales campaigns, or other financial intermediary-sponsored special events. In some instances, this compensation may be made available only to certain financial intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Financial intermediaries may not use sales of the Funds’ shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as the Financial Industry Regulatory Authority, Inc. (“FINRA”). The level of payments made to a financial intermediary in any given year will vary and, in the case of most financial intermediaries, will not exceed 0.05% of the value of assets attributable to the financial intermediary invested in shares of funds in the SSGA FM-fund complex. In certain cases, the payments described in the preceding sentence are subject to minimum payment levels.

If payments to financial intermediaries by the distributor or adviser for a particular mutual fund complex exceed payments by other mutual fund complexes, your financial advisor and the financial intermediary employing him or her may have an incentive to recommend that fund complex over others. Please speak with your financial advisor to learn more about the total amounts paid to your financial advisor and his or her firm by SSGA FD and its affiliates, and by sponsors of other mutual funds he or she may recommend to you. You should also consult disclosures made by your financial intermediary at the time of purchase. Because the Funds pay distribution, service and other fees for the sale of their shares and for services provided to shareholders out of the Funds’ assets on an ongoing basis, over time those fees will increase the cost of an investment in a Fund.

A Fund may pay distribution fees, service fees and other amounts described above at a time when shares of the Fund are not being actively promoted to new investors generally, or when shares of that Fund are unavailable for purchase.

For the fiscal year ended December 31, 2018, the Funds have been informed by SSGA FD that the following expenditures were made using the amounts each Fund paid under its 12b-1 Distribution Plan:


Fund	Advertising		Printing		Compensation to Dealers		Compensation to Sales Personnel		Interest, Carrying or Other Financing Charges		Other*
State Street Institutional Liquid Reserves Fund	$	13	$	3,244	$	493,143	$	58,290		—	$	64,546
State Street Institutional U.S. Government Money Market Fund	$	25	$	12,783	$	1,409,293	$	212,127		—	$	221,327
State Street Institutional Treasury Money Market Fund		—	$	1,424	$	340,653	$	21,375		—	$	20,658
State Street Institutional Treasury Plus Money Market Fund		—	$	1,384	$	24,721	$	20,549		—	$	20,035

*	Includes such items as compensation for travel, conferences and seminars for staff, subscriptions, office charges and professional fees. Rule 12b-1 fees paid by the State Street Ultra Short Bond Fund have been omitted because the Fund had not commenced investment operations as of December 31, 2018.

Set forth below is a list of those financial intermediaries as of May 1, 2019 in which SSGA FD (and its affiliates) as entered into an agreement could pay compensation in the manner described in this “Payments to Financial Intermediaries” section.

• Ariel Distributors, Inc.

• Ascensus Inc.

• AXA Advisors, LLC

• Citibank, NA

• Computershare Trust Company, NA

• GWFS Equities Inc.

• John Hancock Trust Company

• JP Morgan Chase Bank, N.A.

• LaSalle Street Securities

• Mid Atlantic Capital Corp.

• Morgan Stanley Smith Barney LLC

• MSCS Financial Services LLC

• Oppenheimer & Co. Inc.

• Pershing LLC

• Raymond James & Associates, Inc.

• SEI Private Trust Company

• State Street Bank & Trust Company - Wealth Manager Services

• State Street Bank & Trust Company - State Street Global Markets

• State Street Bank and Trust Company

• State Street Capital Markets, LLC

• TD Ameritrade Trust Company

• TD Prime Services, LLC

• The Bank of New York Mellon Corp

• Valic Financial Advisors, Inc.

• Voya Retirement Insurance and Annuity Company

• Wells Fargo Bank, N.A.

• Wells Fargo Clearing Services, LLC

Counsel and Independent Registered Public Accounting Firm

Ropes & Gray LLP serves as counsel to the Trust. The principal business address of Ropes & Gray LLP is 800 Boylston Street, Boston, Massachusetts 02199. Joseph P. Barri LLC, located at 259 Robbins Street, Milton, Massachusetts 02186, serves as independent counsel to the Independent Trustees.

Ernst & Young LLP serves as the independent registered public accounting firm for the Trust and provides (i) audit services and (ii) tax services. In connection with the audit of the 2018 financial statements, the Trust entered into an engagement agreement with Ernst & Young LLP that sets forth the terms of Ernst & Young LLP’s audit engagement. The principal business address of Ernst & Young LLP is 200 Clarendon Street, Boston, Massachusetts 02116.

PORTFOLIO MANAGERS

The following persons serve as the portfolio managers of the Ultra Short Bond Fund as of the date of this SAI. The following table lists the number and types of accounts managed by each individual and assets under management in those accounts as of December 31, 2018:


Portfolio Manager	Registered Investment Company Accounts		Assets Managed (billions)*		Other Pooled Investment Vehicle Accounts		Assets Managed (billions)*		Other Accounts		Assets Managed (billions)*		Total Assets Managed (billions)
Todd Bean		13	$	89.82		18	$	82.09		67	$	86.61	$	258.52
Sean Lussier		13	$	89.82		18	$	82.09		67	$	86.61	$	258.52
Thomas Connelley		13	$	89.82		18	$	82.90		67	$	86.61	$	258.52

*	There are no performance-based fees associated with these accounts.

The portfolio managers do not beneficially own any shares of any Fund as of December 31, 2018.

A portfolio manager that has responsibility for managing more than one account may be subject to potential conflicts of interest because he or she is responsible for other accounts in addition to the Funds. Those conflicts could include preferential treatment of one account over others in terms of: (a) the portfolio manager’s execution of different investment strategies for various accounts; or (b) the allocation of resources or of investment opportunities. Portfolio managers may manage numerous accounts for multiple clients. These accounts may include registered investment companies (which include exchange-traded funds), other types of pooled accounts (e.g., collective investment funds), and separate accounts (i.e., accounts managed on behalf of individuals or public or private institutions). Portfolio managers make investment decisions for each account based on the investment objectives and policies and other relevant investment considerations applicable to that portfolio. A potential conflict of interest may arise as a result of the portfolio managers’ responsibility for multiple accounts with similar investment guidelines. Under these circumstances, a potential investment may be suitable for more than one of the portfolio managers’ accounts, but the quantity of the investment available for purchase is less than the aggregate amount the accounts would ideally devote to the opportunity. Similar conflicts may arise when multiple accounts seek to dispose of the same investment. The portfolio managers may also manage accounts whose objectives and policies differ from that of the Funds. These differences may be such that under certain circumstances, trading activity appropriate for one account managed by the portfolio manager may have adverse consequences for another account managed by the portfolio manager. For example, an account may sell a significant position in a security, which could cause the market price of that security to decrease, while a fund maintained its position in that security.

potential material conflicts. For instance, portfolio managers are normally responsible for all accounts within a certain investment discipline and do not, absent special circumstances, differentiate among the various accounts when allocating resources. Additionally, the Adviser and its advisory affiliates have processes and procedures for allocating investment opportunities among portfolios that are designed to provide a fair and equitable allocation.

SSGA’s culture is complemented and reinforced by a total rewards strategy that is based on a pay for performance philosophy which seeks to offer a competitive pay mix of base salary, benefits, cash incentives and deferred compensation.

Salary is based on a number of factors, including external benchmarking data and market trends, State Street performance, SSGA performance, and individual overall performance. SSGA’s Global Human Resources department regularly participates in compensation surveys in order to provide SSGA with market-based compensation information that helps support individual pay decisions.

Additionally, subject to State Street and SSGA business results, State Street allocates an incentive pool to SSGA to reward its employees. The size of the incentive pool for most business units is based on the firm’s overall profitability and other factors, including performance against risk-related goals. For most SSGA investment teams, SSGA recognizes and rewards performance by linking annual incentive decisions for investment teams to the firm’s or business unit’s profitability and business unit investment performance over a multi-year period.

Incentive pool funding for most active investment teams is driven in part by the post-tax investment performance of fund(s) managed by the team versus the return levels of the benchmark index(es) of the fund(s) on a one-, three- and, in some cases, five-year basis. For most active investment teams, a material portion of incentive compensation for senior staff is deferred over a four-year period into the SSGA Long-Term Incentive (“SSGA LTI”) program. For these teams, The SSGA LTI program indexes the performance of these deferred awards against the post-tax investment performance of fund(s) managed by the team. This is intended to align our investment team’s compensation with client interests, both through annual incentive compensation awards and through the long-term value of deferred awards in the SSGA LTI program.

For the passive equity investment team, incentive pool funding is driven in part by the post-tax 1 and 3-year tracking error of the funds managed by the team against the benchmark indexes of the funds.

The discretionary allocation of the incentive pool to the business units within SSGA is influenced by market-based compensation data, as well as the overall performance of each business unit. Individual compensation decisions are made by the employee’s manager, in conjunction with the senior management of the employee’s business unit. These decisions are based on the overall performance of the employee and, as mentioned above, on the performance of the firm and business unit. Depending on the job level, a portion of the annual incentive may be awarded in deferred compensation, which may include cash and/or Deferred Stock Awards (State Street stock), which typically vest over a four-year period. This helps to retain staff and further aligns SSGA employees’ interests with SSGA clients’ and shareholders’ long-term interests.

SSGA recognizes and rewards outstanding performance by:

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Promoting employee ownership to connect employees directly to the company’s success.

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Using rewards to reinforce mission, vision, values and business strategy.

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Seeking to recognize and preserve the firm’s unique culture and team orientation.

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Providing all employees the opportunity to share in the success of SSGA.

BROKERAGE ALLOCATION AND OTHER PRACTICES

All portfolio transactions are placed on behalf of a Fund by the Adviser. Purchases and sales of securities on a securities exchange are affected through brokers who charge a commission for their services. Ordinarily commissions are not charged on over the counter orders (e.g., fixed income securities) because the Funds pay a spread which is included in the cost of the security and represents the difference between the dealer’s quoted price at which it is willing to sell the security and the dealer’s quoted price at which it is willing to buy the security. When a Fund executes an over the counter order with an electronic communications network or an alternative trading system, a commission is charged because electronic communications networks and alternative trading systems execute such orders on an agency basis. Securities may be purchased from underwriters at prices that include underwriting fees.

In placing a portfolio transaction, the Adviser seeks to achieve best execution. The Adviser’s duty to seek best execution requires the Adviser to take reasonable steps to obtain for the client as favorable an overall result as possible for Fund portfolio transactions under the circumstances, taking into account various factors that are relevant to the particular transaction.

The Adviser refers to and selects from the list of approved trading counterparties maintained by the Adviser’s Credit Risk Management team. In selecting a trading counterparty for a particular trade, the Adviser seeks to weigh relevant factors including, but not limited to the following:

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Prompt and reliable execution;

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The competitiveness of commission rates and spreads, if applicable;

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The financial strength, stability and/or reputation of the trading counterparty;

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The willingness and ability of the executing trading counterparty to execute transactions (and commit capital) of size in liquid and illiquid markets without disrupting the market for the security;

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Local laws, regulations or restrictions;

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The ability of the trading counterparty to maintain confidentiality;

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The availability and capability of execution venues, including electronic communications networks for trading and execution management systems made available to Adviser;

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Market share;

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Liquidity;

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Price;

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Execution related costs;

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History of execution of orders;

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Likelihood of execution and settlement;

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Order size and nature;

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Clearing and settlement capabilities, especially in high volatility market environments;

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Availability of lendable securities;

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Sophistication of the trading counterparty’s trading capabilities and infrastructure/facilities;

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The operational efficiency with which transactions are processed and cleared, taking into account the order size and complexity;

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Speed and responsiveness to the Adviser;

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Access to secondary markets;

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Counterparty exposure; and

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Any other consideration the Adviser believes is relevant to the execution of the order.

In selecting a trading counterparty, the price of the transaction and costs related to the execution of the transaction typically merit a high relative importance, depending on the circumstances. The Adviser does not necessarily select a trading counterparty based upon price and costs but may take other relevant factors into account if it believes that these are important in taking reasonable steps to obtain the best possible result for a Fund under the circumstances. Consequently, the Adviser may cause a client to pay a trading counterparty more than another trading counterparty might have charged for the same transaction in recognition of the value and quality of the brokerage services provided. The following matters may influence the relative importance that the Adviser places upon the relevant factors:

(i) The nature and characteristics of the order or transaction. For example, size of order, market impact of order, limits, or other instructions relating to the order;

(ii) The characteristics of the financial instrument(s) or other assets which are the subject of that order. For example, whether the order pertains to an equity, fixed income, derivative or convertible instrument;

(iii) The characteristics of the execution venues to which that order can be directed, if relevant. For example, availability and capabilities of electronic trading systems;

(iv) Whether the transaction is a ‘delivery versus payment’ or ‘over the counter’ transaction. The creditworthiness of the trading counterparty, the amount of existing exposure to a trading counterparty and trading counterparty settlement capabilities may be given a higher relative importance in the case of ‘over the counter’ transactions; and

(v) Any other circumstances relevant the Adviser believes is relevant at the time.

The process by which trading counterparties are selected to effect transactions is designed to exclude consideration of the sales efforts conducted by broker-dealers in relation to the funds advised by the Adviser.

The Adviser does not currently use the Funds’ assets in connection with third party soft dollar arrangements. While the Adviser does not currently use “soft” or commission dollars paid by the Funds for the purchase of third party research, the Adviser reserves the right to do so in the future.

DECLARATION OF TRUST, CAPITAL STOCK AND OTHER INFORMATION

Capitalization

Under the Declaration of Trust, the Trustees are authorized to issue an unlimited number of shares of each Fund. Upon liquidation or dissolution of a Fund, investors are entitled to share pro rata in the Fund’s net assets available for distribution to its investors. Investments in a Fund have no preference, preemptive, conversion or similar rights, except as determined by the Trustees or as set forth in the Bylaws, and are fully paid and non-assessable, except as set forth below.

Declarations of Trust

The Declarations of Trust of the Trust and the Master Trust each provide that a Trust may redeem shares of a Fund at the redemption price that would apply if the share redemption were initiated by a shareholder. It is the policy of each Trust that, except upon such conditions as may from time to time be set forth in the then current prospectus of a Fund or to facilitate a Trust’s or a Fund’s compliance with applicable law or regulation, a Trust would not initiate a redemption of shares unless it were to determine that failing to do so may have a substantial adverse consequence for a Fund or the Trust.

Each Trust’s Declaration of Trust provides that a Trustee who is not an “interested person” (as defined in the 1940 Act) of a Trust will be deemed independent and disinterested with respect to any demand made in connection with a derivative action or proceeding. It is the policy of each Trust that it will not assert that provision to preclude a shareholder from claiming that a Trustee is not independent or disinterested with respect to any demand made in connection with a derivative action or proceeding; provided, however, that the foregoing policy will not prevent the Trusts from asserting applicable law (including Section 2B of Chapter 182 of the Massachusetts General Laws) to preclude a shareholder from claiming that a Trustee is not independent or disinterested with respect to any demand made in connection with a derivative action or proceeding.

A Trust will not deviate from the foregoing policies in a manner that adversely affects the rights of shareholders of a Fund without the approval of “a vote of a majority of the outstanding voting securities” (as defined in the 1940 Act) of such Fund.

Voting

Each shareholder is entitled to a vote in proportion to the number of Fund shares it owns. Shares do not have cumulative voting rights in the election of Trustees, and shareholders holding more than 50% of the aggregate outstanding shares in the Trust may elect all of the Trustees if they choose to do so. The Trust is not required and has no current intention to hold annual meetings of shareholders but the Trust will hold special meetings of shareholders when in the judgment of the Trustees it is necessary or desirable to submit matters for a shareholder vote.

Massachusetts Business Trust

become subject by reason of being or having been a shareholder of that series and for reimbursement of the shareholder for all expense arising from such liability. Thus the risk of a shareholder incurring financial loss on account of shareholder liability should be limited to circumstances in which the series would be unable to meet its obligations.

PRICING OF SHARES

Pricing of shares of the Funds does not occur on New York Stock Exchange (“NYSE”) holidays. The NYSE is open for trading every weekday except for: (a) the following holidays: New Year’s Day, Martin Luther King, Jr.’s Birthday, Washington’s Birthday (the third Monday in February), Good Friday, Memorial Day, Independence Day, Labor Day, Thanksgiving Day and Christmas; and (b) the preceding Friday or the subsequent Monday when one of the calendar-determined holidays falls on a Saturday or Sunday, respectively. Purchases and withdrawals will be effected at the time of determination of NAV next following the receipt of any purchase or withdrawal order which is determined to be in good order. The Funds’ securities will be valued pursuant to guidelines established by the Board of Trustees.

U.S. Government Fund, Treasury Fund, Treasury Plus Fund and Treasury Obligations Fund

Each Fund seeks to maintain a constant price per share of $1.00 for purposes of sales and redemptions of shares by using the amortized cost valuation method to value its portfolio instruments in accordance with Rule 2a-7 under the 1940 Act. There can be no assurance that the $1.00 NAV per share will be maintained. The amortized cost method involves valuing an instrument at its cost and thereafter assuming a constant amortization to maturity of any discount or premium, even though the portfolio security may increase or decrease in market value, generally in response to changes in interest rates. While this method provides certainty in valuation, it may result in periods during which value, as determined by amortized cost, is higher or lower than the price each Fund would receive if it sold the instrument.

For example, in periods of declining interest rates, the daily yield on each of the Fund’s shares computed by dividing the annualized daily income on the Fund’s portfolio by the NAV based upon the amortized cost valuation technique may tend to be higher than a similar computation made by using a method of valuation based upon market prices and estimates thereof. In periods of rising interest rates, the daily yield on each Fund’s shares computed the same way may tend to be lower than a similar computation made by using a method of calculation based upon market prices and estimates.

The Trustees have established procedures reasonably designed to stabilize each Fund’s price per share at $1.00. These procedures include: (1) the determination of the deviation from $1.00, if any, of each Fund’s NAV using market values; (2) periodic review by the Trustees of the amount of and the methods used to calculate the deviation; and (3) maintenance of records of such determination. The Trustees will promptly consider what action, if any, should be taken if such deviation exceeds 1/2 of one percent.

ILR Fund

The ILR Fund’s NAV per share will float. The ILR Fund determines its NAV per share three times each business day at 9:00am, 12:00pm and 3:00pm Eastern Time (“ET”) except for days when the NYSE’s regular closing is prior to 3 p.m. ET, in which event the ILR Fund determines its final NAV for the day at the earlier closing time (each time when the ILR Fund determines its NAV per share is referred to herein as a “Valuation Time”). The ILR Fund calculates its NAV to four decimal places.

Ultra Short Bond Fund

The Fund determines its NAV per share once each business day as of the close of regular trading on the NYSE. The NAV per share of a Fund is based on the market value of the investments held in the Fund. The NAV of each class of the Fund’s shares is calculated by dividing the value of the assets of the Fund attributable to that class less the liabilities of the Fund attributable to that class by the number of shares in the class outstanding. The Fund values each security or other investment pursuant to guidelines adopted by the Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Funds’ Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii) a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by a Fund occurs after the close of a related exchange but before the determination of the Fund’s NAV. Attempts to determine the fair value of securities or other investments introduce an element of subjectivity to the pricing of securities or other investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the price a Fund would have received had it sold the investment. To the extent that a Fund invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the mutual funds. The prospectuses of these mutual funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

TAXATION OF THE FUNDS

The following discussion of U.S. federal income tax consequences of an investment in the Funds is based on the Internal Revenue Code of 1986, as amended (the “Code”), U.S. Treasury regulations, and other applicable authority, as of the date of this SAI. These authorities are subject to change by legislative or administrative action, possibly with retroactive effect. The following discussion is only a summary of some of the important U.S. federal income tax considerations generally applicable to investments in the Funds. There may be other tax considerations applicable to particular shareholders. Shareholders should consult their own tax advisors regarding their particular situation and the possible application of foreign, state and local tax laws.

Each Fund invests substantially all of its assets in a corresponding Portfolio (which may be a series of State Street Master Funds) (in each case, a “Portfolio”), and so substantially all of each such Fund’s income will result from distributions or deemed distributions, or allocations, as the case may be, from the corresponding Portfolio. Therefore, as applicable, references to the U.S. federal income tax treatment of the Funds, including to the assets owned and the income earned by the Funds, will be to or will include such treatment of the corresponding Portfolio, and, as applicable, the assets owned and the income earned by the corresponding Portfolio. See “Tax Considerations Applicable to Funds Investing in Portfolios Treated as Partnerships” and “Tax Considerations Applicable to Funds Investing in Portfolios Treated as RICs” below for further information.

Special tax rules apply to investments through defined contribution plans and other tax-qualified plans or tax-advantaged arrangements. Shareholders should consult their tax advisers to determine the suitability of shares of a Fund as an investment through such plans and arrangements and the precise effect of an investment on their particular tax situations.

Qualification as a Regulated Investment Company

Each Fund has elected or intends to elect to be treated as a regulated investment company (“RIC”) under Subchapter M of the Code and intends each year to qualify and be eligible to be treated as such. In order to qualify for the special tax treatment accorded RICs and their shareholders, each Fund must, among other things, (a) derive at least 90% of its gross income for each taxable year from (i) dividends, interest, payments with respect to certain securities loans, gains from the sale of securities or foreign currencies, or other income (including but not limited to gains from options, futures or forward contracts) derived with respect to its business of investing in such stock, securities or currencies and (ii) net income derived from interests in “qualified publicly traded partnerships” (as defined below); (b) diversify its holdings so that, at the end of each quarter of the Fund’s taxable year, (i) at least 50% of the value of the Fund’s total assets consists of cash and cash items, U.S. Government securities, securities of other RICs, and other securities limited in respect of any one issuer to a value not greater than 5% of the value of the Fund’s total assets and no more than 10% of the outstanding voting securities of such issuer, and (ii) no more than 25% of its assets are invested, including through corporations in which the Fund owns a 20% or more voting stock interest, (x) in the securities (other than those of the U.S. Government or other RICs) of any one issuer or of two or more issuers which the Fund controls and which are engaged in the same, similar or related trades and businesses, or (y) in the securities of one or more qualified publicly traded partnerships (as defined below); and (c) distribute with respect to each taxable year at least 90% of the sum of its investment company taxable income (as that term is defined in the Code without regard to the deduction for dividends paid – generally taxable ordinary income and the excess, if any, of net short-term capital gains over net long-term capital losses) and net tax-exempt income, for such year.

However, 100% of the net income derived from an interest in a “qualified publicly traded partnership” (a partnership (x) the interests in which are traded on an established securities market or readily tradable on a secondary market or the substantial equivalent thereof, and (y) that derives less than 90% of its income from the qualifying income described in section (a)(i) of the preceding paragraph), will be treated as qualifying income. In general, such entities will be treated as partnerships for federal income tax purposes, because they meet the passive income requirement under Code section 7704(c)(2). Further, although in general the passive loss rules of the Code do not apply to RICs, such rules do apply to a RIC with respect to items attributable to an interest in a qualified publicly traded partnership.

For purposes of the diversification test in (b) above, the term “outstanding voting securities of such issuer” will include the equity securities of a qualified publicly traded partnership. Also, for purposes of the diversification test in (b) above, the identification of the issuer (or, in some cases, issuers) of a particular investment can depend on the terms and conditions of that investment. In some cases, identification of the issuer (or issuers) is uncertain under current law, and an adverse determination or future guidance by the Internal Revenue Service (“IRS”) with respect to issuer identification for a particular type of investment may adversely affect a Fund’s ability to meet the diversification test in (b) above.

If a Fund qualifies as a RIC that is accorded special tax treatment, the Fund will not be subject to federal income tax on income or gains distributed in a timely manner to its shareholders in the form of dividends (including Capital Gain Dividends, as defined below). If a Fund were to fail to meet the income, diversification or distribution test described above, the Fund could in some cases cure such failure, including by paying a Fund-level tax, paying interest or disposing of certain assets. If such Fund were ineligible to or otherwise did not cure such failure for any year, or if such Fund were otherwise to fail to qualify as a RIC accorded special tax treatment in any taxable year, the Fund would be subject to tax at the Fund level on its taxable income at corporate rates, and all distributions from earnings and profits, including any distributions of net tax-exempt income and net capital gains (each as defined below), would be taxable to shareholders as ordinary income. Some portions of such distributions may be eligible for the dividends-received deduction in the case of corporate shareholders and may be eligible to be treated as “qualified dividend income” in the case of shareholders taxed as individuals, provided, in both cases, the shareholder meets certain holding period and other requirements in respect of a Fund’s shares (each as described below). In addition, a Fund could be required to recognize unrealized gains, pay substantial taxes and interest and make substantial distributions before re-qualifying as a RIC that is accorded special tax treatment.

Each Fund intends to distribute at least annually to its shareholders all or substantially all of its investment company taxable income (computed without regard to the dividends-paid deduction) and its net tax-exempt income (if any), and may distribute its net capital gain (that is, the excess of net long-term capital gain over net short-term capital loss, in each case determined with reference to any loss carryforwards). Any taxable income retained by a Fund will be subject to tax at the Fund level at regular corporate rates. If a Fund retains any net capital gain, it will be subject to tax at regular corporate rates on the amount retained, but is permitted to designate the retained amount as undistributed capital gain in a timely notice to its shareholders who (a) will be required to include in income for federal income tax purposes, as long-term capital gain, their shares of such undistributed amount, and (b) will be entitled to credit their proportionate shares of the tax paid by the Fund on such undistributed amount against their federal income tax liabilities, if any, and to claim refunds on a properly-filed U.S. tax return to the extent the credit exceeds such liabilities. If a Fund makes this designation, for U.S. federal income tax purposes, the tax basis of shares owned by a shareholder of the Fund will be increased by an amount equal to the difference between the amount of undistributed capital gains included in the shareholder’s gross income under clause (a) of the preceding sentence and the tax deemed paid by the shareholder under clause (b) of the preceding sentence. The Funds are not required to, and there can be no assurance a Fund will, make this designation if it retains all or a portion of its net capital gain in a taxable year.

In determining its net capital gain, including in connection with determining the amount available to support a Capital Gain Dividend (as defined below), its taxable income, and its earnings and profits, a RIC generally may elect to treat part or all of any post-October capital loss (defined as any net capital loss attributable to the portion, if any, of the taxable year after October 31 or, if there is no such loss, the net long-term capital loss or net short-term capital loss attributable to any such portion of the taxable year) or late-year ordinary loss (generally, the sum of its (i) net ordinary loss, if any, from the sale, exchange or other taxable disposition of property, attributable to the portion, if any, of the taxable year after October 31, and its (ii) other net ordinary loss, if any, attributable to the portion, if any, of the taxable year after December 31) as if incurred in the succeeding taxable year.

If a Fund were to fail to distribute in a calendar year at least an amount equal, in general, to the sum of 98% of its ordinary income for such year and 98.2% of its capital gain net income for the one-year period ending October 31 of such year (or November 30 or December 31, if the Fund is eligible to elect and so elects), plus any such amounts retained from the prior year, the Fund would be subject to a nondeductible 4% excise tax on the undistributed amounts. For purposes of the required excise tax distribution, a RIC’s ordinary gains and losses from the sale, exchange or other taxable disposition of property that would otherwise be taken into account after October 31 of a calendar year (or November 30, if the Fund makes the election referred to above) generally are treated as arising on January 1 of the following calendar year; in the case of a Fund with a December 31 year end that makes the election described above, no such gains or losses will be so treated. Also, for these purposes, a Fund will be treated as having distributed any amount on which it is subject to corporate income tax for the taxable year ending within the calendar year. Each Fund intends generally to make distributions sufficient to avoid imposition of the excise tax, although there can be no assurance that it will be able to do so. Distributions declared by a Fund during October, November and December to shareholders of record on a date in any such month and paid by the Fund during the following January will be treated for federal tax purposes as paid by the Fund and received by shareholders on December 31 of the year in which declared.

Capital losses in excess of capital gains (“net capital losses”) are not permitted to be deducted against a Fund’s net investment income. Instead, potentially subject to certain limitations, a Fund may carry net capital losses from any taxable year forward to subsequent taxable years to offset capital gains, if any, realized during such subsequent taxable years. Distributions from capital gains are generally made after applying any available capital loss carryforwards. Capital loss carryforwards are reduced to the extent they offset current-year net realized capital gains, whether the Fund retains or distributes such gains. A Fund may carry net capital losses forward to one or more subsequent taxable years without expiration; any such carryforward losses will retain their character as short-term or long-term. The Fund must apply such carryforwards first against gains of the same character. See a Fund’s most recent annual shareholder report for the Fund’s available capital loss carryovers as of the end of its most recently ended fiscal year.

Taxation of Distributions Received by Shareholders

For U.S. federal income tax purposes, distributions of investment income are generally taxable to shareholders as ordinary income. Taxes on distributions of capital gains are determined by how long a Fund owned (or is deemed to have owned) the investments that generated them, rather than how long a shareholder has owned his or her Fund shares. In general, a Fund will recognize long-term capital gain or loss on the disposition of assets the Fund has owned (or is deemed to have owned) for more than one year, and short-term capital gain or loss on the disposition of investments the Fund has owned (or is deemed to have owned) for one year or less. Distributions of net-capital gain (that is, the excess of net long-term capital gain over net short-term capital loss) that are properly reported by a Fund as capital gain dividends (“Capital Gain Dividends”) generally will be taxable to a shareholder receiving such distributions as long-term capital gains includible in net capital gain and taxed to individuals at reduced rates relative to ordinary income. Distributions from capital gains are generally made after applying any available capital loss carryovers. The Funds do not expect to distribute Capital Gain Dividends. Distributions of net short-term capital gain (as reduced by any net long-term capital loss for the taxable year) will be taxable to shareholders as ordinary income. Distributions of investment income properly reported by a Fund and, in the case of a Fund investing in a Portfolio treated as a RIC, the Portfolio, as derived from “qualified dividend income” will be taxed in the hands of individuals at the rates applicable to net capital gain, provided holding period and other requirements are met at each of the shareholder, the Portfolio and, in the case of a Fund investing in a Portfolio treated as a RIC, the Fund level. The Funds do not expect Fund distributions to be derived from qualified dividend income.

The Code generally imposes a 3.8% Medicare contribution tax on the net investment income of certain individuals, trusts and estates to the extent their income exceeds certain threshold amounts. For these purposes, “net investment income” generally includes, among other things, (i) distributions paid by a Fund of net investment income and capital gains, and (ii) any net gain from the sale, redemption, exchange or other taxable disposition of Fund shares. Shareholders are advised to consult their tax advisors regarding the possible implications of this additional tax on their investment in a Fund.

If a Fund makes a distribution to a shareholder in excess of the Fund’s current and accumulated earnings and profits in any taxable year, the excess distribution will be treated as a return of capital to the extent of such shareholder’s tax basis in its shares, and thereafter as capital gain. A return of capital is not taxable, but it reduces a shareholder’s tax basis in its shares, thus reducing any loss or increasing any gain on a subsequent taxable disposition by the shareholder of its shares.

Shareholders of a Fund will be subject to federal income taxes as described herein on distributions made by the Fund whether received in cash or reinvested in additional shares of the Fund.

Distributions with respect to a Fund’s shares are generally subject to U.S. federal income tax as described herein to the extent they do not exceed the Fund’s realized income and gains, even though such distributions may economically represent a return of a particular shareholder’s investment. Such distributions are likely to occur in respect of shares purchased at a time when a Fund’s net asset value includes either unrealized gains, or realized but undistributed income or gains, that were therefore included in the price the shareholder paid. Such distributions may reduce the fair market value of the Fund’s shares below the shareholder’s cost basis in those shares. As described above, a Fund is required to distribute realized income and gains regardless of whether the Fund’s net asset value also reflects unrealized losses.

In order for some portion of the dividends received by a Fund shareholder to be “qualified dividend income,” the corresponding Portfolio must meet holding period and other requirements with respect to the dividend-paying stocks held by the Portfolio, the shareholder must meet holding period and other requirements with respect to the Fund’s shares, and in the case of a Fund investing in a Portfolio treated as a RIC, the Fund must meet holding period and other requirements with respect to its shares in the Portfolio. In general, a dividend will not be treated as qualified dividend income (at any of the Portfolio, Fund or shareholder level, as applicable) (a) if the dividend is received with respect to any share of stock held for fewer than 61 days during the 121-day period beginning on the date which is 60 days before the date on which such share becomes ex-dividend with respect to such dividend (or, in the case of certain preferred stock, 91 days during the 181-day period beginning 90 days before such date), (b) to the extent that the recipient is under an obligation (whether pursuant to a short sale or otherwise) to make related payments with respect to positions in substantially similar or related property, (c) if the recipient elects to have the dividend income treated as investment income for purposes of the limitation on deductibility of investment interest, or (d) if the dividend is received from a foreign corporation that is (i) not eligible for the benefits of a comprehensive income tax treaty with the United States (with the exception of dividends paid on stock of such a foreign corporation readily tradable on an established securities market in the United States) or (ii) treated as a passive foreign investment company.

In general, distributions of investment income properly reported by a Fund as derived from qualified dividend income will be treated as qualified dividend income in the hands of a shareholder taxed as an individual, provided the shareholder meets the holding period and other requirements described above with respect to the Fund’s shares. If the aggregate qualified dividends (a) allocated to a Fund by a Portfolio that is treated as a partnership or (b) received by a Fund from a Portfolio that is treated as a RIC, during any taxable year are 95% or more of the Fund’s gross income (excluding net long-term capital gain over net short-term capital loss), then 100% of the Fund’s dividends (other than dividends properly reported as Capital Gain Dividends) will be eligible to be treated as qualified dividend income.

In general, dividends of net investment income received by corporate shareholders of a Fund will qualify for the dividends-received deduction generally available to corporations to the extent of the amount of eligible dividends from domestic corporations received by a Portfolio (a) that is treated as a partnership and allocated to the Fund, or (b) that is treated as a RIC and in turn paid by the Portfolio to the Fund for the taxable year. A dividend so allocated or paid to a Fund will not be treated as a dividend eligible for the dividends-received deduction (at any of the Portfolio, Fund or shareholder level, as applicable) (a) if it has been received with respect to any share of stock that the Portfolio has held for less than 46 days (91 days in the case of certain preferred stock) during the 91-day period beginning on the date which is 45 days before the date on which such share becomes ex-dividend with respect to such dividend (during the 181-day period beginning 90 days before such date in the case of certain preferred stock) or (b) to the extent that the Portfolio is under an obligation (pursuant to a short sale or otherwise) to make related payments with respect to positions in substantially similar or related property. Moreover, a Fund that invests in a corresponding Portfolio that is treated as a RIC must meet similar requirements with respect to its shares of the corresponding Portfolio. Finally, the dividends-received deduction may otherwise be disallowed or reduced (x) if the corporate shareholder fails to satisfy the foregoing requirements with respect to its shares of the Fund or (y) by application of various provisions of the Code (for instance, the dividends-received deduction is reduced in the case of a dividend received on debt-financed portfolio stock (generally, stock acquired with borrowed funds)). The Funds do not expect Fund distributions to be eligible for the dividends-received deduction.

Any distribution of income that is attributable to (a) income received by a Fund in lieu of dividends with respect to securities on loan pursuant to a securities lending transaction or (b) dividend income received by a Fund on securities it temporarily purchased from a counterparty pursuant to a repurchase agreement that is treated for U.S. federal income tax purposes as a loan by the Fund, will not constitute qualified dividend income to individual shareholders and will not be eligible for the dividends-received deduction for corporate shareholders.

If a Fund holds, directly or indirectly, one or more “tax credit bonds” issued on or before December 31, 2017, on one or more applicable dates during a taxable year, the Fund may elect to permit its shareholders to claim a tax credit on their income tax returns equal to each shareholder’s proportionate share of tax credits from the bond otherwise allowed to the Fund. In such a case, shareholders must include in gross income (as interest) their proportionate share of the income attributable to the tax credits. A shareholder’s ability to claim a tax credit associated with one or more tax credit bonds may be subject to certain limitations imposed by the Code, and the amount of the tax credits may not exceed the amount reported by the Fund in a written notice to shareholders. Even if a Fund is eligible to pass through tax credits to shareholders, the Fund may choose not to do so.

Tax Considerations Applicable to Funds Investing in Portfolios Treated as Partnerships

Certain Funds invest substantially all of their investable assets in a corresponding Portfolio that is treated as a partnership for U.S. federal income tax purposes. In such cases the nature and character of each such Fund’s income, gains, losses and deductions will generally be determined at the Portfolio level and each such Fund will be allocated its share of Portfolio income and gains. As applicable, references to income, gains, losses and deductions of a Fund will be to income, gains and losses recognized and deductions accruing at the Portfolio level and allocated to or otherwise taken into account by the Fund, and references to assets of a Fund will be to the Fund’s allocable share of the assets of the corresponding Portfolio.

Such a Fund may be required to redeem a portion of its interest in a Portfolio in order to obtain sufficient cash to make the requisite distributions to maintain its qualification for treatment as a RIC. The Portfolio in turn may be required to sell investments in order to meet such redemption requests, including at a time when it may not be advantageous to do so.

In addition, in certain circumstances, the “wash sale” rules under Section 1091 of the Code may apply to the Funds’ sales of the corresponding Portfolio interests that have generated losses. A wash sale occurs if equity interests of an issuer are sold by a Fund at a loss and the Fund acquires additional interests of that same issuer 30 days before or after the date of the sale. The wash-sale rules could defer losses in a Fund’s hands on corresponding interests in a Portfolio (to the extent such sales are wash sales) for extended (and, in certain cases, potentially indefinite) periods of time.

Tax Considerations Applicable to Funds Investing in Portfolios Treated as RICs

The following considerations are relevant to shareholders of Funds that invest substantially all of their assets in a corresponding Portfolio that intends to elect to be treated and to qualify and be eligible to be treated each year as a RIC.

Substantially all of such a Fund’s income will result from distributions or deemed distributions from the corresponding Portfolio. Additionally, whether a Fund will meet the asset diversification test described above will depend on whether the corresponding Portfolio meets each of the income, diversification and distribution tests. If a Portfolio were to fail to meet any such test and were ineligible to or otherwise were not to cure such failure, the corresponding Fund would as a result itself fail to meet the asset diversification test and might be ineligible or unable to or might otherwise not cure such failure.

Because each Fund invests substantially all of its assets in shares of the corresponding Portfolio, its distributable income and gains will normally consist substantially of distributions from the corresponding Portfolio. To the extent that a Portfolio realizes net losses on its investments for a given taxable year, the corresponding Fund will not be able to benefit from those losses until, and only to the extent that (i) the Portfolio realizes gains that it can reduce by those losses, or (ii) the Fund recognizes its share of those losses when it disposes of shares of the Portfolio in a transaction qualifying for sale or exchange treatment. Moreover, even when a Fund does make such a disposition, any loss will be recognized as a capital loss, a portion of which may be a long-term capital loss. The Funds will not be able to offset any capital losses from its dispositions of shares of the corresponding Portfolio against its ordinary income (including distributions of any net short-term capital gains realized by a Portfolio), and the Fund’s long-term capital losses first offset its long-term capital gains, increasing the likelihood that the Fund’s short-term capital gains are distributed to shareholders as ordinary income.

In addition, in certain circumstances, the “wash sale” rules under Section 1091 of the Code may apply to the Funds’ sales of the corresponding Portfolio shares that have generated losses. A wash sale occurs if shares of an issuer are sold by a Fund at a loss and the Fund acquires additional shares of that same issuer 30 days before or after the date of the sale. The wash-sale rules could defer losses in a Fund’s hands on corresponding Portfolio shares (to the extent such sales are wash sales) for extended (and, in certain cases, potentially indefinite) periods of time.

The foregoing rules may cause the tax treatments of a Fund’s’ gains, losses and distributions to differ at times from the tax treatment that would apply if the Fund invested directly in the types of securities held by the corresponding Portfolio. As a result, investors may receive taxable distributions earlier and recognize higher amounts of capital gain or ordinary income than they otherwise would.

Finally, a RIC generally must look through its 20 percent voting interest in a corporation, including a RIC, to the underlying assets thereof for purposes of the diversification test; special rules potentially provide limited relief from the application of this rule where a RIC owns such an interest in an underlying RIC (as defined below), such as a Portfolio.

Investments in Other RICs.

If a Fund receives dividends from a Portfolio treated as a RIC, or a Portfolio receives dividends from a mutual fund, an ETF or another investment company that qualifies as a RIC (each an “underlying RIC”) and the underlying RIC reports such dividends as qualified dividend income, then the Fund, or Portfolio, as applicable, is permitted, in turn, to report a portion of its distributions as “qualified dividend income,” provided the Fund, or Portfolio, as applicable, meets the holding period and other requirements with respect to shares of the underlying RIC.

If a Fund or Portfolio receives dividends from an underlying RIC and the underlying RIC reports such dividends as eligible for the dividends-received deduction, then the Fund or Portfolio, as applicable, is permitted, in turn, to report a portion of its distributions as eligible for the dividends-received deduction, provided the Fund or Portfolio, as applicable, meets the holding period and other requirements with respect to shares of the underlying RIC.

The foregoing rules may cause the tax treatments of a Fund’s gains, losses and distributions to differ at times from the tax treatment that would apply if the Fund invested directly in the types of securities held by the corresponding Portfolio. As a result, investors may receive taxable distributions earlier and recognize higher amounts of capital gain or ordinary income than they otherwise would.

The Code’s wash sale rule may also apply to certain redemptions and exchanges by non-U.S. shareholders. See “Non-U.S. Shareholders” below.

Tax Implications of Certain Fund Investments

Special Rules for Debt Obligations . Some debt obligations with a fixed maturity date of more than one year from the date of issuance (and zero-coupon debt obligations with a fixed maturity date of more than one year from the date of issuance) will be treated as debt obligations that are issued originally at a discount. Generally, original issue discount (“OID”) is treated as interest income and is included in a Fund’s income and required to be distributed by the Fund over the term of the debt obligation, even though payment of that amount is not received until a later time, upon partial or full repayment or disposition of the debt obligation. In addition, payment-in-kind securities will give rise to income which is required to be distributed and is taxable even though the Fund holding the obligation receives no interest payment in cash on the obligation during the year.

Some debt obligations with a fixed maturity date of more than one year from the date of issuance that are acquired in the secondary market by a Fund may be treated as having “market discount.” Very generally, market discount is the excess of the stated redemption price of a debt obligation (or in the case of an obligation issued with OID, its “revised issue price”) over the purchase price of such obligation. Subject to the discussion below regarding Section 451 of the Code, (i)generally, any gain recognized on the disposition of, and any partial payment of principal on, a debt obligation having market discount is treated as ordinary income to the extent the gain, or principal payment, does not exceed the “accrued market discount” on such debt obligation, (ii) alternatively, a Fund may elect to accrue market discount currently, in which case the Fund will be required to include the accrued market discount in income (as ordinary income) and thus distribute it over the term of the debt obligation, even though payment of that amount is not received until a later time, upon partial or full repayment or disposition of the debt obligation and (iii) the rate at which the market discount accrues, and thus is included in a Fund’s income, will depend upon which of the permitted accrual methods the Fund elects. Notwithstanding the foregoing, effective for taxable years beginning after 2017, Section 451 of the Code generally requires any accrual method taxpayer to take into account items of gross income no later than the time at which such items are taken into account as revenue in the taxpayer’s financial statements. The IRS and the Department of Treasury have announced their intent to issue proposed regulations providing that Section 451 does not apply to accrued market discount. If Section 451 were to apply to the accrual of market discount, each Fund would be required to include in income any market discount as it takes the same into account on its financial statements even if the Fund does not otherwise elect to accrue market discount currently for federal income tax purposes.

If a Fund holds the foregoing kinds of obligations, or other obligations subject to special rules under the Code, the Fund may be required to pay out as an income distribution each year an amount which is greater than the total amount of cash interest the Fund actually received. Such distributions may be made from the cash assets of the Fund or, if necessary, by disposition of portfolio securities including at a time when it may not be advantageous to do so. These dispositions may cause a Fund to realize higher amounts of short-term capital gains (generally taxed to shareholders at ordinary income tax rates) and, in the event the Fund realizes net capital gains from such transactions, its shareholders may receive a larger Capital Gain Dividend than they would have if the Fund had not held such obligations.

Securities Purchased at a Premium . Very generally, where a Fund purchases a bond at a price that exceeds the redemption price at maturity – that is, at a premium – the premium is amortizable over the remaining term of the bond. In the case of a taxable bond, if a Fund makes an election applicable to all such bonds it purchases, which election is irrevocable without consent of the IRS, the Fund reduces the current taxable income from the bond by the amortized premium and reduces its tax basis in the bond by the amount of such offset; upon the disposition or maturity of such bonds acquired on or after January 4, 2013, the Fund is permitted to deduct any remaining premium allocable to a prior period.

A portion of the OID accrued on certain high yield discount obligations may not be deductible to the issuer and will instead be treated as a dividend paid by the issuer for purposes of the dividends-received deduction. In such cases, if the issuer of the high yield discount obligations is a domestic corporation, dividend payments by a Fund may be eligible for the dividends-received deduction to the extent attributable to the deemed dividend portion of such OID.

At-risk or Defaulted Securities . Investments in debt obligations that are at risk of or in default present special tax issues for the Funds. Tax rules are not entirely clear about issues such as when a Fund may cease to accrue interest, OID or market discount; whether, when or to what extent the Fund should recognize market discount on a debt obligation; when and to what extent a Fund may take deductions for bad debts or worthless securities; and how a Fund should allocate payments received on obligations in default between principal and income. These and other related issues will be addressed by a Fund when, as and if it invests in such securities, in order to seek to ensure that it distributes sufficient income to preserve its status as a RIC and does not become subject to U.S. federal income or excise tax.

Certain Investments in Mortgage Pooling Vehicles . Certain Funds may invest directly or indirectly in residual interests in real estate mortgage investment conduits (“REMICs”) (including by investing in residual interests in collateralized mortgage obligations (“CMOs”) with respect to which an election to be treated as a REMIC is in effect) or equity interests in taxable mortgage pools (“TMPs”). Under a notice issued by the IRS in October 2006 and Treasury regulations that have yet to be issued but may apply retroactively, a portion of a Fund’s income (including income allocated to the Fund from certain pass-through entities) that is attributable to a residual interest in a REMIC or an equity interest in a TMP (referred to in the Code as an “excess inclusion”) will be subject to U.S. federal income tax in all events. This notice also provides, and the regulations are expected to provide, that excess inclusion income of a RIC, such as a Fund, will be allocated to shareholders of the RIC in proportion to the dividends received by such shareholders, with the same consequences as if the shareholders held the related interest directly. As a result, a RIC investing in such securities may not be a suitable investment for charitable remainder trusts, as noted below.

to file a tax return, to file a tax return and pay tax on such income, and (iii) in the case of a foreign shareholder will not qualify for any reduction in U.S. federal withholding tax. A shareholder will be subject to U.S. federal income tax on such inclusions notwithstanding any exemption from such income tax otherwise available under the Code.

Foreign Currency Transactions . Any transaction by a Fund in foreign currencies, foreign currency-denominated debt obligations or certain foreign currency options, futures contracts or forward contracts (or similar instruments) may give rise to ordinary income or loss to the extent such income or loss results from fluctuations in the value of the foreign currency concerned. Any such net gains could require a larger dividend toward the end of the calendar year. Any such net losses will generally reduce and potentially require the recharacterization of prior ordinary income distributions. Such ordinary income treatment may accelerate a Fund’s distributions to shareholders and increase the distributions taxed to shareholders as ordinary income. Any net ordinary losses so created cannot be carried forward by the Fund to offset income or gains earned in subsequent taxable years.

Because it is not always possible to identify a foreign corporation as a PFIC, a Fund may incur the tax and interest charges described above in some instances.

Options and Futures . In general, option premiums received by a Fund are not immediately included in the income of the Fund. Instead, the premiums are recognized when the option contract expires, the option is exercised by the holder, or the Fund transfers or otherwise terminates the option (e.g., through a closing transaction). If a call option written by a Fund is exercised and the Fund sells or delivers the underlying stock, the Fund generally will recognize capital gain or loss equal to (a) the sum of the strike price and the option premium received by the Fund minus (b) the Fund’s basis in the stock. Such gain or loss generally will be short-term or long-term depending upon the holding period of the underlying stock. If securities are purchased by a Fund pursuant to the exercise of a put option written by it, the Fund generally will subtract the premium received for purposes of computing its cost basis in the securities purchased. Gain or loss arising in respect of a termination of a Fund’s obligation under an option other than through the exercise of the option will be short-term gain or loss depending on whether the premium income received by the Fund is greater or less than the amount paid by the Fund (if any) in terminating the transaction. Thus, for example, if an option written by a Fund expires unexercised, the Fund generally will recognize short-term gain equal to the premium received.

A Fund’s options activities may include transactions constituting straddles for U.S. federal income tax purposes, that is, that trigger the U.S. federal income tax straddle rules contained primarily in Section 1092 of the Code. Such straddles include, for example, positions in a particular security, or an index of securities, and one or more options that offset the former position, including options that are “covered” by a Fund’s long position in the subject security. Very generally, where applicable, Section 1092 requires (i) that losses be deferred on positions deemed to be offsetting positions with respect to “substantially similar or related property,” to the extent of unrealized gain in the latter, and (ii) that the holding period of such a straddle position that has not already been held for the long-term holding period be terminated and begin anew once the position is no longer part of a straddle. Options on single stocks that are not “deep in the money” may constitute qualified covered calls, which generally are not subject to the straddle rules; the holding period on stock underlying qualified covered calls that are “in the money” although not “deep in the money” will be suspended during the period that such calls are outstanding. Thus, the straddle rules and the rules governing qualified covered calls could cause gains that would otherwise constitute long-term capital gains to be treated as short-term capital gains, and distributions that would otherwise constitute “qualified dividend income” or qualify for the dividends-received deduction to fail to satisfy the holding period requirements and therefore to be taxed as ordinary income or fail to qualify for the dividends-received deduction, as the case may be.

The tax treatment of certain positions entered into by a Fund, including regulated futures contracts, certain foreign currency positions and certain listed non-equity options, will be governed by section 1256 of the Code (“section 1256 contracts”). Gains or losses on section 1256 contracts generally are considered 60% long-term and 40% short-term capital gains or losses (“60/40”), although certain foreign currency gains and losses from such contracts may be treated as ordinary in character. Also, section 1256 contracts held by a Fund at the end of each taxable year (and, for purposes of the 4% excise tax, on certain other dates as prescribed under the Code) are “marked to market” with the result that unrealized gains or losses are treated as though they were realized and the resulting gain or loss is treated as ordinary or 60/40 gain or loss, as applicable.

Derivatives, Hedging, and Related Transactions . In addition to the special rules described above in respect of futures and options transactions, a Fund’s transactions in other derivative instruments (e.g., forward contracts and swap agreements), as well as any of its hedging, short sale, securities loan or similar transactions, may be subject to one or more special tax rules (e.g., notional principal contract, straddle, constructive sale, wash sale and short sale rules). These rules may affect whether gains and losses recognized by a Fund are treated as ordinary or capital, accelerate the recognition of income or gains to the Fund, defer losses to the Fund, and cause adjustments in the holding periods of the Fund’s securities, thereby affecting whether capital gains and losses are treated as short-term or long-term. These rules could therefore affect the amount, timing and/or character of distributions to shareholders.

Book-Tax Differences . Certain of a Fund’s investments in derivative instruments and foreign currency-denominated instruments, and any of the Fund’s transactions in foreign currencies and hedging activities, are likely to produce a difference between its book income and the sum of its taxable income and net tax-exempt income (if any). If such a difference arises, and a Fund’s book income is less than the sum of its taxable income and net tax-exempt income, the Fund could be required to make distributions exceeding book income to qualify as a RIC that is accorded special tax treatment and to avoid an entity-level tax. In the alternative, if a Fund’s book income exceeds the sum of its taxable income (including realized capital gains) and net tax-exempt income, the distribution (if any) of such excess generally will be treated as (i) a dividend to the extent of the Fund’s remaining earnings and profits (including earnings and profits arising from tax-exempt income), (ii) thereafter, as a return of capital to the extent of the recipient’s basis in its shares, and (iii) thereafter as gain from the sale or exchange of a capital asset.

Foreign Taxation

A Fund’s income, proceeds and gains from sources within foreign countries may be subject to non-U.S. withholding or other taxes, which will reduce the yield of those investments. Tax conventions between certain countries and the United States may reduce or eliminate such taxes. Shareholders generally will not be entitled separately to claim a credit or deduction in respect of non-U.S. taxes paid or treated as paid by the Fund.

Backup Withholding

A Fund generally is required to withhold and remit to the U.S. Treasury a percentage of the taxable distributions and redemption proceeds paid to any individual shareholder who fails to properly furnish the Fund with a correct taxpayer identification number (“TIN”), who has under-reported dividend or interest income, or who fails to certify to the Fund that he or she is not subject to such withholding.

Backup withholding is not an additional tax. Any amounts withheld may be credited against the shareholder’s U.S. federal income tax liability, provided the appropriate information is furnished to the IRS.

Tax-Exempt Shareholders

Income of a RIC that would be unrelated business taxable income (“UBTI”) if earned directly by a tax-exempt entity will not generally constitute UBTI when distributed to a tax-exempt shareholder of the RIC. Notwithstanding this “blocking” effect, a tax-exempt shareholder could realize UBTI by virtue of its investment in a Fund if shares in the Fund constitute debt-financed property in the hands of the tax-exempt shareholder within the meaning of Code Section 514(b).

A tax-exempt shareholder may also recognize UBTI if a Fund recognizes “excess inclusion income” derived from direct or indirect investments in residual interests in REMICS or equity interests in TMPs if the amount of such income recognized by the Fund exceeds the Fund’s investment company taxable income (after taking into account deductions for dividends paid by the Fund).

In addition, special tax consequences apply to charitable remainder trusts (“CRTs”) that invest in RICs that invest directly or indirectly in residual interests in REMICs or equity interests in TMPs. Under legislation enacted in December 2006, a CRT (as defined in section 664 of the Code) that realizes any UBTI for a taxable year must pay an excise tax annually of an amount equal to such UBTI. Under IRS guidance issued in October 2006, a CRT will not recognize UBTI as a result of investing in a RIC that recognizes “excess inclusion income.” Rather, if at any time during any taxable year a CRT (or one of certain other tax-exempt shareholders, such as the United States, a state or political subdivision, or an agency or instrumentality thereof, and certain energy cooperatives) is a record holder of a share in a RIC that recognizes “excess inclusion income,” then the RIC will be subject to a tax on that portion of its “excess inclusion income” for the taxable year that is allocable to such shareholders at the highest federal corporate income tax rate. The extent to which this IRS guidance remains applicable in light of the December 2006 legislation is unclear. To the extent permitted under the 1940 Act, each Fund may elect to specially allocate any such tax to the applicable CRT, or other shareholder, and thus reduce such shareholder’s distributions for the year by the amount of the tax that relates to such shareholder’s interest in a Fund. CRTs are urged to consult their tax advisors concerning the consequences of investing in each Fund.

Redemptions and Exchanges

treated as short-term capital gain or loss. However, any loss realized upon a taxable disposition of Fund shares held by a shareholder for six months or less will be treated as long-term, rather than short-term, to the extent of any Capital Gain Dividends received (or deemed received) by the shareholder with respect to the shares. Further, subject to the discussion below regarding money market funds, all or a portion of any loss realized upon a taxable disposition of Fund shares generally will be disallowed under the Code’s “wash sale” rule if other substantially identical shares are purchased, including by means of dividend reinvestment, within 30 days before or after the disposition. In such a case, the basis of the newly purchased shares will be adjusted to reflect the disallowed loss.

The IRS permits a simplified method of accounting for gains and losses realized upon the disposition of shares of a regulated investment company that is a money market fund. Very generally, rather than realizing gain or loss upon each redemption of a share, a shareholder of a Fund using such method of accounting will recognize gain or loss with respect to such a Fund’s shares for a given computation period (the shareholder’s taxable year or shorter period selected by the shareholder) equal to the value of all the Fund shares held by the shareholder on the last day of the computation period, less the value of all Fund shares held by the shareholder on the last day of the preceding computation period, less the shareholder’s net investment in the Fund (generally, purchases minus redemptions) made during the computation period. The IRS has also published guidance providing that the “wash sale” rule of the Code – disallowing losses on taxable dispositions of Fund shares where other substantially identical shares are purchased, including by means of dividend reinvestment, within 30 days before or after the disposition—will not apply to redemptions of shares in a so-called floating NAV money market fund, such as the ILR Fund. Shareholders of a Fund are urged to consult their own tax advisors regarding their investment in the Fund.

Upon the redemption or exchange of shares of a Fund, the Fund or, in the case of shares purchased through a financial intermediary, the financial intermediary may be required to provide you and the IRS with cost basis and certain other related tax information about the Fund shares you redeemed or exchanged. See the Funds’ prospectuses for more information.

Tax Shelter Reporting

Under Treasury regulations, if a shareholder recognizes a loss of $2 million or more for an individual shareholder or $10 million or more for a corporate shareholder, the shareholder must file with the IRS a disclosure statement on IRS Form 8886. Direct shareholders of portfolio securities are in many cases excepted from this reporting requirement, but under current guidance, shareholders of a RIC are not excepted. Future guidance may extend the current exception from this reporting requirement to shareholders of most or all RICs. The fact that a loss is reportable under these regulations does not affect the legal determination of whether the taxpayer’s treatment of the loss is proper. Shareholders should consult their tax advisers to determine the applicability of these regulations in light of their individual circumstances.

Non-U.S. Shareholders

Non-U.S. shareholders in a Fund should consult their tax advisors concerning the tax consequences of ownership of shares in the Fund. Distributions by a Fund to shareholders that are not “U.S. persons” within the meaning of the Code ( “foreign shareholders”) properly reported by the Fund as (1) Capital Gain Dividends, (2) short-term capital gain dividends, and (3) interest-related dividends, each as defined and subject to certain conditions described below, generally are not subject to withholding of U.S. federal income tax.

In general, the Code defines (1) “short-term capital gain dividends” as distributions of net short-term capital gains in excess of net long-term capital losses and (2) “interest-related dividends” as distributions from U.S.-source interest income of types similar to those not subject to U.S. federal income tax if earned directly by an individual foreign shareholder, in each case to the extent such distributions are properly reported as such by a Fund in a written notice to shareholders.

The exceptions to withholding for Capital Gain Dividends and short-term capital gain dividends do not apply to (A) distributions to an individual foreign shareholder who is present in the United States for a period or periods aggregating 183 days or more during the year of the distribution and (B) distributions attributable to gain that is treated as effectively connected with the conduct by the foreign shareholder of a trade or business within the United States under special rules regarding the disposition of U.S. real property interests as described below. If a Fund invests in a RIC that pays such distributions to the Fund, such distributions retain their character as not subject to withholding if properly reported when paid by the Fund to foreign shareholders. The exception to withholding for interest-related dividends does not apply to distributions to a foreign shareholder (i) that has not provided a satisfactory statement that the beneficial owner is not a U.S. person, (ii) to the extent that the dividend is attributable to certain interest on an obligation if the foreign shareholder is the issuer or is a 10% shareholder of the issuer, (iii) that is within certain foreign countries that have inadequate information exchange with the United States, or (iv) to the extent the dividend is attributable to interest paid by a person that is a related person of the foreign shareholder and the foreign shareholder is a controlled foreign corporation). A RIC is permitted to report such parts of its dividends as are eligible to be treated as interest-related or short-term capital gain dividends, but is not required to do so. In the case of shares held through an intermediary, the intermediary may withhold even if a Fund reports all or a portion of a payment as an interest-related or short-term capital gain dividend to shareholders.

Foreign shareholders should contact their intermediaries regarding the application of withholding rules to their accounts.

Distributions by a Fund to foreign shareholders other than Capital Gain Dividends, short-term capital gain dividends and interest-related dividends (e.g., dividends attributable to dividend and foreign-source interest income or to short-term capital gains or U.S. source interest income to which the exception from withholding described above does not apply) are generally subject to withholding of U.S. federal income tax at a rate of 30% (or lower applicable treaty rate).

A foreign shareholder is not, in general, subject to U.S. federal income tax on gains (and is not allowed a deduction for losses) realized on the sale of shares of a Fund unless (a) such gain is effectively connected with the conduct of a trade or business carried on by such holder within the United States, (b) in the case of an individual holder, the holder is present in the United States for a period or periods aggregating 183 days or more during the year of the sale and certain other conditions are met, or (c) the special rules relating to gain attributable to the sale or exchange of “U.S. real property interests” (“USRPIs”) apply to the foreign shareholder’s sale of shares of the Fund (as described below).

Foreign shareholders with respect to whom income from a Fund is effectively connected with a trade or business conducted by the foreign person within the United States will in general be subject to U.S. federal income tax on the income derived from the Fund at the graduated rates applicable to U.S. citizens, residents or domestic corporations, whether such income is received in cash or reinvested in shares of the Fund and, in the case of a foreign corporation, may also be subject to a branch profits tax. If a foreign shareholder is eligible for the benefits of a tax treaty, any effectively connected income or gain will generally be subject to U.S. federal income tax on a net basis only if it is also attributable to a permanent establishment maintained by the shareholder in the United States. More generally, foreign shareholders who are residents in a country with an income tax treaty with the United States may obtain different tax results than those described herein, and are urged to consult their tax advisors.

Special rules would apply if a Fund were a qualified investment entity (“QIE”) because it is either a “U.S. real property holding corporation” (“USRPHC”) or would be a USRPHC but for the operation of certain exceptions to the definition thereof. Very generally, a USRPHC is a domestic corporation that holds USRPIs the fair market value of which equals or exceeds 50% of the sum of the fair market values of the corporation’s USRPIs, interests in real property located outside the United States, and other trade or business assets. USRPIs are generally defined as any interest in U.S. real property and any interest (other than solely as a creditor) in a USRPHC or, very generally, an entity that has been a USRPHC in the last five years. A Fund that holds, directly or indirectly, significant interests in REITs may be a USRPHC. Interests in domestically controlled QIEs, including REITs and RICs that are QIEs, not-greater-than-10% interests in publicly traded classes of stock in REITs and not-greater-than-5% interests in publicly traded classes of stock in RICs generally are not USRPIs, but these exceptions do not apply for purposes of determining whether a Fund is a QIE. If an interest in a Fund were a USRPI, the Fund would be required to withhold U.S. tax on the proceeds of a share redemption by a greater-than-5% foreign shareholder, in which case such foreign shareholder generally would also be required to file U.S. tax returns and pay any additional taxes due in connection with the redemption.

If a Fund were a QIE under a special “look-through” rule, any distributions by the Fund to a foreign shareholder attributable directly or indirectly to (i) distributions received by the Fund from a lower-tier REIT that the Fund is required to treat as USRPI gain in its hands and (ii) gains realized on the disposition of USRPIs by the Fund, would retain their character as gains realized from USRPIs in the hands of the Fund’s foreign shareholders and would be subject to U.S. tax withholding. In addition, such distributions could result in the foreign shareholder being required to file a U.S. tax return and pay tax on the distributions at regular U.S. federal income tax rates. The consequences to a foreign shareholder, including the rate of such withholding and character of such distributions (e.g., as ordinary income or USRPI gain), would vary depending upon the extent of the foreign shareholder’s current and past ownership of the Fund. Each Fund generally does not expect that it will be a QIE.

Foreign shareholders of a Fund also may be subject to “wash sale” rules to prevent the avoidance of the tax-filing and –payment obligations discussed above through the sale and repurchase of Fund shares.

Foreign shareholders should consult their tax advisers and, if holding shares through intermediaries, their intermediaries, concerning the application of these rules to their investment in a Fund.

In order for a foreign shareholder to qualify for any exemptions from withholding described above or from lower withholding tax rates under income tax treaties, or to establish an exemption from back back-up withholding, the foreign shareholder must comply with special certification and filing requirements relating to its non-U.S. status (including, in general, furnishing an IRS Form W-8BEN, IRS Form W-8 BEN-E, or substitute form). Non-U.S. investors in a Fund should consult their tax advisers in this regard.

Special rules (including withholding and reporting requirements) apply to foreign partnerships and those holding Fund shares through foreign partnerships. Additional considerations may apply to foreign trusts and estates. Investors holding Fund shares through foreign entities should consult their tax advisers about their particular situation.

A foreign shareholder may be subject to state and local tax and to the U.S. federal estate tax in addition to the U.S. federal income tax on income referred to above.

Shareholder Reporting Obligations With Respect To Foreign Bank and Financial Accounts

Shareholders that are U.S. persons and own, directly or indirectly, more than 50% of a Fund by vote or value could be required to report annually their “financial interest” in the Fund’s “foreign financial accounts,” if any, on FinCEN Form 114, Report of Foreign Bank and Financial Accounts (“FBAR”). Shareholders should consult a tax advisor, and persons investing in a Fund through an intermediary should contact their intermediary, regarding the applicability to them of this reporting requirement.

Other Reporting and Withholding Requirements

Sections 1471-1474 of the Code and the U.S. Treasury and IRS guidance issued thereunder (collectively, “FATCA”) generally require a Fund to obtain information sufficient to identify the status of each of its shareholders under FATCA or under an applicable intergovernmental agreement (an “IGA”) between the United States and a foreign government. If a shareholder fails to provide the requested information or otherwise fails to comply with FATCA or an IGA, the Fund may be required to withhold under FATCA at a rate of 30% with respect to that shareholder on ordinary dividends it pays. The IRS and the Department of Treasury have issued proposed regulations providing that these withholding rules will not apply to the gross proceeds of share redemptions or Capital Gain Dividends a Portfolio pays. If a payment by a Fund is subject to FATCA withholding, the Fund is required to withhold even if such payment would otherwise be exempt from withholding under the rules applicable to foreign shareholders described above (e.g., short-term capital gain dividends and interest-related dividends).

Each prospective investor is urged to consult its tax adviser regarding the applicability of FATCA and any other reporting requirements with respect to the prospective investor’s own situation, including investments through an intermediary.

General Considerations

The U.S. federal income tax discussion set forth above is for general information only. Prospective investors should consult their tax advisers regarding the specific U.S. federal income tax consequences of purchasing, holding, and disposing of shares of the Fund, as well as the effects of state, local, foreign, and other tax laws and any proposed tax law changes.

UNDERWRITER

SSGA FD serves as the Funds’ distributor pursuant to the Distribution Agreement by and between SSGA FD and the Trust. Pursuant to the Distribution Agreement, the Funds pay SSGA FD fees under the Rule 12b-1 Plan in effect for the Funds. For a description of the fees paid to SSGA FD under the Rule 12b-1 Plan, see “Distribution Plans,” above. SSGA FD is not obligated to sell any specific number of shares and will sell shares of a Fund on a continuous basis only against orders to purchase shares. The principal business address of SSGA FD is One Iron Street, Boston, MA 02210.

FINANCIAL STATEMENTS

The audited financial statements for the fiscal year ended December 31, 2018 for the Funds in operation at that date are included in the Annual Report of the Trust (the “Annual Report”), which was filed with the SEC on March 6, 2019 as part of the Trust’s filing on Form N-CSR (SEC Accession No. 0001193125-19-065518) and are incorporated into this SAI by reference. The Annual Report is available, without charge, upon request, by calling (877) 521-4083.

APPENDIX A

RATINGS OF DEBT INSTRUMENTS

MOODY’S INVESTORS SERVICE, INC. (“MOODY’S”)

GLOBAL LONG-TERM RATING SCALE

Ratings assigned on Moody’s global long-term rating scale are forward-looking opinions of the relative credit risks of financial obligations issued by non-financial corporates, financial institutions, structured finance vehicles, project finance vehicles, and public sector entities. Long-term ratings are assigned to issuers or obligations with an original maturity of one year or more and reflect both on the likelihood of a default on contractually promised payments and the expected financial loss suffered in the event of default.

Aaa : Obligations rated Aaa are judged to be of the highest quality, subject to the lowest level of credit risk.

Aa : Obligations rated Aa are judged to be of high quality and are subject to very low credit risk.

A : Obligations rated A are judged to be upper-medium grade and are subject to low credit risk.

Baa : Obligations rated Baa are judged to be medium-grade and subject to moderate credit risk and as such may possess certain speculative characteristics.

Ba : Obligations rated Ba are judged to be speculative and are subject to substantial credit risk.

B : Obligations rated B are considered speculative and are subject to high credit risk.

Caa : Obligations rated Caa are judged to be speculative of poor standing and are subject to very high credit risk.

Ca : Obligations rated Ca are highly speculative and are likely in, or very near, default, with some prospect of recovery of principal and interest.

C : Obligations rated C are the lowest rated and are typically in default, with little prospect for recovery of principal or interest.

Note: Moody’s appends numerical modifiers 1, 2, and 3 to each generic rating classification from Aa through Caa. The modifier 1 indicates that the obligation ranks in the higher end of its generic rating category; the modifier 2 indicates a mid-range ranking; and the modifier 3 indicates a ranking in the lower end of that generic rating category. Additionally, a “(hyb)” indicator is appended to all ratings of hybrid securities issued by banks, insurers, finance companies, and securities firms.*

By their terms, hybrid securities allow for the omission of scheduled dividends, interest, or principal payments, which can potentially result in impairment if such an omission occurs. Hybrid securities may also be subject to contractually allowable write-downs of principal that could result in impairment. Together with the hybrid indicator, the long-term obligation rating assigned to a hybrid security is an expression of the relative credit risk associated with that security.

GLOBAL SHORT-TERM RATING SCALE

Ratings assigned on Moody’s global short-term rating scale are forward-looking opinions of the relative credit risks of financial obligations issued by non-financial corporates, financial institutions, structured finance vehicles, project finance vehicles, and public sector entities. Short-term ratings are assigned to obligations with an original maturity of thirteen months or less and reflect both on the likelihood of a default on contractually promised payments and the expected financial loss suffered in the event of default.

P-1 : Issuers (or supporting institutions) rated Prime-1 have a superior ability to repay short-term debt obligations.

P-2 : Issuers (or supporting institutions) rated Prime-2 have a strong ability to repay short-term debt obligations.

P-3 : Issuers (or supporting institutions) rated Prime-3 have an acceptable ability to repay short-term obligations.

NP : Issuers (or supporting institutions) rated Not Prime do not fall within any of the Prime rating categories.

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S&P GLOBAL RATINGS (“S&P”)

ISSUE CREDIT RATING DEFINITIONS

An S&P Global Ratings issue credit rating is a forward-looking opinion about the creditworthiness of an obligor with respect to a specific financial obligation, a specific class of financial obligations, or a specific financial program (including ratings on medium-term note programs and commercial paper programs). It takes into consideration the creditworthiness of guarantors, insurers, or other forms of credit enhancement on the obligation and takes into account the currency in which the obligation is denominated. The opinion reflects S&P Global Ratings’ view of the obligor’s capacity and willingness to meet its financial commitments as they come due, and this opinion may assess terms, such as collateral security and subordination, which could affect ultimate payment in the event of default.

Issue credit ratings can be either long-term or short-term. Short-term ratings are generally assigned to those obligations considered short-term in the relevant market. Short-term ratings are also used to indicate the creditworthiness of an obligor with respect to put features on long-term obligations. Medium-term notes are assigned long-term ratings.

LONG-TERM ISSUE CREDIT RATINGS*

AAA : An obligation rated ‘AAA’ has the highest rating assigned by S&P Global Ratings. The obligor’s capacity to meet its financial commitments on the obligation is extremely strong.

AA : An obligation rated ‘AA’ differs from the highest-rated obligations only to a small degree. The obligor’s capacity to meet its financial commitments on the obligation is very strong.

A : An obligation rated ‘A’ is somewhat more susceptible to the adverse effects of changes in circumstances and economic conditions than obligations in higher-rated categories. However, the obligor’s capacity to meet its financial commitments on the obligation is still strong.

BBB : An obligation rated ‘BBB’ exhibits adequate protection parameters. However, adverse economic conditions or changing circumstances are more likely to weaken the obligor’s capacity to meet its financial commitments on the obligation.

BB; B; CCC; CC; and C: Obligations rated ‘BB’, ‘B’, ‘CCC’, ‘CC’, and ‘C’ are regarded as having significant speculative characteristics. ‘BB’ indicates the least degree of speculation and ‘C’ the highest. While such obligations will likely have some quality and protective characteristics, these may be outweighed by large uncertainties or major exposure to adverse conditions.

BB : An obligation rated ‘BB’ is less vulnerable to nonpayment than other speculative issues. However, it faces major ongoing uncertainties or exposure to adverse business, financial, or economic conditions that could lead to the obligor’s inadequate capacity to meet its financial commitments on the obligation.

B : An obligation rated ‘B’ is more vulnerable to nonpayment than obligations rated ‘BB’, but the obligor currently has the capacity to meet its financial commitments on the obligation. Adverse business, financial, or economic conditions will likely impair the obligor’s capacity or willingness to meet its financial commitments on the obligation.

CCC : An obligation rated ‘CCC’ is currently vulnerable to nonpayment, and is dependent upon favorable business, financial, and economic conditions for the obligor to meet its financial commitments on the obligation. In the event of adverse business, financial, or economic conditions, the obligor is not likely to have the capacity to meet its financial commitments on the obligation.

CC : An obligation rated ‘CC’ is currently highly vulnerable to nonpayment. The ‘CC’ rating is used when a default has not yet occurred, but S&P Global Ratings expects default to be a virtual certainty, regardless of the anticipated time to default.

C : An obligation rated ‘C’ is currently highly vulnerable to nonpayment, and the obligation is expected to have lower relative seniority or lower ultimate recovery compared with obligations that are rated higher.

D : An obligation rated ‘D’ is in default or in breach of an imputed promise. For non-hybrid capital instruments, the ‘D’ rating category is used when payments on an obligation are not made on the date due, unless S&P Global Ratings believes that such payments will be made within five business days in the absence of a stated grace period or within the earlier of the stated grace period or 30 calendar days. The ‘D’ rating also will be used upon the filing of a bankruptcy petition or the taking of similar action and where default on an obligation is a virtual certainty, for example due to automatic stay provisions. An obligation’s rating is lowered to ‘D’ if it is subject to a distressed exchange offer.

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NR: This indicates that no rating has been requested, or that there is insufficient information on which to base a rating, or that S&P Global Ratings does not rate a particular obligation as a matter of policy.

*	The ratings from ‘AA’ to ‘CCC’ may be modified by the addition of a plus (+) or minus (-) sign to show relative standing within the major rating categories.

SHORT-TERM ISSUE CREDIT RATINGS

A-1: A short-term obligation rated ‘A-1’ is rated in the highest category by S&P Global Ratings. The obligor’s capacity to meet its financial commitments on the obligation is strong. Within this category, certain obligations are designated with a plus sign (+). This indicates that the obligor’s capacity to meet its financial commitments on these obligations is extremely strong.

A-2: A short-term obligation rated ‘A-2’ is somewhat more susceptible to the adverse effects of changes in circumstances and economic conditions than obligations in higher rating categories. However, the obligor’s capacity to meet its financial commitments on the obligation is satisfactory.

A-3: A short-term obligation rated ‘A-3’ exhibits adequate protection parameters. However, adverse economic conditions or changing circumstances are more likely to weaken an obligor’s capacity to meet its financial commitments on the obligation.

B: A short-term obligation rated ‘B’ is regarded as vulnerable and has significant speculative characteristics. The obligor currently has the capacity to meet its financial commitments; however, it faces major ongoing uncertainties that could lead to the obligor’s inadequate capacity to meet its financial commitments.

C: A short-term obligation rated ‘C’ is currently vulnerable to nonpayment and is dependent upon favorable business, financial, and economic conditions for the obligor to meet its financial commitments on the obligation.

D: A short-term obligation rated ‘D’ is in default or in breach of an imputed promise. For non-hybrid capital instruments, the ‘D’ rating category is used when payments on an obligation are not made on the date due, unless S&P Global Ratings believes that such payments will be made within any stated grace period. However, any stated grace period longer than five business days will be treated as five business days. The ‘D’ rating also will be used upon the filing of a bankruptcy petition or the taking of a similar action and where default on an obligation is a virtual certainty, for example due to automatic stay provisions. An obligation’s rating is lowered to ‘D’ if it is subject to a distressed exchange offer.

FITCH RATINGS. (“FITCH”)

ISSUER DEFAULT RATINGS

Rated entities in a number of sectors, including financial and non-financial corporations, sovereigns, insurance companies and certain sectors within public finance, are generally assigned Issuer Default Ratings (IDRs). IDRs are also assigned to certain entities in global infrastructure and project finance. IDRs opine on an entity’s relative vulnerability to default on financial obligations. The threshold default risk addressed by the IDR is generally that of the financial obligations whose non-payment would best reflect the uncured failure of that entity. As such, IDRs also address relative vulnerability to bankruptcy, administrative receivership or similar concepts.

In aggregate, IDRs provide an ordinal ranking of issuers based on the agency’s view of their relative vulnerability to default, rather than a prediction of a specific percentage likelihood of default.

AAA: Highest credit quality.

‘AAA’ ratings denote the lowest expectation of default risk. They are assigned only in cases of exceptionally strong capacity for payment of financial commitments. This capacity is highly unlikely to be adversely affected by foreseeable events.

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AA: Very high credit quality.

‘AA’ ratings denote expectations of very low default risk. They indicate very strong capacity for payment of financial commitments. This capacity is not significantly vulnerable to foreseeable events. A: High credit quality.

‘A’ ratings denote expectations of low default risk. The capacity for payment of financial commitments is considered strong. This capacity may, nevertheless, be more vulnerable to adverse business or economic conditions than is the case for higher ratings.

BBB: Good credit quality.

‘BBB’ ratings indicate that expectations of default risk are currently low. The capacity for payment of financial commitments is considered adequate, but adverse business or economic conditions are more likely to impair this capacity.

BB: Speculative.

‘BB’ ratings indicate an elevated vulnerability to default risk, particularly in the event of adverse changes in business or economic conditions over time; however, business or financial flexibility exists that supports the servicing of financial commitments.

B: Highly speculative.

‘B’ ratings indicate that material default risk is present, but a limited margin of safety remains. Financial commitments are currently being met; however, capacity for continued payment is vulnerable to deterioration in the business and economic environment.

CCC: Substantial credit risk.

Default is a real possibility.

CC: Very high levels of credit risk.

Default of some kind appears probable.

C: Near default

A default or default-like process has begun, or the issuer is in standstill, or for a closed funding vehicle, payment capacity is irrevocably impaired. Conditions that are indicative of a ‘C’ category rating for an issuer include:

a.	the issuer has entered into a grace or cure period following non-payment of a material financial obligation;

b.	the issuer has entered into a temporary negotiated waiver or standstill agreement following a payment default on a material financial obligation;

c.	the formal announcement by the issuer or their agent of a distressed debt exchange;

d.	a closed financing vehicle where payment capacity is irrevocably impaired such that it is not expected to pay interest and/or principal in full during the life of the transaction, but where no payment default is imminent.

RD: Restricted default.

‘RD’ ratings indicate an issuer that in Fitch’s opinion has experienced:

a.	an uncured payment default on a bond, loan or other material financial obligation, but

b.	has not entered into bankruptcy filings, administration, receivership, liquidation, or other formal winding-up procedure, and

c.	has not otherwise ceased operating.

This would include:

i.	the selective payment default on a specific class or currency of debt;

ii.	the uncured expiry of any applicable grace period, cure period or default forbearance period following a payment default on a bank loan, capital markets security or other material financial obligation;

iii.	the extension of multiple waivers or forbearance periods upon a payment default on one or more material financial obligations, either in series or in parallel; ordinary execution of a distressed debt exchange on one or more material financial obligations.

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D: Default.

‘D’ ratings indicate an issuer that in Fitch’s opinion has entered into bankruptcy filings, administration, receivership, liquidation or other formal winding-up procedure or that has otherwise ceased business.

Default ratings are not assigned prospectively to entities or their obligations; within this context, non-payment on an instrument that contains a deferral feature or grace period will generally not be considered a default until after the expiration of the deferral or grace period, unless a default is otherwise driven by bankruptcy or other similar circumstance, or by a distressed debt exchange.

In all cases, the assignment of a default rating reflects the agency’s opinion as to the most appropriate rating category consistent with the rest of its universe of ratings and may differ from the definition of default under the terms of an issuer’s financial obligations or local commercial practice.

SHORT-TERM RATINGS ASSIGNED TO ISSUERS AND OBLIGATIONS

A short-term issuer or obligation rating is based in all cases on the short-term vulnerability to default of the rated entity and relates to the capacity to meet financial obligations in accordance with the documentation governing the relevant obligation. Short-term deposit ratings may be adjusted for loss severity. Short-Term Ratings are assigned to obligations whose initial maturity is viewed as “short term” based on market convention. Typically, this means up to 13 months for corporate, sovereign, and structured obligations and up to 36 months for obligations in U.S. public finance markets.

F1: Highest Short-Term Credit Quality. Indicates the strongest intrinsic capacity for timely payment of financial commitments; may have an added “+” to denote any exceptionally strong credit feature.

F2: Good Short-Term Credit Quality. Good intrinsic capacity for timely payment of financial commitments.

F3: Fair Short-Term Credit Quality. The intrinsic capacity for timely payment of financial commitments is adequate.

B: Speculative Short-Term Credit Quality. Minimal capacity for timely payment of financial commitments, plus heightened vulnerability to near term adverse changes in financial and economic conditions.

C: High Short-Term Default risk. Default is a real possibility.

RD: Restricted Default. Indicates an entity that has defaulted on one or more of its financial commitments, although it continues to meet other financial obligations. Typically applicable to entity ratings only.

D: Default. Indicates a broad-based default event for an entity, or the default of a short-term obligation.

Note: The modifiers “+” or “-” may be appended to a rating to denote relative status within major rating categories. For example, the rating category ‘AA’ has three notch-specific rating levels (‘AA+’; ‘AA’; ‘AA-’; each a rating level). Such suffixes are not added to ‘AAA’ ratings. For corporate finance obligation ratings, they are not appended to rating categories below the ‘CCC’. For all other sectors/obligations, they are not assigned to rating categories below the ‘B’.

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APPENDIX B – TRUST’S PROXY VOTING PROCEDURES

SSGA FUNDS

STATE STREET MASTER FUNDS

STATE STREET INSTITUTIONAL INVESTMENT TRUST

ELFUN GOVERNMENT MONEY MARKET FUND

ELFUN TAX-EXEMPT INCOME FUND

ELFUN INCOME FUND

ELFUN DIVERSIFIED FUND

ELFUN INTERNATIONAL EQUITY FUND

ELFUN TRUSTS

STATE STREET NAVIGATOR SECURITIES LENDING TRUST

STATE STREET INSTITUTIONAL FUNDS

STATE STREET VARIABLE INSURANCE SERIES FUNDS, INC. (THE “COMPANY”) ¹

PROXY VOTING POLICY AND PROCEDURES

As of September 20, 2017

The Board of Trustees/Directors of the Trust/Company (each series thereof, a “Fund”) have adopted the following policy and procedures with respect to voting proxies relating to portfolio securities held by the Trust/Company’s investment portfolios.

1. Proxy Voting Policy

The policy of the Trust/Company is to delegate the responsibility for voting proxies relating to portfolio securities held by the Trust/Company to SSGA Funds Management, Inc., the Trust/Company’s investment adviser (the “Adviser”), subject to the Trustees/Directors’ continuing oversight.

2. Fiduciary Duty

The right to vote proxies with respect to a portfolio security held by the Trust/Company is an asset of the Trust/Company. The Adviser acts as a fiduciary of the Trust/Company and must vote proxies in a manner consistent with the best interest of the Trust/Company and its shareholders.

3. Proxy Voting Procedures

A. At least annually, the Adviser shall present to the Boards of Trustees/Directors its policies, procedures and other guidelines for voting proxies (“Policy”) and the policy of any Sub- adviser (as defined below) to which proxy voting authority has been delegated (see Section 9 below). In addition, the Adviser shall notify the Trustees/Directors of material changes to its Policy or the policy of any Sub – adviser promptly and not later than the next regular meeting of the Board of Trustees/Directors after such amendment is implemented.

B. At least annually, the Adviser shall present to the Boards of Trustees/Directors its policy for managing conflicts of interests that may arise through the Adviser’s proxy voting activities. In addition, the Adviser shall report any Policy overrides involving portfolio securities held by a Fund to the Trustees/Directors at the next regular meeting of the Board of Trustees/Directors after such override(s) occur.

Unless otherwise noted, the singular term “Trust/Company” used throughout this document means each of SSGA Funds, State Street Master Funds, State Street Institutional Investment Trust, State Street Navigator Securities Lending Trust, Elfun Government Money Market Fund, Elfun Tax-Exempt Income Fund, Elfun Income Fund, Elfun Diversified Fund, Elfun International Equity Fund, Elfun Trusts, State Street Institutional Funds, and State Street Variable Insurance Series Funds, Inc.

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C. At least annually, the Adviser shall inform the Trustees/Director that a record is available with respect to each proxy voted with respect to portfolio securities of the Trust/Company during the year. Also see Section 5 below.

4. Revocation of Authority to Vote

The delegation by the Trustees/Directors of the authority to vote proxies relating to portfolio securities of the Trust/Company may be revoked by the Trustees/Directors, in whole or in part, at any time.

5. Annual Filing of Proxy Voting Record

The Adviser shall provide the required data for each proxy voted with respect to portfolio securities of the Trust/Company to the Trust/Company or its designated service provider in a timely manner and in a format acceptable to be filed in the Trust/Company’s annual proxy voting report on Form N-PX for the twelve-month period ended June 30. Form N-PX is required to be filed not later than August 31 of each year.

6. Retention and Oversight of Proxy Advisory Firms

A. In considering whether to retain or continue retaining a particular proxy advisory firm, the Adviser will ascertain whether the proxy advisory firm has the capacity and competency to adequately analyze proxy issues, act as proxy voting agent as requested, and implement the Policy. In this regard, the Adviser will consider, at least annually, among other things, the adequacy and quality of the proxy advisory firm’s staffing and personnel and the robustness of its policies and procedures regarding its ability to identify and address any conflicts of interest. The Adviser shall, at least annually, report to Boards of Trustees/Directors regarding the results of this review.

B. The Adviser will request quarterly and annual reporting from any proxy advisory firm retained by the Adviser, and hold ad hoc meetings with such proxy advisory firm, in order to determine whether there has been any business changes that might impact the proxy advisory firm’s capacity or competency to provide proxy voting advice or services or changes to the proxy advisory firm’s conflicts policies or procedures. The Adviser will also take reasonable steps to investigate any material factual error, notified to the Adviser by the proxy advisory firm or identified by the Adviser, made by the proxy advisory firm in providing proxy voting services.

7. Periodic Sampling

The Adviser will periodically sample proxy votes to review whether they complied with the Policy. The Adviser shall, at least annually, report to the Boards of Trustees/Directors regarding the frequency and results of the sampling performed.

8. Disclosures

A. The Trust/Company shall include in its registration statement:

1. A description of this policy and of the policies and procedures used by the Adviser to determine how to vote proxies relating to portfolio securities; and

1.A statement disclosing that information regarding how the Trust/Company voted proxies relating to portfolio securities during the most recent twelve-month period ended June 30 is available without charge, upon request, by calling the Trust/Company’s toll-free telephone number; or through a specified Internet address; or both; and on the Securities and Exchange Commission’s (the “SEC”) website.

B. The Trust/Company shall include in its annual and semi-annual reports to shareholders:

1. A statement disclosing that a description of the policies and procedures used by or on behalf of the Trust/Company to determine how to vote proxies relating to portfolio securities of the Funds is available without charge, upon request, by calling the Trust/Company’s toll-free telephone number; through a specified Internet address, if applicable; and on the SEC’s website; and

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2. A statement disclosing that information regarding how the Trust/Company voted proxies relating to portfolio securities during the most recent twelve-month period ended June 30 is available without charge, upon request, by calling the Trust/Company’s toll-free telephone number; or through a specified Internet address; or both; and on the SEC’s website.

9. Sub-Advisers

For certain Funds, the Adviser may retain investment management firms (“Sub-advisers”) to provide day-to-day investment management services to the Funds pursuant to sub-advisory agreements. It is the policy of the Trust/Company that the Adviser may delegate proxy voting authority with respect to a Fund to a Sub-adviser. Pursuant to such delegation, a Sub-adviser is authorized to vote proxies on behalf of the applicable Fund or Funds for which it serves as sub-adviser, in accordance with the Sub-adviser’s proxy voting policies and procedures.

10. Review of Policy

The Trustees/Directors shall review this policy to determine its continued sufficiency as necessary from time to time.

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APPENDIX C – ADVISER’S PROXY VOTING PROCEDURES AND GUIDELINES

March 2019

Global Proxy Voting and Engagement Principles

State Street Global Advisors, one of the industry’s largest institutional asset managers, is the investment management arm of State Street Corporation, a leading provider of financial services to institutional investors. As an investment manager, State Street Global Advisors has discretionary proxy voting authority over most of its client accounts, and State Street Global Advisors votes these proxies in the manner that we believe will most likely protect and promote the long-term economic value of client investments as described in this document ¹ .

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Global Proxy Voting and Engagement Principles

State Street Global Advisors maintains Proxy Voting and Engagement Guidelines for select markets, including: Australia, the European Union, Japan, New Zealand, North America (Canada and the US), the UK and Ireland, and emerging markets. International markets not covered by our market-specific guidelines are reviewed and voted in a manner that is consistent with our Global Proxy Voting and Engagement Principles; however, State Street Global Advisors also endeavors to show sensitivity to local market practices when voting in these various markets.

State Street Global Advisors’ Approach to Proxy Voting and Issuer Engagement

At State Street Global Advisors, we take our fiduciary duties as an asset manager very seriously. We have a dedicated team of corporate governance professionals who help us carry out our duties as a responsible investor. These duties include engaging with companies, developing and enhancing in-house corporate governance guidelines, analyzing corporate governance issues on a case-by-case basis at the company level, and exercising our voting rights. The underlying goal is to maximize shareholder value.

Our Global Proxy Voting and Engagement Principles (the “Principles”) may take different perspectives on common governance issues that vary from one market to another. Similarly, engagement activity may take different forms in order to best achieve long-term engagement goals. We believe that proxy voting and engagement with portfolio companies is often the most direct and productive way for shareholders to exercise their ownership rights. This comprehensive toolkit is an integral part of the overall investment process.

We believe engagement and voting activity have a direct relationship. As a result the integration of our engagement activities, while leveraging the exercise of our voting rights, provides a meaningful shareholder tool that we believe protects and enhances the long-term economic value of the holdings in our client accounts. We maximize our voting power and engagement by maintaining a centralized proxy voting and active ownership process covering all holdings, regardless of strategy. Despite the vast investment strategies and objectives across State Street Global Advisors, the fiduciary responsibilities of share ownership and voting for which State Street Global Advisors has voting discretion are carried out with a single voice and objective.

The Principles support governance structures that we believe add to, or maximize shareholder value, for the companies held in our clients’ portfolios. We conduct issuer specific engagements with companies to discuss

our principles, including sustainability related risks. In addition we encourage issuers to find ways to increase the amount of direct communication board members have with shareholders. Direct communication with executive board members and independent non-executive directors is critical to helping companies understand shareholder concerns. Conversely, we conduct collaborative engagement activities with multiple shareholders and communicate with company representatives about common concerns where appropriate.

In conducting our engagements, we also evaluate the various factors that influence the corporate governance framework of a country, including the macroeconomic conditions and broader political system, the quality of regulatory oversight, the enforcement of property and shareholder rights, and the independence of the judiciary. We understand that regulatory requirements and investor expectations relating to governance practices and engagement activities differ from country-to-country. As a result, we engage with issuers, regulators, or a combination of the two depending upon the market. We are also a member of various investor associations that seek to address broader corporate governance related policy at the country level as well as issuer specific concerns at a company level.

The State Street Global Advisors Asset Stewardship Team may collaborate with members of the Active Fundamental and various other investment teams to engage with companies on corporate governance issues and to address any specific concerns. This facilitates our comprehensive approach to information gathering as it relates to shareholder items that are to be voted upon at upcoming shareholder meetings. We also conduct issuer- specific engagements with companies covering various corporate governance and sustainability related topics outside of proxy season.

The Asset Stewardship Team employs a blend of quantitative and qualitative research, analysis, and data in order to support screens that identify issuers where active engagement may be necessary to protect and promote shareholder value. Issuer engagement may also be event driven, focusing on issuer-specific corporate governance, sustainability concerns, or more broad industry-related trends. We also give consideration to the size of our total position of the issuer in question and/or the potential negative governance, performance profile, and circumstance at hand. As a result, we believe issuer engagement can take many forms and be triggered by numerous circumstances. The following approaches represent how we define engagement methods:


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Global Proxy Voting and Engagement Principles

Active

We use screening tools designed to capture a mix of company specific data including governance and sustainability profiles to help us focus our voting and engagement activity.

We will actively seek direct dialogue with the board and management of companies that we have identified through our screening processes. Such engagements may lead to further monitoring to ensure that the company improves its governance or sustainability practices. In these cases, the engagement process represents the most meaningful opportunity for us to protect long-term shareholder value from excessive risk due to poor governance and sustainability practices.

Reactive

Reactive engagement is initiated by the issuers. We routinely discuss specific voting issues and items with the issuer community. Reactive engagement is an opportunity to address not only voting items, but also a wide range of governance and sustainability issues.

We have established an engagement protocol that further describes our approach to issuer engagement.

Measurement

Assessing the effectiveness of our issuer engagement process is often difficult. In order to limit the subjectivity of effectiveness measurement, we actively seek issuer feedback and monitor the actions issuers take post-engagement in order to identify tangible changes. Thus we are able to establish indicators to gauge how issuers respond to our concerns and to what degree these responses satisfy our requests. It is also important to note that successful engagement activity can be measured over differing time periods depending upon the relevant facts and circumstances. Engagements can last as briefly as a single meeting or span multiple years.

Depending upon the issue and whether the engagement activity is reactive, recurring, or active, engagement with issuers can take the form of written communication, conference calls, or in-person meetings. We believe active engagement is best conducted directly with company management or board members. Collaborative engagement, where multiple shareholders communicate with company representatives, can serve as a potential forum for issues that are not identified by us as requiring active engagement. An example of such a forum is a shareholder conference call.

Proxy Voting Procedure

Oversight

The Asset Stewardship Team is responsible for developing and implementing the Proxy Voting and Engagement Guidelines (the “Guidelines”), case-by-case voting items, issuer engagement activities, and research and analysis of governance-related issues. The implementation of the Guidelines is overseen by the State Street Global Advisors Global Proxy Review Committee (“PRC”), a committee of investment, compliance and legal professionals, who provide guidance on proxy issues as described in greater detail below. Oversight of the proxy voting process is ultimately the responsibility of the State Street Global Advisors Investment Committee (“IC”). The IC reviews and approves amendments to the Guidelines. The PRC reports to the IC, and may refer certain significant proxy items to that committee.

Proxy Voting Process

In order to facilitate our proxy voting process, we retain Institutional Shareholder Services Inc. (“ISS”), a firm with expertise in proxy voting and corporate governance. We utilize ISS’s services in three ways: (1) as our proxy voting agent (providing State Street Global Advisors with vote execution and administration services), (2) for applying the Guidelines, and (3) as providers of research and analysis relating to general corporate governance issues and specific proxy items.

The Asset Stewardship Team reviews the Guidelines with ISS on an annual basis or on a case-by-case basis. On most routine proxy voting items (e.g., ratification of auditors), ISS will affect the proxy votes in accordance with the Guidelines.

In other cases, the Asset Stewardship Team will evaluate the proxy solicitation to determine how to vote based upon facts, circumstances consistency with our Principles and accompanying Guidelines.

In some instances, the Asset Stewardship Team may refer significant issues to the PRC for a determination of the proxy vote. In addition, in determining whether to refer a proxy vote to the PRC, the Asset Stewardship Team will consider whether a material conflict of interest exists between the interests of our client and those of State Street Global Advisors or its affiliates (as explained in greater detail in our Conflict Mitigation Guidelines).


State Street Global Advisors		C-3

Global Proxy Voting and Engagement Principles

We vote in all markets where it is feasible; however, we may refrain from voting meetings when power of attorney documentation is required, where voting will have a material impact on our ability to trade the security, where issuer-specific special documentation is required, or where various market or issuer certifications are required. We are unable to vote proxies when certain custodians, used by our clients, do not offer proxy voting in a jurisdiction or when they charge a meeting specific fee in excess of the typical custody service agreement.

Conflict of Interest

See our standalone Conflict Mitigation Guidelines.

Proxy Voting and Engagement Principles

Directors and Boards

The election of directors is one of the most important fiduciary duties we perform as a shareholder. We believe that well-governed companies can protect and pursue shareholder interests better and withstand the challenges of an uncertain economic environment. As such we seek to vote director elections in a way that we believe will maximize the long-term value of each portfolio’s holdings.

Principally a board acts on behalf of shareholders by protecting their interests and preserving their rights. This concept establishes the standard by which board and director performance is measured. In order to achieve this fundamental principle, the role of the board is to carry out its responsibilities in the best long-term interest of the company and its shareholders. An independent and effective board oversees management, provides guidance on strategic matters, selects the CEO and other senior executives, creates a succession plan for the board and management, provides risk oversight, and assesses the performance of the CEO and management. In contrast, management implements the business and capital allocation strategies and runs the company’s day-to-day operations. As part of our engagement process, we routinely discuss the importance of these responsibilities with the boards of issuers.

We believe the quality of a board is a measure of director independence, director succession planning, board diversity, evaluations and refreshment, and company governance practices. In voting to elect nominees, we consider many factors. We believe independent directors are crucial to good corporate governance; they help management establish sound corporate governance policies and practices. A sufficiently independent board will effectively monitor management, maintain appropriate governance practices, and perform oversight functions necessary to protect

shareholder interests. We also believe the right mix of skills, independence, diversity, and qualifications among directors provides boards with the knowledge and direct experience to manage risks and operating structures that are often complex and industry-specific.

Accounting and Audit-Related Issues

We believe audit committees are critical and necessary as part of the board’s risk oversight role. The audit committee is responsible for setting out an internal audit function that provides robust audit and internal control systems designed to effectively manage potential and emerging risks to the company’s operations and strategy. We believe audit committees should have independent directors as members, and we will hold the members of the audit committee responsible for overseeing the management of the audit function.

The disclosure and availability of reliable financial statements in a timely manner is imperative for the investment process. As a result board oversight of the internal controls and the independence of the audit process are essential if investors are to rely upon financial statements. It is important for the audit committee to appoint external auditors who are independent from management; we expect auditors to provide assurance of a company’s financial condition.

Capital Structure, Reorganization and Mergers

The ability to raise capital is critical for companies to carry out strategy, to grow, and to achieve returns above their cost of capital. The approval of capital raising activities is fundamental to a shareholder’s ability to monitor the amounts of proceeds and to ensure capital is deployed efficiently. Altering the capital structure of a company is a critical decision for boards. When making such a decision we believe the company should disclose a comprehensive business rationale that is consistent with corporate strategy and not overly dilutive to its shareholders.

Mergers or reorganization of the structure of a company often involve proposals relating to reincorporation, restructurings, liquidations, and other major changes to the corporation.

Proposals that are in the best interests of shareholders, demonstrated by enhancing share value or improving the effectiveness of the company’s operations, will be supported. In evaluating mergers and acquisitions, we consider the adequacy of the consideration and the impact of the corporate governance provisions to shareholders. In all cases, we use our discretion in order to maximize shareholder value.


State Street Global Advisors		C-4

Global Proxy Voting and Engagement Principles

Occasionally, companies add anti-takeover provisions that reduce the chances of a potential acquirer to make an offer, or to reduce the likelihood of a successful offer. We do not support proposals that reduce shareholders’ rights, entrench management, or reduce the likelihood of shareholders’ right to vote on reasonable offers.

Compensation

We consider the board’s responsibility to include identifying the appropriate level of executive compensation. Despite the differences among the types of plans and the awards possible, there is a simple underlying philosophy that guides our analysis of executive compensation; we believe that there should be a direct relationship between executive compensation and company performance over the long term.

Shareholders should have the opportunity to assess whether pay structures and levels are aligned with business performance. When assessing remuneration reports, we consider factors such as adequate disclosure of various remuneration elements, absolute and relative pay levels, peer selection and benchmarking, the mix of long-term and short-term incentives, alignment of pay structures with shareholder interests, as well as with corporate strategy and performance. We may oppose remuneration reports where pay seems misaligned with shareholders’ interests. We may also consider executive compensation practices when re-electing members of the remuneration committee.

We recognize that compensation policies and practices are unique from market to market; often there are significant differences between the level of disclosures, the amount and forms of compensation paid, and the ability of shareholders to approve executive compensation practices. As a result, our ability to assess the appropriateness of executive compensation is often dependent on market practices and laws.

Environmental and Social Issues

As a fiduciary, State Street Global Advisors takes a comprehensive approach to engaging with our portfolio companies about material environmental and social (sustainability) issues. We use our voice and our vote through engagement, proxy voting, and thought leadership in order to communicate with issuers and educate market participants about our perspective on important sustainability topics. Our Asset Stewardship program prioritization process allows us to proactively identify companies for engagement and voting in order to mitigate sustainability risks in our portfolio. Through engagement, we address a broad range of topics that align with our thematic priorities and build long-term relationships with issuers. When voting, we fundamentally consider whether the adoption of a shareholder proposal addressing a material

sustainability issue would promote long-term shareholder value in the context of the company’s existing practices and disclosures as well as existing market practice.

For more information on our approach to environmental and social issues, please see our Global Proxy Voting and Engagement Guidelines for Environmental and Social Issues available at ssga.com/about-us/asset-stewardship.html .

General/Routine

Although we do not seek involvement in the day-to-day operations of an organization, we recognize the need for conscientious oversight and input into management decisions that may affect a company’s value. We support proposals that encourage economically advantageous corporate practices and governance, while leaving decisions that are deemed to be routine or constitute ordinary business to management and the board of directors.

Fixed Income Stewardship

The two elements of our fixed income stewardship program are:

Proxy Voting:

While matters that arise for a vote at bondholder meetings vary by jurisdiction, examples of common proxy voting resolutions at bondholder meetings include:

•

Approving amendments to debt covenants and/or terms of issuance

•

Authorizing procedural matters, such as filing of required documents/other formalities

•

Approving debt restructuring plans

•

Abstaining from challenging the bankruptcy trustees

•

Authorizing repurchase of issued debt security

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Approving the placement of unissued debt securities under the control of directors

•

Approving spin-off/absorption proposals

Given the nature of the items that arise for vote at bondholder meetings, we take a case-by-case approach to voting bondholder resolutions. Where necessary, we will engage with issuers on voting matters prior to arriving at voting decisions. All voting decisions will be made in the best interest of our clients.

Issuer Engagement:

We recognize that debt holders have limited leverage with companies on a day-to-day basis. However, we believe that given the size of our holdings in corporate debt, we can meaningfully influence ESG practices of companies through issuer engagement. Our guidelines for engagement with fixed income issuers broadly follow the engagement guidelines for our equity holdings as described above.


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Global Proxy Voting and Engagement Principles

Securities on Loan

For funds in which we act as trustee, we may recall securities in instances where we believe that a particular vote will have a material impact on the fund(s). Several factors shape this process. First, we must receive notice of the vote in sufficient time to recall the shares on or before the record date. In many cases, we do not receive timely notice, and we are unable to recall the shares on or before the record date. Second, State Street Global Advisors may exercise its discretion and recall shares if it believes that the benefit of voting shares will outweigh the foregone lending income. This determination requires State Street Global Advisors, with the information available at the time, to form judgments about events or outcomes that are difficult

to quantify. Given our expertise and vast experience, we believe that the recall of securities will rarely provide an economic benefit that outweighs the cost of the foregone lending income.

Reporting

Any client who wishes to receive information on how its proxies were voted should contact its State Street Global Advisors relationship manager.

These Global Proxy Voting and Engagement Guidelines are also applicable to State Street Global Advisors Funds Management, Inc. State Street Global Advisors Funds Management, Inc. is an SEC-registered investment adviser. State Street Global Advisors Funds Management, Inc., State Street Global Advisors Trust Company, and other advisory affiliates of State Street make up State Street Global Advisors, the investment management arm of State Street Corporation.

ssga.com

State Street Global Advisors Worldwide Entities

Abu Dhabi: State Street Global Advisors Limited, Middle East Branch, 42801, 28, Al Khatem Tower, Abu Dhabi Global Market Square, Al Mayah Island, Abu Dhabi, United Arab Emirates. Regulated by ADGM Financial Services Regulatory Authority. T: +971 2 245 9000. Australia: State Street Global Advisors, Australia, Limited (ABN 42 003 914 225) is the holder of an Australian Financial Services Licence (AFSL Number 238276). Registered office: Level 17, 420 George Street, Sydney, NSW 2000, Australia T: +612 9240 7600. F: +612 9240 7611. Belgium: State Street Global Advisors Belgium, Chaussée de La Hulpe 120, 1000 Brussels, Belgium. T: 32 2 663 2036, F: 32 2 672 2077. SSGA Belgium is a branch office of State Street Global Advisors Limited. State Street Global Advisors Ireland Limited, registered in Ireland with company number 145221, authorized and regulated by the Central Bank of Ireland, and whose registered office is at 78 Sir John Rogerson’s Quay, Dublin 2. Canada: State Street Global Advisors, Ltd., 770 Sherbrooke Street West, Suite 1200 Montreal, Quebec, H3A 1G1, T: +514 282 2400 and 30 Adelaide Street East Suite 500, Toronto, Ontario M5C 3G6. T: +647 775 5900. Dubai: State Street Global Advisors Limited, DIFC Branch, Central Park Towers, Suite 15-38 (15th floor), P.O Box 26838, Dubai International Financial Centre (DIFC), Dubai, United Arab Emirates. Regulated by the Dubai Financial Services Authority (DFSA). T: +971 (0)4 4372800, F: +971 (0)4 4372818. France: State Street Global Advisors Ireland Limited, Paris branch is a branch of State Street Global Advisors Ireland Limited, registered in Ireland with company number 145221, authorized and regulated by the Central Bank of Ireland, and whose registered office is at 78 Sir John Rogerson’s Quay, Dublin 2. State Street Global Advisors Ireland Limited, Paris Branch, is registered in France with company number RCS Nanterre 832 734 602 and whose office is at Immeuble Défense Plaza, 23-25 rue Delarivière-Lefoullon, 92064 Paris La Défense Cedex, France. T: (+33) 1 44 45 40 00. F: (+33) 1 44 45 41 92. Germany: State Street Global Advisors GmbH, Brienner Strasse 59, D-80333 Munich. Authorized and regulated by the Bundesanstalt für Finanzdienstleistungsaufsicht (“BaFin”). Registered with the Register of Commerce Munich HRB 121381. T: +49 (0)89 55878 400. F: +49 (0)89 55878 440. Hong Kong: State Street Global Advisors Asia Limited, 68/F, Two International Finance Centre, 8 Finance Street, Central, Hong Kong. T: +852 2103-0288. F: +852 2103 0200. Ireland: State Street Global Advisors Ireland Limited is regulated by the Central Bank of Ireland. Registered office address 78 Sir John

Rogerson’s Quay, Dublin 2. Registered number 145221. T: +353 (0)1 776 3000. F: +353 (0)1 776 3300. Italy: State Street Global Advisors Ireland Limited, Milan Branch (Sede Secondaria di Milano) is a branch of State Street Global Advisors Ireland Limited, registered in Ireland with company number 145221, authorized and regulated by the Central Bank of Ireland, and whose registered office is at 78 Sir John Rogerson’s Quay, Dublin 2. State Street Global Advisors Ireland Limited, Milan Branch (Sede Secondaria di Milano), is registered in Italy with company number 10495250960 - R.E.A. 2535585 and VAT number 10495250960and whose office is at Via dei Bossi, 4 - 20121 Milano, Italy. T: +39 02 32066 100. F: +39 02 32066 155. Japan: State Street Global Advisors (Japan) Co., Ltd., Toranomon Hills Mori Tower 25F 1-23-1 Toranomon, Minato-ku, Tokyo 105-6325 Japan, T: +81-3-4530-7380 Financial Instruments Business Operator, Kanto Local Financial Bureau (Kinsho #345) , Membership: Japan Investment Advisers Association, The Investment Trust Association, Japan, Japan Securities Dealers’ Association. Netherlands: State Street Global Advisors Netherlands, Apollo Building, 7th floor Herikerbergweg 29 1101 CN Amsterdam, Netherlands. Telephone: 31 20 7181701. SSGA Netherlands is a branch office of State Street Global Advisors Ireland Limited, registered in Ireland with company number 145221, authorized and regulated by the Central Bank of Ireland, and whose registered office is at 78 Sir John Rogerson’s Quay, Dublin 2. Singapore: State Street Global Advisors Singapore Limited, 168, Robinson Road, #33-01 Capital Tower, Singapore 068912 (Company Reg. No: 200002719D, regulated by the Monetary Authority of Singapore). Telephone: +65 6826 7555. F: +65 6826 7501. Switzerland: State Street Global Advisors AG, Beethovenstr. 19, CH-8027 Zurich. Authorized and regulated by the Eidgenössische Finanzmarktaufsicht (“FINMA”). Registered with the Register of Commerce Zurich CHE-105.078.458. T: +41 (0)44 245 70 00. Facsimile F: +41 (0)44 245 70 16. United Kingdom: State Street Global Advisors Limited. Authorized and regulated by the Financial Conduct Authority. Registered in England. Registered No. 2509928. VAT No. 5776591 81. Registered office: 20 Churchill Place, Canary Wharf, London, E14 5HJ. T: 020 3395 6000. F: 020 3395 6350. United States: State Street Global Advisors, One Iron Street, Boston MA 02210. T: +1 617 786 3000.

Investing involves risk including the risk of loss of principal.

The whole or any part of this work may not be reproduced, copied or transmitted or any of its contents disclosed to third parties without State Street Global Advisor’s express written consent.


State Street Global Advisors		C-6		© 2019 State Street Corporation. All Rights Reserved. ID15919 0319 Exp. Date: 03/31/2020

March 2019

2019 State Street Global Advisors Conflict Mitigation Guidelines

State Street Corporation has a comprehensive standalone Conflicts of Interest Policy and other policies that address a range of conflicts of interests identified. In addition, State Street Global Advisors, the asset management business of State Street Corporation, maintains a conflicts register that identifies key conflicts and describes systems in place to mitigate the conflicts. This guidance ¹ is designed to act in conjunction with related policies and practices employed by other groups within the organization. Further, they complement those policies and practices by providing specific guidance on managing the conflicts of interests that may arise through State Street Global Advisors’ proxy voting and engagement activities.

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2019 State Street Global Advisors Conflict Mitigation Guidelines

Managing Conflicts of Interest Related to Proxy Voting

State Street Global Advisors has policies and procedures designed to prevent undue influence on State Street Global Advisors’ voting activities that may arise from relationships between proxy issuers or companies and State Street Corporation, State Street Global Advisors, State Street Global Advisors affiliates, State Street Global Advisors Funds or State Street Global Advisors Fund affiliates.

Protocols designed to help mitigate potential conflicts of interest include:

•

Providing sole voting discretion to members of State Street Global Advisors’ Asset Stewardship team. Members of the Asset Stewardship team may from time to time discuss views on proxy voting matters, company performance, strategy etc. with other State Street Corporation or State Street Global Advisors employees including portfolio managers, senior executives and relationship managers. However, final voting decisions are made solely by the Asset Stewardship team, in a manner that is consistent with the best interests of all clients, taking into account various perspectives on risks and opportunities with a view of maximizing the value of client assets;

•

Exercising a singular vote decision for each ballot item regardless of our investment strategy;

•

Prohibiting members of State Street Global Advisors’ Asset Stewardship team from disclosing State Street Global Advisors’ voting decision to any individual not affiliated with the proxy voting process prior to the meeting or date of written consent, as the case may be;

•

Mandatory disclosure by members of the State Street Global Advisors’ Asset Stewardship team, Global Proxy Review Committee (“PRC”) and Investment Committee (“IC”) of any personal conflict of interest (e.g., familial relationship with company management, serves as a director on the board of a listed company) to the Head of the Asset Stewardship team. Members are required to recuse themselves from any engagement or proxy voting activities related to the conflict;

•

In certain instances, client accounts and/or State Street Global Advisors pooled funds, where State Street Global Advisors acts as trustee, may hold shares in State Street Corporation or other State Street Global Advisors affiliated entities, such as mutual funds affiliated with State Street Global Advisors Funds Management, Inc. In general, State Street Global Advisors will outsource any voting decision relating to a shareholder meeting of State Street Corporation or other State Street Global Advisors affiliated entities to independent outside third parties. Delegated third parties exercise vote decisions based upon State Street Global Advisors’ Proxy Voting and Engagement Guidelines (“Guidelines”); and

•

Reporting of voting guideline overrides, if any, to the PRC on a quarterly basis.

In general, we do not believe matters that fall within the Guidelines and are voted consistently with the Guidelines present any potential conflicts, since the vote on the matter has effectively been determined without reference to the soliciting entity. However, where matters do not fall within the Guidelines or where we believe that voting in accordance with the Guidelines is unwarranted, we conduct an additional review to determine whether there is a conflict of interest. In circumstances where a conflict has been identified and either: (i) the matter does not fall clearly within the Guidelines; or (ii) State Street Global Advisors determines that voting in accordance with such guidance is not in the best interests of its clients, the Head of the Asset Stewardship team will determine whether a material relationship exists. If so, the matter is referred to the PRC. The PRC then reviews the matter and determines whether a conflict of interest exists, and if so, how to best resolve such conflict. For example, the PRC may (i) determine that the proxy vote does not give rise to a conflict due to the issues presented, (ii) refer the matter to the IC for further evaluation or (iii) retain an independent fiduciary to determine the appropriate vote.

These Managing Conflicts of Interest Arising From State Street Global Advisors’ Proxy Voting and Engagement Activity Guidelines are also applicable to State Street Global Advisors Funds Management, Inc. State Street Global Advisors Funds Management, Inc. is an SEC-registered investment adviser. State Street Global Advisors Funds Management, Inc., State Street Global Advisors Trust Company, and other advisory affiliates of State Street make up State Street Global Advisors, the investment management arm of State Street Corporation.

State Street Global Advisors

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2019 State Street Global Advisors Conflict Mitigation Guidelines

ssga.com

State Street Global Advisors Worldwide Entities

Abu Dhabi: State Street Global Advisors Limited, Middle East Branch, 42801, 28, Al Khatem Tower, Abu Dhabi Global Market Square, Al Mayah Island, Abu Dhabi, United Arab Emirates. T: +971 2 245 9000. Australia: State Street Global Advisors, Australia, Limited (ABN 42 003 914 225) is the holder of an Australian Financial Services Licence (AFSL Number 238276). Registered office: Level 17, 420 George Street, Sydney, NSW 2000, Australia. T: +612 9240 7600. F: +612 9240 7611.

Belgium: State Street Global Advisors Belgium, Chaussée de La Hulpe 120, 1000 Brussels, Belgium. T: 32 2 663 2036. F: 32 2 672 2077. SSGA Belgium is a branch office of State Street Global Advisors Limited. State Street Global Advisors Limited is authorized and regulated by the Financial Conduct Authority in the United Kingdom. Canada: State Street Global Advisors, Ltd., 770 Sherbrooke Street West, Suite 1200 Montreal, Quebec, H3A 1G1, T: +514 282 2400 and 30 Adelaide Street East Suite 500, Toronto, Ontario M5C 3G6. T: +647 775 5900. Dubai: State Street Global Advisors Limited, DIFC Branch, Central Park Towers, Suite 15 -38 (15th floor), P.O Box 26838, Dubai International Financial Centre (DIFC), Dubai, United Arab Emirates. Regulated by the Dubai Financial Services Authority (DFSA). T: +971 (0)4-4372800. France: State Street Global Advisors Ireland Limited, Paris branch is a branch of State Street Global Advisors Ireland Limited, registered in Ireland with company number 145221, authorized and regulated by the Central Bank of Ireland, and whose registered office is at 78 Sir John Rogerson’s Quay, Dublin 2. State Street Global Advisors Ireland Limited, Paris Branch, is registered in France with company number RCS Nanterre 832 734 602 and whose office is at Immeuble Défense Plaza, 23-25 rue Delarivière-Lefoullon, 92064 Paris La Défense Cedex, France. T: (+33) 1 44 45 40 00. F: (+33) 1 44 45 41 92. Germany: State Street Global Advisors GmbH, Brienner Strasse 59, D-80333 Munich. Authorized and regulated by the Bundesanstalt für Finanzdienstleistungsaufsicht (“BaFin”). Registered with the Register of Commerce Munich HRB 121381. T: +49 (0)89 55878 400. F: +49 (0)89 55878 440. Hong Kong: State Street Global Advisors Asia Limited, 68/F, Two International Finance Centre, 8 Finance Street, Central, Hong Kong. T: +852 2103 0288. F: +852 2103 0200. Ireland: State Street Global Advisors Ireland Limited is regulated by the Central Bank of

Ireland. Registered office address 78 Sir John Rogerson’s Quay, Dublin 2. Registered number 145221. T: +353 (0)1 776 3000. F: +353 (0)1 776 3300. Italy: State Street Global Advisors Limited, Milan Branch (Sede Secondaria di Milano) is a branch of State Street Global Advisors Limited, a company registered in the UK, authorized and regulated by the Financial Conduct Authority (FCA ), with a capital of GBP 62,350,000, and whose registered office is at 20 Churchill Place, London E14 5HJ. State Street Global Advisors Limited, Milan Branch (Sede Secondaria di Milano), is registered in Italy with company number 06353340968 - R.E.A. 1887090 and VAT number 06353340968 and whose office is at Via dei Bossi, 4 - 20121 Milano, Italy. T: 39 02 32066 100. F: 39 02 32066 155. Japan: State Street Global Advisors (Japan) Co., Ltd., Toranomon Hills Mori Tower 25F 1-23-1 Toranomon, Minato-ku, Tokyo 105-6325 Japan, T: +81-3-4530-7380 Financial Instruments Business Operator, Kanto Local Financial Bureau (Kinsho #345) , Membership: Japan Investment Advisers Association, The Investment Trust Association, Japan, Japan Securities Dealers’ Association. Netherlands: State Street Global Advisors Netherlands, Apollo Building, 7th floor Herikerbergweg 29 1101 CN Amsterdam, Netherlands. T: 31 20 7181701. SSGA Netherlands is a branch office of State Street Global Advisors Limited. State Street Global Advisors Limited is authorized and regulated by the Financial Conduct Authority in the United Kingdom. Singapore: State Street Global Advisors Singapore Limited, 168, Robinson Road, #33-01 Capital Tower, Singapore 068912 (Company Reg. No: 200002719D, regulated by the Monetary Authority of Singapore). T: +65 6826 7555. F: +65 6826 7501. Switzerland: State Street Global Advisors AG, Beethovenstr. 19, CH-8027 Zurich. Authorized and regulated by the Eidgenössische Finanzmarktaufsicht (“FINMA”). Registered with the Register of Commerce Zurich CHE-105.078.458. T: +41 (0)44 245 70 00. F: +41 (0)44 245 70 16. United Kingdom: State Street Global Advisors Limited. Authorized and regulated by the Financial Conduct Authority. Registered in England. Registered No. 2509928. VAT No. 5776591 81. Registered office: 20 Churchill Place, Canary Wharf, London, E14 5HJ. T: 020 33 95 6000. F: 020 3395 6350. United States: State Street Global Advisors, One Iron Street, Boston MA 02210. T: +1 617 786 3000.

The whole or any part of this work may not be reproduced, copied or transmitted or any of its contents disclosed to third parties without SSGA’s express written consent.

State Street Global Advisors

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ID15922 0319 Exp. Date: 03/31/2020

Global Proxy Voting and Engagement Guidelines for Environmental and Social Issues

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Global Proxy Voting and Engagement Guidelines for Environmental and Social Issues

Overview

Our primary fiduciary obligation to our clients is to maximize the long-term returns of their investments. It is our view that material environmental and social (sustainability) issues can both create risk as well as generate long-term value in our portfolios. This philosophy provides the foundation for our value-based approach to Asset Stewardship.

We use our voice and our vote through engagement, proxy voting, and thought leadership in order to communicate with issuers and educate market participants about our perspective on important sustainability topics. Our Asset Stewardship program prioritization process allows us to proactively identify companies for engagement and voting in order to mitigate sustainability risks in our portfolio.

Through engagement, we address a broad range of topics that align with our thematic priorities and build long-term relationships with issuers. Engagements are often multi- year exercises. We share our views of key topics and also seek to understand the disclosure and practices of issuers. We leverage our long-term relationship with companies to effect change. Voting on sustainability issues is mainly driven through shareholder proposals. However, we may take voting action against directors even in the absence of shareholder proposals for unaddressed concerns pertaining to sustainability matters.

In this document we provide additional transparency into our approach to engagement and voting on sustainability- related matters.

Our Approach to Assessing Materiality and Relevance of Sustainability Issues

While we believe that sustainability-related factors can expose potential investment risks as well as drive long-term value creation, the materiality of specific sustainability issues varies from industry to industry and company by company. With this in mind, we leverage several distinct frameworks as well as additional resources to inform our views on the materiality of a sustainability issue at a given company including:

•

The Sustainability Accounting Standards Board (SASB) Materiality Map

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The Task Force on Climate-related Financial Disclosures (TCFD) Framework

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Disclosure expectations in a company’s given regulatory environment

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Market expectations for the sector and industry

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Other existing third party frameworks, such as the CDP (formally the Carbon Disclosure Project)

•

Our proprietary R-Factor ¹ score

We expect companies to disclose information regarding their approach to identifying material sustainability-related risks and the management policies and practices in place to address such issues. We support efforts by companies to demonstrate the ways in which sustainability is incorporated into operations, business activities, and most importantly, long-term business strategy.

Approach to Engagement on Sustainability Issues

State Street Global Advisors holds more than 12,000 listed equities across its global portfolios. The success of our engagement process is due to our ability to prioritize and optimally allocate resources. Our approach is driven by:

1) Proprietary Screens

We have developed proprietary in-house sustainability screens to help identify companies for proactive engagement. These screens leverage our proprietary R-Factor score to identify sector and industry outliers for engagement and voting on sustainability issues.

2) Thematic Prioritization

As part of our annual stewardship planning process we identify thematic sustainability priorities that will be addressed during most engagement meetings. We develop our priorities based upon several factors, including client feedback, emerging sustainability trends, developing macroeconomic conditions, and evolving regulations. These engagements not only inform our voting decisions but also allow us to monitor improvement over time and to contribute to our evolving perspectives on priority areas. Insights from these engagements are shared with clients through our publicly available Annual Stewardship Report.

Voting on Sustainability Proposals

Historically, shareholder proposals addressing sustainability-related topics have been most common in the U.S. and Japanese markets. However, we have observed such proposals being filed in additional markets, including Australia, the UK, and continental Europe.

Agnostic of market, sustainability-related shareholder proposals address diverse topics and typically ask companies to either improve sustainability-related disclosure or enhance their practices. Common topics for sustainability-related shareholder proposals include:

•

Climate-related issues

•

Sustainable practices

•

Gender equity

•

Campaign contributions and lobbying

•

Labor and human rights

•

Animal welfare


State Street Global Advisors		C-11

Global Proxy Voting and Engagement Guidelines for Environmental and Social Issues

We take a case-by-case approach to voting on shareholder proposals related to sustainability topics and consider the following when reaching a final vote decision:

•

The materiality of the sustainability topic in the proposal to the company’s business and sector (see “Our Approach to Assessing Materiality and Relevance of Sustainability Issues” above)

•

The content and intent of the proposal

•

Whether the adoption of such a proposal would promote long-term shareholder value in the context of the company’s disclosure and practices

•

The level of board involvement in the oversight of the company’s sustainability practices

•

Quality of engagement and responsiveness to our feedback

•

Binding nature of proposal or prescriptiveness of proposal

Vote Options for Sustainability- Related Proposals

•

State Street Global Advisors votes For (support for proposal) if the issue is material and the company has poor disclosure and/or practices relative to our expectations.

•

State Street Global Advisors votes Abstain (some reservations) if the issue is material and the company’s disclosure and/or practices could be improved relative to our expectations.

•

State Street Global Advisors votes Against (no support for proposal) if the issue is non-material and/or the company’s disclosure and/or practices meet our expectations.

¹	State Street Global Advisors’ proprietary scoring model, which aligns with SASB’s materiality map.

ssga.com

State Street Global Advisors Worldwide Entities

2103-0288. F: +852 2103 0200. Ireland: State Street Global Advisors Ireland Limited is regulated by the Central Bank of Ireland. Registered office address 78 Sir John Rogerson’s Quay, Dublin 2. Registered number 145221. T: +353 (0)1 776 3000. F: +353 (0)1 776 3300. Italy: State Street Global Advisors Ireland Limited, Milan Branch (Sede Secondaria di Milano) is a branch of State Street Global Advisors Ireland Limited, registered in Ireland with company number 145221, authorized and regulated by the Central Bank of Ireland, and whose registered office is at 78 Sir John Rogerson’s Quay, Dublin 2. State Street Global Advisors Ireland Limited, Milan Branch (Sede Secondaria di Milano), is registered in Italy with company number 10495250960 - R.E.A. 2535585 and VAT number 10495250960and whose office is at Via dei Bossi, 4 - 20121 Milano, Italy. T: +39 02 32066 100. F: +39 02 32066 155. Japan: State Street Global Advisors (Japan) Co., Ltd., Toranomon Hills Mori Tower 25F 1-23-1 Toranomon, Minato-ku, Tokyo 105-6325 Japan, T: +81-3-4530-7380 Financial Instruments Business Operator, Kanto Local Financial Bureau (Kinsho #345) , Membership: Japan Investment Advisers Association, The Investment Trust Association, Japan, Japan Securities Dealers’ Association. Netherlands: State Street Global Advisors Netherlands, Apollo Building, 7th floor Herikerbergweg 29 1101 CN Amsterdam, Netherlands. Telephone: 31 20 7181701. SSGA Netherlands is a branch office of State Street Global Advisors Ireland Limited, registered in Ireland with company number 145221, authorized and regulated by the Central Bank of Ireland, and whose registered office is at 78 Sir John Rogerson’s Quay, Dublin 2. Singapore: State Street Global Advisors Singapore Limited, 168, Robinson Road, #33-01 Capital Tower, Singapore 068912 (Company Reg. No: 200002719D, regulated by the Monetary Authority of Singapore). Telephone: +65 6826 7555. F: +65 6826 7501. Switzerland: State Street Global Advisors AG, Beethovenstr. 19, CH-8027 Zurich. Authorized and regulated by the Eidgenössische Finanzmarktaufsicht (“FINMA”). Registered with the Register of Commerce Zurich CHE-105.078.458. T: +41 (0)44 245 70 00. Facsimile F: +41 (0)44 245 70 16. United Kingdom: State Street Global Advisors Limited. Authorized and regulated by the Financial Conduct Authority. Registered in England. Registered No. 2509928. VAT No. 5776591 81. Registered office: 20 Churchill Place, Canary Wharf, London, E14 5HJ. T: 020 3395 6000. F: 020 3395 6350. United States: State Street Global Advisors, One Iron Street, Boston MA 02210. T: +1 617 786 3000.

State Street Global Advisors

C-12

ID15998 0319 Exp. Date: 03/31/2020

March 2019

Proxy Voting and Engagement Guidelines

North America

(United States & Canada)

State Street Global Advisors’ North America Proxy Voting and Engagement Guidelines ¹ outline our expectations of companies listed on stock exchanges in the US and Canada. These guidelines complement and should be read in conjunction with State Street Global Advisors’ Global Proxy Voting and Engagement Principles, which provide a detailed explanation of our approach to voting and engaging with companies, and State Street Global Advisors’ Conflict Mitigation Guidance.

LOGO

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Proxy Voting and Engagement Guidelines

State Street Global Advisors’ North America Proxy Voting and Engagement Guidelines address areas, including board structure, director tenure, audit related issues, capital structure, executive compensation, as well as environmental, social, and other governance-related issues of companies listed on stock exchanges in the US and Canada (“North America”). Principally, we believe the primary responsibility of the board of directors is to preserve and enhance shareholder value and protect shareholder interests. In order to carry out their primary responsibilities, directors have to undertake activities that range from setting strategy and overseeing executive management to monitoring the risks that arise from a company’s business, including risks related to sustainability issues. Further, good corporate governance necessitates the existence of effective internal controls and risk management systems, which should be governed by the board.

When voting and engaging with companies in global markets, we consider market specific nuances in the manner that we believe will most likely protect and promote the long-term economic value of client investments. We expect companies to observe the relevant laws and regulations of their respective markets, as well as country specific best practice guidelines and corporate governance codes. When we feel that a country’s regulatory requirements do not address some of the key philosophical principles that we believe are fundamental to its global voting guidelines, we may hold companies in such markets to our global standards.

In its analysis and research about corporate governance issues in North America, we expect all companies to act in a transparent manner and to provide detailed disclosure on board profiles, related-party transactions, executive compensation, and other governance issues that impact shareholders’ long-term interests. Further, as a founding member of the Investor Stewardship Group (“ISG”), we proactively monitor companies’ adherence to the Corporate Governance Principles for US listed companies. Consistent with the “comply-or-explain” expectations established by the principles, we encourage companies to proactively disclose their level of compliance with the principles. In instances of non-compliance when companies cannot explain the nuances of their governance structure effectively, either publicly or through engagement, we may vote against the independent board leader.

State Street Global Advisors’ Proxy Voting and Engagement Philosophy

remuneration, accounting, and environmental and social issues. We have established robust corporate governance principles and practices that are backed with extensive analytical expertise to understand the complexities of the corporate governance landscape. We engage with companies to provide insight on the principles and practices that drive our voting decisions. We also conduct proactive engagements to address significant shareholder concerns and environmental, social, and governance (“ESG”) issues in a manner consistent with maximizing shareholder value.

The team works alongside members of State Street Global Advisors’ Active Fundamental and various other investment teams, collaborating on issuer engagements and providing input on company specific fundamentals. We are also a member of various investor associations that seek to address broader corporate governance related policy issues in North America.

State Street Global Advisors is a signatory to the United Nations Principles of Responsible Investment (“UNPRI”) and is compliant with the US Investor Stewardship Group Principles. We are committed to sustainable investing and are working to further integrate ESG principles into investment and corporate governance practices, where applicable and consistent with our fiduciary duty.

Directors and Boards

State Street Global Advisors believes that a well constituted board of directors, with a balance of skills, expertise, and independence, provides the foundations for a well governed company. We view board quality as a measure of director independence, director succession planning, board diversity, evaluations and refreshment, and company governance practices. We vote for the election/re-election of directors on a case-by-case basis after considering various factors, including board quality, general market practice, and availability of information on director skills and expertise. In principle, we believe independent directors are crucial to robust corporate governance and help management establish sound corporate governance policies and practices. A sufficiently independent board will most effectively monitor management and perform oversight functions necessary to protect shareholder interests. Further, we expect boards of Russell 3000 and TSX listed companies to have at least one female board member.

Director related proposals include issues submitted to shareholders that deal with the composition of the board or with members of a corporation’s board of directors. In deciding the director nominee to support, we consider numerous factors.


State Street Global Advisors		C-14

Proxy Voting and Engagement Guidelines

Director Elections

Our director election guideline focuses on companies’ governance profile to identify if a company demonstrates appropriate governance practices or if it exhibits negative governance practices. Factors we consider when evaluating governance practices include, but are not limited to the following:

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Shareholder rights

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Board independence

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Board structure

If a company demonstrates appropriate governance practices, we believe a director should be classified as independent based upon the relevant listing standards or local market practice standards. In such cases, the composition of the key oversight committees of a board should meet the minimum standards of independence. Accordingly, we will vote against a nominee at a company with appropriate governance practices if the director is classified as non-independent under relevant listing standards or local market practice and serves on a key committee of the board (compensation, audit, nominating, or committees required to be fully independent by local market standards).

Conversely, if a company demonstrates negative governance practices, State Street Global Advisors believes the classification standards for director independence should be elevated. In such circumstances, we will evaluate all director nominees based upon the following classification standards:

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Is the nominee an employee of or related to an employee of the issuer or its auditor?

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Does the nominee provide professional services to the issuer?

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Has the nominee attended an appropriate number of board meetings?

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Has the nominee received non-board related compensation from the issuer?

In the US market where companies demonstrate negative governance practices, these stricter standards will apply not only to directors who are a member of a key committee but to all directors on the board as market practice permits. Accordingly, we will vote against a nominee (with the exception of the CEO) where the board has inappropriate governance practices and is considered not independent based on the above independence criteria.

Additionally, we may withhold votes from directors based on the following:

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Overall average board tenure is excessive. In assessing excessive tenure, we give consideration to factors such as the preponderance of long tenured directors, board refreshment practices, and classified board structures

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Directors attend less than 75% of board meetings without appropriate explanation or providing reason for their failure to meet the attendance threshold

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CEOs of a public company who sit on more than three public company boards

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Director nominees who sit on more than six public company boards

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Directors of companies that have not been responsive to a shareholder proposal that received a majority shareholder support at the last annual or special meeting

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Consideration can be warranted if management submits the proposal(s) on the ballot as a binding management proposal, recommending shareholders vote for the particular proposal(s)

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Directors of companies have unilaterally adopted/ amended company bylaws that negatively impact our shareholder rights (such as fee-shifting, forum selection, and exclusion service bylaws) without putting such amendments to a shareholder vote

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Compensation committee members where there is a weak relationship between executive pay and performance over a five-year period

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Audit committee members if non-audit fees exceed 50% of total fees paid to the auditors

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Directors who appear to have been remiss in their duties

Director Related Proposals

We generally vote for the following director related proposals:

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Discharge of board members’ duties, in the absence of pending litigation, regulatory investigation, charges of fraud, or other indications of significant concern

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Proposals to restore shareholders’ ability in order to remove directors with or without cause

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Proposals that permit shareholders to elect directors to fill board vacancies

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Shareholder proposals seeking disclosure regarding the company, board, or compensation committee’s use of compensation consultants, such as company name, business relationship(s), and fees paid


State Street Global Advisors		C-15

Proxy Voting and Engagement Guidelines

We generally vote against the following director related proposals:

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Requirements that candidates for directorships own large amounts of stock before being eligible to be elected

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Proposals that relate to the “transaction of other business as properly comes before the meeting,” which extend “blank check” powers to those acting as proxy

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Proposals requiring two candidates per board seat

Majority Voting

We will generally support a majority vote standard based on votes cast for the election of directors.

We will generally vote to support amendments to bylaws that would require simple majority of voting shares (i.e. shares cast) to pass or to repeal certain provisions.

Annual Elections

We generally support the establishment of annual elections of the board of directors. Consideration is given to the overall level of board independence and the independence of the key committees, as well as the existence of a shareholder rights plan.

Cumulative Voting

We do not support cumulative voting structures for the election of directors.

Separation Chair/CEO

We analyze proposals for the separation of Chair/CEO on a case-by-case basis taking into consideration numerous factors, including the appointment of and role played by a lead director, a company’s performance, and the overall governance structure of the company.

Proxy Access

In general, we believe that proxy access is a fundamental right and an accountability mechanism for all long-term shareholders. We will consider proposals relating to proxy access on a case-by-case basis. We will support shareholder proposals that set parameters to empower long-term shareholders while providing management the flexibility to design a process that is appropriate for the company’s circumstances.

We will review the terms of all other proposals and will support those proposals that have been introduced in the spirit of enhancing shareholder rights.

Considerations include the following:

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The ownership thresholds and holding duration proposed in the resolution

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The binding nature of the proposal

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The number of directors that shareholders may be able to nominate each year

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Company governance structure

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Shareholder rights

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Board performance

Age/Term Limits

Generally, we will vote against age and term limits unless the company is found to have poor board refreshment and director succession practices, and has a preponderance of non-executive directors with excessively long tenures serving on the board.

Approve Remuneration of Directors

Generally, we will support directors’ compensation, provided the amounts are not excessive relative to other issuers in the market or industry. In making our determination, we review whether the compensation is overly dilutive to existing shareholders.

Indemnification

Generally, we support proposals to limit directors’ liability and/or expand indemnification and liability protection if he or she has not acted in bad faith, gross negligence, or reckless disregard of the duties involved in the conduct of his or her office.

Classified Boards

We generally support annual elections for the board of directors.

Confidential Voting

We will support confidential voting.

Board Size

We will support proposals seeking to fix the board size or designate a range for the board size and will vote against proposals that give management the ability to alter the size of the board outside of a specified range without shareholder approval.

Audit-Related Issues

Ratifying Auditors and Approving Auditor Compensation

We support the approval of auditors and auditor compensation provided that the issuer has properly disclosed audit and non-audit fees relative to market practice and the audit fees are not deemed excessive. We deem audit fees to be excessive if the non-audit fees for the prior year constituted 50% or more of the total fees paid to the auditor. We will also support the disclosure of auditor and consulting relationships when the same or related


State Street Global Advisors		C-16

Proxy Voting and Engagement Guidelines

entities are conducting both activities and will support the establishment of a selection committee responsible for the final approval of significant management consultant contract awards where existing firms are already acting in an auditing function.

In circumstances where “other” fees include fees related to initial public offerings, bankruptcy emergence, and spin-offs, and the company makes public disclosure of the amount and nature of those fees which are determined to be an exception to the standard “non-audit fee” category, then such fees may be excluded from the non-audit fees considered in determining the ratio of non-audit to audit/audit-related fees/tax compliance and preparation for purposes of determining whether non-audit fees are excessive.

We will support the discharge of auditors and requirements that auditors attend the annual meeting of shareholders. ²

Capital-Related Issues

Capital structure proposals include requests by management for approval of amendments to the certificate of incorporation that will alter the capital structure of the company.

The most common request is for an increase in the number of authorized shares of common stock, usually in conjunction with a stock split or dividend. Typically, we support requests that are not unreasonably dilutive or enhance the rights of common shareholders. In considering authorized share proposals, the typical threshold for approval is 100% over current authorized shares. However, the threshold may be increased if the company offers a specific need or purpose (merger, stock splits, growth purposes, etc.). All proposals are evaluated on a case-by-case basis taking into account the company’s specific financial situation.

Increase in Authorized Common Shares

In general, we support share increases for general corporate purposes up to 100% of current authorized stock.

We support increases for specific corporate purposes up to 100% of the specific need plus 50% of current authorized common stock for US and Canadian firms.

When applying the thresholds, we will also consider the nature of the specific need, such as mergers and acquisitions and stock splits.

Increase in Authorized Preferred Shares

We vote on a case-by-case basis on proposals to increase the number of preferred shares.

Generally, we will vote for the authorization of preferred stock in cases where the company specifies the voting, dividend, conversion, and other rights of such stock and the terms of the preferred stock appear reasonable.

We will support proposals to create “declawed” blank check preferred stock (stock that cannot be used as a takeover defense). However, we will vote against proposals to increase the number of blank check preferred stock authorized for issuance when no shares have been issued or reserved for a specific purpose.

Unequal Voting Rights

We will not support proposals authorizing the creation of new classes of common stock with superior voting rights and will vote against new classes of preferred stock with unspecified voting, conversion, dividend distribution, and other rights. In addition, we will not support capitalization changes that add “blank check” classes of stock (i.e. classes of stock with undefined voting rights) or classes that dilute the voting interests of existing shareholders.

However, we will support capitalization changes that eliminate other classes of stock and/or unequal voting rights.

Mergers and Acquisitions

Mergers or the reorganization of the structure of a company often involve proposals relating to reincorporation, restructurings, liquidations, and other major changes to the corporation.

Proposals that are in the best interests of the shareholders, demonstrated by enhancing share value or improving the effectiveness of the company’s operations, will be supported.

In general, provisions that are not viewed as economically sound or are thought to be destructive to shareholders’ rights are not supported.

We will generally support transactions that maximize shareholder value. Some of the considerations include the following:

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Offer premium

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Strategic rationale

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Board oversight of the process for the recommended transaction, including, director and/or management conflicts of interest

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Offers made at a premium and where there are no other higher bidders

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Offers in which the secondary market price is substantially lower than the net asset value


State Street Global Advisors		C-17

Proxy Voting and Engagement Guidelines

We may vote against a transaction considering the following:

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Offers with potentially damaging consequences for minority shareholders because of illiquid stock, especially in some non-US markets

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Offers where we believe there is a reasonable prospect for an enhanced bid or other bidders

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The current market price of the security exceeds the bid price at the time of voting

Anti–Takeover Issues

Typically, these are proposals relating to requests by management to amend the certificate of incorporation or bylaws to add or to delete a provision that is deemed to have an anti-takeover effect. The majority of these proposals deal with management’s attempt to add some provision that makes a hostile takeover more difficult or will protect incumbent management in the event of a change in control of the company.

Proposals that reduce shareholders’ rights or have the effect of entrenching incumbent management will not be supported.

Proposals that enhance the right of shareholders to make their own choices as to the desirability of a merger or other proposal are supported.

Shareholder Rights Plans

US We will support mandates requiring shareholder approval of a shareholder rights plans (“poison pill”) and repeals of various anti-takeover related provisions.

In general, we will vote against the adoption or renewal of a US issuer’s shareholder rights plan (“poison pill”).

We will vote for an amendment to a shareholder rights plan (“poison pill”) where the terms of the new plans are more favorable to shareholders’ ability to accept unsolicited offers (i.e. if one of the following conditions are met: (i) minimum trigger, flip-in or flip-over of 20%, (ii) maximum term of three years, (iii) no “dead hand,” “slow hand,” “no hand” nor similar feature that limits the ability of a future board to redeem the pill, and (iv) inclusion of a shareholder redemption feature (qualifying offer clause), permitting ten percent of the shares to call a special meeting or seek a written consent to vote on rescinding the pill if the board refuses to redeem the pill 90 days after a qualifying offer is announced).

Canada We analyze proposals for shareholder approval of a shareholder rights plan (“poison pill”) on a case-by-case basis taking into consideration numerous factors, including but not limited to, whether it conforms to ‘new generation’ rights plans and the scope of the plan.

Special Meetings

We will vote for shareholder proposals related to special meetings at companies that do not provide shareholders the right to call for a special meeting in their bylaws if:

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The company also does not allow shareholders to act by written consent

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The company allows shareholders to act by written consent but the ownership threshold for acting by written consent is set above 25% of outstanding shares

We will vote for shareholder proposals related to special meetings at companies that give shareholders (with a minimum 10% ownership threshold) the right to call for a special meeting in their bylaws if:

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The current ownership threshold to call for a special meeting is above 25% of outstanding shares

We will vote for management proposals related to special meetings.

Written Consent

We will vote for shareholder proposals on written consent at companies if:

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The company does not have provisions in their bylaws giving shareholders the right to call for a special meeting

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The company allows shareholders the right to call for a special meeting, but the current ownership threshold to call for a special meeting is above 25% of outstanding shares

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The company has a poor governance profile

We will vote management proposals on written consent on a case-by-case basis.

Super–Majority

We will generally vote against amendments to bylaws requiring super-majority shareholder votes to pass or repeal certain provisions. We will vote for the reduction or elimination of super-majority vote requirements, unless management of the issuer was concurrently seeking to or had previously made such a reduction or elimination.

Remuneration Issues

Despite the differences among the types of plans and the awards possible there is a simple underlying philosophy that guides the analysis of all compensation plans; namely, the terms of the plan should be designed to provide an incentive for executives and/or employees to align their interests with those of the shareholders and thus work toward enhancing shareholder value. Plans that benefit participants only when the shareholders also benefit are those most likely to be supported.


State Street Global Advisors		C-18

Proxy Voting and Engagement Guidelines

Advisory Vote on Executive Compensation and Frequency

State Street Global Advisors believes executive compensation plays a critical role in aligning executives interest with shareholder’s, attracting, retaining and incentivizing key talent, and ensuring positive correlation between the performance achieved by management and the benefits derived by shareholders. We support management proposals on executive compensation where there is a strong relationship between executive pay and performance over a five-year period. We seek adequate disclosure of various compensation elements, absolute and relative pay levels, peer selection and benchmarking, the mix of long-term and short-term incentives, alignment of pay structures with shareholder interests as well as with corporate strategy, and performance. Further shareholders should have the opportunity to assess whether pay structures and levels are aligned with business performance on an annual basis.

In Canada, where advisory votes on executive compensation are not commonplace, we will rely primarily upon engagement to evaluate compensation plans.

Employee Equity Award Plans

We consider numerous criteria when examining equity award proposals. Generally we do not vote against plans for lack of performance or vesting criteria. Rather the main criteria that will result in a vote against an equity award plan are:

Excessive voting power dilution To assess the dilutive effect, we divide the number of shares required to fully fund the proposed plan, the number of authorized but unissued shares and the issued but unexercised shares by the fully diluted share count. We review that number in light of certain factors, such as the industry of the issuer.

Historical option grants Excessive historical option grants over the past three years. Plans that provide for historical grant patterns of greater than five to eight percent are generally not supported.

Repricing We will vote against any plan where repricing is expressly permitted. If a company has a history of repricing underwater options, the plan will not be supported.

Other criteria include the following:

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Number of participants or eligible employees

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The variety of awards possible

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The period of time covered by the plan

There are numerous factors that we view as negative. If combined they may result in a vote against a proposal. Factors include:

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Grants to individuals or very small groups of participants

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“Gun-jumping” grants which anticipate shareholder approval of a plan or amendment

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The power of the board to exchange “underwater” options without shareholder approval. This pertains to the ability of a company to reprice options, not the actual act of repricing described above

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Below market rate loans to officers to exercise their options

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The ability to grant options at less than fair market value;

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Acceleration of vesting automatically upon a change in control

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Excessive compensation (i.e. compensation plans which we deem to be overly dilutive)

Share Repurchases If a company makes a clear connection between a share repurchase program and its intent to offset dilution created from option plans and the company fully discloses the amount of shares being repurchased, the voting dilution calculation may be adjusted to account for the impact of the buy back.

Companies will not have any such repurchase plan factored into the dilution calculation if they do not (i) clearly state the intentions of any proposed share buy-back plan, (ii) disclose a definitive number of the shares to be bought back, (iii) specify the range of premium/discount to market price at which a company can repurchase shares, and (iv) disclose the time frame during which the shares will be bought back..

162(m) Plan Amendments If a plan would not normally meet our criteria described above, but was primarily amended to add specific performance criteria to be used with awards that were designed to qualify for performance- based exception from the tax deductibility limitations of Section 162(m) of the Internal Revenue Code, then we will support the proposal to amend the plan.

Employee Stock Option Plans

We generally vote for stock purchase plans with an exercise price of not less than 85% of fair market value. However, we take market practice into consideration.

Compensation Related Items

We generally support the following proposals:

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Expansions to reporting of financial or compensation- related information within reason

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Proposals requiring the disclosure of executive retirement benefits if the issuer does not have an independent compensation committee


State Street Global Advisors		C-19

Proxy Voting and Engagement Guidelines

We generally vote against the following proposal:

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Retirement bonuses for non-executive directors and auditors

Miscellaneous/Routine Items

We generally support the following miscellaneous/routine governance items:

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Reimbursement of all appropriate proxy solicitation expenses associated with the election when voting in conjunction with support of a dissident slate

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Opting-out of business combination provision

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Proposals that remove restrictions on the right of shareholders to act independently of management

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Liquidation of the company if the company will file for bankruptcy if the proposal is not approved

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Shareholder proposals to put option repricings to a shareholder vote

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General updating of, or corrective amendments to, charter and bylaws not otherwise specifically addressed herein, unless such amendments would reasonably be expected to diminish shareholder rights (e.g. extension of directors’ term limits, amending shareholder vote requirement to amend the charter documents, insufficient information provided as to the reason behind the amendment)

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Change in corporation name

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Mandates that amendments to bylaws or charters have shareholder approval

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Management proposals to change the date, time, and/or location of the annual meeting unless the proposed change is unreasonable

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Repeals, prohibitions or adoption of anti-greenmail provisions

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Management proposals to implement a reverse stock split when the number of authorized shares will be proportionately reduced and proposals to implement a reverse stock split to avoid delisting

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Exclusive forum provisions

State Street Global Advisors generally does not support the following miscellaneous/routine governance items:

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Proposals requesting companies to adopt full tenure holding periods for their executives

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Reincorporation to a location that we believe has more negative attributes than its current location of incorporation

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Shareholder proposals to change the date, time, and/or location of the annual meeting unless the current scheduling or location is unreasonable

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Proposals to approve other business when it appears as a voting item

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Proposals giving the board exclusive authority to amend the bylaws

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Proposals to reduce quorum requirements for shareholder meetings below a majority of the shares outstanding unless there are compelling reasons to support the proposal

Environmental and Social Issues

More Information

Any client who wishes to receive information on how its proxies were voted should contact its State Street Global Advisors relationship manager.

These Proxy Voting and Engagement Guidelines are also applicable to SSGA Funds Management, Inc.” SSGA Funds Management, Inc. is an SEC-registered investment adviser. SSGA Funds Management, Inc., State Street Global Advisors Trust Company, and other advisory affiliates of State Street make up State Street Global Advisors, the investment management arm of State Street Corporation.

²	Common for non-US issuers; request from the issuer to discharge from liability the directors or auditors with respect to actions taken by them during the previous year.


State Street Global Advisors		C-20

Proxy Voting and Engagement Guidelines

ssga.com

State Street Global Advisors Worldwide Entities

is regulated by the Central Bank of Ireland. Registered office address 78 Sir John Rogerson’s Quay, Dublin 2. Registered number 145221. T: +353 (0)1 776 3000. F: +353 (0)1 776 3300. Italy: State Street Global Advisors Ireland Limited, Milan Branch (Sede Secondaria di Milano) is a branch of State Street Global Advisors Ireland Limited, registered in Ireland with company number 145221, authorized and regulated by the Central Bank of Ireland, and whose registered office is at 78 Sir John Rogerson’s Quay, Dublin 2. State Street Global Advisors Ireland Limited, Milan Branch (Sede Secondaria di Milano), is registered in Italy with company number 10495250960 - R.E.A. 2535585 and VAT number 10495250960and whose office is at Via dei Bossi, 4 - 20121 Milano, Italy. T: +39 02 32066 100. F: +39 02 32066 155. Japan: State Street Global Advisors (Japan) Co., Ltd., Toranomon Hills Mori Tower 25F 1-23-1 Toranomon, Minato-ku, Tokyo 105-6325 Japan, T: +81-3-4530-7380 Financial Instruments Business Operator, Kanto Local Financial Bureau (Kinsho #345) , Membership: Japan Investment Advisers Association, The Investment Trust Association, Japan, Japan Securities Dealers’ Association. Netherlands: State Street Global Advisors Netherlands, Apollo Building, 7th floor Herikerbergweg 29 1101 CN Amsterdam, Netherlands. Telephone: 31 20 7181701. SSGA Netherlands is a branch office of State Street Global Advisors Ireland Limited, registered in Ireland with company number 145221, authorized and regulated by the Central Bank of Ireland, and whose registered office is at 78 Sir John Rogerson’s Quay, Dublin 2. Singapore: State Street Global Advisors Singapore Limited, 168, Robinson Road, #33-01 Capital Tower, Singapore 068912 (Company Reg. No: 200002719D, regulated by the Monetary Authority of Singapore). Telephone: +65 6826 7555. F: +65 6826 7501. Switzerland: State Street Global Advisors AG, Beethovenstr. 19, CH-8027 Zurich. Authorized and regulated by the Eidgenössische Finanzmarktaufsicht (“FINMA”). Registered with the Register of Commerce Zurich CHE-105.078.458. T: +41 (0)44 245 70 00. Facsimile F: +41 (0)44 245 70 16. United Kingdom: State Street Global Advisors Limited. Authorized and regulated by the Financial Conduct Authority. Registered in England. Registered No. 2509928. VAT No. 5776591 81. Registered office: 20 Churchill Place, Canary Wharf, London, E14 5HJ. T: 020 3395 6000. F: 020 3395 6350. United States: State Street Global Advisors, One Iron Street, Boston MA 02210. T: +1 617 786 3000.

The whole or any part of this work may not be reproduced, copied or transmitted or any of its contents disclosed to third parties without SSGA’s express written consent.


State Street Global Advisors		C-21		© 2019 State Street Corporation. All Rights Reserved. ID15918 0319 Exp. Date: 03/31/2020

March 2019

Proxy Voting and Engagement Guidelines

Australia and New Zealand

State Street Global Advisors’ Australia and New Zealand Proxy Voting and Engagement Guidelines ¹ outline our expectations of companies listed on stock exchanges in Australia and New Zealand. These guidelines complement and should be read in conjunction with State Street Global Advisors’ Global Proxy Voting and Engagement Principles that provide a detailed explanation of our approach to voting and engaging with companies and State Street Global Advisors’ Conflict Mitigation Guidelines.

LOGO

C-22

Proxy Voting and Engagement Guidelines

State Street Global Advisors’ Australia and New Zealand Proxy Voting and Engagement Guidelines address areas including board structure, audit related issues, capital structure, remuneration, environmental, social, and other governance related issues. Principally we believe the primary responsibility of the board of directors is to preserve and enhance shareholder value and protect shareholder interests. In order to carry out their primary responsibilities, directors have to undertake activities that range from setting strategy and overseeing executive management to monitoring the risks that arise from a company’s business, including risks related to sustainability issues. Further, good corporate governance necessitates the existence of effective internal controls and risk management systems, which should be governed by the board.

When voting and engaging with companies in global markets, we consider market specific nuances in the manner that we believe will best protect and promote the long-term economic value of client investments. We expect companies to observe the relevant laws and regulations of their respective markets as well as country specific best practice guidelines, and corporate governance codes. We may hold companies in such markets to our global standards when we feel that a country’s regulatory requirements do not address some of the key philosophical principles that we believe are fundamental to our global voting guidelines.

In our analysis and research into corporate governance issues in Australia and New Zealand, we expect all companies at a minimum to comply with the ASX Corporate Governance Principles and proactively monitor companies’ adherence to the principles. Consistent with the ‘comply or explain’ expectations established by the Principles, we encourage companies to proactively disclose their level of compliance with the Principles. In instances of non-compliance when companies cannot explain the nuances of their governance structure effectively, either publicly or through engagement, we may vote against the independent board leader. On some governance matters, such as composition of audit committees, we hold Australian companies to our global standards requiring all directors on the committee to be independent of management.

State Street Global Advisors’ Proxy Voting and Engagement Philosophy

remuneration, accounting, and environmental and social issues. We have established robust corporate governance principles and practices that are backed with extensive analytical expertise in order to understand the complexities of the corporate governance landscape. We engage with companies to provide insight on the principles and practices that drive our voting decisions. We also conduct proactive engagement to address significant shareholder concerns and environmental, social and governance (“ESG”) issues in a manner consistent with maximizing shareholder value.

The team works alongside members of State Street Global Advisors’ Active Fundamental and Asia-Pacific (“APAC”) investment teams, collaborating on issuer engagement and providing input on company specific fundamentals. We are also a member of various investor associations that seek to address broader corporate governance related policy issues in the region.

State Street Global Advisors is a signatory to the United Nations Principles of Responsible Investment (“UNPRI”). We are committed to sustainable investing and are working to further integrate ESG principles into investment and corporate governance practices where applicable and consistent with our fiduciary duty.

Directors and Boards

State Street Global Advisors believes that a well constituted board of directors with a good balance of skills, expertise, and independence provides the foundations for a well governed company. We view board quality as a measure of director independence, director succession planning, board diversity, evaluations and refreshment, and company governance practices. We vote for the election/re-election of directors on a case-by-case basis after considering various factors including board quality, general market practice, and availability of information on director skills and expertise. In principle, we believe independent directors are crucial to corporate governance and help management establish sound ESG policies and practices. A sufficiently independent board will most effectively monitor management and perform oversight functions necessary to protect shareholder interests. We expect boards of ASX 300 and New Zealand listed companies to be comprised of at least a majority of independent directors. At all other Australian listed companies, we expect boards to be comprised of at least one-third independent directors. Further, we expect boards of ASX 300 listed companies to have at least one female board member.


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Our broad criteria for director independence in Australia and New Zealand include factors such as:

•

Participation in related-party transactions and other business relations with the company

•

Employment history with company

•

Relations with controlling shareholders

•

Family ties with any of the company’s advisers, directors, or senior employees

When considering the election or re-election of a director, we also consider the number of outside board director-ships that a non-executive and an executive may undertake and attendance at board meetings. In addition, we monitor other factors that may influence the independence of a non-executive director, such as performance-related pay, cross-directorships, significant shareholdings, and tenure. We support the annual election of directors and encourages Australian and New Zealand companies to adopt this practice.

While we are generally supportive of having the roles of chairman and CEO separated in the Australian and New Zealand markets, we assess the division of responsibilities between chairman and CEO on a case-by-case basis, giving consideration to factors such as company-specific circumstances, overall level of independence on the board and general corporate governance standards in the company. Similarly, we will monitor for circumstances in which a combined chairman/CEO is appointed or where a former CEO becomes chairman.

We may also consider board performance and directors who appear to be remiss in the performance of their oversight responsibilities when analyzing their suitability for reappointment (e.g. fraud, criminal wrongdoing and breach of fiduciary responsibilities).

We believe companies should have committees for audit, remuneration, and nomination oversight. The audit committee is responsible for monitoring the integrity of the financial statements of the company, appointing external auditors, monitoring their qualifications and independence, and their effectiveness and resource levels. ASX Corporate Governance Principles requires listed companies to have an audit committee of at least three members all of whom are non-executive directors and a majority of whom are independent directors. It also requires that the committee be chaired by an independent director who is not the chair of the board. We hold Australian and New Zealand companies to our global standards for developed financial markets by requiring that all members of the audit committee be independent directors.

In our analysis of boards, we consider whether board members have adequate skills to provide effective oversight of corporate strategy, operations, and risks, including environmental and social issues. Boards should also have a regular evaluation process in place to assess the effectiveness of the board and the skills of board members to address issues, such as emerging risks, changes to corporate strategy, and diversification of operations and geographic footprint. The nomination committee is responsible for evaluating and reviewing the balance of skills, knowledge, and experience of the board. It also ensures that adequate succession plans are in place for directors and the CEO. We may vote against the re-election of members of the nomination committee if the board has failed to address concerns over board structure or succession.

Executive pay is another important aspect of corporate governance. We believe that executive pay should be determined by the board of directors. We expect companies to have in place remuneration committees to provide independent oversight over executive pay. ASX Corporate Governance Principles requires listed companies to have a remuneration committee of at least three members all of whom are non-executive directors and a majority of whom are independent directors. Since Australia has a non-binding vote on pay with a two-strike rule requiring a board spill vote in the event of a second strike, we believe that the vote provides investors a mechanism to address concerns they may have on the quality of oversight provided by the board on remuneration issues. Accordingly our voting guidelines accommodate local market practice.

Indemnification and limitations on liability

Generally, State Street Global Advisors supports proposals to limit directors’ liability and/or expand indemnification and liability protection up to the limit provided by law, if he or she has not acted in bad faith, gross negligence, or reckless disregard of the duties involved in the conduct of his or her office.

Audit-Related Issues

Companies should have robust internal audit and internal control systems designed for effective management of any potential and emerging risks to company operations and strategy. The responsibility of setting out an internal audit function lies with the audit committee, which should have independent non-executive directors designated as members.


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Appointment of External Auditors

State Street Global Advisors believes that a company’s auditor is an essential feature of an effective and transparent system of external supervision. Shareholders should be given the opportunity to vote on their appointment or to re-appoint at the annual meeting. When appointing external auditors and approving audit fees, we will take into consideration the level of detail in company disclosures. We will generally not support resolutions if adequate breakdown is not provided and if non-audit fees are more than 50% of audit fees. In addition, we may vote against members of the audit committee if we have concerns with audit-related issues or if the level of non-audit fees to audit fees is significant. In certain circumstances, we may consider auditor tenure when evaluating the audit process.

Shareholder Rights and Capital-Related Issues

Share Issuances

The ability to raise capital is critical for companies to carry out strategy, to grow, and toachieve returns above their cost of capital. The approval of capital raising activities is fundamental to shareholders’ ability to monitor the returns and to ensure capital is deployed efficiently. State Street Global Advisors supports capital increases that have sound business reasons and are not excessive relative to a company’s existing capital base.

Pre-emption rights are a fundamental right for shareholders to protect their investment in a company. Where companies seek to issue new shares without pre-emption rights, we may vote against if such authorities are greater than 20% of the issued share capital. We may also vote against resolutions seeking authority to issue capital with pre-emption rights if the aggregate amount allowed seems excessive and is not justified by the board. Generally, we are against capital issuance proposals greater than 100% of the issued share capital when the proceeds are not intended for specific purpose.

Share Repurchase Programs

We generally support proposals to repurchase shares, unless the issuer does not clearly state the business purpose for the program, a definitive number of shares to be repurchased, and the timeframe for the repurchase. We may vote against share repurchase requests that allow share repurchases during a takeover period.

Dividends

against if the payout is excessive given the company’s financial position. Particular attention will be warranted when the payment may damage the company’s long-term financial health.

Mergers and Acquisitions

Mergers or reorganization of the company structure often involve proposals relating to reincorporation, restructurings, liquidations, and other major changes to the corporation. Proposals that are in the best interests of shareholders, demonstrated by enhancing share value or improving the effectiveness of the company’s operations, will be supported. In general, provisions that are not viewed as financially sound or are thought to be destructive to shareholders’ rights are not supported. We will generally support transactions that maximize shareholder value. Some of the considerations include:

•

Offer premium

•

Strategic rationale

•

Board oversight of the process for the recommended transaction, including, director and/or management conflicts of interest

•

Offers made at a premium and where there are no other higher bidders

•

Offers in which the secondary market price is substantially lower than the net asset value

We may vote against a transaction considering the following:

•

Offers with potentially damaging consequences for minority shareholders because of illiquid stock

•

Offers where we believe there is a reasonable prospect for an enhanced bid or other bidders

•

The current market price of the security exceeds the bid price at the time of voting

Anti-Takeover Measures

We oppose anti-takeover defenses, such as authorities for the board to issue warrants convertible into shares to existing shareholders during a hostile takeover.

Remuneration

Executive Pay

There is a simple underlying philosophy that guides State Street Global Advisors’ analysis of executive pay; there should be a direct relationship between remuneration and company performance over the long term. Shareholders should have the opportunity to assess whether pay structures and levels are aligned with business performance. When assessing remuneration reports, we consider various


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Proxy Voting and Engagement Guidelines

factors, such as adequate disclosure of different remuneration elements, absolute and relative pay levels, peer selection and benchmarking, the mix of long-term and short-term incentives, alignment of pay structures with shareholder interests as well as with corporate strategy and performance. State Street Global Advisors may oppose remuneration reports in which there seems to be a misalignment between pay and shareholders’ interests and where incentive policies and schemes have a re-test option or feature. We may also vote against the re-election of members of the remuneration committee if we have serious concerns about remuneration practices and if the company has not been responsive to shareholder pressure to review its approach.

Equity Incentive Plans

We may not support proposals on equity-based incentive plans where insufficient information is provided on matters, such as grant limits, performance metrics, performance, and vesting periods and overall dilution. Generally, we do not support options under such plans being issued at a discount to market price nor plans that allow for re-testing of performance metrics.

Non-Executive Director Pay

Authorities that seek shareholder approval for non-executive directors’ fees generally are not controversial. We generally support resolutions regarding directors’ fees unless disclosure is poor and we are unable to determine whether the fees are excessive relative to fees paid by other comparable companies. We will evaluate any non-cash or performance-related pay to non-executive directors on a company-by-company basis.

Risk Management

companies to disclose ways in which the board provides oversight on its risk management system and to identify key risks facing the company. Boards should also review existing and emerging risks that evolve in tandem with the political and economic landscape or as companies diversify or expand their operations into new areas.

Environmental and Social Issues

More Information

Any client who wishes to receive information on how its proxies were voted should contact its State Street Global Advisors relationship manager.

These Proxy Voting and Engagement Guidelines are also applicable to SSGA Funds Management, Inc. SSGA Funds Management, Inc. is an SEC-registered investment adviser. SSGA Funds Management, Inc., State Street Global Advisors Trust Company, and other advisory affiliates of State Street make up State Street Global Advisors, the investment management arm of State Street Corporation.


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ssga.com

State Street Global Advisors Worldwide Entities

The whole or any part of this work may not be reproduced, copied or transmitted or any of its contents disclosed to third parties without State Street Global Advisor’s’s express written consent.

State Street Global Advisors

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ID15919 0319 Exp. Date: 03/31/2020

March 2019

Proxy Voting and Engagement Guidelines

Europe

State Street Global Advisors’ European Proxy Voting and Engagement Guidelines ¹ cover different corporate governance frameworks and practices in European markets, excluding the United Kingdom and Ireland. These guidelines complement and should be read in conjunction with State Street Global Advisors’ Global Proxy Voting and Engagement Principles that provide a detailed explanation of our approach to voting and engaging with companies and State Street Global Advisors’ Conflict Mitigation Guidelines.

LOGO

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Proxy Voting and Engagement Guidelines

State Street Global Advisors’ Proxy Voting and Engagement Guidelines in European markets address areas, such as board structure, audit related issues, capital structure, remuneration, environmental, social, and other governance related issues. Principally, we believe the primary responsibility of the board of directors is to preserve and enhance shareholder value, and to protect shareholder interests. In order to carry out their primary responsibilities, directors have to undertake activities that range from setting strategy and overseeing executive management, to monitoring the risks that arise from a company’s business, including risks related to sustainability issues. Further, good corporate governance necessitates the existence of effective internal controls and risk management systems, which should be governed by the board.

When voting and engaging with companies in European markets, we consider market-specific nuances in the manner that we believe will most likely protect and promote the long-term financial value of client investments. We expect companies to observe the relevant laws and regulations of their respective markets as well as country-specific best practice guidelines and corporate governance codes. We may hold companies in some markets to our global standards when we feel that a country’s regulatory requirements do not address some of the key philosophical principles that we believe are fundamental to our global voting guidelines.

In our analysis and research into corporate governance issues in European companies, we also consider guidance issued by the European Commission and country-specific governance codes. We proactively monitor companies’ adherence to applicable guidance and requirements. Consistent with the diverse “comply-or-explain” expectations established by guidance and codes, we encourage companies to proactively disclose their level of compliance with applicable provisions and requirements. In cases of non-compliance, when companies cannot explain the nuances of their governance structure effectively, either publicly or through engagement, we may vote against the independent board leader.

State Street Global Advisors’ Proxy Voting and Engagement Philosophy

Corporate governance and sustainability issues are an integral part of the investment process. The Asset Stewardship Team consists of investment professionals with expertise in corporate governance and company law, remuneration, accounting, and environmental and social issues. We have established robust corporate governance principles and practices that are backed with extensive analytical expertise in order to understand the complexities of the corporate governance landscape. We engage with companies to provide insight on the principles and practices

that drive our voting decisions. We also conduct proactive engagement to address significant shareholder concerns and environmental, social, and governance (“ESG”) issues in a manner consistent with maximizing shareholder value.

The team works alongside members of State Street Global Advisors’ Active Fundamental and Europe, Middle East, and Africa (“EMEA”) investment teams, collaborating on issuer engagement and providing input on company-specific fundamentals. We are also a member of various investor associations that seek to address broader corporate governance related policy issues in European markets.

State Street Global Advisors is a signatory to the United Nations Principles of Responsible Investment (“UNPRI”). We are committed to sustainable investing; thus we are working to further integrate ESG principles into investment and corporate governance practices where applicable and consistent with our fiduciary duty.

Directors and Boards

We believe that a well constituted board of directors, with a balance of skills, expertise and independence, provides the foundations for a well governed company. We view board quality as a measure of director independence, director succession planning, board diversity, evaluations and refreshment, and company governance practices. We vote for the election/re-election of directors on a case-by-case basis after considering various factors, including board quality, general market practice, and availability of information on director skills and expertise. In principle, we believe independent directors are crucial to good corporate governance and help management establish sound corporate governance policies and practices. A sufficiently independent board will most effectively monitor management and perform oversight functions necessary to protect shareholder interests. Further we expect boards of STOXX Europe 600 listed companies to have at least one female board member.

Our broad criteria for director independence in European companies include factors such as:

•

Participation in related–party transactions and other business relations with the company

•

Employment history with the company

•

Relations with controlling shareholders

•

Family ties with any of the company’s advisers, directors, or senior employees

•

Employee and government representatives; and

•

Overall average board tenure and individual director tenure at issuers with classified and de-classified boards, respectively


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Proxy Voting and Engagement Guidelines

While overall board independence requirements and board structures differ from market to market, we consider voting against directors we deem non–independent if overall board independence is below one-third or if overall independence level is below 50% after excluding employee-representatives and/or directors elected in accordance with local laws who are not elected by shareholders. We also assess the division of responsibilities between chairman and CEO on a case-by- case basis, giving consideration to factors, such as overall level of independence on the board and general corporate governance standards in the company. We may support a proposal to discharge the board if a company fails to meet adequate governance standards or board level independence.

When considering the election or re-election of a non- executive director, we also consider the number of outside board directorships a non-executive holds, attendance at board meetings, and cross-directorships. In addition, we may vote against the election of a director whose biographical disclosures are insufficient to assess his or her role on the board and/or independence.

Although we generally are in favor of the annual election of directors, we recognize that director terms vary considerably in different European markets. We may vote against article/bylaw changes that seek to extend director terms. In addition, we may vote against directors if their terms extend beyond four years in certain markets.

We believe companies should have relevant board level committees for audit, remuneration, and nomination oversight. The audit committee is responsible for monitoring the integrity of the financial statements of the company, appointing external auditors, monitoring their qualifications and independence, and assessing effectiveness and resource levels. Similarly executive pay is an important aspect of corporate governance, and it should be determined by the board of directors. We expect companies to have remuneration committees to provide independent oversight of executive pay. We may vote against nominees who are executive members of audit or remuneration committees.

In its analysis of boards, we consider whether board members have adequate skills to provide effective oversight of corporate strategy, operations, and risks, including environmental and social issues. Boards should also have a regular evaluation process in place to assess the effectiveness of the board and the skills of board members to address issues such as emerging risks, changes to corporate strategy, and diversification of operations and geographic footprint.

In certain European markets it is not uncommon for the election of directors to be presented in a single slate. In these cases, where executives serve on the audit or the remuneration committees, we may vote against the entire slate.

We may also consider factors such as board performance and directors who appear to be remiss in the performance of their oversight responsibilities (e.g. fraud, criminal wrongdoing, and breach of fiduciary responsibilities).

Indemnification and Limitations on Liability

Generally, we support proposals to limit directors’ liability and/or expand indemnification and liability protection up to the limit provided by law if a director has not acted in bad faith, with gross negligence, or with reckless disregard of the duties involved in the conduct of his or her office.

Audit-Related Issues

Appointment of External Auditors

We believe that a company’s auditor is an essential feature of an effective and transparent system of external supervision. Shareholders should be given the opportunity to vote on their appointment or re-appoint them at the annual meeting. When appointing external auditors and approving audit fees, we consider the level of detail in company disclosures; we will generally not support such resolutions if adequate breakdown is not provided and if non-audit fees are more than 50% of audit fees. In addition, we may vote against members of the audit committee if we have concerns with audit related issues or if the level of non-audit fees to audit fees is significant. We may consider auditor tenure when evaluating the audit process in certain circumstances.

Limit Legal Liability of External Auditors

We generally oppose limiting the legal liability of audit firms as we believe this could create a negative impact on the quality of the audit function.

Shareholder Rights and Capital-Related Issues

In some European markets, differential voting rights continue to exist. State Street Global Advisors supports the “one share one vote” policy and favors a share structure


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where all shares have equal voting rights. We believe pre-emption rights should be introduced for shareholders in order to provide adequate protection from excessive dilution from the issuance of new shares or convertible securities to third parties or a small number of select shareholders.

Unequal Voting Rights

We generally oppose proposals authorizing the creation of new classes of common stock with superior voting rights. We will generally oppose the creation of new classes of preferred stock with unspecified voting, conversion, dividend distribution, and other rights. In addition, we will not support capitalization changes that add classes of stock with undefined voting rights or classes that may dilute the voting interests of existing shareholders. We support proposals to abolish voting caps and capitalization changes that eliminate other classes of stock and/or unequal voting rights.

Increase in Authorized Capital

The ability to raise capital is critical for companies to carry out strategy, to grow, and to achieve returns above their cost of capital. The approval of capital raising activities is fundamental to shareholders’ ability to monitor returns and to ensure capital is deployed efficiently. We support capital increases that have sound business reasons and are not excessive relative to a company’s existing capital base.

Pre-emption rights are a fundamental right for shareholders to protect their investment in a company. Where companies seek to issue new shares whilst disapplying pre-emption rights, we may vote against if such authorities are greater than 20% of the issued share capital. We may also vote against resolutions that seek authority to issue capital with pre-emption rights if the aggregate amount allowed seems excessive and is not justified by the board. Generally, we oppose capital issuance proposals greater than 100% of the issued share capital when the proceeds are not intended for a specific purpose.

Share Repurchase Programs

We typically support proposals to repurchase shares; however, there are exceptions in some cases. We do not support repurchases in cases if the issuer does not clearly state the business purpose for the program, a definitive number of shares to be repurchased, the range of premium/ discount to market price at which the company can repurchase shares, and the timeframe for the repurchase. We may vote against share repurchase requests that allow share repurchases during a takeover period.

Dividends

We generally support dividend payouts that constitute 30% or more of net income. We may vote against the dividend payouts if the dividend payout ratio has been consistently below 30% without adequate explanation or the payout is excessive given the company’s financial position. Particular attention will be paid to cases in which the payment may damage the company’s long-term financial health.

Related-Party Transactions

Some companies in European markets have a controlled ownership structure and have complex cross-shareholdings between subsidiaries and parent companies (“related companies”). Such structures may result in the prevalence of related-party transactions between the company and its various stakeholders, such as directors and management, subsidiaries, and shareholders. In markets where shareholders are required to approve such transactions, we expect companies to provide details of the transaction, such as the nature, the value, and the purpose of such a transaction. We also encourage independent directors to ratify such transactions. Further we encourage companies to describe the level of independent board oversight and the approval process, including details of any independent valuations provided by financial advisors on related- party transactions.

Mergers and Acquisitions

Mergers or restructurings often involve proposals relating to reincorporation, restructurings, mergers, liquidation, and other major changes to the corporation. Proposals will be supported if they are in the best interests of the shareholders, which is demonstrated by enhancing share value or improving the effectiveness of the company’s operations. In general provisions that are not viewed as financially sound or are thought to be destructive to shareholders’ rights are not supported.

We will generally support transactions that maximize shareholder value. Some of the considerations include the following:

•

Offer premium

•

Strategic rationale

•

Board oversight of the process for the recommended transaction, including director and/or management conflicts of interest

•

Offers made at a premium and where there are no other higher bidders

•

Offers in which the secondary market price is substantially lower than the net asset value


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Proxy Voting and Engagement Guidelines

We may vote against a transaction considering the following:

•

Offers with potentially damaging consequences for minority shareholders because of illiquid stock

•

Offers where we believe there is a reasonable prospect for an enhanced bid or other bidders

•

The current market price of the security exceeds the bid price at the time of voting.

Anti–Takeover Measures

European markets have diverse regulations concerning the use of share issuances as takeover defenses, with legal restrictions lacking in some markets. We support the one-share, one-vote policy. For example, dual-class capital structures entrench certain shareholders and management, insulating them from possible takeovers. We oppose unlimited share issuance authorizations because they can be used as antitakeover devices. They have the potential for substantial voting and earnings dilution. We also monitor the duration of time for authorities to issue shares, as well as whether there are restrictions and caps on multiple issuance authorities during the specified time periods. We oppose antitakeover defenses such as authorities for the board, when subject to a hostile takeover to issue warrants convertible into shares to existing shareholders.

Remuneration

Executive Pay

Despite the differences among the various types of plans and awards , there is a simple underlying philosophy that guides our analysis of executive pay; there should be a direct relationship between remuneration and company performance over the long term.

Shareholders should have the opportunity to assess whether pay structures and levels are aligned with business performance. When assessing remuneration reports, we consider factors such as adequate disclosure of remuneration elements, absolute and relative pay levels, peer selection and benchmarking, the mix of long-term and short-term incentives, alignment of pay structures with shareholder interests as well as with corporate strategy and performance. We may oppose remuneration reports where pay seems misaligned with shareholders’ interests. We may also vote against the re-election of members of the remuneration committee if we have serious concerns about remuneration practices and if the company has not been responsive to shareholder pressure to review its approach.

Equity Incentives Plans

We may not support proposals regarding equity-based incentive plans where insufficient information is provided on matters, including grant limits, performance metrics, performance and vesting periods, and overall dilution. Generally we do not support options under such plans being issued at a discount to market price or plans that allow for retesting of performance metrics.

Non–Executive Director Pay

In European markets, proposals seeking shareholder approval for non-executive directors’ fees are generally not controversial. We typically support resolutions regarding directors’ fees unless disclosure is poor and we are unable to determine whether the fees are excessive relative to fees paid by comparable companies. We will evaluate any non-cash or performance-related pay to non-executive directors on a company-by-company basis.

Risk Management

We believe that risk management is a key function of the board, which is responsible for setting the overall risk appetite of a company and for providing oversight on the risk management process established by senior executives at a company. We allow boards discretion regarding the ways in which they provide oversight in this area. However, we expect companies to disclose how the board provides oversight on its risk management system and risk identification. Boards should also review existing and emerging risks, as they can change with a changing political and economic landscape or as companies diversify or expand their operations into new areas.

Environmental and Social Issues


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sustainability issue would promote long-term shareholder value in the context of the company’s existing practices and disclosures as well as existing market practice.

More Information

Any client who wishes to receive information on how its proxies were voted should contact its State Street Global Advisors relationship manager.

These Proxy Voting and Engagement Guidelines are also applicable to State Street Global Advisors Funds Management, Inc. State Street Global Advisors Funds Management, Inc. is an SEC-registered investment adviser. State Street Global Advisors Funds Management, Inc., State Street Global Advisors Trust Company, and other advisory affiliates of State Street make up State Street Global Advisors, the investment management arm of State Street Corporation.

ssga.com

State Street Global Advisors Worldwide Entities

The whole or any part of this work may not be reproduced, copied or transmitted or any of its contents disclosed to third parties without State Street Global Advisor’s express written consent.


State Street Global Advisors		C-33		© 2019 State Street Corporation. All Rights Reserved. ID15919 0319 Exp. Date: 03/31/2020

March 2019

Proxy Voting and Engagement Guidelines

Japan

State Street Global Advisors’ Japan Proxy Voting and Engagement Guidelines ¹ outline our expectations of companies listed on stock exchanges in Japan. These guidelines complement and should be read in conjunction with State Street Global Advisors’ overarching Global Proxy Voting and Engagement Guidelines, which provide a detailed explanation of our approach to voting and engaging with companies and State Street Global Advisors’ Conflict Mitigation Guidelines.

LOGO

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Proxy Voting and Engagement Guidelines

State Street Global Advisors’ Proxy Voting and Engagement Guidelines in Japan address areas including: board structure, audit related issues, capital structure, remuneration, environmental, social, and other governance- related issues. Principally, we believe the primary responsibility of the board of directors is to preserve and enhance shareholder value and protect shareholder interests. In order to carry out their primary responsibilities, directors have to undertake activities that range from setting strategy and overseeing executive management to monitoring the risks that arise from a company’s business, including risks related to sustainability issues. Further, good corporate governance necessitates the existence of effective internal controls and risk management systems, which should be governed by the board.

When voting and engaging with companies in Japan, State Street Global Advisors takes into consideration the unique aspects of Japanese corporate governance structures. We recognize that under Japanese corporate law, companies may choose between two structures of corporate governance: the statutory auditor system or the committee structure. Most Japanese boards predominantly consist of executives and non-independent outsiders affiliated through commercial relationships or cross-shareholdings. Nonetheless, when evaluating companies, State Street Global Advisors expects Japanese companies to address conflicts of interest and risk management and to demonstrate an effective process for monitoring management. In our analysis and research regarding corporate governance issues in Japan, we expect all companies at a minimum to comply with Japan’s Corporate Governance Principles and proactively monitor companies’ adherence to the principles. Consistent with the ‘comply or explain’ expectations established by the Principles, we encourage companies to proactively disclose their level of compliance with the Principles. In instances of non-compliance when companies cannot explain the nuances of their governance structure effectively, either publicly or through engagement, we may vote against the board leader.

State Street Global Advisors’ Proxy Voting and Engagement Philosophy

In our view, corporate governance and sustainability issues are an integral part of the investment process. The Asset Stewardship Team consists of investment professionals with expertise in corporate governance and company law, remuneration, accounting, and environmental and social issues. We have established robust corporate governance principles and practices that are backed with extensive analytical expertise to understand the complexities of the corporate governance landscape. We engage with companies to provide insight on the principles and practices that drive

our voting decisions. We also conduct proactive engagement to address significant shareholder concerns and environmental, social, and governance (“ESG”) issues in a manner consistent with maximizing shareholder value.

The team works alongside members of State Street Global Advisors’ Active Fundamental and Asia-Pacific (“APAC”) Investment teams; the teams collaborate on issuer engagement and provide input on company specific fundamentals. We are also a member of various investor associations that seek to address broader corporate governance related policy issues in Japan.

State Street Global Advisors is a signatory to the United Nations Principles of Responsible Investment (“UNPRI”) and is compliant with Japan’s Stewardship Code and Corporate Governance Code. We are committed to sustainable investing and are working to further integrate ESG principles into investment and corporate governance practices where applicable and consistent with our fiduciary duty.

Directors and Boards

State Street Global Advisors believes that a well constituted board of directors with a balance of skills, expertise, and independence, provides the foundation for a well governed company. We view board quality as a measure of director independence, director succession planning, board diversity, evaluations and refreshment, and company governance practices. We vote for the election/re-election of directors on a case-by-case basis after considering various factors, including board quality, general market practice, and availability of information on director skills and expertise. In principle, we believe independent directors are crucial to robust corporate governance and help management establish sound corporate governance policies and practices. A sufficiently independent board will most effectively monitor management and perform oversight functions that are necessary to protect shareholder interests. Further we expect boards of TOPIX 500 listed companies to have at least one female board member.

Japanese companies have the option of having a traditional board of directors with statutory auditors, a board with a committee structure, or a hybrid board with a board level audit committee. We will generally support companies that seek shareholder approval to adopt a committee or hybrid board structure.

Most Japanese issuers prefer the traditional statutory auditor structure. Statutory auditors act in a quasi- compliance role, as they are not involved in strategic decision-making nor are they part of the formal management decision process. Statutory auditors attend board meetings but do not have voting rights at the board; however,


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they have the right to seek an injunction and conduct broad investigations of unlawful behavior in the company’s operations.

State Street Global Advisors will support the election of statutory auditors, unless the outside statutory auditor nominee is regarded as non-independent based on our criteria, the outside statutory auditor has attended less than 75 percent of meetings of the board of directors or board of statutory auditors during the year under review, or the statutory auditor has been remiss in the performance of their oversight responsibilities (fraud, criminal wrong doing, and breach of fiduciary responsibilities).

For companies with a statutory auditor structure there is no legal requirement that boards have outside directors; however, we believe there should be a transparent process of independent and external monitoring of management on behalf of shareholders.

•

We believe that boards of TOPIX 500 companies should have at least three independent directors or be at least one-third independent, whichever requires fewer independent directors. Otherwise, we may oppose the board leader who is responsible for the director nomination process.

•

For controlled, non-TOPIX 500 companies with a statutory auditor structure or hybrid structure, we may oppose the board leader if the board does not have at least two independent directors.

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For non-controlled, non-TOPIX 500 companies with a statutory auditor structure or hybrid structure, State Street Global Advisors may oppose the board leader, if the board does not have at least two outside directors.

For companies with a committee structure or a hybrid board structure, we also take into consideration the overall independence level of the committees. In determining director independence, we consider the following factors:

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Participation in related-party transactions and other business relations with the company

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Past employment with the company

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Professional services provided to the company

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Family ties with the company

Regardless of board structure, we may oppose the election of a director for the following reasons:

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Failure to attend board meetings

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In instances of egregious actions related to a director’s service on the board

Indemnification and Limitations on Liability

Generally, State Street Global Advisors supports proposals to limit directors’ and statutory auditors’ liability and/or expand indemnification and liability protection up to the limit provided by law, if he or she has not acted in bad faith, gross negligence, or reckless disregard of the duties involved in the conduct of his or her office. We believe limitations and indemnification are necessary to attract and retain qualified directors.

Audit-Related Items

State Street Global Advisors believes that a company’s auditor is an essential feature of an effective and transparent system of external supervision. Shareholders should have the opportunity to vote on the appointment of the auditor at the annual meeting.

Ratifying External Auditors

We generally support the appointment of external auditors unless the external auditor is perceived as being non- independent and there are concerns about the accounts presented and the audit procedures followed.

Limiting Legal Liability of External Auditors

We generally oppose limiting the legal liability of audit firms as we believe this could create a negative impact on the quality of the audit function.

Capital Structure, Reorganization, and Mergers

State Street Global Advisors supports the “one share one vote” policy and favors a share structure where all shares have equal voting rights. We support proposals to abolish voting caps or multiple voting rights and will oppose measures to introduce these types of restrictions on shareholder rights.

We believe pre-emption rights should be introduced for shareholders. This can provide adequate protection from excessive dilution due to the issuance of new shares or convertible securities to third parties or a small number of select shareholders.

Unequal Voting Rights

We generally oppose proposals authorizing the creation of new classes of common stock with superior voting rights. We will generally oppose new classes of preferred stock with unspecified voting, conversion, dividend distribution, and other rights. In addition, we will not support capitalization changes that add classes of stock with undefined voting rights or classes that may dilute the voting interests of existing shareholders.


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However, we will support capitalization changes that eliminate other classes of stock and/or unequal voting rights.

Increase in Authorized Capital

We generally support increases in authorized capital where the company provides an adequate explanation for the use of shares. In the absence of an adequate explanation, we may oppose the request if the increase in authorized capital exceeds 100% of the currently authorized capital. Where share issuance requests exceed our standard threshold, we will consider the nature of the specific need, such as mergers, acquisitions and stock splits.

Dividends

We generally support dividend payouts that constitute 30% or more of net income. We may vote against the dividend payouts if the dividend payout ratio has been consistently below 30% without adequate explanation; or, the payout is excessive given the company’s financial position. Particular attention will be paid where the payment may damage the company’s long-term financial health.

Share Repurchase Programs

Companies are allowed under Japan Corporate Law to amend their articles to authorize the repurchase of shares at the board’s discretion. We will oppose an amendment to articles allowing the repurchase of shares at the board’s discretion. We believe the company should seek shareholder approval for a share repurchase program at each year’s AGM, providing shareholders the right to evaluate the purpose of the repurchase.

Mergers and Acquisitions

Mergers or reorganizing the structure of a company often involve proposals relating to reincorporation, restructurings, mergers, liquidations, and other major changes to the corporation. We will support proposals that are in the best interests of the shareholders, demonstrated by enhancing share value or improving the effectiveness of the company’s operations. In general, provisions that are deemed to be destructive to shareholders’ rights or financially detrimental are not supported.

We evaluate mergers and structural reorganizations on a case-by-case basis. We will generally support transactions that maximize shareholder value. Some of the considerations include, but are not limited to the following:

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Offer premium

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Strategic rationale

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Board oversight of the process for the recommended transaction, including director and/or management conflicts of interest

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Offers made at a premium and where there are no other higher bidders

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Offers in which the secondary market price is substantially lower than the net asset value

We may vote against a transaction considering the following:

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Offers with potentially damaging consequences for minority shareholders because of illiquid stock

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Offers where we believe there is a reasonable prospect for an enhanced bid or other bidders

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Offers in which the current market price of the security exceeds the bid price at the time of voting

Anti-Takeover Measures

In general, State Street Global Advisors believes that adoption of poison pills that have been structured to protect management and to prevent takeover bids from succeeding is not in shareholders’ interest. A shareholder rights plan may lead to management entrenchment. It may also discourage legitimate tender offers and acquisitions. Even if the premium paid to companies with a shareholder rights plan is higher than that offered to unprotected firms, a company’s chances of receiving a takeover offer in the first place may be reduced by the presence of a shareholder rights plan.

Proposals that reduce shareholders’ rights or have the effect of entrenching incumbent management will not be supported.

Proposals that enhance the right of shareholders to make their own choices as to the desirability of a merger or other proposal are supported.

Shareholder Rights Plans

In evaluating the adoption or renewal of a Japanese issuer’s shareholder rights plans (“poison pill”), we consider the following conditions: (i) release of proxy circular with details of the proposal with adequate notice in advance of meeting, (ii) minimum trigger of over 20%, (iii) maximum term of three years, (iv) sufficient number of independent directors, (v) presence of an independent committee, (vi) annual election of directors, and (vii) lack of protective or entrenchment features. Additionally, we consider the length of time that a shareholder rights plan has been in effect.


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In evaluating an amendment to a shareholder rights plan (“poison pill”), in addition to the conditions above, we will also evaluate and consider supporting proposals where the terms of the new plans are more favorable to shareholders’ ability to accept unsolicited offers.

Compensation

In Japan, excessive compensation is rarely an issue. Rather, the problem is the lack of connection between pay and performance. Fixed salaries and cash retirement bonuses tend to comprise a significant portion of the compensation structure while performance-based pay is generally a small portion of the total pay. State Street Global Advisors, where possible, seeks to encourage the use of performance-based compensation in Japan as an incentive for executives and as a way to align interests with shareholders.

Adjustments to Aggregate Compensation Ceiling for Directors

Remuneration for directors is generally reasonable. Typically, each company sets the director compensation parameters as an aggregate thereby limiting the total pay to all directors. When requesting a change, a company must disclose the last time the ceiling was adjusted, and management provides the rationale for the ceiling increase. We will generally support proposed increases to the ceiling if the company discloses the rationale for the increase. We may oppose proposals to increase the ceiling if there has been corporate malfeasance or sustained poor performance.

Annual Bonuses for Directors/Statutory Auditors

In Japan, since there are no legal requirements that mandate companies to seek shareholder approval before awarding a bonus, we believe that existing shareholder approval of the bonus should be considered best practice. As a result, we support management proposals on executive compensation where there is a strong relationship between executive pay and performance over a five-year period.

Retirement Bonuses for Directors/Statutory Auditors

Retirement bonuses make up a sizeable portion of directors’ and auditors’ lifetime compensation and are based upon board tenure. While many companies in Japan have abolished this practice, there remain many proposals seeking shareholder approval for the total amounts paid to directors and statutory auditors as a whole. In general, we support these payments unless the recipient is an outsider or in instances where the amount is not disclosed.

Stock Plans

Most option plans in Japan are conservative, particularly at large companies. Japanese corporate law requires companies to disclose the monetary value of the stock options for directors and/or statutory auditors. Some companies do not disclose the maximum number of options that can be issued per year and shareholders are unable to evaluate the dilution impact. In this case, we cannot calculate the dilution level and, therefore, we may oppose such plans for poor disclosure. We also oppose plans that allow for the repricing of the exercise price.

Deep Discount Options

As Japanese companies move away from the retirement bonus system, deep discount options plans have become more popular. Typically, the exercise price is set at JPY 1 per share. We evaluate deep discount options using the same criteria used to evaluate stock options as well as considering the vesting period.

Environmental and Social Issues


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Miscellaneous/Routine Items

Expansion of Business Activities

Japanese companies’ articles of incorporation strictly define the types of businesses in which a company is permitted to engage. In general, State Street Global Advisors views proposals that expand and diversify the company’s business activities as routine and non-contentious. We will monitor instances in which there has been an inappropriate acquisition and diversification away from the company’s main area of competence that resulted in a decrease of shareholder value.

More Information

Any client who wishes to receive information on how its proxies were voted should contact its State Street Global Advisors relationship manager.

These Proxy Voting and Engagement Guidelines are also applicable to SSGA Funds Management, Inc. SSGA Funds Management, Inc.is an SEC-registered investment adviser. SSGA Funds Management, Inc., State Street Global Advisors Trust Company, and other advisory affiliates of State Street make up State Street Global Advisors, the investment management arm of State Street Corporation.

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Proxy Voting and Engagement Guidelines

United Kingdom and Ireland

State Street Global Advisors’, United Kingdom and Ireland Proxy Voting and Engagement Guidelines ¹ outline our expectations of companies listed on stock exchanges in the United Kingdom and Ireland. These guidelines complement and should be read in conjunction with State Street Global Advisors’ Global Proxy Voting and Engagement Principles, which provide a detailed explanation of our approach to voting and engaging with companies and State Street Global Advisors’ Conflict Mitigation Guidelines.

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Proxy Voting and Engagement Guidelines

State Street Global Advisors’ United Kingdom (“UK”) and Ireland Proxy Voting and Engagement Guidelines address areas including board structure, audit related issues, capital structure, remuneration, environmental, social and other governance related issues. Principally, we believe the primary responsibility of a board of directors is to preserve and enhance shareholder value and to protect shareholder interests. In order to carry out their primary responsibilities, directors have to undertake activities that range from setting strategy, overseeing executive management, and monitoring the risks that arise from a company’s business, including risks related to sustainability issues. Further, good corporate governance necessitates the existence of effective internal controls and risk management systems, which should be governed by the board.

When voting and engaging with companies in global markets, we consider market specific nuances in the manner that we believe will most likely protect and promote the long-term economic value of client investments. We expect companies to observe the relevant laws and regulations of their respective markets as well as country-specific best practice guidelines and corporate governance codes. When we identify that a country’s regulatory requirements do not address some of the key philosophical principles that we believe are fundamental to our global voting guidelines, we may hold companies in such markets to our global standards.

In our analysis and research into corporate governance issues in the UK and Ireland, we expect all companies, regardless of domicile, that obtain a primary listing on the London Stock Exchange or the Irish Stock Exchange to comply with the UK Corporate Governance Code and proactively monitor companies’ adherence to the Code. Consistent with the ‘comply or explain’ expectations established by the Code, we encourage companies to proactively disclose their level of compliance with the Code. In instances of non-compliance in which companies cannot explain the nuances of their governance structure effectively, either publicly or through engagement, we may vote against the independent board leader.

State Street Global Advisors’ Proxy Voting and Engagement Philosophy

our voting decisions. We also conduct proactive engagement to address significant shareholder concerns and environmental, social and governance (“ESG”) issues in a manner consistent with maximizing shareholder value.

The team works alongside members of SSGA’s Active Fundamental and Europe, Middle East, and Africa (“EMEA”) Investment teams. We collaborate on issuer engagement and provide input on company specific fundamentals. We are also a member of various investor associations that seek to address broader corporate governance related policy issues in the UK and European markets.

State Street Global Advisors is a signatory to the United Nations Principles of Responsible Investment (“UNPRI”) and is compliant with the UK Stewardship Code. We are committed to sustainable investing and are working to further integrate ESG principles into investment and corporate governance practice where applicable and consistent with our fiduciary duty.

Directors and Boards

We believe that a well constituted board of directors, with a balance of skills, expertise and independence, provides the foundations for a well governed company. We view board quality as a measure of director independence, director succession planning, board diversity, evaluations and refreshment, and company governance practices. We vote for the election/re-election of directors on a case-by-case basis after considering various factors, including board quality, general market practice, and availability of information on director skills and expertise. In principle, we believe independent directors are crucial to robust corporate governance and help management establish sound corporate governance policies and practices. A sufficiently independent board will most effectively monitor management and perform oversight functions necessary to protect shareholder interests. Further, we expect boards of FTSE 350 listed companies to have at least one female board member.

Our broad criteria for director independence for UK companies include factors such as:

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Participation in related-party transactions and other business relations with the company

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Employment history with company

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Excessive tenure and a preponderance of long-tenured directors

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Relations with controlling shareholders

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Family ties with any of the company’s advisers, directors or senior employees

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If the company classifies the director as non-independent


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When considering the election or re-election of a director, we also consider the number of outside board directorships a non-executive and an executive may undertake as well as attendance at board meetings. In addition, we monitor other factors that may influence the independence of a non-executive director, such as performance related pay, cross-directorships and significant shareholdings. We support the annual election of directors.

While we are generally supportive of having the roles of chairman and CEO separated in the UK market, we assess the division of responsibilities between chairman and CEO on a case-by-case basis, giving consideration to factors, such as the company’s specific circumstances, overall level of independence on the board and general corporate governance standards in the company. Similarly we monitor for circumstances in which a combined chairman/CEO is appointed or a former CEO becomes chairman.

We may also consider factors such as board performance and directors who appear to be remiss in the performance of their oversight responsibilities when considering their suitability for reappointment (e.g. fraud, criminal wrongdoing and breach of fiduciary responsibilities).

We believe companies should have committees for audit, remuneration, and nomination oversight. The audit committee is responsible for monitoring the integrity of the financial statements of the company, the appointment of external auditors, auditor qualifications and independence, and effectiveness and resource levels. Similarly executive pay is an important aspect of corporate governance, and it should be determined by the board of directors. We expect companies to have remuneration committees to provide independent oversight over executive pay. We will vote against nominees who are executive members of audit or remuneration committees.

We consider whether board members have adequate skills to provide effective oversight of corporate strategy, operations, and risks, including environmental and social issues. Boards should also have a regular evaluation process in place to assess the effectiveness of the board and the skills of board members to address issues such as emerging risks, changes to corporate strategy, and diversification of operations and geographic footprint. The nomination committee is responsible for evaluating and reviewing the balance of skills, knowledge, and experience of the board. It also ensures that adequate succession plans are in place for directors and the CEO. We may vote against the re-election of members of the nomination committee if, over time, the board has failed to address concerns over board structure or succession.

Indemnification and Limitations on Liability

Generally, we support proposals to limit directors’ liability and/or expand indemnification and liability protection up to the limit provided by law. This holds if a director has not acted in bad faith, gross negligence, nor reckless disregard of the duties involved in the conduct of his or her office.

Audit-Related Issues

Appointment of External Auditors

State Street Global Advisors believes that a company’s auditor is an essential feature of an effective and transparent system of external supervision. Shareholders should be given the opportunity to vote on their appointment or re-appoint at the annual meeting. When appointing external auditors and approving audit fees, we take into consideration the level of detail in company disclosures and will generally not support such resolutions if an adequate breakdown is not provided and if non-audit fees are more than 50% of audit fees. In addition, we may vote against members of the audit committee if we have concerns with audit-related issues or if the level of non-audit fees to audit fees is significant. In certain circumstances, we may consider auditor tenure when evaluating the audit process.

Limit Legal Liability of External Auditors

We generally oppose limiting the legal liability of audit firms because we believe this could create a negative impact on the quality of the audit function.

Shareholder Rights and Capital-Related Issues

Share Issuances

The ability to raise capital is critical for companies to carry out strategy, to grow, and to achieve returns above their cost of capital. The approval of capital raising activities is essential to shareholders’ ability to monitor returns and to ensure capital is deployed efficiently. We support capital increases that have sound business reasons and are not excessive relative to a company’s existing capital base.


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Pre-emption rights are a fundamental right for shareholders to protect their investment in a company. Where companies seek to issue new shares without pre-emption rights, we may vote against if such authorities are greater than 20% of the issued share capital. We may also vote against resolutions that seek authority to issue capital with pre-emption rights if the aggregate amount allowed seems excessive and is not justified by the board. Generally, we are against capital issuance proposals greater than 100% of the issued share capital when the proceeds are not intended for a specific purpose.

Share Repurchase Programs

We generally support a proposal to repurchase shares. However, this is not the case if the issuer does not clearly state the business purpose for the program, a definitive number of shares to be repurchased, the range of premium/ discount to market price at which a company can repurchase shares, and the timeframe for the repurchase. We may vote against share repurchase requests that allow share repurchases during a takeover period.

Dividends

We generally support dividend payouts that constitute 30% or more of net income. We may vote against the dividend payouts if the dividend payout ratio has been consistently below 30% without adequate explanation or the payout is excessive given the company’s financial position. Particular attention will be paid where the payment may damage the company’s long term financial health.

Mergers and Acquisitions

Mergers or reorganizing the structure of a company often involve proposals relating to reincorporation, restructurings, mergers, liquidations, and other major changes to the corporation. Proposals that are in the best interests of the shareholders, demonstrated by enhancing share value or improving the effectiveness of the company’s operations, will be supported. In general, provisions that are not viewed as financially sound or are thought to be destructive to shareholders’ rights and are not supported.

We will generally support transactions that maximize shareholder value. Some of the considerations include the following:

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Offer premium

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Strategic rationale

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Board oversight of the process for the recommended transaction, including, director and/or management conflicts of interest

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Offers made at a premium and where there are no other higher bidders

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Offers in which the secondary market price is substantially lower than the net asset value

We may vote against a transaction considering the following:

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Offers with potentially damaging consequences for minority shareholders because of illiquid stock

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Offers in which we believe there is a reasonable prospect for an enhanced bid or other bidders

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The current market price of the security exceeds the bid price at the time of voting

Anti-Takeover Measures

We oppose anti-takeover defenses such as authorities for the board when subject to a hostile takeover to issue warrants convertible into shares to existing shareholders.

Remuneration

Executive Pay

Despite the differences among the types of plans and awards possible, there is a simple underlying philosophy that guides our analysis of executive pay, There should be a direct relationship between remuneration and company performance over the long term.

Shareholders should have the opportunity to assess whether pay structures and levels are aligned with business performance. When assessing remuneration policies and reports, we consider adequate disclosure of various remuneration elements, absolute and relative pay levels, peer selection and benchmarking, the mix of long-term and short-term incentives, alignment of pay structures with shareholder interests as well as with corporate strategy and performance. We may oppose remuneration reports where pay seems misaligned with shareholders’ interests. We may also vote against the re-election of members of the remuneration committee if we have serious concerns about remuneration practices or if the company has not been responsive to shareholder concerns.

Equity Incentive Plans

We may not support proposals on equity-based incentive plans where insufficient information is provided on matters such as grant limits, performance metrics, performance, vesting periods, and overall dilution. Generally we do not support options under such plans being issued at a discount to market price or plans that allow for re-testing of performance metrics.

Non-Executive Director Pay

Authorities that seek shareholder approval for non-executive directors’ fees are generally not controversial. We typically support resolutions regarding directors’ fees unless disclosure is poor and we are unable to determine whether they are excessive relative to fees paid by comparable companies. We will evaluate any non-cash or performance related pay to non-executive directors on a company- by- company basis.


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Risk Management

State Street Global Advisors believes that risk management is a key function of the board, which is responsible for setting the overall risk appetite of a company and for providing oversight of the risk management process established by senior executives at a company. We allow boards discretion over how they provide oversight in this area. We expect companies to disclose how the board provides oversight on its risk management system and risk identification. Boards should also review existing and emerging risks as they can evolve with a changing political and economic landscape or as companies diversify their operations into new areas.

Environmental and Social Issues

companies for engagement and voting in order to mitigate sustainability risks in our portfolio. Through engagement, we address a broad range of topics that align with our thematic priorities and build long-term relationships with issuers. When voting, we fundamentally consider whether the adoption of a shareholder proposal addressing a material sustainability issue would promote long-term shareholder value in the context of the company’s existing practices and disclosures as well as existing market practice.

More Information

Any client who wishes to receive information on how its proxies were voted should contact its State Street Global Advisors relationship manager.


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Proxy Voting and Engagement Guidelines

Rest of the World

State Street Global Advisors’ Rest of the World Proxy Voting and Engagement Guidelines ¹ cover different corporate governance frameworks and practices in international markets not covered under specific country/regional guidelines. These guidelines complement and should be read in conjunction with State Street Global Advisors’ overarching Global Proxy Voting and Engagement Principles, which provide a detailed explanation of our approach to voting and engaging with companies and State Street Global Advisors’ Conflict Mitigation Guidelines.

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At State Street Global Advisors, we recognize that countries in international markets that are not covered under specific country/regional guidelines are disparate in their corporate governance frameworks and practices. We also evaluate the various factors that contribute to the corporate governance framework of a country. These factors include but are not limited to: (i) the macroeconomic conditions and broader political system in a country; (ii) quality of regulatory oversight, enforcement of property and shareholder rights, and (iii) the independence of judiciary. This guidance pertains to international markets not covered under specific country/regional guidelines, specifically emerging markets. While emerging market countries tend to pose broad common governance issues across all markets, such as concentrated ownership, poor disclosure of financial and related-party transactions, and weak enforcement of rules and regulation, our proxy voting guidelines are designed to identify and to address specific governance concerns in each market.

State Street Global Advisors’ Proxy Voting and Engagement Philosophy in Emerging Markets

State Street Global Advisors’ approach to proxy voting and issuer engagement in emerging markets is designed to increase the value of our investments through the mitigation of governance risks. The overall quality of the corporate governance framework in an emerging market country drives the level of governance risks investors assign to a country. Thus improving the macro governance framework in a country may help to reduce governance risks and to increasethe overall value of our holdings over time. In order to improve the overall governance framework and practices in a country, members of our Asset Stewardship team endeavor to engage with representatives from regulatory agencies and stock markets to highlight potential concerns with the macro governance framework of a country. We are also a member of various investor associations that seek to address broader corporate governance-related policy issues in emerging markets. To help mitigate company specific risk, the State Street Global Advisors Asset Stewardship Team works alongside members of the Active Fundamental and emerging market specialists to engage with emerging market companies on governance issues and address any specific concerns or to get more information regarding shareholder items that are to be voted on at upcoming shareholder meetings. This integrated approach to engagement drives our proxy voting and engagement philosophy in emerging markets.

Our proxy voting guidelines in emerging markets address six broad areas:

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Directors and Boards

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Accounting and Audit Related Issues

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Shareholder Rights and Capital Related Issues

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Remuneration

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Environmental and Social Issues

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General/Routine Issues

Directors and Boards

We believe that a well constituted board of directors with a balance of skills, expertise, and independence provides the foundation for a well governed company. However, several factors, such as low overall independence level requirements by market regulators, poor biographical disclosure of director profiles, prevalence of related-party transactions, and the general resistance from controlling shareholders to increase board independence, render the election of directors as one of the most important fiduciary duties we perform in emerging market companies.

We vote for the election/re-election of directors on a case-by-case basis after considering various factors, including general market practice and availability of information on director skills and expertise. We expect companies to meet minimum overall board independence standards as defined in a corporate governance code or market practice. Therfore, in several countries, we will vote against select non-independent directors if overall board independence levels do not meet market standards.

Our broad criteria for director independence in emerging market companies include factors such as:

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Participation in related-party transactions

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Employment history with company

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Relations with controlling shareholders and other employees

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Attendance levels

In some countries, market practice calls for the establishment of a board level audit committee. In such cases, we believe companies should have an audit committee that is responsible for monitoring the integrity of the financial statements of the company and appointing external auditors. It should also monitor their qualifications, independence,effectiveness, and resource levels. Based upon our desire to enhance the quality of financial and accounting oversight provided by independent directors, we expect that listed companies have an audit committee that is constituted of a majority of independent directors.


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Proxy Voting and Engagement Guidelines

Audit-Related Issues

The disclosure and availability of reliable financial statements in a timely manner is imperative for the investment process. As a result, board oversight of internal controls and the independence of the audit process are essential if investors are to rely upon financial statements. We believe that audit committees provide the necessary oversight for the selection and appointment of auditors, the company’s internal controls, and the accounting policies, and the overall audit process. In emerging markets, we encourage boards to appoint an audit committee composed of a majority of independent auditors.

Appointment of External Auditors

We believe that a company’s auditor is an essential feature of an effective and transparent system of external supervision. Shareholders should be given the opportunity to vote on their appointment or re-appointment at the annual meeting. We believe that it is imperative for audit committees to select outside auditors who are independent from management.

Shareholder Rights and Capital-Related Issues

State Street Global Advisors believes that changes to a company’s capital structure such as changes in authorized share capital, share repurchase, and debt issuances, are critical decisions made by the board. We believe the company should have a business rationale that is consistent with corporate strategy and should not overly dilute its shareholders.

Related Party Transactions

Most companies in emerging markets have a controlled ownership structure that often includes complex cross- shareholdings between subsidiaries and parent companies (“related companies”). As a result, there is a high prevalence of related-party transactions between the company and its various stakeholders such as directors and management. In addition, inter-group loan and loan guarantees provided to related companies are some of the other related-party transactions that increase the risk profile of companies. In markets where shareholders are required to approve such transactions, we expect companies to provide details about the transaction, such as its nature, value, and purpose. This also encourages independent directors to ratify such transactions. Further we encourage companies to describe the level of independent board oversight and the approval process, including details of any independent valuations provided by financial advisors on related-party transactions.

Share Repurchase Programs

With regard to share repurchase programs, we expect companies to clearly state the business purpose for the program and a definitive number of shares to be repurchased.

Mergers and Acquisitions

Mergers or reorganization of the structure of a company often involve proposals relating to reincorporation, restructurings, liquidations, and other major changes to the corporation. Proposals that are in the best interests of the shareholders, demonstrated by enhancing share value or improving the effectiveness of the company’s operations, will be supported. In general, provisions that are not viewed as financially sound or are thought to be destructive to shareholders’ rights are not supported.

We evaluate mergers and structural reorganizations on a case-by-case basis. We generally support transactions that maximize shareholder value. Some of the considerations include, but are not limited to the following:

•

Offer premium

•

Strategic rationale

•

Board oversight of the process for the recommended transaction, including, director and/or management conflicts of interest

•

Offers made at a premium and where there are no other higher bidders

•

Offers in which the secondary market price is substantially lower than the net asset value

We may vote against a transaction considering the following:

•

Offers with potentially damaging consequences for minority shareholders because of illiquid stock

•

Offers where we believe there is a reasonable prospect for an enhanced bid or other bidders

•

The current market price of the security exceeds the bid price at the time of voting

We will actively seek direct dialogue with the board and management of companies that we have identified through our screening processes. Such engagements may lead to further monitoring to ensure the company improves its governance or sustainability practices. In these cases, the engagement process represents the most meaningful opportunity for State Street Global Advisors to protect long-term shareholder value from excessive risk due to poor governance and sustainability practices.


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Proxy Voting and Engagement Guidelines

Remuneration

We consider it to be the board’s responsibility to set appropriate levels of executive remuneration. Despite the differences among the types of plans and the potential awards, there is a simple underlying philosophy that guides our analysis of executive remuneration; there should be a direct relationship between executive compensation and company performance over the long term. In emerging markets, we encourage companies to disclose information on senior executive remuneration.

With regard to director remuneration, we support director pay provided the amounts are not excessive relative to other issuers in the market or industry and are not overly dilutive to existing shareholders.

Environmental and Social Issues

with issuers. When voting, we fundamentally consider whether the adoption of a shareholder proposal addressing a material sustainability issue would promote long-term shareholder value in the context of the company’s existing practices and disclosures as well as existing market practice.

General/Routine Issues

Some of the other issues that are routinely voted on in emerging markets include approving the allocation of income and accepting financial statements and statutory reports. For these voting items, our guidelines consider several factors, such as historical dividend payouts, pending litigation, governmental investigations, charges of fraud, or other indication of significant concerns.

More Information

Any client who wishes to receive information on how its proxies were voted should contact its State Street Global Advisors relationship manager.


State Street Global Advisors		C-49

Proxy Voting and Engagement Guidelines

ssga.com

State Street Global Advisors Worldwide Entities

Rogerson’s Quay, Dublin 2. Registered number 145221. T: +353 (0)1 776 3000. F: +353 (0)1 776 3300. Italy: State Street Global Advisors Ireland Limited, Milan Branch (Sede Secondaria di Milano) is a branch of State Street Global Advisors Ireland Limited, registered in Ireland with company number 145221, authorized and regulated by the Central Bank of Ireland, and whose registered office is at 78 Sir John Rogerson’s Quay, Dublin 2. State Street Global Advisors Ireland Limited, Milan Branch (Sede Secondaria di Milano), is registered in Italy with company number 10495250960 - R.E.A. 2535585 and VAT number 10495250960 and whose office is at Via dei Bossi, 4 - 20121 Milano, Italy. T: +39 02 32066 100. F: +39 02 32066 155. Japan: State Street Global Advisors (Japan) Co., Ltd., Toranomon Hills Mori Tower 25F 1-23-1 Toranomon, Minato-ku, Tokyo 105-6325 Japan, T: +81-3-4530-7380 Financial Instruments Business Operator, Kanto Local Financial Bureau (Kinsho #345) , Membership: Japan Investment Advisers Association, The Investment Trust Association, Japan, Japan Securities Dealers’ Association. Netherlands: State Street Global Advisors Netherlands, Apollo Building, 7th floor Herikerbergweg 29 1101 CN Amsterdam, Netherlands. Telephone: 31 20 7181701. SSGA Netherlands is a branch office of State Street Global Advisors Ireland Limited, registered in Ireland with company number 145221, authorized and regulated by the Central Bank of Ireland, and whose registered office is at 78 Sir John Rogerson’s Quay, Dublin 2. Singapore: State Street Global Advisors Singapore Limited, 168, Robinson Road, #33-01 Capital Tower, Singapore 068912 (Company Reg. No: 200002719D, regulated by the Monetary Authority of Singapore). Telephone: +65 6826 7555. F: +65 6826 7501. Switzerland: State Street Global Advisors AG, Beethovenstr. 19, CH-8027 Zurich. Authorized and regulated by the Eidgenössische Finanzmarktaufsicht (“FINMA”). Registered with the Register of Commerce Zurich CHE-105.078.458. T: +41 (0)44 245 70 00. Facsimile F: +41 (0)44 245 70 16. United Kingdom: State Street Global Advisors Limited. Authorized and regulated by the Financial Conduct Authority. Registered in England. Registered No. 2509928. VAT No. 5776591 81. Registered office: 20 Churchill Place, Canary Wharf, London, E14 5HJ. T: 020 3395 6000. F: 020 3395 6350. United States: State Street Global Advisors, One Iron Street, Boston MA 02210. T: +1 617 786 3000.

Investing involves risk including the risk of loss of principal.

The whole or any part of this work may not be reproduced, copied or transmitted or any of its contents disclosed to third parties without State Street Global Advisors’ express written consent.

State Street Global Advisors

C-50

ID15918 0319 Exp. Date: 03/31/2020

STATE STREET INSTITUTIONAL INVESTMENT TRUST

(the “Trust”)

One Iron Street

Boston, Massachusetts 02210


FUND	TICKER
STATE STREET EQUITY 500 INDEX II PORTFOLIO		SSEYX
STATE STREET AGGREGATE BOND INDEX PORTFOLIO		SSAFX
STATE STREET GLOBAL EQUITY EX-U.S. INDEX PORTFOLIO		SSGVX
STATE STREET SMALL/MID CAP EQUITY INDEX PORTFOLIO		SSMHX
STATE STREET ULTRA SHORT TERM BOND PORTFOLIO		SSTEX

STATEMENT OF ADDITIONAL INFORMATION

April 30, 2019

This Statement of Additional Information (“SAI”) relates to the prospectuses dated April 30, 2019, as may be revised and/or supplemented from time to time thereafter, for each of the Portfolios listed above (each, a “Prospectus” and collectively, the “Prospectuses”).

The SAI is not a prospectus and should be read in conjunction with the Prospectuses. A copy of each Prospectus can be obtained free of charge by calling (866) 392-0869 or by written request to the Trust at the address listed above.

The Trust’s audited financial statements for the fiscal year ended December 31, 2018, including the independent registered public accounting firm reports thereon, are included in the Trust’s annual reports and are incorporated into this SAI by reference. Copies of the Trust’s annual reports and semiannual reports are available, without charge, upon request, by calling (866) 392-0869 or by written request to the Trust at the address above.

TABLE OF CONTENTS


General			3

Description of the Portfolios and Their Investments and Risks			4

Additional Investments and Risks			4

Management of the Trust			28

Proxy Voting Procedures			37

Control Persons and Principal Holders of Securities			37

Investment Advisory and Other Services			39

Portfolio Managers			42

Brokerage Allocation and Other Practices			44

Declaration of Trust, Capital Stock and Other Information			46

Pricing of Shares			47

Taxation of the Portfolios			47

Underwriter			57

Financial Statements			58

Appendix A - Ratings of Debt Instruments			A-1

Appendix B - Trust’s Proxy Voting Procedures			B-1

Appendix C - Adviser’s Proxy Voting Procedures and Guidelines			C-1

GENERAL

The Trust was organized as a business trust under the laws of The Commonwealth of Massachusetts on February 16, 2000.

The Trust is an open-end management investment company. The Trust includes the following diversified series:

•

State Street Equity 500 Index Fund;

•

State Street Aggregate Bond Index Fund;

•

State Street Institutional Liquid Reserves Fund;

•

State Street Institutional U.S. Government Money Market Fund;

•

State Street Institutional Treasury Money Market Fund;

•

State Street Institutional Treasury Plus Money Market Fund;

•

State Street Treasury Obligations Money Market Fund;

•

State Street Target Retirement Fund;

•

State Street Target Retirement 2015 Fund;

•

State Street Target Retirement 2020 Fund;

•

State Street Target Retirement 2025 Fund;

•

State Street Target Retirement 2030 Fund;

•

State Street Target Retirement 2035 Fund;

•

State Street Target Retirement 2040 Fund;

•

State Street Target Retirement 2045 Fund;

•

State Street Target Retirement 2050 Fund;

•

State Street Target Retirement 2055 Fund;

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State Street Target Retirement 2060 Fund;

•

State Street Global Equity ex-U.S. Index Fund;

•

State Street Emerging Markets Equity Index Fund;

•

State Street Equity 500 Index II Portfolio (the “Equity 500 Index II Portfolio”);

•

State Street Aggregate Bond Index Portfolio (the “Aggregate Bond Index Portfolio”);

•

State Street Global Equity ex-U.S. Index Portfolio (the “Global Equity ex-U.S. Index Portfolio”);

•

State Street Hedged International Developed Equity Index Fund;

•

State Street International Developed Equity Index Fund;

•

State Street Small/Mid Cap Equity Index Fund;

•

State Street Small/Mid Cap Equity Index Portfolio (the “Small/Mid Cap Equity Index Portfolio”);

•

State Street Cash Reserves Fund

•

State Street Cash Reserves Portfolio

•

State Street Ultra Short Term Bond Fund;

•

State Street Ultra Short Term Bond Portfolio (the “Ultra Short Term Bond Portfolio”);

•

State Street Defensive Global Equity Fund;

The Trust includes the following non-diversified series:

•

State Street International Value Spotlight Fund.

•

State Street China Equity Select Fund

The Equity 500 Index II Portfolio, the Aggregate Bond Index Portfolio, the Global Equity ex-U.S. Index Portfolio, the Small/Mid Cap Equity Index Portfolio and the Ultra Short Term Bond Portfolio are referred to in this SAI as the “Portfolios,” and each Portfolio may be referred to in context as the “Portfolio.”

The Equity 500 Index II Portfolio, Aggregate Bond Index Portfolio, Global Equity ex-U.S. Index Portfolio, and the Small/Mid Cap Equity Index Portfolio are referred to in this SAI as the “Index Portfolios.”

DESCRIPTION OF THE PORTFOLIOS AND THEIR INVESTMENTS AND RISKS

Each Portfolio’s Prospectus contains information about the investment objective and policies of that Portfolio. This SAI should only be read in conjunction with the Prospectus of the Portfolio or Portfolios in which you intend to invest.

In addition to the principal investment strategies and the principal risks of the Portfolios described in each Portfolio’s Prospectus, a Portfolio may employ other investment practices and may be subject to additional risks, which are described below.

Additional Information Concerning the MSCI All Country World Index ex USA (the “MSCI Index”)

The Global Equity ex-U.S. Index Portfolio is not sponsored, endorsed, sold or promoted by Morgan Stanley Capital International Inc. (“MSCI”). MSCI makes no representation or warranty, express or implied, to the owners of shares of the Global Equity ex-U.S. Index Portfolio or any member of the public regarding the advisability of investing in securities generally or in the Global Equity ex-U.S. Index Portfolio particularly or the ability of the MSCI Index to track general performance. MSCI’s only relationship to the Global Equity ex-U.S. Index Portfolio is the licensing of certain trademarks and trade names of MSCI and of the MSCI Index, which is determined, composed and calculated by MSCI without regard to the Global Equity ex-U.S. Index Portfolio. MSCI has no obligation to take the needs of the Global Equity ex-U.S. Index Portfolio or the owners of shares of the Global Equity ex-U.S. Index Portfolio into consideration in determining, composing or calculating the MSCI Index. MSCI is not responsible for and has not participated in the determination of the price and number of shares of the Global Equity ex-U.S. Index Portfolio or the timing of the issuance or sale of shares of Global Equity ex-U.S. Index Portfolio, or calculation of the equation by which shares of the Global Equity ex-U.S. Index Portfolio are redeemable for cash. MSCI has no obligation or liability in connection with the administration, marketing or trading of shares of the Global Equity ex-U.S. Index Portfolio.

MSCI does not guarantee the accuracy or the completeness of the MSCI Index or any data included therein and MSCI shall have no liability for any errors, omissions or interruptions therein. MSCI makes no warranty, express or implied, as to results to be obtained by the Global Equity ex-U.S. Index Portfolio, owners of shares of the Global Equity ex-U.S. Index Portfolio or any other person or entity from the use of the MSCI Index or any data included therein. MSCI makes no express or implied warranties, and expressly disclaims all warranties of merchantability or fitness for a particular purpose or use with respect to the MSCI Index or any data included therein. Without limiting any of the foregoing, in no event shall MSCI have any liability for any special, punitive, indirect or consequential damages (including lost profits), even if notified of the possibility of such damages.

ADDITIONAL INVESTMENTS AND RISKS

To the extent consistent with its investment objective and restrictions, each Portfolio may invest in the following instruments and use the following techniques, and is subject to the following additional risks.

Auction Rate Securities

The Portfolios, except for the Small/Mid Cap Equity Index Portfolio, may invest in auction rate municipal securities, which permit the holder to sell the securities in an auction at par value at specified intervals. The dividend or interest is typically reset by “Dutch” auction in which bids are made by broker-dealers and other institutions for a certain amount of securities at a specified minimum yield. The rate set by the auction is the lowest interest or dividend rate that covers all securities offered for sale. While this process is designed to permit auction rate securities to be traded at par value, there is the risk that an auction will fail due to insufficient demand for the securities. A Portfolio will take the time remaining until the next scheduled auction date into account for purposes of determining the securities’ duration.

Bonds

The Portfolios, except for the Small/Mid Cap Equity Index Portfolio, may invest a portion of their assets in bonds. A bond is an interest-bearing security issued by a company, governmental unit or, in some cases, a non-U.S. entity. The issuer of a bond has a contractual obligation to pay interest at a stated rate on specific dates and to repay principal (the bond’s face value) periodically or on

a specified maturity date; provided, however, a zero coupon bond pays no interest to its holder during its life. The value of a zero coupon bond to a Portfolio consists of the difference between such bond’s face value at the time of maturity and the price for which it was acquired, which may be an amount significantly less than its face value (sometimes referred to as a “deep discount” price).

An issuer may have the right to redeem or “call” a bond before maturity, in which case the investor may have to reinvest the proceeds at lower market rates. Most bonds bear interest income at a “coupon” rate that is fixed for the life of the bond. The value of a fixed rate bond usually rises when market interest rates fall, and falls when market interest rates rise. Accordingly, a fixed rate bond’s yield (income as a percent of the bond’s current value) may differ from its coupon rate as its value rises or falls. Fixed rate bonds generally are also subject to inflation risk, which is the risk that the value of the bond or income from the bond will be worth less in the future as inflation decreases the value of money. This could mean that, as inflation increases, the “real” value of the assets of a Portfolio holding fixed rate bonds can decline, as can the value of the Portfolio’s distributions. Other types of bonds bear income at an interest rate that is adjusted periodically. Because of their adjustable interest rates, the value of “floating-rate” or “variable-rate” bonds fluctuates much less in response to market interest rate movements than the value of fixed rate bonds. A Portfolio may treat some of these bonds as having a shorter maturity for purposes of calculating the weighted average maturity of its investment portfolio. Bonds may be senior or subordinated obligations. Senior obligations generally have the first claim on a corporation’s earnings and assets and, in the event of liquidation, are paid before subordinated obligations. Bonds may be unsecured (backed only by the issuer’s general creditworthiness) or secured (also backed by specified collateral).

The investment return of corporate bonds reflects interest on the bond and changes in the market value of the bond. The market value of a corporate bond may be affected by the credit rating of the corporation, the corporation’s performance and perceptions of the corporation in the market place. There is a risk that the issuers of the securities may not be able to meet their obligations on interest or principal payments at the time called for by such a security.

Cash Reserves

Each Portfolio may hold portions of its assets in cash or short-term debt instruments with remaining maturities of 397 days or less pending investment or to meet anticipated redemptions and day-to-day operating expenses. Short-term debt instruments consist of: (i) short-term obligations of the U.S. Government, its agencies, instrumentalities, authorities or political subdivisions; (ii) other short-term debt securities rated at the time of purchase Aa or higher by Moody’s Investors Service, Inc. (“Moody’s”) or AA or higher by S&P or, if unrated, of comparable quality in the opinion of SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”); (iii) commercial paper; (iv) bank obligations, including negotiable certificates of deposit, time deposits and bankers’ acceptances; and (v) repurchase agreements.

Cleared Derivatives Transactions

Transactions in some types of swaps are required to be centrally cleared. In a cleared derivatives transaction, a Portfolio’s counterparty to the transaction is a central derivatives clearing organization, or clearing house, rather than a bank or broker. Because the Portfolios are not members of a clearing house, and only members of a clearing house can participate directly in the clearing house, the Portfolios hold cleared derivatives through accounts at clearing members. In cleared derivatives transactions, a Portfolio will make payments (including margin payments) to and receive payments from a clearing house through its accounts at clearing members. Clearing members guarantee performance of their clients’ obligations to the clearing house. Centrally cleared derivative arrangements may be less favorable to a Portfolio than bilateral (non-cleared) arrangements. For example, a Portfolio may be required to provide greater amounts of margin for cleared derivatives transactions than for bilateral derivatives transactions. Also, in contrast to bilateral derivatives transactions, in some cases following a period of notice to a Portfolio, a clearing member generally can require termination of existing cleared derivatives transactions at any time or an increase in margin requirements above the margin that the clearing member required at the beginning of a transaction. Clearing houses also have broad rights to increase margin requirements for existing transactions or to terminate transactions at any time. A Portfolio is subject to risk if it enters into a derivatives transaction that is required to be cleared (or which the Adviser expects to be cleared), and no clearing member is willing or able to clear the transaction on a Portfolio’s behalf. In that case, the transaction might have to be terminated, and a Portfolio could lose some or all of the benefit of the transaction, including loss of an increase in the value of the transaction and loss of hedging protection. In addition, the documentation governing the relationship between a Portfolio and clearing members is drafted by the clearing members and generally is less favorable to a Portfolio than typical bilateral derivatives documentation. For example, documentation relating to cleared derivatives generally includes a one-way indemnity by the Portfolio in favor of the clearing member for losses the clearing member incurs as the Portfolio’s clearing member. Also, such documentation typically does not provide the Portfolio any remedies if the clearing member defaults or becomes insolvent.

Counterparty risk with respect to derivatives has been and will continue to be affected by new rules and regulations relating to the derivatives market. With respect to a centrally cleared transaction, a party is subject to the credit risk of the clearing house and the clearing member through which it holds its cleared position. Credit risk of market participants with respect to centrally cleared derivatives is concentrated in a few clearing houses, and it is not clear how an insolvency proceeding of a clearing house would be conducted and what impact an insolvency of a clearing house would have on the financial system. A clearing member is obligated by contract and regulation to segregate all funds received from customers with respect to cleared derivatives positions from the clearing member’s proprietary assets. However, all funds and other property received by a clearing member from its customers with respect to cleared derivatives are generally held by the clearing member on a commingled basis in an omnibus account (which can be invested in instruments permitted under the regulations). Therefore, a Portfolio might not be fully protected in the event of the bankruptcy of the Portfolio’s clearing member because the Portfolio would be limited to recovering only a pro rata share of the funds held by the clearing member on behalf of customers, with a claim against the clearing member for any deficiency. Also, the clearing member is required to transfer to the clearing house the amount of margin required by the clearing house for cleared derivatives, which amount is generally held in an omnibus account at the clearing house for all customers of the clearing member. Regulations promulgated by the Commodity Futures Trading Commission (the “CFTC”) require that the clearing member notify the clearing house of the initial margin provided by the clearing member to the clearing house that is attributable to each customer. However, if the clearing member does not accurately report the Portfolio’s initial margin, the Portfolio is subject to the risk that a clearing house will use the assets attributable to it in the clearing house’s omnibus account to satisfy payment obligations a defaulting customer of the clearing member has to the clearing house. In addition, clearing members generally provide the clearing house the net amount of variation margin required for cleared swaps for all of its customers, rather than individually for each customer. A Portfolio is therefore subject to the risk that a clearing house will not make variation margin payments owed to the Portfolio if another customer of the clearing member has suffered a loss and is in default, and the risk that the Portfolio will be required to provide additional variation margin to the clearing house before the clearing house will move the Portfolio’s cleared derivatives positions to another clearing member. In addition, if a clearing member does not comply with the applicable regulations or its agreement with the Portfolio, or in the event of fraud or misappropriation of customer assets by a clearing member, the Portfolio could have only an unsecured creditor claim in an insolvency of the clearing member with respect to the margin held by the clearing member.

Swap Execution Facilities

Certain derivatives contracts are required to be executed through swap execution facilities (“SEFs”). A SEF is a trading platform where multiple market participants can execute derivatives by accepting bids and offers made by multiple other participants in the platform. Such requirements may make it more difficult and costly for investment funds, such as a Portfolio, to enter into highly tailored or customized transactions. Trading swaps on a SEF may offer certain advantages over traditional bilateral over-the-counter trading, such as ease of execution, price transparency, increased liquidity and/or favorable pricing. Execution through a SEF is not, however, without additional costs and risks, as parties are required to comply with SEF and CFTC rules and regulations, including disclosure and recordkeeping obligations, and SEF rights of inspection, among others. SEFs typically charge fees, and if a Portfolio executes derivatives on a swap execution facility through a broker intermediary, the intermediary may impose fees as well. A Portfolio also may be required to indemnify a SEF, or a broker intermediary who executes swaps on a SEF on the Portfolio’s behalf, against any losses or costs that may be incurred as a result of the Portfolio’s transactions on the SEF. In addition, a Portfolio may be subject to execution risk if it enters into a derivatives transaction that is required to be cleared, and no clearing member is willing to clear the transaction on the Portfolio’s behalf. In that case, the transaction might have to be terminated, and the Portfolio could lose some or all of the benefit of any increase in the value of the transaction after the time of the trade.

Risks Associated with Derivatives Regulation

The U.S. government has enacted legislation that provides for new regulation of the derivatives market, including clearing, margin, reporting, and registration requirements. The European Union and some other countries are implementing similar requirements, which will affect a Portfolio when it enters into a derivatives transaction with a counterparty organized in that country or otherwise subject to that country’s derivatives regulations. Clearing rules and other new rules and regulations could, among other things, restrict a Portfolio’s ability to engage in, or increase the cost to a Portfolio of, derivatives transactions, for example, by making some types of derivatives no longer available to the Portfolio, increasing margin or capital requirements, or otherwise limiting liquidity or increasing transaction costs. While the new rules and regulations and central clearing of some derivatives transactions are designed to reduce systemic risk (i.e., the risk that the interdependence of large derivatives dealers could cause them to suffer liquidity, solvency or other challenges simultaneously), there is no assurance that they will achieve that result, and in the meantime, as noted above, central clearing and related requirements expose the Portfolios to new kinds of costs and risks.

These and other regulations are new and evolving, so their potential impact on the Portfolios and the financial system are not yet known.

Commodities

General . The Index Portfolios may invest in commodities. There are several additional risks associated with transactions in commodity futures contracts, swaps on commodity futures contracts, commodity forward contracts and other commodities instruments. In the commodity instruments markets, producers of the underlying commodity may decide to hedge the price risk of selling the commodity by selling commodity instruments today to lock in the price of the commodity at delivery tomorrow. In order to induce speculators to purchase the other side of the same commodity instrument, the commodity producer generally must sell the commodity instrument at a lower price than the expected future spot price. Conversely, if most hedgers in the commodity instruments market are purchasing commodity instruments to hedge against a rise in prices, then speculators will only sell the other side of the commodity instrument at a higher future price than the expected future spot price of the commodity. The changing nature of the hedgers and speculators in the commodity markets will influence whether futures prices are above or below the expected future spot price, which can have significant implications for the Portfolios. If the nature of hedgers and speculators in commodity instruments markets has shifted when it is time for a Portfolio to reinvest the proceeds of a maturing contract in a new commodity instrument, the Portfolio might reinvest at a higher or lower future price, or choose to pursue other investments. The commodities which underlie commodity instruments may be subject to additional economic and non-economic variables, such as drought, floods, weather, livestock disease, embargoes, tariffs, and international economic, political and regulatory developments. These factors may have a larger impact on commodity prices and commodity-linked instruments than on traditional securities. Certain commodities are also subject to limited pricing flexibility because of supply and demand factors. Others are subject to broad price fluctuations as a result of the volatility of the prices for certain raw materials and the instability of supplies of other materials. These additional variables may create additional investment risks which subject a Portfolio’s investments to greater volatility than other investments. Also, unlike the financial instruments markets, in the commodity instruments markets there are costs of physical storage associated with purchasing the underlying commodity. The price of the commodity instruments contract will reflect the storage costs of purchasing the physical commodity, including the time value of money invested in the physical commodity. To the extent that the storage costs for an underlying commodity change while a Portfolio is invested in instruments on that commodity, the value of the commodity instrument may change proportionately.

A Portfolio’s ability to invest in commodity-linked investments may be limited by the Portfolio’s intention to qualify as a regulated investment company (“RIC”) under the Internal Revenue Code of 1986, as amended (the “Code”) and could bear on the ability of a Portfolio to so qualify. See “Taxation of the Portfolios” below.

Commodity-Linked Investments . The Index Portfolios may invest in commodity-linked investments. The Portfolios may seek to provide exposure to the investment returns of real assets that trade in the commodity markets through commodity-linked derivative securities, such as structured notes, discussed below, which are designed to provide this exposure without direct investment in physical commodities or commodities futures contracts. Real assets are assets such as oil, gas, industrial and precious metals, livestock, and agricultural or meat products, or other items that have tangible properties, as compared to stocks or bonds, which are financial instruments. In choosing investments, the Adviser seeks to provide exposure to various commodities and commodity sectors. The value of commodity-linked derivative securities held by a Portfolio may be affected by a variety of factors, including, but not limited to, overall market movements and other factors affecting the value of particular industries or commodities, such as weather, disease, embargoes, acts of war or terrorism, or political and regulatory developments.

historically tended to increase. Of course, there cannot be any guarantee that these investments will perform in that manner in the future, and at certain times the price movements of commodity-linked instruments have been parallel to those of debt and equity securities. Commodities have historically tended to increase and decrease in value during different parts of the business cycle than financial assets. Nevertheless, at various times, commodities prices may move in tandem with the prices of financial assets and thus may not provide overall portfolio diversification benefits. Under favorable economic conditions, a Portfolio’s investments may be expected to underperform an investment in traditional securities. Over the long term, the returns on the Portfolio’s investments are expected to exhibit low or negative correlation with stocks and bonds.

Because commodity-linked investments are available from a relatively small number of issuers, a Portfolio’s investments will be particularly subject to counterparty risk, which is the risk that the issuer of the commodity-linked derivative (which issuer may also serve as counterparty to a substantial number of the Portfolio’s commodity-linked and other derivative investments) will not fulfill its contractual obligations.

A Portfolio’s ability to invest in commodity-linked investments may be limited by the Portfolio’s intention to qualify as a RIC and could bear on the ability of a Portfolio to so qualify. See “Taxation of the Portfolios” below.

Credit Default Swaps and Total Return Swaps

The Portfolios, except for the Small/Mid Cap Equity Index Portfolio and the Ultra Short Term Bond Portfolio, may enter into a credit default swap or a total return swap to gain market exposure, manage liquidity, increase total returns or for hedging purposes. Credit default swaps and total return swaps are typically governed by the standard terms and conditions of an ISDA Master Agreement.

A credit default swap involves a protection buyer and a protection seller. A Portfolio may be either a protection buyer or seller. The protection buyer in a credit default swap makes periodic premium payments to the protection seller during the swap term in exchange for the protection seller agreeing to make certain defined payments to the protection buyer in the event certain defined credit events occur with respect to a particular security, issuer or basket of securities. A total return swap involves a total return receiver and a total return payor. A Portfolio may either be a total return receiver or payor. Generally, the total return payor sells to the total return receiver an amount equal to all cash flows and price appreciation on a defined security or asset payable at periodic times during the swap term (i.e., credit risk) in return for a periodic payment from the total return receiver based on a designated interest rate (e.g., LIBOR) and spread plus the amount of any price depreciation on the reference security or asset. The total return payor does not need to own the underlying security or asset to enter into a total return swap. The final payment at the end of the swap term includes final settlement of the current market price of the underlying reference security or asset, and payment by the applicable party for any appreciation or depreciation in value. Usually, collateral must be posted by the total return receiver to secure the periodic interest-based and market price depreciation payments depending on the credit quality of the underlying reference security and creditworthiness of the total return receiver, and the collateral amount is marked-to-market daily equal to the market price of the underlying reference security or asset between periodic payment dates.

In both credit default swaps and total return swaps, the same general risks inherent to derivative transactions are present; however, the use of credit default swaps and total return swaps can involve greater risks than if a Portfolio had invested in the reference obligation directly since, in addition to general market risks, credit default swaps and total return swaps are subject to counterparty credit risk, leverage risk, hedging risk, correlation risk and liquidity risk. A Portfolio will enter into a credit default swap or a total return swap only with counterparties that the Adviser determines to meet certain standards of creditworthiness. In a credit default swap, a buyer generally also will lose its premium and recover nothing should no credit event occur and the swap is held to its termination date. If a credit event were to occur, the value of any deliverable obligation received by the seller, coupled with the upfront or periodic payments previously received, may be less than the full notional value it pays to the buyer, resulting in a loss of value to the seller. A Portfolio’s obligations under a credit default swap agreement will be accrued daily (offset against any amounts owing to the Portfolio).

Swaps are highly specialized instruments that require investment techniques, risk analyses, and tax planning different from those associated with the ownership of stocks, bonds, and other traditional investments. The use of a swap agreement requires an understanding not only of the referenced obligation, reference rate, or index, but also of the swap agreement itself. Because some swap agreements have a leverage component, adverse changes in the value or level of the underlying asset, reference rate, or index can result in a loss substantially greater than the amount invested in the swap itself. Certain swaps have the potential for unlimited loss, regardless of the size of the initial investment.

When effecting such transactions, cash or other liquid assets held by a Portfolio of a dollar amount sufficient to meet a Portfolio’s obligations under the swap agreement will be segregated on the Portfolio’s records at the trade date and maintained until the transaction is settled. Such segregated assets will be marked to market on a daily basis, and if the market value of such assets declines, additional cash or other assets will be segregated so that the market value of the segregated assets will equal the amount of such Portfolio’s obligations under the swap agreement.

A Portfolio’s exposure under a credit default swap may be considered leverage and be subject to the risks associated with derivative investments, including liquidity risk and counterparty risk.

Custodial Risk

Eurodollar Certificates of Deposit (“ECDs”), Eurodollar Time Deposits (“ETDs”) and Yankee Certificates of Deposit (“YCDs”)

The Portfolios, except for the Small/Mid Cap Equity Index Portfolio, may invest in ECDs, ETDs and YCDs. ECDs and ETDs are U.S. dollar denominated certificates of deposit and time deposits, respectively, issued by non-U.S. branches of domestic banks and non-U.S. banks. YCDs are U.S. dollar denominated certificates of deposit issued by U.S. branches of non-U.S. banks.

Different risks than those associated with the obligations of domestic banks may exist for ECDs, ETDs and YCDs because the banks issuing these instruments, or their domestic or non-U.S. branches, are not necessarily subject to the same regulatory requirements that apply to domestic banks, such as loan limitations, examinations and reserve, accounting, auditing, recordkeeping and public reporting requirements. Obligations of non-U.S. issuers also involve risks such as future unfavorable political and economic developments, withholding or other taxes, seizures of non-U.S. deposits, currency controls, interest limitations, and other governmental restrictions that might affect repayment of principal or payment of interest, or the ability to honor a credit commitment.

Foreign Currency Transactions and Foreign Currency Derivatives

The Portfolios, except for the Small/Mid Cap Equity Index Portfolio and the Ultra Short Term Bond Portfolio, may enter into a variety of different foreign currency transactions, including, by way of example, currency forward transactions, spot transactions, futures and forward contracts, swaps, or options. Most of these transactions are entered into “over the counter,” and a Portfolio assumes the risk that the counterparty may be unable or unwilling to perform its obligations, in addition to the risk of unfavorable or unanticipated changes in the values of the currencies underlying the transactions. Certain types of over-the-counter currency transactions may be uncollateralized, and a Portfolio may not be able to recover all or any of the assets owed to it under such transactions if its counterparty should default. In some markets or in respect of certain currencies, a Portfolio may be required, or agree, in SSGA FM’s discretion, to enter into foreign currency transactions via the custodian’s relevant sub-custodian. SSGA FM may be subject to a conflict of interest in agreeing to any such arrangements on behalf of the Portfolio. Such transactions executed directly with the sub-custodian are executed at a rate determined solely by such sub-custodian. Accordingly, a Portfolio may not receive the best pricing of such currency transactions. Regulatory changes in a number of jurisdictions may require that certain currency transactions be subject to central clearing, or be subject to new or increased collateral requirements. These changes could increase the costs of currency transactions to a Portfolio and may make certain transactions unavailable; they may also increase the credit risk of such transactions to a Portfolio.

Foreign Securities

The Index Portfolios are permitted to invest in foreign securities. Foreign securities include securities of foreign companies and foreign governments (or agencies or subdivisions thereof). If a Portfolio’s securities are held abroad, the countries in which such securities may be held and the sub-custodian holding them must be approved by the Board of Trustees of the Trust (the “Board of Trustees” or the “Board”) or its delegate under applicable rules adopted by the Securities and Exchange Commission (“SEC”). In buying foreign securities, a Portfolio may convert U.S. dollars into foreign currency, but only to effect securities transactions on foreign securities exchanges and not to hold such currency as an investment.

The globalization and integration of the world economic system and related financial markets have made it increasingly difficult to define issuers geographically. Accordingly, each Portfolio intends to construe geographic terms such as “foreign,” “non-U.S.” “European,” “Latin American,” and “Asian,” in the manner that affords to the Portfolio the greatest flexibility in seeking to achieve its investment objective(s). Specifically, in circumstances where the investment objective and/or strategy is to invest at least some percentage of a Portfolio’s assets in foreign securities, etc., the Portfolios will take the view that a security meets this description so long as the issuer of a security is tied economically to the particular country or geographic region indicated by words of the relevant investment objective and/or strategy (the “Relevant Language”). For these purposes the issuer of a security is deemed to have that tie if:

(i)

The issuer is organized under the laws of the country or a country within the geographic region suggested by the Relevant Language or maintains its principal place of business in that country or region; or

(ii)

The securities are traded principally in the country or region suggested by the Relevant Language; or

(iii)

The issuer, during its most recent fiscal year, derived at least 50% of its revenues or profits from goods produced or sold, investments made, or services performed in the country or region suggested by the Relevant Language or has at least 50% of its assets in that country or region.

In addition, the Portfolios intend to treat derivative securities (e.g., call options) by reference to the underlying security. Conversely, if the investment objective and/or strategy of a Portfolio limits the percentage of assets that may be invested in “foreign securities,” etc. or prohibits such investments altogether, the Portfolios intend to categorize securities as “foreign,” etc. only if the security possesses all of the attributes described above in clauses (i), (ii) and (iii).

Investments in foreign securities involve special risks and considerations. As foreign companies are not generally subject to uniform accounting, auditing and financial reporting standards, practices and requirements comparable to those applicable to domestic companies, there may be less publicly available information about a foreign company than about a domestic company. For example, foreign markets have different clearance and settlement procedures. Delays in settlement could result in temporary periods when assets of the Portfolios are uninvested. The inability of a Portfolio to make intended security purchases due to settlement problems could cause it to miss certain investment opportunities. They may also entail certain other risks, such as the possibility of one or more of the following: imposition of dividend or interest withholding or other taxes (in each case, which taxes could potentially be confiscatory), higher brokerage costs, thinner trading markets, currency blockages or transfer restrictions, expropriation, nationalization, military coups or other adverse political or economic developments; less government supervision and regulation of securities exchanges, brokers and listed companies; and the difficulty of enforcing obligations in other countries. Purchases of foreign securities are usually made in foreign currencies and, as a result, a Portfolio may incur currency conversion costs and may be affected favorably or unfavorably by changes in the value of foreign currencies against the U.S. dollar. Further, it may be more difficult for the Portfolios’ agents to keep currently informed about corporate actions which may affect the prices of portfolio securities. Communications between the United States and foreign countries may be less reliable than within the United States, thus increasing the risk of delayed settlements of portfolio transactions or loss of certificates for portfolio securities. Certain markets may require payment for securities before delivery. Each Portfolio’s ability and decisions to purchase and sell portfolio securities may be affected by laws or regulations relating to the convertibility of currencies and repatriation of assets.

A number of current significant political, demographic and economic developments may affect investments in foreign securities and in securities of companies with operations overseas. Such developments include dramatic political changes in government and economic policies in several Eastern European countries and the republics composing the former Soviet Union, as well as the unification of the European Economic Community. The course of any one or more of these events and the effect on trade barriers, competition and markets for consumer goods and services are uncertain. Similar considerations are of concern with respect to developing countries. For example, the possibility of revolution and the dependence on foreign economic assistance may be greater in these countries than in developed countries. Management seeks to mitigate the risks associated with these considerations through diversification and active professional management.

Forward Commitments

Each Portfolio may invest in forward commitments. Each Portfolio may contract to purchase securities for a fixed price at a future date beyond customary settlement time consistent with the Portfolio’s ability to manage its investment portfolio and meet redemption requests. A Portfolio may dispose of a commitment prior to settlement if it is appropriate to do so and realize short-term profits or losses upon such sale. When effecting such transactions, cash or other liquid assets (such as liquid high quality debt obligations) held by a Portfolio of a dollar amount sufficient to make payment for the portfolio securities to be purchased will be segregated on the Portfolio’s records at the trade date and maintained until the transaction is settled. Such segregated assets will be marked to market on a daily basis, and if the market value of such assets declines, additional cash or assets will be segregated so that the market value of the segregated assets will equal the amount of such Portfolio’s obligations. Forward commitments involve a risk of loss if the value of the security to be purchased declines prior to the settlement date, or if the other party fails to complete the transaction.

Futures Contracts and Options on Futures

Each Index Portfolio may enter into futures contracts on securities in which it may invest or on indices comprised of such securities and may purchase and write call and put options on such contracts.

Futures contracts. A financial futures contract is a contract to buy or sell a specified quantity of financial instruments such as U.S. Treasury bills, notes and bonds at a specified future date at a price agreed upon when the contract is made. An index futures contract is a contract to buy or sell specified units of an index at a specified future date at a price agreed upon when the contract is made. The value of a unit is based on the current value of the index. Under such contracts no delivery of the actual securities making up the index takes place. Rather, upon expiration of the contract, settlement is made by exchanging cash in an amount equal to the difference between the contract price and the closing price of the index at expiration, net of variation margin previously paid. Futures contracts are traded in the United States only on commodity exchanges or boards of trade — known as “contract markets” — approved for such trading by the CFTC, and must be executed through a futures commission merchant or brokerage firm which is a member of the relevant contract market.

Although many futures contracts by their terms call for actual delivery or acceptance of commodities or securities, in most cases the contracts are closed out before the settlement date without the making or taking of delivery, but rather by entering into an offsetting contract (a “closing transaction”). Upon entering into a futures contract, a Portfolio is required to deposit initial margin with the Fund’s futures commission merchant. The initial margin serves as a “good faith” deposit that a Portfolio will honor its potential future commitments. Subsequent payments (called “variation margin” or “maintenance margin”) to and from the broker are made on a daily basis as the price of the underlying security or commodity fluctuates, making the long and short positions in the futures contract more or less valuable, a process known as “marking to the market.” If a Portfolio is unable to enter into a closing transaction, the amount of the Portfolio’s potential loss may be unlimited. Futures contracts also involve brokerage costs.

Each Portfolio will not commit more than 5% of the market value of its total assets to initial margin deposits on futures and premiums paid for options on futures.

Registration under the Commodity Exchange Act.

The Portfolios are operated by persons who have claimed an exclusion from the definition of the term “commodity pool operator” with respect to the Portfolios under the Commodity Exchange Act (the “CEA”), and therefore, are not subject to registration or regulation as a commodity pool operator under the CEA. As a result, the Portfolios are limited in their ability to trade instruments subject to the CFTC’s jurisdiction, including commodity futures (which include futures on broad-based securities indexes, interest rate futures and currency futures), options on commodity futures, certain swaps or other investments (whether directly or indirectly through investments in other investment vehicles).

Under this exclusion, a Portfolio must satisfy one of the following two trading limitations whenever it enters into a new commodity trading position: (1) the aggregate initial margin and premiums required to establish the Portfolio’s positions in CFTC-regulated instruments may not exceed 5% of the liquidation value of the Portfolio’s portfolio (after accounting for unrealized profits and unrealized losses on any such investments); or (2) the aggregate net notional value of such instruments, determined at the time the most recent position was established, may not exceed 100% of the liquidation value of the Portfolio’s portfolio (after accounting for unrealized profits and unrealized losses on any such positions). A Portfolio would not be required to consider its exposure to such instruments if they were held for “bona fide hedging” purposes, as such term is defined in the rules of the CFTC. In addition to meeting one of the foregoing trading limitations, a Portfolio may not market itself as a commodity pool or otherwise as a vehicle for trading in the markets for CFTC-regulated instruments.

Options on futures contracts . In return for the premium paid, options on futures contracts give the purchaser the right to assume a position in a futures contract at the specified option exercise price at any time during the period of the option. Options on futures are similar to options on securities except that options on futures give the purchaser the right, in return for the premium paid, to assume a position in a futures contract (a long position if the option is a call and a short position if the option is a put) at a specified exercise price at any time during the period of the option. Upon exercise of the option, the delivery of the futures position by the writer of the option to the holder of the option will be accompanied by delivery of the accumulated balance in the writer’s futures margin account which represents the amount by which the market price of the futures contract, at exercise, exceeds (in the case of a call) or is less than (in the case of a put) the exercise price of the option on the futures. If an option is exercised on the last trading day prior to its expiration date, the settlement will be made entirely in cash. Purchasers of options who fail to exercise their options prior to the exercise date suffer a loss of the premium paid.

As with options on securities, the holder or writer of an option may terminate his position by selling or purchasing an offsetting option. There is no guarantee that such closing transactions can be effected.

A Portfolio will be required to deposit initial margin and maintenance margin with respect to put and call options on futures contracts written by it pursuant to brokers’ requirements similar to those described above in connection with the discussion of futures contracts.

Risks of transactions in futures contracts and related options . Successful use of futures contracts by a Portfolio is subject to the Adviser’s ability to predict movements in various factors affecting financial markets. Compared to the purchase or sale of futures contracts, the purchase of call or put options on futures contracts involves less potential risk to a Portfolio because the maximum amount at risk is the premium paid for the options (plus transaction costs). However, there may be circumstances when the purchase of a call or put option on a futures contract would result in a loss to a Portfolio when the purchase or sale of a futures contract would not, such as when there is no movement in the prices of the hedged investments. The writing of an option on a futures contract involves risks similar to those risks relating to the sale of futures contracts.

The use of options and futures strategies involves the risk of imperfect correlation among movements in the prices of the securities underlying the futures and options purchased and sold by the Portfolio, of the options and futures contracts themselves, and, in the case of hedging transactions, of the securities which are the subject of a hedge. The successful use of these strategies further depends on the ability of the Adviser to forecast interest rates and market movements correctly.

There is no assurance that higher than anticipated trading activity or other unforeseen events might not, at times, render certain market clearing facilities inadequate, and thereby result in the institution by exchanges of special procedures which may interfere with the timely execution of customer orders.

To reduce or eliminate a position held by a Portfolio, the Portfolio may seek to close out such a position. The ability to establish and close out positions will be subject to the development and maintenance of a liquid secondary market. It is not certain that this market will develop or continue to exist for a particular futures contract or option. Reasons for the absence of a liquid secondary market on an exchange include the following: (i) there may be insufficient trading interest in certain contracts or options; (ii) restrictions may be imposed by an exchange on opening transactions or closing transactions or both; (iii) trading halts, suspensions or other restrictions may be imposed with respect to particular classes or series of contracts or options, or underlying securities; (iv) unusual or unforeseen circumstances may interrupt normal operations on an exchange; (v) the facilities of an exchange or a clearing corporation may not at all times be adequate to handle current trading volume; or (vi) one or more exchanges could, for economic or other reasons, decide or be compelled at some future date to discontinue the trading of contracts or options (or a particular class or series of contracts or options), in which event the secondary market on that exchange for such contracts or options (or in the class or series of contracts or options) would cease to exist, although outstanding contracts or options on the exchange that had been issued by a clearing corporation as a result of trades on that exchange would likely continue to be exercisable in accordance with their terms.

U.S. Treasury security futures contracts and options . Some U.S. Treasury security futures contracts require the seller to deliver, or the purchaser to take delivery of, the type of U.S. Treasury security called for in the contract at a specified date and price; others may be settled in cash. Options on U.S. Treasury security futures contracts give the purchaser the right in return for the premium paid to assume a position in a U.S. Treasury security futures contract at the specified option exercise price at any time during the period of the option. Successful use of U.S. Treasury security futures contracts by a Portfolio is subject to the Adviser’s ability to predict movements in the direction of interest rates and other factors affecting markets for debt securities. For example, if a Portfolio has sold U.S. Treasury security futures contracts in order to hedge against the possibility of an increase in interest rates which would adversely affect the values of securities held in its portfolio, and the prices of the Portfolio’s securities increase instead as a result of a decline in interest rates, the Portfolio will lose part or all of the benefit of the increased value of its securities which it has hedged because it will have offsetting losses in its futures positions. In addition, in such situations, if the Portfolio has insufficient cash, it may have to sell securities to meet daily maintenance margin requirements at a time when it may be disadvantageous to do so.

There is also a risk that price movements in U.S. Treasury security futures contracts and related options will not correlate closely with price movements in markets for particular securities. For example, if a Portfolio has hedged against a decline in the values of tax-exempt securities held by it by selling Treasury security futures and the values of Treasury securities subsequently increase while the values of the Portfolio’s tax-exempt securities decrease, the Portfolio would incur losses on both the Treasury security futures contracts written by it and the tax-exempt securities held in its portfolio.

Government Mortgage-Related Securities

The Government National Mortgage Association (“GNMA” or “Ginnie Mae”) is the principal federal government guarantor of mortgage-related securities. GNMA is a wholly-owned U.S. Government corporation within the Department of Housing and Urban Development. It guarantees, with the full faith and credit of the United States, full and timely payment of all monthly principal and interest on its mortgage-related securities. GNMA pass-through securities are considered to have a relatively low risk of default in that (1) the underlying mortgage loan portfolio is comprised entirely of government-backed loans and (2) the timely payment of both principal and interest on the securities is guaranteed by the full faith and credit of the U.S. Government, regardless of whether they have been collected. GNMA pass-through securities are, however, subject to the same interest rate risk as comparable privately issued mortgage-related securities. Therefore, the effective maturity and market value of a Portfolio’s GNMA securities can be expected to fluctuate in response to changes in interest rate levels.

High Yield Securities

The Portfolios, except for the Small/Mid Cap Equity Index Portfolio and the Ultra Short Term Bond Portfolio, may invest a portion of their assets in high yield debt securities (commonly known as “junk bonds”). Investment in high yield securities generally provides greater income and increased opportunity for capital appreciation than investments in higher quality securities, but they also typically entail greater price volatility and credit risk. These high yield securities are regarded as predominantly speculative with respect to the issuer’s continuing ability to meet principal and interest payments. Analysis of the creditworthiness of issuers of debt securities that are high yield may be more complex than for issuers of higher quality debt securities. In addition, high yield securities are often issued by smaller, less creditworthy companies or by highly leveraged (indebted) firms, but can also be issued by governments. Such issuers are generally less able than more financially stable issuers to make scheduled payments of interest and principal. The risks posed by securities issued under such circumstances are substantial.

Investing in high yield debt securities involves risks that are greater than the risks of investing in higher quality debt securities. These risks include: (i) changes in credit status, including weaker overall credit conditions of issuers and risks of default; (ii) industry, market and economic risk; and (iii) greater price variability and credit risks of certain high yield securities such as zero coupon and payment-in-kind securities. While these risks provide the opportunity for maximizing return over time, they may result in greater volatility of the value of a Portfolio than a fund that invests in higher-rated securities.

Furthermore, the value of high yield securities may be more susceptible to real or perceived adverse economic, company or industry conditions than is the case for higher quality securities. The market values of certain of these lower-rated and unrated debt securities tend to reflect individual issuer developments to a greater extent than do higher-rated securities which react primarily to fluctuations in the general level of interest rates, and tend to be more sensitive to economic conditions than are higher-rated securities. Adverse market, credit or economic conditions could make it difficult at certain times to sell certain high yield securities held by a Portfolio.

The secondary market on which high yield securities are traded may be less liquid than the market for higher grade securities. Less liquidity in the secondary trading market could adversely affect the price at which a Portfolio could sell a high yield security, and could adversely affect the daily net asset value per share of a Portfolio. When secondary markets for high yield securities are less liquid than the market for higher grade securities, it may be more difficult to value the securities because there is less reliable, objective data available. However, an Index seeks to include primarily high yield securities that the Index provider believes have greater liquidity than the broader high yield securities market as a whole.

The use of credit ratings as a principal method of selecting high yield securities can involve certain risks. For example, credit ratings evaluate the safety of principal and interest payments, not the market value risk of high yield securities. Also, credit rating agencies may fail to change credit ratings in a timely fashion to reflect events since the security was last rated.

Illiquid Securities

Each Portfolio may invest in illiquid securities. Each Portfolio will invest no more than 15% of its net assets in illiquid securities, including repurchase agreements and time deposits of more than seven days’ duration. The absence of a regular trading market for illiquid securities imposes additional risks on investments in these securities. Illiquid securities may be difficult to value and may often be disposed of only after considerable expense and delay.

Industrial Development and Private Activity Bonds (Ultra Short Term Bond Portfolio only)

Private activity bonds are considered municipal securities if the interest paid thereon is exempt from federal income tax and are issued by or on behalf of public authorities to raise money to finance various privately operated facilities for business and manufacturing, housing, sports, and pollution control. These bonds are also used to finance public facilities such as airports, mass transit systems, ports and parking. The payment of the principal and interest on such bonds is dependent solely on the ability of the facility’s user to meet its financial obligations and the value of any real or personal property pledged as security for such payment. Interest income on these bonds may be an item of tax preference subject to federal alternative minimum tax for individuals and corporations.

Infrastructure-Related Companies Risk

Infrastructure-related companies include companies that primarily own, manage, develop and/or operate infrastructure assets, including transportation, utility, energy and/or telecommunications assets. Infrastructure-related businesses are subject to a variety of factors that may adversely affect their business or operations, including high interest costs in connection with capital construction programs, insurance costs, costs associated with environmental and other regulations, the effects of an economic slowdown, surplus capacity or technological obsolescence, industry competition, labor relations, rate caps or rate changes, uncertainties concerning availability of fuel at reasonable prices, the effects of energy conservation policies, natural disasters, terrorist attacks and other factors. Certain infrastructure-related entities, particularly telecommunications and utilities companies, are subject to extensive regulation by various governmental authorities. The costs of complying with governmental regulations, delays or failures to receive required regulatory approvals or the enactment of new adverse regulatory requirements may adversely affect infrastructure-related companies. Infrastructure-related companies may also be affected by service interruption and/or legal challenges due to environmental, operational or other conditions or events, and the imposition of special tariffs and changes in tax laws, regulatory policies and accounting standards. There is also the risk that corruption may negatively affect publicly-funded infrastructure projects, especially in non-U.S. markets, resulting in work stoppage, delays and cost overruns. Other risks associated with infrastructure-related companies include uncertainties resulting from such companies’ diversification into new domestic and international businesses, as well as agreements by any such companies linking future rate increases to inflation or other factors not directly related to the actual operating profits of the enterprise.

Insured Municipal Securities (Ultra Short Term Bond Portfolio only)

Insured municipal securities are those for which scheduled payments of interest and principal are guaranteed by a private (non-governmental) insurance company. The insurance entitles a fund to receive only the face or par value of the securities held by the fund, but the ability to be paid is limited to the claims paying ability of the insurer. The insurance does not guarantee the market value of the municipal securities or the net asset value of a fund’s shares. Insurers are selected based upon the diversification of its portfolio and the strength of the management team which contributes to the claims paying ability of the entity. However, the Adviser selects securities based upon the underlying credit with bond insurance viewed as an enhancement only. The Adviser’s objective is to have an enhancement that provides additional liquidity to insulate against volatility in changing markets.

Investment Grade Bonds

The Portfolios may invest in corporate notes and bonds that are rated investment-grade by a nationally recognized statistical rating organization (“NRSRO”) or, if unrated, are of comparable quality to the rated securities described above, as determined by the Adviser, in accordance with procedures established by the Board of Trustees. Investment-grade securities include securities rated Baa or higher by Moody’s or BBB- or higher by S&P (and securities of comparable quality); securities rated Baa by Moody’s or BBB by S&P may have speculative characteristics.

Lending of Portfolio Securities

Each Index Portfolio may lend portfolio securities to certain creditworthy borrowers in U.S. and non-U.S. markets in an amount not to exceed 40% of the value of its net assets. The borrowers provide collateral that is marked to market daily in an amount at least equal to the current market value of the securities loaned. A Portfolio may terminate a loan at any time and obtain the securities loaned. A Portfolio receives the value of any interest or cash or non-cash distributions paid on the loaned securities. A Portfolio cannot vote proxies for securities on loan, but may recall loans to vote proxies if a material issue affecting the Fund’s economic interest in the investment is to be voted upon. Efforts to recall such securities promptly may be unsuccessful, especially for foreign securities or thinly traded securities, and may involve expenses to a Fund. Distributions received on loaned securities in lieu of dividend payments (i.e., substitute payments) would not be considered qualified dividend income.

With respect to loans that are collateralized by cash, the borrower typically will be entitled to receive a fee based on the amount of cash collateral. A Portfolio is compensated by the difference between the amount earned on the reinvestment of cash collateral and the fee paid to the borrower. In the case of collateral other than cash, a Portfolio is compensated by a fee paid by the borrower equal to a percentage of the market value of the loaned securities. Any cash collateral may be reinvested in certain high quality short-term instruments either directly on behalf of the lending Portfolio or through one or more joint accounts or funds, which may include those managed by the Adviser. A Portfolio could lose money due to a decline in the value of collateral provided for loaned securities or any investments made with cash collateral. Certain non-cash collateral or investments made with cash collateral may have a greater risk of loss than other non-cash collateral or investments.

A Portfolio may pay a portion of the interest or fees earned from securities lending to a borrower as described above, and to one or more securities lending agents approved by the Board of Trustees of the Trust (the “Board”) who administer the lending program for the Funds in accordance with guidelines approved by the Board. In such capacity, the lending agent provides the following services to the Funds in connection with the Funds’ securities lending activities: (i) locating borrowers among an approved list of prospective borrowers; (ii) causing the delivery of loaned securities from a Portfolio to borrowers; (iii) monitoring the value of loaned securities, the value of collateral received, and other lending parameters; (iv) seeking additional collateral, as necessary, from borrowers; (v) receiving and holding collateral from borrowers, and facilitating the investment and reinvestment of all or substantially all cash collateral in an investment vehicle designated by the Funds; (vi) returning collateral to borrowers; (vii) facilitating substitute dividend, interest, and other distribution payments to the Funds from borrowers; (viii) negotiating the terms of each loan of securities, including but not limited to the amount of any loan premium, and monitoring the terms of securities loan agreements with prospective borrowers for consistency with the requirements of the Funds’ Securities Lending Authorization Agreement; (ix) selecting securities, including amounts (percentages), to be loaned; (x) recordkeeping and accounting servicing; and (xi) arranging for return of loaned securities to the Portfolio in accordance with the terms of the Securities Lending Authorization Agreement. State Street Bank and Trust Company (“State Street”), an affiliate of the Trust, has been approved by the Board to serve as securities lending agent for each Index Portfolio and the Trust has entered into an agreement with State Street for such services. Among other matters, the Trust has agreed to indemnify State Street for certain liabilities. State Street has received an order of exemption from the SEC under Sections 17(a), 17(d) and 12(d)(1) under the 1940 Act to serve as the lending agent for affiliated investment companies such as the Trust, to invest the cash collateral received from loan transactions in an affiliated cash collateral fund and to receive a fee based on a share of the revenue generated from such transactions.

Securities lending involves exposure to certain risks, including operational risk (i.e., the risk of losses resulting from problems in the settlement and accounting process especially so in certain international markets such as Taiwan), “gap” risk (i.e., the risk of a mismatch between the return on cash collateral reinvestments and the fees a Portfolio has agreed to pay a borrower), risk of loss of collateral, credit, legal, counterparty and market risk. If a securities lending counterparty were to default, a Portfolio would be subject to the risk of a possible delay in receiving collateral (or the proceeds of its liquidation) or in recovering the loaned securities. In the event a borrower does not return a Fund’s securities as agreed, the Portfolio may experience losses if the proceeds received from liquidating the collateral do not at least equal the value of the loaned security at the time the collateral is liquidated, plus the transaction costs incurred in purchasing replacement securities. Although State Street has agreed to provide a Portfolio with indemnification in the event of a borrower default, a Portfolio is still exposed to the risk of losses in the event a borrower does not return a Portfolio’s securities as agreed. For example, delays in recovery of lent securities may cause a Portfolio to lose the opportunity to sell the securities at a desirable price with guaranteed delivery provisions.

Market Disruption and Geopolitical Risk

Securities markets may be susceptible to market manipulation (e.g., the potential manipulation of the London Interbank Offered Rate (LIBOR)) or other fraudulent trade practices, which could disrupt the orderly functioning of these markets or adversely affect the value of investments traded in these markets, including investments of a Portfolio.

Recent political activity in the U.S. has increased the risk that the U.S. could default on some or any of its obligations. While it is impossible to predict the consequences of such an unprecedented event, it is likely that a default by the U.S. would be highly disruptive to the U.S. and global securities markets and could significantly impair the value of the Portfolios’ investments. Similarly, political events within the U.S. at times have resulted, and may in the future result, in a shutdown of government services, which could negatively affect the U.S. economy, decrease the value of many Portfolio investments, and increase uncertainty in or impair the operation of the U.S. or other securities markets.

To the extent a Portfolio has focused its investments in the stock market index of a particular region, adverse geopolitical and other events could have a disproportionate impact on the Portfolio.

Mortgage-Backed Security Rolls

The Portfolios, except for the Small/Mid Cap Equity Index Portfolio and the Ultra Short Term Bond Portfolio, may enter into “forward roll” transactions with respect to mortgage-related securities issued by GNMA, FNMA or FHLMC. In a forward roll transaction, a Portfolio will sell a mortgage-related security to a bank or other permitted entity and simultaneously agree to repurchase a similar security from the institution at a later date at an agreed upon price. The mortgage securities that are repurchased will

typically bear the same interest rate as those sold, but generally will be collateralized by different pools of mortgages with different prepayment histories than those sold. A Portfolio that engages in a forward roll transaction forgoes principal and interest paid on the securities sold during the roll period, but is compensated by the difference between the current sales price and the lower forward price for the future purchase. In addition, a Portfolio earns interest by investing the transaction proceeds during the roll period. A forward roll transaction may create investment leverage. A Portfolio is subject to the risk that the value of securities to be purchased pursuant to a forward roll transaction will decline over the roll period, and that the Portfolio’s counterparty may be unwilling or unable to perform its obligations to the Portfolio. Upon entering into a mortgage-backed security roll, the participating Portfolio will segregate on its records cash, U.S. Government securities or other high-grade debt securities in an amount sufficient to cover its obligation under the roll.

Mortgage-Related Securities

The Portfolios, except for the Small/Mid Cap Equity Index Portfolio, may invest in mortgage-related securities. Mortgage-related securities represent an interest in a pool of, or are secured by, mortgage loans. Mortgage-related securities may be issued or guaranteed by (i) U.S. Government agencies or instrumentalities such as GNMA, FNMA and FHLMC or (ii) other issuers, including private companies.

Besides the scheduled repayment of principal, repayments of principal may result from the voluntary prepayment, refinancing or foreclosure of the underlying mortgage loans. If property owners make unscheduled prepayments of their mortgage loans, these prepayments will typically result in early payment of the applicable mortgage-related securities. The occurrence of mortgage prepayments is affected by a variety of factors including the level of interest rates, general economic conditions, the location and age of the mortgage, and other social and demographic conditions. During periods of falling interest rates, the rate of mortgage prepayments tends to increase, thereby tending to decrease the life of mortgage-related securities. During periods of rising interest rates, the rate of mortgage prepayments usually decreases, thereby tending to increase the life of mortgage-related securities. Because of the possibility of prepayments (and due to scheduled repayments of principal), mortgage-related securities are less effective than other types of securities as a means of “locking in” attractive long-term interest rates. Prepayments would have to be reinvested at lower rates. As a result, these securities may have less potential for capital appreciation during periods of declining interest rates than other securities of comparable maturities, although they may have a similar risk of decline in market value during periods of rising interest rates. Prepayments may also significantly shorten the effective maturities of these securities, especially during periods of declining interest rates. Conversely, during periods of rising interest rates, a reduction in prepayments may increase the effective maturities of these securities, subjecting them to a greater risk of decline in market value in response to rising interest rates than traditional debt securities, and, therefore, potentially increasing the volatility of the Portfolios.

Stripped mortgage-related securities are usually structured with two classes that receive different portions of the interest and principal distributions on a pool of mortgage loans. The yield to maturity on an interest only or “IO” class of stripped mortgage-related securities is extremely sensitive not only to changes in prevailing interest rates but also to the rate of principal payments (including prepayments) on the underlying assets. A rapid rate of principal prepayments may have a measurable adverse effect on a Portfolio’s yield to maturity to the extent it invests in IOs. If the assets underlying the IO experience greater than anticipated prepayments of principal, a Portfolio may fail to recoup fully, or at all, its initial investment in these securities. Conversely, principal only securities or “POs” tend to increase in value if prepayments are greater than anticipated and decline if prepayments are slower than anticipated. The secondary market for stripped mortgage-related securities may be more volatile and less liquid than that for other mortgage-related securities, potentially limiting a Portfolio’s ability to buy or sell those securities at any particular time.

Municipal and Municipal-Related Securities

Municipal securities may bear fixed, floating or variable rates of interest or may be zero coupon securities. Municipal securities are generally of two types: general obligations and revenue obligations. General obligations are backed by the full faith and credit of the issuer. These securities include tax anticipation notes, bond anticipation notes, general obligation bonds and commercial paper. Revenue obligations are backed by the revenues generated from a specific project or facility and include industrial development bonds and private activity bonds. Tax anticipation notes are issued to finance working capital needs of municipalities and are generally issued in anticipation of future tax revenues. Bond anticipation notes are issued in expectation of the issuer obtaining longer-term financing.

Municipal Leases (Ultra Short Term Bond Portfolio only)

The Portfolio may purchase participation interests in municipal obligations, including municipal lease/purchase agreements. Municipal leases are an undivided interest in a portion of an obligation in the form of a lease or installment purchase issued by a state or local government to acquire equipment or facilities. These instruments may have fixed, floating or variable rates of interest, with remaining maturities of 13 months or less. Certain participation interests may permit a Portfolio to demand payment on not more than seven days’ notice, for all or any part of the Portfolio’s interest, plus accrued interest.

Municipal leases frequently have special risks not normally associated with general obligation or revenue bonds. Some leases or contracts include “non-appropriation” clauses, which provide that the governmental issuer has no obligation to make future payments under the lease or contract unless money is appropriated for such purpose by the appropriate legislative body on a yearly or other periodic basis. To reduce these risks, a Portfolio will only purchase municipal leases subject to a non-appropriation clause when the payment of principal and accrued interest is backed by a letter of credit or guarantee of a bank.

Whether a municipal lease agreement will be considered illiquid for the purpose of the Portfolios’ restriction on investments in illiquid securities will be determined in accordance with procedures established by the Board of Trustees.

Options

The Index Portfolios may purchase and sell put and call options to enhance investment performance and to protect against changes in market prices. There is no assurance that a Portfolio’s use of put and call options will achieve its desired objective, and a Portfolio’s use of options may result in losses to the Portfolio.

Covered call options . A Portfolio may write ( i.e ., sell) covered call options to realize a greater current return through the receipt of premiums than it would realize on its securities alone. Such option transactions may also be used as a limited form of hedging against a decline in the price of securities owned by a Portfolio.

A call option gives the holder the right to purchase, and obligates the writer to sell, a security at the exercise price at any time before the expiration date. A call option is “covered” if the writer, at all times while obligated as a writer, either owns the underlying securities (or comparable securities satisfying the cover requirements of the securities exchanges), or has the right to acquire such securities through immediate conversion of securities. A Portfolio may write covered call options or uncovered call options.

A Portfolio will receive a premium from writing a call option, which increases the Portfolio’s return on the underlying security in the event the option expires unexercised or is closed out at a profit. The amount of the premium reflects, among other things, the relationship between the exercise price and the current market value of the underlying security, the volatility of the underlying security, the amount of time remaining until expiration, current interest rates, and the effect of supply and demand in the options market and in the market for the underlying security.

In return for the premium received when it writes a covered call option, a Portfolio gives up some or all of the opportunity to profit from an increase in the market price of the securities covering the call option during the life of the option. A Portfolio retains the risk of loss should the price of such securities decline. If the option expires unexercised, a Portfolio realizes a gain equal to the premium, which may be offset by a decline in price of the underlying security. If the option is exercised, a Portfolio realizes a gain or loss equal to the difference between the Portfolio’s cost for the underlying security and the proceeds of sale (exercise price minus commissions) plus the amount of the premium.

A Portfolio may terminate a call option that it has written before it expires by entering into a closing purchase transaction. A Portfolio may enter into closing purchase transactions in order to free itself to sell the underlying security or to write another call on the security, realize a profit on a previously written call option, or protect a security from being called in an unexpected market rise. Any

profits from a closing purchase transaction may be offset by a decline in the value of the underlying security. Conversely, because increases in the market price of a call option will generally reflect increases in the market price of the underlying security, any loss resulting from a closing purchase transaction is likely to be offset in whole or in part by unrealized appreciation of the underlying security owned by a Portfolio.

Uncovered call options . Writing uncovered call options may enable a Portfolio to realize income without committing capital to the ownership of the underlying securities or instruments; however, writing uncovered calls are riskier than writing covered calls because there is no underlying security held by a Portfolio that can act as a partial hedge. When a Portfolio has written an uncovered call option, the Portfolio will not necessarily hold securities offsetting the risk to the Portfolio. As a result of writing a call option without holding the underlying the securities, if the call option were exercised, a Portfolio might be required to purchase the security that is the subject of the call at the market price at the time of exercise. The Portfolio’s exposure on such an option is theoretically unlimited. There is also a risk, especially with less liquid preferred and debt securities, that the security may not be available for purchase. Uncovered calls have speculative characteristics.

Covered put options . A Portfolio may write covered put options in order to enhance its current return. Such options transactions may also be used as a limited form of hedging against an increase in the price of securities that the Portfolio plans to purchase. A put option gives the holder the right to sell, and obligates the writer to buy, a security at the exercise price at any time before the expiration date. A put option may be “covered” if the writer earmarks or otherwise segregates liquid assets equal to the price to be paid if the option is exercised minus margin on deposit.

By writing a put option, a Portfolio assumes the risk that it may be required to purchase the underlying security for an exercise price higher than its then current market value, resulting in a potential capital loss unless the security later appreciates in value.

A Portfolio may terminate a put option that it has written before it expires by entering into a closing purchase transaction. Any loss from this transaction may be partially or entirely offset by the premium received on the terminated option.

Purchasing put and call options . A Portfolio may also purchase put options to protect portfolio holdings against a decline in market value. This protection lasts for the life of the put option because a Portfolio, as a holder of the option, may sell the underlying security at the exercise price regardless of any decline in its market price. In order for a put option to be profitable, the market price of the underlying security must decline sufficiently below the exercise price to cover the premium and transaction costs that a Portfolio must pay. These costs will reduce any profit the Portfolio might have realized had it sold the underlying security instead of buying the put option.

A Portfolio may purchase call options to hedge against an increase in the price of securities that the Portfolio wants ultimately to buy. Such hedge protection is provided during the life of the call option since a Portfolio, as holder of the call option, is able to buy the underlying security at the exercise price regardless of any increase in the underlying security’s market price. In order for a call option to be profitable, the market price of the underlying security must rise sufficiently above the exercise price to cover the premium and transaction costs. These costs will reduce any profit a Portfolio might have realized had it bought the underlying security at the time it purchased the call option.

A Portfolio may also purchase put and call options to attempt to enhance its current return.

Options on foreign securities . A Portfolio may purchase and sell options on foreign securities if the Adviser believes that the investment characteristics of such options, including the risks of investing in such options, are consistent with the Portfolio’s investment objective. It is expected that risks related to such options will not differ materially from risks related to options on U.S. securities. However, position limits and other rules of foreign exchanges may differ from those in the United States. In addition, options markets in some countries, many of which are relatively new, may be less liquid than comparable markets in the United States.

Options on securities indices . A Portfolio may write or purchase options on securities indices. Index options are similar to options on individual securities in that the purchaser of an index option acquires the right to buy (in the case of a call) or sell (in the case of a put), and the writer undertakes the obligation to sell or buy (as the case may be), units of an index at a stated exercise price during the term of the option. Instead of the right to take or make actual delivery of securities, the holder of an index option has the right to receive a cash “exercise settlement amount.” This amount is equal to the amount by which the fixed exercise price of the option exceeds (in the case of a put) or is less than (in the case of a call) the closing value of the underlying index on the date of the exercise, multiplied by a fixed “index multiplier.”

Price movements in securities which a Portfolio owns or intends to purchase probably will not correlate perfectly with movements in the level of a securities index and, therefore, if a Portfolio uses an option for hedging purposes, it bears the risk of a loss on a securities index option which is not completely offset by movements in the price of such securities. Because securities index options are settled in cash, a call writer cannot determine the amount of its settlement obligations in advance and, unlike call writing on a specific security, cannot provide in advance for, or cover, its potential settlement obligations by acquiring and holding underlying securities. A Portfolio may, however, cover call options written on a securities index by holding a mix of securities which substantially replicate the movement of the index or by holding a call option on the securities index with an exercise price no higher than the call option sold.

Compared to the purchase or sale of futures contracts, the purchase of call or put options on an index involves less potential risk to a Portfolio because the maximum amount at risk is the premium paid for the options plus transactions costs. The writing of a put or call option on an index involves risks similar to those risks relating to the purchase or sale of index futures contracts.

Risks involved in the use of options . The successful use of a Portfolio’s options strategies depends on the ability of the Adviser to forecast correctly interest rate and market movements. For example, if a Portfolio were to write a call option based on the Adviser’s expectation that the price of the underlying security would fall, but the price were to rise instead, the Portfolio could be required to sell the security upon exercise at a price below the current market price. Similarly, if a Portfolio were to write a put option based on the Adviser’s expectation that the price of the underlying security would rise, but the price were to fall instead, the Portfolio could be required to purchase the security upon exercise at a price higher than the current market price.

When a Portfolio purchases an option, it runs the risk that it will lose its entire investment in the option in a relatively short period of time, unless the Portfolio exercises the option or enters into a closing sale transaction before the option’s expiration. If the price of the underlying security does not rise (in the case of a call) or fall (in the case of a put) to an extent sufficient to cover the option premium and transaction costs, a Portfolio will lose part or all of its investment in the option. This contrasts with an investment by a Portfolio in the underlying security, since the Portfolio will not realize a loss if the security’s price does not change.

The effective use of options also depends on a Portfolio’s ability to terminate option positions at times when the Adviser deems it desirable to do so. There is no assurance that a Portfolio will be able to effect closing transactions at any particular time or at an acceptable price.

If a secondary market in options were to become unavailable, a Portfolio could no longer engage in closing transactions. Lack of investor interest might adversely affect the liquidity of the market for particular options or series of options. A market may discontinue trading of a particular option or options generally. In addition, a market could become temporarily unavailable if unusual events — such as volume in excess of trading or clearing capability — were to interrupt its normal operations.

A market may at times find it necessary to impose restrictions on particular types of options transactions, such as opening transactions. For example, if an underlying security ceases to meet qualifications imposed by the market or the Options Clearing Corporation, new series of options on that security will no longer be opened to replace expiring series, and opening transactions in existing series may be prohibited. If an options market were to become unavailable, a Portfolio as a holder of an option would be able to realize profits or limit losses only by exercising the option, and the Portfolio, as option writer, would remain obligated under the option until expiration or exercise.

Disruptions in the markets for the securities underlying options purchased or sold by a Portfolio could result in losses on the options. If trading is interrupted in an underlying security, the trading of options on that security is normally halted as well. As a result, a Portfolio as purchaser or writer of an option will be unable to close out its positions until options trading resumes, and it may be faced with considerable losses if trading in the security reopens at a substantially different price. In addition, the Options Clearing Corporation or options markets may impose exercise restrictions. If a prohibition on exercise is imposed at the time when trading in the option has also been halted, a Portfolio as purchaser or writer of an option will be locked into its position until one of the two restrictions has been lifted. If the Options Clearing Corporation were to determine that the available supply of an underlying security appears insufficient to permit delivery by the writers of all outstanding calls in the event of exercise, it may prohibit indefinitely the exercise of put options. A Portfolio, as holder of such a put option, could lose its entire investment if the prohibition remained in effect until the put option’s expiration.

Foreign-traded options are subject to many of the same risks presented by internationally-traded securities. In addition, because of time differences between the United States and various foreign countries, and because different holidays are observed in different countries, foreign options markets may be open for trading during hours or on days when U.S. markets are closed. As a result, option premiums may not reflect the current prices of the underlying interest in the United States.

Over-the-counter (“OTC”) options purchased by a Portfolio and assets held to cover OTC options written by the Portfolio may, under certain circumstances, be considered illiquid securities for purposes of any limitation on the Portfolio’s ability to invest in illiquid securities.

Other Asset-Backed Securities

In addition to the mortgage-related securities discussed above, the Portfolios, except for the Small/Mid Cap Equity Index Portfolio, may invest in asset-backed securities that are not mortgage-related. Asset-backed securities other than mortgage-related securities represent undivided fractional interests in pools of instruments, such as consumer loans, and are typically similar in structure to mortgage-related pass-through securities. Payments of principal and interest are passed through to holders of the securities and are typically supported by some form of credit enhancement, such as a letter of credit, surety bond, limited guarantee by another entity, or by priority to certain of the borrower’s other securities. The degree of credit-enhancement, if any, varies, applying only until exhausted and generally covering only a fraction of the security’s par value.

The value of such asset-backed securities is affected by changes in the market’s perception of the asset backing the security, changes in the creditworthiness of the servicing agent for the instrument pool, the originator of the instruments, or the financial institution providing any credit enhancement and the expenditure of any portion of any credit enhancement. The risks of investing in asset-backed securities are ultimately dependent upon payment of the underlying instruments by the obligors, and a Portfolio would generally have no recourse against the obligee of the instruments in the event of default by an obligor. The underlying instruments are subject to prepayments which shorten the duration of asset-backed securities and may lower their return, in generally the same manner as described above for prepayments of pools of mortgage loans underlying mortgage-related securities.

Pre-Refunded Municipal Securities

Purchase of Other Investment Company Shares

The Portfolios may, to the extent permitted under the 1940 Act and exemptive rules and orders thereunder, invest in shares of other investment companies, which include funds managed by SSGA FM, which invest exclusively in money market instruments or in investment companies with investment policies and objectives which are substantially similar to those of the Portfolios. These investments may be made temporarily, for example, to invest uncommitted cash balances or, in limited circumstances, to assist in meeting shareholder redemptions, or as long-term investments.

Real Estate Investment Trusts (“REITs”)

The Portfolios, except for the Small/Mid Cap Equity Index Portfolio and the Ultra Short Term Bond Portfolio, may invest in REITs. REITs pool investors’ funds for investment primarily in income producing real estate or real estate loans or interests. A REIT is not taxed on income distributed to shareholders if it complies with several requirements relating to its organization, ownership, assets, and income and a requirement that it distribute to its shareholders at least 90% of its taxable income (other than net capital gains) for each taxable year. REITs can generally be classified as Equity REITs, Mortgage REITs and Hybrid REITs. Equity REITs, which invest the majority of their assets directly in real property, derive their income primarily from rents. Equity REITs can also realize capital gains by selling properties that have appreciated in value. Mortgage REITs, which invest the majority of their assets in real estate mortgages, derive their income primarily from interest payments. Hybrid REITs combine the characteristics of both Equity REITs and Mortgage REITs. A Portfolio will not invest in real estate directly, but only in securities issued by real estate companies. However, a Portfolio may be subject to risks similar to those associated with the direct ownership of real estate (in addition to securities markets risks) because of its policy of concentration in the securities of companies in the real estate industry. These include declines in the value of real estate, risks related to general and local economic conditions, dependency on management skill, heavy cash flow dependency, possible lack of availability of mortgage funds, overbuilding, extended vacancies of properties, increased competition, increases in property taxes and operating expenses, changes in zoning laws, losses due to costs resulting from the clean-up of environmental problems, liability to third parties for damages resulting from environmental problems, casualty or condemnation losses, limitations on rents, changes in neighborhood values, the appeal of properties to tenants and changes in interest rates. Investments in REITs may subject Portfolio shareholders to duplicate management and administrative fees.

beneficial tax treatment available to REITs under the Code, or to maintain their exemptions from registration under the 1940 Act. The above factors may also adversely affect a borrower’s or a lessee’s ability to meet its obligations to the REIT. In the event of a default by a borrower or lessee, the REIT may experience delays in enforcing its rights as a mortgagee or lessor and may incur substantial costs associated with protecting investments.

Repurchase Agreements

The Portfolios may enter into repurchase agreements with banks, other financial institutions, such as broker-dealers, and other institutional counterparties. Under a repurchase agreement, a Portfolio purchases securities from a financial institution that agrees to repurchase the securities at the Portfolio’s original purchase price plus interest within a specified time. A Portfolio will limit repurchase transactions to those member banks of the Federal Reserve System, broker-dealers and other financial institutions whose creditworthiness the Adviser considers satisfactory. Should the counterparty to a transaction fail financially, the Portfolio may encounter delay and incur costs before being able to sell the securities, or may be prevented from realizing on the securities. Further, the amount realized upon the sale of the securities may be less than that necessary to fully compensate the Portfolio.

Reverse Repurchase Agreements

Section 4(a)(2) Commercial Paper/Rule 144A Securities

Each Portfolio, except for the Small/Mid Cap Equity Index Portfolio, may invest in commercial paper issued in reliance on the so called “private placement” exemption from registration afforded by Section 4(a)(2) of the Securities Act of 1933, as amended (“1933 Act”) (“Section 4(a)(2) paper”).

There can be no assurance that a liquid trading market will exist at any time for any particular Section 4(a)(2) paper or Rule 144A securities.

Special Risk Considerations of Investing in China.

Certain Portfolios may invest in securities of Chinese issuers. Investing in securities of Chinese issuers, including by investing in A Shares, involves certain risks and considerations not typically associated with investing in securities of U.S. issuers, including, among others, (i) more frequent (and potentially widespread) trading suspensions and government interventions with respect to Chinese issuers, resulting in a lack of liquidity and in price volatility, (ii) currency revaluations and other currency exchange rate fluctuations or blockage, (iii) the nature and extent of intervention by the Chinese government in the Chinese securities markets, whether such intervention will continue and the impact of such intervention or its discontinuation, (iv) the risk of nationalization or expropriation of assets, (v) the risk that the Chinese government may decide not to continue to support economic reform programs, (vi) limitations on the use of brokers, (vii) potentially higher rates of inflation, (viii) the unavailability of consistently-reliable economic data, (ix) the relatively small size and absence of operating history of many Chinese companies, (x) accounting, auditing and financial reporting standards in China are different from U.S. standards and, therefore, disclosure of certain material information may not be available, (xi) greater political, economic, social, legal and tax-related uncertainty, (xii) higher market volatility caused by any potential regional territorial conflicts or natural disasters, (xiii) higher dependence on exports and international trade, (xiv) the risk of increased trade tariffs, embargoes and other trade limitations, (xv) restrictions on foreign ownership, and (xvi) custody risks associated with investing

through programs to access Chinese securities. Significant portions of the Chinese securities markets may become rapidly illiquid, as Chinese issuers have the ability to suspend the trading of their equity securities, and have shown a willingness to exercise that option in response to market volatility and other events. The liquidity of Chinese securities may shrink or disappear suddenly and without warning as a result of adverse economic, market or political events, or adverse investor perceptions, whether or not accurate.

Tax Exempt Commercial Paper (Ultra Short Term Bond Portfolio only)

The Portfolio may invest in tax exempt commercial paper. Tax exempt commercial paper is a short-term obligation with a stated maturity of 365 days or less. It is typically issued to finance seasonal working capital needs or as short-term financing in anticipation of longer term financing. Each instrument may be backed only by the credit of the issuer or may be backed by some form of credit enhancement, typically in the form of a guarantee by a commercial bank. Commercial paper backed by guarantees of foreign banks may involve additional risk due to the difficulty of obtaining and enforcing judgments against such banks and the generally less restrictive regulations to which such banks are subject. A Portfolio will only invest in commercial paper rated at the time of purchase not less than Prime-1 by Moody’s, A-1 by S&P or F-1 by Fitch Ratings. See Appendix A for more information on the ratings of debt instruments.

Tender Option Bonds (Ultra Short Term Bond Portfolio only)

Total Return Swaps, Equity Swaps and Interest Rate Swaps

The Index Portfolios may contract with a counterparty to pay a stream of cash flows and receive the total return of an index or a security for purposes of attempting to obtain a particular desired return at a lower cost to a Portfolio than if the Portfolio had invested directly in an instrument that yielded that desired return. A Portfolio’s return on a swap will depend on the ability of its counterparty to perform its obligations under the swap. The Adviser will cause a Portfolio to enter into swap agreements only with counterparties that would be eligible for consideration as repurchase agreement counterparties under the Portfolio’s repurchase agreement guidelines.

A Portfolio may enter into interest rate swap transactions with respect to any security it is entitled to hold. Interest rate swaps involve the exchange by a Portfolio with another party of their respective rights to receive interest, e.g., an exchange of floating rate payments for fixed rate payments. The Portfolios expect to enter into these transactions primarily to preserve a return or spread on a particular investment or portion of its portfolio or to protect against any increase in the price of securities it anticipates purchasing at a later date. The Portfolios generally intend to use these transactions as a hedge and not as a speculative investment. For example, a Portfolio may enter into an interest rate swap in order to protect against declines in the value of fixed income securities held by the Portfolio. In such an instance, the Portfolio may agree with a counterparty to pay a fixed rate (multiplied by a notional amount) and the counterparty to pay a floating rate multiplied by the same notional amount. If interest rates rise, resulting in a diminution in the value of a Portfolio, the Portfolio would receive payments under the swap that would offset, in whole or in part, such diminution in value; if interest rates fall, the Portfolio would likely lose money on the swap transaction.

Treasury Inflation-Protected Securities

The Portfolios, except for the Small/Mid Cap Equity Index Portfolio, may invest in Inflation-Protection Securities (“TIPSs”), a type of inflation-indexed Treasury security. TIPSs typically provide for semiannual payments of interest and a payment of principal at maturity. In general, each payment will be adjusted to take into account any inflation or deflation that occurs between the issue date of the security and the payment date based on the Consumer Price Index for All Urban Consumers (“CPI-U”).

U.S. Government Securities

The Portfolios may purchase U.S. Government securities. The types of U.S. Government obligations in which the Portfolios may at times invest include: (1) U.S. Treasury obligations and (2) obligations issued or guaranteed by U.S. Government agencies and instrumentalities which are supported by any of the following: (a) the full faith and credit of the U.S. Treasury, (b) the right of the issuer to borrow an amount limited to a specific line of credit from the U.S. Treasury, (c) discretionary authority of the U.S. Government agency or instrumentality, or (d) the credit of the instrumentality (examples of agencies and instrumentalities are: Federal Land Banks, Federal Housing Administration, Federal Farm Credit Bank, Farmers Home Administration, Export-Import Bank of the United States, Central Bank for Cooperatives, Federal Intermediate Credit Banks, Federal Home Loan Banks, General Services Administration, Maritime Administration, Tennessee Development Bank, Asian-American Development Bank, International Bank for Reconstruction and Development and Federal National Mortgage Association). No assurance can be given that in the future the U.S. Government will provide financial support to U.S. Government securities it is not obligated to support.

U.S. Registered Securities of Non-U.S. Issuers

The Index Portfolios may purchase publicly traded common stocks of non-U.S. corporations.

Investing in U.S. registered, dollar-denominated, securities issued by non-U.S. issuers involves some risks and considerations not typically associated with investing in U.S. companies. These include differences in accounting, auditing and financial reporting standards, the possibility of expropriation or confiscatory taxation, adverse changes in investment or exchange control regulations, political instability which could affect U.S. investments in non-U.S. countries, and potential restrictions of the flow of international capital. Non-U.S. companies may be subject to less governmental regulation than U.S. issuers. Moreover, individual non-U.S. economies may differ favorably or unfavorably from the U.S. economy in such respects as growth of gross domestic product, rate of inflation, capital reinvestment, resource self-sufficiency and balance of payment positions.

A Portfolio’s investment in common stock of non-U.S. corporations may also be in the form of American Depositary Receipts (“ADRs”), Global Depositary Receipts (“GDRs”) and European Depositary Receipts (“EDRs”) (collectively “Depositary Receipts”). Depositary Receipts are receipts, typically issued by a bank or trust company, which evidence ownership of underlying securities issued by a non-U.S. corporation. For ADRs, the depository is typically a U.S. financial institution and the underlying securities are issued by a non-U.S. issuer. For other Depositary Receipts, the depository may be a non-U.S. or a U.S. entity, and the underlying securities may have a non-U.S. or a U.S. issuer. Depositary Receipts will not necessarily be denominated in the same currency as their underlying securities. Generally, ADRs, in registered form, are designed for use in the U.S. securities markets, and EDRs, in bearer form, are designated for use in European securities markets. GDRs are tradable both in the United States and in Europe and are designed for use throughout the world. A Portfolio may invest in unsponsored Depositary Receipts. The issuers of unsponsored Depositary Receipts are not obligated to disclose material information in the United States, and, therefore, there may be less information available regarding such issuers and there may not be a correlation between such information and the market value of the Depositary Receipts.

Variable Amount Master Demand Notes

The Portfolios, except for the Small/Mid Cap Equity Index Portfolio, may invest in variable amount master demand notes which are unsecured obligations that are redeemable upon demand and are typically unrated. These instruments are issued pursuant to written agreements between their issuers and holders. The agreements permit the holders to increase (subject to an agreed maximum) and the holders and issuers to decrease the principal amount of the notes, and specify that the rate of interest payable on the principal fluctuates according to an agreed formula. Generally, changes in interest rates will have a smaller effect on the market value of these securities than on the market value of comparable fixed income obligations. Thus, investing in these securities generally allows less opportunity for capital appreciation and depreciation than investing in comparable fixed income securities. There may be no active secondary market with respect to a particular variable rate instrument.

Variable and Floating Rate Securities

The Portfolios, except for the Small/Mid Cap Equity Index Portfolio, may invest in variable and floating rate securities. Variable rate securities are instruments issued or guaranteed by entities such as (1) U.S. Government, or an agency or instrumentality thereof, (2) corporations, (3) financial institutions, (4) insurance companies or (5) trusts that have a rate of interest subject to adjustment at regular intervals but less frequently than annually. A variable rate security provides for the automatic establishment of a new interest rate on set dates. Interest rates on these securities are ordinarily tied to widely recognized market rates, which are typically set once a day. These rates may change as often as twice daily. Generally, changes in interest rates will have a smaller effect on the market value of variable and floating rate securities than on the market value of comparable fixed income obligations. Thus, investing in variable and floating rate securities generally allows less opportunity for capital appreciation and depreciation than investing in comparable fixed income securities. Variable rate obligations will be deemed to have a maturity equal to the period remaining until the next readjustment of the interest rate.

When-Issued, Delayed Delivery and Forward Commitment Transactions

To secure an advantageous price or yield, certain Portfolios may purchase securities on a when-issued, delayed delivery, to-be-announced (“TBA”) or forward commitment basis and may sell securities on a forward commitment or delayed delivery basis. A Portfolio will enter into when-issued, delayed delivery, TBA or forward commitment transactions for the purpose of acquiring securities and not for the purpose of leverage.

When purchasing a security on a when-issued, delayed delivery, TBA or forward commitment basis, a Portfolio assumes the rights and risks of ownership of the security, including the risk of price and yield fluctuations, and takes such fluctuations into account when determining its net asset value. When such transactions are negotiated, certain terms may be fixed at the time the commitment is made, but delivery and payment for the securities takes place at a later date. In general, a Portfolio does not pay for the securities until received and does not start earning interest or other income until the contractual settlement date. A Portfolio may take delivery of the securities or it may sell the securities before the settlement date.

At the time of delivery of the securities, the value may be more or less than the purchase or sale price. If a Portfolio remains substantially fully invested at a time when when-issued, delayed delivery, TBA or forward commitment purchases are outstanding, the purchases may result in a form of leverage and give rise to increased volatility of the Portfolio’s net asset value. Default by, or bankruptcy of, a counterparty to a when-issued, delayed delivery, TBA or forward commitment transaction would expose the Portfolio to possible losses because of an adverse market action, expenses or delays in connection with the purchase or sale of the pools specified in such transaction. Purchases of when-issued, delayed delivery, TBA or forward commitment securities also involve a risk of loss if the seller fails to deliver after the value of the securities has risen.

Cash or other liquid assets in an amount equal to the amount of a Portfolio’s when-issued, delayed-delivery, TBA or forward commitment purchase obligations will be earmarked on the Portfolio’s books. There is no guarantee, however, that such earmarking will be successful in reducing or eliminating the leveraging effect of such transactions or the risks associated with leverage.

A TBA transaction involves a commitment to purchase securities sold for a fixed price where the underlying securities are announced at a future date. The seller does not specify the particular securities to be delivered. Instead, a Portfolio agrees to accept any security that meets specified terms. For example, in a TBA mortgage-backed security transaction, a Portfolio and the seller would agree upon the issuer, interest rate and terms of the underlying mortgages. The seller would not identify the specific underlying mortgages until it issues the security. For this reason, in a TBA transaction, a Portfolio commits to purchase securities for which all specific information is not yet known at the time of the trade, particularly the exact face amount in forward commitment mortgage-backed securities transactions. The purchaser in a TBA transaction generally is subject to increased market risk and interest rate risk because the delivered securities may be less favorable than anticipated by the purchaser.

Certain Portfolios may also enter into a forward commitment to sell securities it owns. The use of forward commitments enables a Fund to hedge against anticipated changes in interest rates and prices. In a forward sale, a Portfolio does not participate in gains or losses on the security occurring after the commitment date. Forward commitments to sell securities also involve a risk of loss if the seller fails to take delivery after the value of the securities has declined. Forward commitment transactions involve additional risks similar to those associated with investments in options and futures contracts.

Recently finalized rules of the Financial Industry Regulatory Authority, Inc. (“FINRA”) would impose mandatory margin requirements for “Covered Agency Transactions,” which include TBA Transactions, certain transactions in pass-through mortgage-backed securities or small-business administration-backed asset-backed securities and transactions in collateralized mortgage obligations, in each case where such transactions have delayed contractual settlement dates of a specified period. There are limited exceptions to these margin requirements. Covered Agency Transactions historically have not been required to be collateralized. The collateralization of Covered Agency Transactions is intended to mitigate counterparty credit risk between trade and settlement, but could increase the cost of such transactions and impose added operational complexity.

Zero Coupon Securities

The Portfolios, except for the Small/Mid Cap Equity Index Portfolio, may invest in zero coupon securities. Zero coupon securities are notes, bonds and debentures that: (1) do not pay current interest and are issued at a substantial discount from par value; (2) have been stripped of their unmatured interest coupons and receipts; or (3) pay no interest until a stated date one or more years into the future. These securities also include certificates representing interests in such stripped coupons and receipts. Generally, changes in interest rates will have a greater impact on the market value of a zero coupon security than on the market value of the comparable securities that pay interest periodically during the life of the instrument. In the case of any zero-coupon debt obligations with a fixed maturity date of more than one year from the date of issuance that are treated as issued originally at a discount, a Portfolio will be required to accrue original issue discount (“OID”) for U.S. federal income tax purposes and may as a result be required to pay out as an income distribution an amount which is greater than the total amount of cash interest the Portfolio actually received. To generate sufficient cash to make the requisite distributions to maintain its qualification for treatment as a RIC, a Portfolio may be required to sell investments, including at a time when it may not be advantageous to do so.

Privately-issued stripped securities are not themselves guaranteed by the U.S. Government, but the future payment of principal or interest on U.S. Treasury obligations which they represent is so guaranteed.

Asset Segregation and Coverage

A Portfolio may be required to earmark or otherwise segregate liquid assets in respect of its obligations under derivatives transactions that involve contractual obligations to pay in the future, or a Portfolio may engage in other measures to “cover” its obligations with respect to such transactions. The amounts that are earmarked or otherwise segregated may be based on the notional value of the derivative or on the daily mark-to-market obligation under the derivatives contract and may be reduced by amounts on deposit with the applicable broker or counterparty to the derivatives transaction. In certain circumstances, a Portfolio may enter into an offsetting position rather than earmarking or segregating liquid assets. A Portfolio may modify its asset segregation and coverage policies from time to time. Although earmarking or segregating may in certain cases have the effect of limiting a Portfolio’s ability to engage in derivatives transactions, the extent of any such limitation will depend on a variety of factors, including the method by which the Portfolio determines the nature and amount of assets to be earmarked or segregated.

Fundamental Investment Restrictions

The Trust has adopted the following restrictions applicable to the Portfolios, which may not be changed without the affirmative vote of a “majority of the outstanding voting securities” of a Portfolio, which is defined in the 1940 Act to mean the affirmative vote of the lesser of (1) more than 50% of the outstanding shares of the Portfolio and (2) 67% or more of the shares present at a meeting if more than 50% of the outstanding shares are present at the meeting in person or by proxy.

A Portfolio may borrow money and issue senior securities to the extent consistent with applicable law from time to time.

A Portfolio may make loans, including to affiliated investment companies, to the extent consistent with applicable law from time to time.

A Portfolio may purchase or sell commodities to the extent consistent with applicable law from time to time.

A Portfolio may purchase, sell or hold real estate to the extent consistent with applicable law from time to time.

A Portfolio may underwrite securities to the extent consistent with applicable law from time to time.

For the State Street Equity 500 Index II Portfolio, State Street Global Equity ex-U.S. Index Portfolio, and the State Street Aggregate Bond Index Portfolio:

A Portfolio may not purchase any security if, as a result, 25% or more of the Portfolio’s total assets (taken at current value) would be invested in a particular industry (for purposes of this restriction, investment companies are not considered to constitute a particular industry or group of industries), except as is consistent with applicable law from time to time and as follows: each Portfolio is permitted to invest without limit in “government securities” (as defined in the 1940 Act) and tax-exempt securities issued by a U.S. territory or possession, a state or local government, or a political subdivision of any of the foregoing. Each Portfolio may concentrate its investments in securities of issuers in the same industry as may be necessary to approximate the composition of the Portfolio’s underlying Index.

For Ultra Short Term Bond Portfolio:

A Portfolio may not purchase any security if, as a result, 25% or more of the Portfolio’s total assets (taken at current value) would be invested in a particular industry (for purposes of this restriction, investment companies are not considered to constitute a particular industry or group of industries), except as is consistent with applicable law from time to time and as follows: the Portfolio is permitted to invest without limit in “government securities” (as defined in the 1940 Act) and tax-exempt securities issued by a U.S. territory or possession, a state or local government, or a political subdivision of any of the foregoing.

For purposes of the above investment limitation number 6, in the case of a tax-exempt bond issued by a non-governmental user, where the tax-exempt bond is backed only by the assets and revenues of the non-governmental user, then such non-governmental user would be deemed to be the sole issuer. For each Portfolio, all percentage limitations (except the limitation to borrowings) on investments will apply at the time of the making of an investment and shall not be considered violated unless an excess or deficiency occurs or exists immediately after and as a result of such investment. Except for the investment restrictions expressly identified as fundamental, or to the extent designated as such in the Prospectus with respect to a Portfolio, the other investment policies described in this SAI or in the Prospectus are not fundamental and may be changed by approval of the Trustees without shareholder approval.

Non-Fundamental Investment Restrictions

In addition, it is contrary to the present policies of the Equity 500 Index II Portfolio and Global Equity Ex-U.S. Index Portfolio to invest in securitized instruments (including asset-backed securities, mortgage-backed securities, or asset-backed commercial paper) nor sweep excess cash into any non-governmental money market fund.

Names Rule Policy

To the extent a Portfolio is subject to Rule 35d-1 under the 1940 Act, the Portfolio has an investment policy, described in the Portfolio’s prospectus, to, under normal circumstances, invest at least 80% of its assets in the particular types of investments suggested by the Portfolio’s name (a “Name Policy”). “Assets” for the purposes of a Name Policy are net assets plus the amount of any borrowings for investment purposes. The percentage limitation applies at the time of purchase of an investment. A Portfolio’s Name Policy may be changed by the Board of Trustees of the Trust without shareholder approval. However, to the extent required by SEC regulations, shareholders will be provided with at least sixty (60) days’ notice prior to any change in a Portfolio’s Name Policy.

Additional Information

Fundamental Investment Restrictions (1) through (5), as numbered above limit a Portfolio’s ability to engage in certain investment practices and purchase securities or other instruments to the extent consistent with applicable law as that law changes from time to time. Applicable law includes the 1940 Act, the rules or regulations thereunder and applicable orders of the SEC as are currently in place. In addition, interpretations and guidance provided by the SEC staff may be taken into account, where deemed appropriate by a Portfolio, to determine if an investment practice or the purchase of securities or other instruments is permitted by applicable law. As such, the effects of these limitations will change as the statute, rules, regulations or orders (or, if applicable, interpretations) change, and no shareholder vote will be required or sought when such changes permit or require a resulting change in practice.

Disclosure of Portfolio Holdings

Introduction

The policies set forth below to be followed by State Street Bank and Trust Company (“State Street”) and SSGA FM (collectively, the “Service Providers”) for the disclosure of information about the portfolio holdings of the SSGA Funds, State Street Master Funds, and State Street Institutional Investment Trust (each, a “Trust”). These disclosure policies are intended to ensure compliance by the Service Providers and the Trust with applicable regulations of the federal securities laws, including the 1940 Act and the Investment Advisers Act of 1940, as amended. The Board of Trustees of the Trust must approve all material amendments to the policy.

General Policy

It is the policy of the Service Providers to protect the confidentiality of client holdings and prevent the selective disclosure of non-public information concerning the Trust.

No information concerning the portfolio holdings of the Trust may be disclosed to any party (including shareholders) except as provided below. The Service Providers are not permitted to receive compensation or other consideration in connection with disclosing information about a Portfolio’s portfolio to third parties. In order to address potential conflicts between the interest of Portfolio shareholders, on the one hand, and those of the Service Providers or any affiliated person of those entities or of the Portfolio, on the other hand, the Portfolios’ policies require that non-public disclosures of information regarding the Portfolio’s portfolio may be made only if there is a legitimate business purpose consistent with fiduciary duties to all shareholders of the Portfolio.

The Board of Trustees of the Trust exercises continuing oversight over the disclosure of each Portfolio’s holdings by (i) overseeing the implementation and enforcement of the portfolio holding disclosure policy, Codes of Ethics and other relevant policies of each Portfolio and its Service Providers by the Trust’s Chief Compliance Officer (“CCO”) and (2) considering reports and recommendations by the Trust’s CCO concerning any material compliance matters (as defined in Rule 38a-1 under the 1940 Act). The Board reserves the right to amend the policy at any time without prior notice in its sole discretion.

Publicly Available Information. Any party may disclose portfolio holdings information after the holdings are publicly available.

Disclosure of the complete holdings of each Portfolio is required to be made quarterly within 60 days of the end of the Portfolio’s fiscal quarter in the Annual Report and Semi-Annual Report to Portfolio shareholders and in the monthly holdings report on Form N-PORT, with every third month made available to the public by the SEC 60 days after the end of the Portfolios’ fiscal quarter. You can find SEC filings on the SEC’s website, www.sec.gov. Each Portfolio will also make complete portfolio holdings available generally no later than 60 calendar days after the end of the Portfolio’s fiscal quarter or subsequent to periodic portfolio holdings disclosure in the Portfolio’s filings with the SEC or on their website.

Information about each Portfolio’s 10 largest holdings generally is posted on its corresponding feeder fund’s website at SSGAFunds.com for the relevant feeder fund of the Index Portfolios within 30 days following the end of each month.

Press Interviews Brokers and Other Discussions

Trading Desk Reports

Miscellaneous

Confidentiality Agreement . No non-public disclosure of the Trust’s portfolio holdings will be made to any party unless such party has signed a written Confidentiality Agreement. For purposes of the disclosure policies, any Confidentiality Agreement must be in a form and substance acceptable to, and approved by, the Trust’s officers.

Evaluation Service Providers. There are numerous mutual fund evaluation services (such as Morningstar, Inc. and Broadridge Financial Solutions, Inc., formerly Lipper, Inc.) and due diligence departments of broker-dealers and wirehouses that regularly analyze the portfolio holdings of mutual funds in order to monitor and report on various attributes. These services and departments then distribute the results of their analysis to the public, paid subscribers and/or in-house brokers. In order to facilitate the review of the Trust by these services and departments, the Trust may distribute (or authorize the Service Providers and the Trust’s custodian or fund accountants to distribute) month-end portfolio holdings to such services and departments only if such entity has executed a confidentiality agreement.

MANAGEMENT OF THE TRUST

The Board of Trustees is responsible for overseeing generally the management, activities and affairs of the Portfolios and has approved contracts with various organizations to provide, among other services, day-to-day management required by the Trust (see the section called “Investment Advisory and Other Services”). The Board has engaged the Adviser to manage the Portfolios on a day-to day basis. The Board is responsible for overseeing the Adviser and other service providers in the operation of the Trust in accordance with the provisions of the 1940 Act, applicable Massachusetts law and regulation, other applicable laws and regulations, and the Amended and Restated Declaration of Trust. The Trustees listed below are also Trustees of the SSGA Funds, the State Street Master Funds and the State Street Navigator Securities Lending Trust (the “Navigator Trust”) and their respective series. Except for Messrs. Ross and Taber, the Trustees listed below are also Trustees of State Street Institutional Funds and State Street Variable Insurance Series Funds, Inc., Elfun Diversified Fund, Elfun Government Money Market Fund, Elfun Tax-Exempt Income Fund, Elfun Income Fund, Elfun International Equity Fund and Elfun Trusts (collectively, the “Elfun Funds”). The following table provides information with respect to each Trustee, including those Trustees who are not considered to be “interested” as that term is defined in the 1940 Act (the “Independent Trustees”), and each officer of the Trusts.


NAME, ADDRESS, AND YEAR OF BIRTH	POSITION(S) HELD WITH TRUST	TERM OF OFFICE AND LENGTH OF TIME SERVED	PRINCIPAL OCCUPATION DURING PAST FIVE YEARS AND RELEVANT EXPERIENCE	NUMBER OF FUNDS IN FUND COMPLEX OVERSEEN BY TRUSTEE†	OTHER DIRECTORSHIPS HELD BY TRUSTEE DURING PAST FIVE YEARS
INDEPENDENT TRUSTEES

Michael F. Holland c/o SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1944	Trustee and Co-Chairperson of the Board	Term: Indefinite Elected: 7/99	Chairman, Holland & Company L.L.C. (investment adviser) (1995- present).	71	Director, the Holland Series Fund, Inc.; Director, The China Fund, Inc.; Director, The Taiwan Fund, Inc. (2007-2017); Director, Reaves Utility Income Fund, Inc.; and Director, Blackstone/GSO Loans (and Real Estate) Funds.

Patrick J. Riley c/o SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1948	Trustee and Co-Chairperson of the Board	Term: Indefinite Elected: 1/14	2002 to May 2010, Associate Justice of the Superior Court, Commonwealth of Massachusetts; 1985 to 2002, Partner, Riley, Burke & Donahue, L.L.P. (law firm); 1998 to Present, Independent Director, State Street Global Advisers Ireland, Ltd. (investment company); 1998 to Present, Independent Director, SSGA Liquidity plc (formerly, SSGA Cash Management Fund plc);	71	Board Director and Chairman, SPDR Europe 1PLC Board (2011-Present); Board Director and Chairman, SPDR Europe II, PLC (2013- Present).


NAME, ADDRESS, AND YEAR OF BIRTH	POSITION(S) HELD WITH TRUST	TERM OF OFFICE AND LENGTH OF TIME SERVED	PRINCIPAL OCCUPATION DURING PAST FIVE YEARS AND RELEVANT EXPERIENCE	NUMBER OF FUNDS IN FUND COMPLEX OVERSEEN BY TRUSTEE†	OTHER DIRECTORSHIPS HELD BY TRUSTEE DURING PAST FIVE YEARS
			January 2009 to Present, Independent Director, SSGA Fixed Income plc; and January 2009-2019, Independent Director, SSGA Qualified Funds PLC.

John R. Costantino c/o SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1946	Trustee and Co-Chairperson of the Qualified Legal Compliance Committee	Term: Indefinite Elected: 12/18	Managing General Partner, NGN Capital LLC (2006 – present); and Managing Director, Vice President of Walden Capital Management (1996 – present).	71	Director of Kleinfeld Bridal Corp. (March 2016 – present); Trustee of Neuroscience Research Institute (1986 – present); Trustee of Fordham University (1989 – 1995 and 2001 – 2007) and Trustee Emeritus (2007 – present); Trustee of GE Funds (1993 – February 2011); Director of Artes Medical (2006 – 2008); and Trustee of Gregorian University Foundation (1992 – 2007).

Richard D. Shirk c/o SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1945	Trustee and Co-Chairperson of the Qualified Legal Compliance Committee	Term: Indefinite Elected: 1/14	March 2001 to April 2002, Chairman (1996 to March 2001, President and Chief Executive Officer), Cerulean Companies, Inc. (holding company) (Retired); 1992 to March 2001, President and Chief Executive Officer, Blue Cross Blue Shield of Georgia (health insurer, managed healthcare).	71	1998 to December 2008, Chairman, Board Member and December 2008 to Present, Investment Committee Member, Healthcare Georgia Foundation (private foundation); September 2002 to 2012, Lead Director and Board Member, Amerigroup Corp. (managed health care); 1999 to 2013, Board Member and (since 2001) Investment Committee Member, Woodruff Arts Center; and 2003 to 2009, Trustee, Gettysburg College; Board member, Aerocare Holdings, Regenesis Biomedical Inc.

Rina K. Spence c/o SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1948	Trustee and Co-Chairperson of the Audit Committee, Co-Chairperson of the Nominating Committee and Co-Chairperson	Term: Indefinite Elected: 7/99	President of SpenceCare International LLC (international healthcare consulting) (1999 – present); Chief Executive Officer, IEmily.com (health internet company) (2000 – 2001); Chief Executive Officer of Consensus Pharmaceutical, Inc. (1998 – 1999); Founder, President and Chief Executive Officer of Spence Center for Women’s Health (1994 –	71	Trustee, Eastern Enterprise (utilities) (1988 – 2000); Director, Berkshire Life Insurance Company of America (1993 – 2009).


NAME, ADDRESS, AND YEAR OF BIRTH	POSITION(S) HELD WITH TRUST	TERM OF OFFICE AND LENGTH OF TIME SERVED	PRINCIPAL OCCUPATION DURING PAST FIVE YEARS AND RELEVANT EXPERIENCE	NUMBER OF FUNDS IN FUND COMPLEX OVERSEEN BY TRUSTEE†	OTHER DIRECTORSHIPS HELD BY TRUSTEE DURING PAST FIVE YEARS
	of the Governance Committee		1998); President and CEO, Emerson Hospital (1984 – 1994); Honorary Consul for Monaco in Boston (2015 – present).

Bruce D. Taber c/o SSGA Funds Management, Inc. One Iron Street Boston, MA 02111 YOB: 1943	Trustee and Chairperson of the Valuation Committee, Co-Chairperson of the Nominating Committee and Co-Chairperson of the Governance Committee	Term: Indefinite Elected: 1/14	Retired; 1999 to 2016, Partner, Zenergy LLC (a technology company providing Computer Modeling and System Analysis to the General Electric Power Generation Division); Until December 2008, Independent Director, SSGA Cash Management Fund plc; Until December 2008, Independent Director, State Street Global Advisers Ireland, Ltd. (investment companies).	53

Michael A. Jessee c/o SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1946	Trustee and Co-Chairperson of the Valuation Committee	Term: Indefinite Appointed: 7/16 Elected: 12/18	Retired; formerly, President and Chief Executive Officer of the Federal Home Loan Bank of Boston (1989 – 2009); Trustee, Randolph-Macon College (2004 – 2016).	71

Donna M. Rapaccioli c/o SSGA Funds Management, Inc. One Iron Street Boston, MA 02210YOB: 1962	Trustee and Co-Chairperson of the Audit Committee	Term: Indefinite Elected: 12/18	Dean of the Gabelli School of Business (2007 – present) and Accounting Professor (1987 – present) at Fordham University.	71	Trustee of Emmanuel College (2010 – present); Director- Graduate Management Admissions Council (2015 – present).

INTERESTED TRUSTEES ⁽¹⁾

Ellen M. Needham ⁽²⁾ SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1967	Trustee and President	Term: Indefinite Elected: 12/18	President and Director, SSGA Funds Management, Inc. (2001 – present); Senior Managing Director, State Street Global Advisors (1992 – present); Director, State Street Global Advisors Funds Distributors, LLC (May 2017 – present).*	71	None.

James E. Ross ⁽³⁾ SSGA Funds Management, Inc.	Trustee	Term: Indefinite Appointed:	Chairman and Director, SSGA Funds Management, Inc. (2005-present); Executive	189	SSGA SPDR ETFs Europe I plc (Director) (November 2016 – present); SSGA SPDR ETFs

NAME, ADDRESS,

AND YEAR OF BIRTH

POSITION(S)

HELD WITH

TRUST

TERM OF

OFFICE AND

LENGTH OF

TIME SERVED

PRINCIPAL OCCUPATION

DURING PAST FIVE YEARS

AND RELEVANT

EXPERIENCE

NUMBER OF

FUNDS IN

FUND

COMPLEX

OVERSEEN

BY TRUSTEE†

OTHER

DIRECTORSHIPS

HELD BY TRUSTEE

DURING PAST FIVE

YEARS

One Iron Street

Boston, MA 02210

YOB: 1965

2/07

Vice President, State Street Global Advisors (2012-present); Chief Executive Officer and Director, State Street Global Advisors Funds Distributors, LLC (May 2017 – present); Director, State Street Global Markets, LLC (2013 – April 2017); President, SSGA Funds Management, Inc. (2005 – 2012); Principal,

State Street Global Advisors (2000-2005).

Europe II plc (Director) (November 2016 – present).

†	For the purpose of determining the number of portfolios overseen by the Trustees, “Fund Complex” comprises registered investment companies for which SSGA FM serves as investment adviser.

(1)	The individuals listed below are Trustees who are “interested persons,” as defined in the 1940 Act, of the Trusts (“Interested Trustees”).

(2)	Ms. Needham is an Interested Trustee because of her employment by SSGA FM, an affiliate of the Trust.

(3)	Mr. Ross is an Interested Trustee because of his employment by SSGA FM, an affiliate of the Trust.

*	Served in various capacities and/or with various affiliated entities during noted time period.

The following lists the principal officers for the Trust, as well as their mailing addresses and ages, positions with the Trust and length of time served, and present and principal occupations:


NAME, ADDRESS, AND YEAR OF BIRTH	POSITION(S) HELD WITH TRUST	TERM OF OFFICE AND LENGTH OF TIME SERVED	PRINCIPAL OCCUPATION DURING PAST FIVE YEARS
OFFICERS:

Ellen M. Needham SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1967	President, Trustee	Term: Indefinite Elected: 10/12	President and Director, SSGA Funds Management, Inc. (2001 – present); Senior Managing Director, State Street Global Advisors (1992 –present); Director, State Street Global Advisors Funds Distributors, LLC (May 2017 – present).

Bruce S. Rosenberg SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1961	Treasurer	Term: Indefinite Elected: 2/16	Managing Director, State Street Global Advisors and SSGA Funds Management, Inc. (July 2015 – present); Director, Credit Suisse (April 2008 – July 2015).

Ann M. Carpenter SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1966	Vice President and Deputy Treasurer	Term: Indefinite Elected: 10/12 Term: Indefinite Elected: 2/16	Chief Operating Officer, SSGA Funds Management, Inc. (April 2005 – present) ; Managing Director, State Street Global Advisors. (2005 –present).

Chad C. Hallett SSGA Funds Management, Inc. One Iron Street Boston, MA 02210	Deputy Treasurer	Term: Indefinite Elected: 2/16	Vice President, State Street Global Advisors and SSGA Funds Management, Inc. (November 2014 – present); Vice President, State Street Bank and Trust Company (2001 –November 2014).*
YOB: 1969


NAME, ADDRESS, AND YEAR OF BIRTH	POSITION(S) HELD WITH TRUST	TERM OF OFFICE AND LENGTH OF TIME SERVED	PRINCIPAL OCCUPATION DURING PAST FIVE YEARS

Darlene Anderson-Vasquez SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1968	Deputy Treasurer	Term: Indefinite Elected: 11/16	Managing Director, State Street Global Advisors and SSGA Funds Management, Inc. (May 2016 – present); Senior Vice President, John Hancock Investments (September 2007 – May 2016).

Arthur A. Jensen SSGA Funds Management, Inc. 1600 Summer Street Stamford, CT 06905 YOB: 1966	Deputy Treasurer	Term: Indefinite Elected: 11/16	Vice President State Street Global Advisors and SSGA Funds Management, Inc. (July 2016 – present); Deputy Treasurer of Elfun Funds (July 2016 – present); Treasurer of State Street Institutional Funds, State Street Variable Insurance Series Funds, Inc. and GE Retirement Savings Plan Funds (June 2011 – present); Treasurer of Elfun Funds (June 2011– July 2016); Mutual Funds Controller of GE Asset Management Incorporated (April 2011 – July 2016).

Sujata Upreti SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1974	Assistant Treasurer	Term: Indefinite Elected: 2/16	Vice President, State Street Global Advisors and SSGA Funds Management, Inc. (May 2015 – present); Assistant Director, Cambridge Associates, LLC (July 2014 – January 2015); Vice President, Bank of New York Mellon (July 2012 – August 2013); Manager, PricewaterhouseCoopers, LLP (September 2003 – July 2012).

Daniel Foley SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1972	Assistant Treasurer	Term: Indefinite Elected: 2/16	Vice President, State Street Global Advisors and SSGA Funds Management, Inc. (April 2007 – present).*

Daniel G. Plourde SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1980	Assistant Treasurer	Term: Indefinite Elected: 5/17	Vice President, State Street Global Advisors and SSGA Funds Management, Inc. (May 2015 – present); Officer, State Street Bank and Trust Company (March 2009 – May 2015).

Brian Harris SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1973	Chief Compliance Officer, Anti-Money Laundering Officer and Code of Ethics Compliance Officer	Term: Indefinite Elected: 11/13 Term: Indefinite Elected: 9/16	Managing Director, State Street Global Advisors and SSGA Funds Management, Inc. (June 2013—Present); Senior Vice President and Global Head of Investment Compliance, BofA Global Capital Management (September 2010 – May 2013).

Joshua A. Weinberg SSGA Funds Management, Inc. One Iron Street Boston, MA 02210 YOB: 1978	Chief Legal Officer	Term: Indefinite Elected: 2/15	Managing Director and Managing Counsel, State Street Global Advisors (2011 – present)*; Clerk, SSGA Funds Management, Inc. (2013 – present); Associate, Financial Services Group, Dechert LLP (2005 – 2011).

Jesse D. Hallee State Street Bank and Trust Company 100 Summer Street, 7 ^th Floor Boston, MA 02111	Secretary	Term: Indefinite Elected: 9/16	Vice President and Managing Counsel, State Street Bank and Trust Company (2013 – present); Vice President and Counsel, Brown Brothers Harriman & Co. (2007-2013).
YOB: 1976

*	Served in various capacities and/or with various affiliated entities during noted time period.

Summary of Trustees’ Qualifications

Following is a summary of the experience, attributes and skills which qualify each Trustee to serve on the Board of Trustees of the Trust and State Street Master Funds.

Standing Committees

The Board of Trustees has established various committees to facilitate the timely and efficient consideration of various matters of importance to Independent Trustees, the Trust, and the Trust’s shareholders and to facilitate compliance with legal and regulatory requirements. Currently, the Board has created an Audit Committee, Governance Committee, Nominating Committee, Valuation Committee and Qualified Legal Compliance Committee.

attention of the Trust’s Secretary, at the address of the principal executive offices of the Trust. Shareholder recommendations must be delivered to, or mailed and received at, the principal executive offices of the Trust not less than sixty (60) calendar days nor more than ninety (90) calendar days prior to the date of the Board or shareholder meeting at which the nominee candidate would be considered for election. The Governance Committee performs an annual self-evaluation of Board members. During the fiscal year ended December 31, 2018, the Governance Committee held one meeting and the Nominating Committee held two meeting.

The Qualified Legal Compliance Committee (the “QLCC”) is composed of all the Independent Trustees. The primary functions of the QLCC are to receive quarterly reports from the Trust’s CCO; to oversee generally the Trust’s responses to regulatory inquiries; and to investigate matters referred to it by the Chief Legal Officer and make recommendations to the Board regarding the implementation of an appropriate response to evidence of a material violation of the securities laws or breach of fiduciary duty or similar violation by the Trust, its officers or the Trustees. During the fiscal year ended December 31, 2018, the QLCC held four meetings.

Leadership Structure and Risk Management Oversight

The Board has delegated management of the Trust to service providers who are responsible for the day-to-day management of risks applicable to the Trust. The Board oversees risk management for the Trust in several ways. The Board receives regular reports from both the CCO and administrator for the Trust, detailing the results of the Trust’s compliance with its Board-adopted policies and procedures, the investment policies and limitations of the Portfolios, and applicable provisions of the federal securities laws and the Code. As needed, the Adviser discusses management issues regarding the Trust with the Board, soliciting the Board’s input on many aspects of management, including potential risks to the Portfolios. The Board’s Audit Committee also receives reports on various aspects of risk that might affect the Trust and offers advice to management, as appropriate. The Trustees also meet in executive session with the independent counsel to the Independent Trustees, the independent registered public accounting firm, counsel to the Trust, the CCO and representatives of management, as needed. Through these regular reports and interactions, the Board oversees the risk management parameters for the Trust, which are effected on a day-to-day basis by service providers to the Trust.

Trustee Ownership of Securities of the Trust, Adviser and Distributor

As of December 31, 2018, none of the Independent Trustees or their immediate family members had any ownership of securities of the Adviser or State Street Global Advisors Funds Distributors, LLC (“SSGA FD”), the Trust’s distributor, or any person directly or indirectly controlling, controlled by or under common control with the Adviser or SSGA FD.

The following table sets forth information describing the dollar range of the Trust’s equity securities beneficially owned by each Trustee as of December 31, 2018.


	Dollar Range Of Equity Securities In The Portfolios		Aggregate Dollar Range Of Equity Securities In All Registered Investment Companies Overseen By Trustees In Family of Investment Companies
Name of Independent Trustee
Michael F. Holland		None		None
Patrick J. Riley		None		Over $100,000
Richard D. Shirk		None		Over $100,000
Rina K. Spence		None		None
Bruce D. Taber		None		Over $100,000
Michael A. Jessee		None		None
John R. Costantino ⁽¹⁾		None		None
Donna M. Rapaccioli ⁽¹⁾		None		None
Name of Interested Trustees
James E. Ross		None		Over $100,000
Ellen M. Needham ⁽¹⁾		None		None

⁽¹⁾	Mr. Costantino and Mses. Rapaccioli and Needham became Trustees effective December 18, 2018.

Trustee Compensation

As of January 1, 2019, except as noted below, each Independent Trustee receives for his or her services to the State Street Master Funds, the State Street Institutional Investment Trust, the SSGA Funds, the Elfun Funds, the Navigator Trust, State Street Institutional Funds and State Street Variable Insurance Series Funds, Inc. a $195,000 annual base retainer in addition to $22,500 for each in-person meeting $6,000 for each special in-person meeting and $2,500 for each telephonic meeting from the Trusts. The Trust pays a fixed allocation of $18,000 per Fund. The Co-Chairpersons receive an additional $50,000 annual retainer. The annual base retainer paid to Mr. Taber is $164,000 in light of the fact that Mr. Taber does not serve as a member of the Board of Trustees of the Elfun Funds, and the Board of Directors of State Street Institutional Funds and State Street Variable Insurance Series Funds, Inc. The Independent Trustees are reimbursed for travel and other out-of-pocket expenses in connection with meeting attendance. As of the date of this SAI, the Trustees are not paid pension or retirement benefits as part of the Trust’s expenses.

The Trust’s officers are compensated by the Adviser and its affiliates.

The following table sets forth the total remuneration of Trustees and officers of the Trust for the fiscal year ended December 31, 2018:


	AGGREGATE COMPENSATION FROM THE TRUST		PENSION OR RETIREMENT BENEFITS ACCRUED AS PART OF TRUST EXPENSES		ESTIMATED ANNUAL BENEFITS UPON RETIREMENT		TOTAL COMPENSATION FROM TRUST & FUND COMPLEX PAID TO TRUSTEES
NAME OF INDEPENDENT TRUSTEE
Michael F. Holland	$	109,882	$	0	$	0	$	330,500
William L. Marshall ⁽¹⁾	$	88,093	$	0	$	0	$	287,500
Patrick J. Riley	$	110,816	$	0	$	0	$	337,500
Richard D. Shirk	$	88,093	$	0	$	0	$	287,500
Rina K. Spence	$	88,093	$	0	$	0	$	287,500
Bruce D. Taber	$	87,202	$	0	$	0	$	281,500
Douglas T. Williams ⁽¹⁾	$	88,093	$	0	$	0	$	287,500
Michael A. Jessee	$	88,093	$	0	$	0	$	287,500
John R. Costantino ⁽²⁾	$	0	$	0	$	0	$	170,000
Donna M. Rapaccioli ⁽²⁾	$	0	$	0	$	0	$	160,000
NAME OF INTERESTED TRUSTEES
James E. Ross	$	0	$	0	$	0	$	0
Ellen M. Needham ⁽²⁾	$	0	$	0	$	0	$	0

⁽¹⁾	Messrs. Marshall and Williams retired as Trustees effective as of the close of business on December 18, 2018.

⁽²⁾	Mr. Costantino and Mses. Rapaccioli and Needham became Trustees effective December 18, 2018.

PROXY VOTING PROCEDURES

The Trust has adopted proxy voting procedures pursuant to which the Trust delegates the responsibility for voting proxies relating to portfolio securities held by the Portfolios to the Adviser, as part of the Adviser’s general management of the Portfolios, subject to the Board’s continuing oversight. A copy of the Trust’s proxy voting procedures is located in Appendix B and a copy of the Adviser’s proxy voting procedures is located in Appendix C.

Shareholders may receive information regarding how the Portfolios voted proxies relating to portfolio securities during the most recent 12-month period ending June 30 (i) by calling (877) 521-4083 or (ii) on the SEC’s website at www.sec.gov.

CONTROL PERSONS AND PRINCIPAL HOLDERS OF SECURITIES

As of April 23, 2019, the Trustees and officers of the Trust owned in the aggregate less than 1% of the shares of each class (if applicable) of each Portfolio.

Persons or organizations owning more than 25% of the voting shares of a Portfolio may be presumed to “control” (as that term is defined in the 1940 Act) a Portfolio. As a result, these persons or organizations could have the ability to approve or reject those matters submitted to the shareholders of such Portfolio for their approval.

As of April 23, 2019, to the knowledge of the Trust, the following persons held of record or beneficially through one or more accounts 25% or more of the outstanding shares of a Portfolio.


Name and Address	Percentage
State Street Equity 500 Index II Portfolio
State Street Equity 500 Index Fund One Iron Street Boston, MA 02210		31.14	%

As of April 23, 2019, to the knowledge of the Trust, the following persons held of record or beneficially through one or more accounts 5% or more of the outstanding shares of a Portfolio.


Name and Address	Percentage
State Street Equity 500 Index II Portfolio
State Street Target Retirement 2020 Fund One Iron Street Boston, MA 02210		7.35	%
State Street Equity 500 Index II Portfolio
State Street Target Retirement 2025 Fund One Iron Street Boston, MA 02210		11.49	%
State Street Equity 500 Index II Portfolio
State Street Target Retirement 2030 Fund One Iron Street Boston, MA 02210		12.57	%
State Street Equity 500 Index II Portfolio
State Street Target Retirement 2035 Fund One Iron Street Boston, MA 02210		11.13	%
State Street Equity 500 Index II Portfolio
State Street Target Retirement 2040 Fund One Iron Street Boston, MA 02210		9.27	%


Name and Address	Percentage
State Street Equity 500 Index II Portfolio
State Street Target Retirement 2045 Fund One Iron Street Boston, MA 02210		7.03	%
State Street Aggregate Bond Index Portfolio
State Street Target Retirement 2020 Fund One Iron Street Boston, MA 02210		23.77	%
State Street Target Retirement 2015 Fund One Iron Street Boston, MA 02210		5.67	%
State Street Target Retirement 2025 Fund One Iron Street Boston, MA 02210		20.56	%
State Street Target Retirement 2030 Fund One Lincoln Street Boston, MA 02111		14.95	%
State Street Target Retirement 2035 Fund One Iron Street Boston, MA 02210		10.36	%
State Street Aggregate Bond Index Fund One Iron Street Boston, MA 02210		14.82	%
State Street Global Equity ex-US Index Portfolio
State Street Target Retirement 2020 Fund One Iron Street Boston, MA 02210		6.85	%
State Street Target Retirement 2025 Fund One Iron Street Boston, MA 02210		11.75	%
State Street Target Retirement 2030 Fund One Iron Street Boston, MA 02210		13.72	%
State Street Target Retirement 2035 Fund One Iron Street Boston, MA 02210		12.66	%
State Street Target Retirement 2040 Fund One Iron Street Boston, MA 02210		10.95	%
State Street Target Retirement 2045 Fund One Iron Street Boston, MA 02210		8.73	%
State Street Target Retirement 2050 Fund One Iron Street Boston, MA 02210		5.72	%
State Street Global Equity Ex-Us Index Feeder Fund One Iron Street Boston, MA 02210		21.65	%
State Street Small/Mid Cap Equity Index Portfolio
State Street Target Retirement 2020 Feeder Fund One Iron Street Boston, MA 02210		6.29	%
State Street Target Retirement 2025 Feeder Fund One Iron Street Boston, MA 02210		11.67	%


Name and Address	Percentage
State Street Target Retirement 2030 Feeder Fund One Iron Street Boston, MA 02210		15.04	%
State Street Target Retirement 2035 Feeder Fund One Iron Street Boston, MA 02210		15.25	%
State Street Target Retirement 2040 Feeder Fund One Iron Street Boston, MA 02210		14.62	%
State Street Target Retirement 2045 Feeder Fund One Iron Street Boston, MA 02210		12.77	%
State Street Target Retirement 2050 Feeder Fund One Iron Street Boston, MA 02210		8.59	%
State Street Small Midcap Equity Index Fund One Iron Street Boston, MA 02210		8.58	%

INVESTMENT ADVISORY AND OTHER SERVICES

Investment Advisory Agreement

SSGA FM is responsible for the investment management of the Portfolios pursuant to the Amended and Restated Investment Advisory Agreement dated November 17, 2015, as amended from time to time (the “Advisory Agreement”), by and between the Adviser and the Trust. The Adviser is a wholly-owned subsidiary of State Street Global Advisors, Inc., which itself is a wholly-owned subsidiary of State Street Corporation, a publicly held financial holding company. State Street is a wholly-owned subsidiary of State Street Corporation.

The Portfolios do not pay an advisory fee to SSGA FM.

The Adviser and its affiliates may have deposit, loan and other commercial banking relationships with the issuers of obligations that may be purchased on behalf of the Portfolios, including outstanding loans to such issuers that could be repaid in whole or in part with the proceeds of securities so purchased. Such affiliates deal, trade and invest for their own accounts in such obligations and are among the leading dealers of various types of such obligations. The Adviser has informed the Portfolios that, in making its investment decisions, it will not obtain or use material non-public information in its possession or in the possession of any of its affiliates. In making investment recommendations for a Portfolio, the Adviser will not inquire or take into consideration whether an issuer of securities proposed for purchase or sale by the Portfolio is a customer of the Adviser, its parent or its subsidiaries or affiliates and, in dealing with its customers, the Adviser, its parent, subsidiaries and affiliates will not inquire or take into consideration whether securities of such customers were held by any portfolio managed by the Adviser or any such affiliate.

In certain instances there may be securities that are suitable for a Portfolio as well as for one or more of the Adviser’s other clients. Investment decisions for the Trust and for the Adviser’s other clients are made with a view to achieving their respective investment objectives. It may develop that a particular security is bought or sold for only one client even though it might be held by, or bought or sold for, other clients. Likewise, a particular security may be bought for one or more clients when one or more clients are selling that same security. Some simultaneous transactions are inevitable when several clients receive investment advice from the same investment adviser, particularly when the same security is suitable for the investment objectives of more than one client. When two or more clients are simultaneously engaged in the purchase or sale of the same security, the securities are allocated among clients in a manner believed to be equitable to each. The Trust recognizes that in some cases this system could have a detrimental effect on the price or volume of the security as far as a Portfolio is concerned. However, it is believed that the ability of each Portfolio to participate in volume transactions will produce better executions for the Portfolios.

Total Annual Fund Operating Expense Waivers . The Adviser has contractually agreed with the Trust, through April 30, 2020 (i) to waive up to the full amount of the advisory fee, if any, payable by a Portfolio, and/or (ii) to reimburse a Portfolio for expenses to the extent that Total Annual Fund Operating Expenses (subject to certain exclusions as described in each Portfolio’s Prospectus) exceed the following percentage of average daily net assets on an annual basis with respect to the below-listed Portfolios:


Fund	Expense Limitation
Equity 500 Index II Portfolio		0.02	%
Aggregate Bond Index Portfolio		0.025	%
Global Equity ex-U.S. Index Portfolio		0.08	%
Small/Mid Cap Equity Index Portfolio		0.03	%

Administrator

SSGA FM serves as the administrator for the Portfolios pursuant to an Amended and Restated Administration Agreement. Under the Amended and Restated Administration Agreement, SSGA FM is obligated to continuously provide business management services to the Trust and the Portfolios and will generally, subject to the general oversight of the Trustees and except as otherwise provided in the Amended and Restated Administration Agreement, manage all of the business and affairs of the Trust.

The administration fees paid to SSGA FM as the administrator for the fiscal years ended December 31, 2016, December 31, 2017, and December 31, 2018 are set forth in the table below:


Portfolio	Fiscal year ended December 31, 2016		Fiscal year ended December 31, 2017		Fiscal year ended December 31, 2018
Equity 500 Index II Portfolio	$	2,666	$	5,785	$	0
Aggregate Bond Index Portfolio	$	466	$	1,400	$	0
Global Equity ex-U.S. Index Portfolio	$	949	$	3,470	$	0
Small/Mid Cap Equity Index Portfolio	$	247	$	954	$	0

The administration fees paid by the Ultra Short Term Bond Portfolio have been omitted because the Portfolio had not commenced investment operations as of December 31, 2018.

Sub-Administrator, Custody, Fund Accounting and Transfer Agency

State Street serves as the sub-administrator for the Trust, pursuant to a sub-administration agreement dated June 1, 2015 (the “Sub-Administration Agreement”). State Street serves as the custodian for the Trust, pursuant to a custody agreement dated April 11, 2012 (the “Custody Agreement”). Under the Sub-Administration Agreement, State Street is obligated to provide certain sub-administrative services to the Trust. Under the Custody Agreement, State Street is obligated to provide certain custody services to the Trust, as well as basic portfolio recordkeeping required by the Trust for regulatory and financial reporting purposes. State Street also serves as the transfer agent for the Portfolios, pursuant to a transfer agency agreement dated February 28, 2000. State Street is a wholly owned subsidiary of State Street Corporation, a publicly held financial holding company, and is affiliated with the Adviser. State Street’s mailing address is State Street Financial Center, One Lincoln Street, Boston, Massachusetts 02111-2900.

As consideration for transfer agency, sub-administration services, State Street receives an annual fee from the Adviser (payable monthly). As consideration for custody and fund accounting services, each Portfolio pays State Street an annual fee (payable monthly) based on the average monthly net assets of each Portfolio. Each Portfolio also pays State Street transaction and service fees for these services and reimburses State Street for out-of-pocket expenses.

The sub-administration, custodian and transfer agency fees paid to State Street for the last three fiscal years are set forth in the table below.


Portfolio	Fiscal year ended December 31, 2016		Fiscal year ended December 31, 2017		Fiscal year ended December 31, 2018
Equity 500 Index II Portfolio	$	104,064	$	221,594	$	366,437
Aggregate Bond Index Portfolio	$	18,175	$	53,670	$	124,114
Global Equity ex-U.S. Index Portfolio	$	513,066	$	355,582	$	789,977
Small/Mid Cap Equity Index Portfolio ⁽¹⁾	$	13,338	$	36,574	$	104,584

The sub-administration, custodian and transfer agency paid by the Ultra Short Term Bond Portfolio have been omitted because the Portfolio had not commenced investment operations as of December 31, 2018.

Securities Lending

The Portfolio’s Board has approved each Portfolio’s participation in a securities lending program. Under the securities lending program, each Portfolio has retained State Street to serve as the securities lending agent.

For the fiscal year ended December 31, 2018, the income earned by each Portfolio as well as the fees and/or compensation paid by each Portfolio (in dollars) pursuant to the Master Amended and Restated Securities Lending Authorization Agreement among SSGA Funds, State Street Institutional Investment Trust, and State Street Master Funds, each on behalf of its respective series, and State Street (the “Securities Lending Authorization Agreement”) were as follows:


			Fees and/or compensation paid by the Portfolio for securities lending activities and related services
	Gross income earned by the Portfolio from securities lending activities		Fees paid to State Street from a revenue split		Fees paid for any cash collateral management service (including fees deducted from a pooled cash collateral reinvestment vehicle) that are not included in a revenue split		Administrative fees not included in a revenue split		Indemnification fees not included in a revenue split		Rebate (paid to borrower)		Other fees not included in a revenue split		Aggregate fees/ compensation paid by the Portfolio for securities lending activities		Net income from securities lending activities
State Street Equity 500 Index II Portfolio	$	59,356	$	5,990	$	397	$	0.00	$	0.00	$	19,033	$	0.00	$	25,420	$	33,935
State Street Global Equity ex-U.S. Index Portfolio	$	1,046,631	$	109,338	$	9,266	$	0.00	$	0.00	$	308,482	$	0.00	$	427,087	$	619,544

For the fiscal year ended December 31, 2018, State Street, acting as agent of the Portfolios, provided the following services to the Portfolios in connection with the Portfolios’ securities lending activities: (i) locating borrowers among an approved list of prospective borrowers; (ii) monitoring the value of loaned securities, the value of collateral received and other lending parameters; (iii) seeking additional collateral, as necessary, from borrowers; (iv) receiving and holding collateral from borrowers, and facilitating the investment and reinvestment of all or substantially all cash collateral in an investment vehicle designated by the Portfolios; (v) returning collateral to borrowers; (vi) facilitating substitute dividend, interest, and other distribution payments to the Portfolios from borrowers; (vii) negotiating the terms of each loan of securities, including but not limited to the amount of any loan premium, and monitoring the terms of securities loan agreements with prospective borrowers for consistency with the requirements of the Portfolios’ Securities Lending Authorization Agreement; (viii) selecting securities, including amounts (percentages), to be loaned; (ix) recordkeeping and accounting servicing; and (x) arranging for return of loaned securities to the Portfolios in accordance with the terms of the Securities Lending Authorization Agreement.

Codes of Ethics

The Trust, the Adviser, and SSGA FD have each adopted a code of ethics (together, the “Codes of Ethics”) pursuant to Rule 17j-1 under the 1940 as required by applicable law, which is designed to prevent affiliated persons of the Trust, the Adviser and SSGA FD from engaging in deceptive, manipulative or fraudulent activities in connection with securities held or to be acquired by the Portfolios (which may also be held by persons subject to the Codes of Ethics). The Codes of Ethics permit personnel, subject to the Codes of Ethics and their provisions and subject to certain limitations, to invest in securities for their personal investment accounts, including securities that may be purchased or held by the Trust, Adviser, State Street or SSGA FD.

Distributor

SSGA FD (the “Distributor”) serves as the distributor of the Portfolios. SSGA FD is an indirect wholly-owned subsidiary of State Street Corporation. SSGA FD’s mailing address is One Iron Street, Boston, MA 02210.

Shareholder Servicing and Distribution Plans

Investments in the Portfolios are not subject to any sales load or redemption fee. Assets of the Portfolios are not subject to a Rule 12b-1 fee.

Counsel and Independent Registered Public Accounting Firm

PORTFOLIO MANAGERS

The following persons serve as the portfolio managers of the Portfolios as of the date of this SAI. The following table lists the number and types of accounts managed by each individual and assets under management in those accounts as of December 31, 2018:


Portfolio Manager	Registered Investment Company Accounts		Assets Managed (billions)*		Other Pooled Investment Vehicle Accounts		Assets Managed (billions)		Other Accounts		Assets Managed (billions)*		Total Assets Managed (billions)
Michael Feehily		141	$	495.53		251	$	281.41		448	$	247.59	$	1,024.53
Karl Schneider		141	$	495.53		251	$	281.41		448	$	247.59	$	1,024.53
Ted Janowsky		141	$	495.53		251	$	281.41		448	$	247.59	$	1,024.53
Amy Scofield		141	$	495.53		251	$	281.41		448	$	247.59	$	1,024.53
Olga Winner		141	$	495.53		251	$	281.41		448	$	247.59	$	1,024.53
Marc DiCosimo		31	$	58.57		107	$	74.64		138	$	67.31	$	200.52
Joanna Madden		31	$	58.57		107	$	74.64		138	$	67.31	$	200.52
Todd Bean		13	$	89.82		18	$	82.09		67	$	86.61	$	258.52
Sean Lussier		13	$	89.82		18	$	82.09		67	$	86.61	$	258.52
Thomas Connelley		13	$	89.82		18	$	82.90		67	$	86.61	$	258.52

*	There are no performance-based fees associated with these accounts.

The portfolio managers do not beneficially own any shares of any Portfolio as of December 31, 2018.

A potential conflict of interest may arise as a result of the portfolio managers’ responsibility for multiple accounts with similar investment guidelines. Under these circumstances, a potential investment may be suitable for more than one of the portfolio managers’ accounts, but the quantity of the investment available for purchase is less than the aggregate amount the accounts would ideally devote to the opportunity. Similar conflicts may arise when multiple accounts seek to dispose of the same investment. The portfolio managers may also manage accounts whose objectives and policies differ from that of the Portfolios. These differences may be such that under certain circumstances, trading activity appropriate for one account managed by the portfolio manager may have adverse consequences for another account managed by the portfolio manager. For example, an account may sell a significant position in a security, which could cause the market price of that security to decrease, while a fund maintained its position in that security.

A potential conflict may arise when the portfolio managers are responsible for accounts that have different advisory fees. The difference in fees could create an incentive for the portfolio manager to favor one account over another, for example, in terms of access to investment opportunities. Another potential conflict may arise when the portfolio manager has an investment in one or more accounts that participate in transactions with other accounts. His or her investment(s) may create an incentive for the portfolio manager to favor one account over another. The Adviser has adopted policies and procedures reasonably designed to address these potential material conflicts. For instance, portfolio managers are normally responsible for all accounts within a certain investment discipline and do not, absent special circumstances, differentiate among the various accounts when allocating resources. Additionally, the Adviser and its advisory affiliates have processes and procedures for allocating investment opportunities among portfolios that are designed to provide a fair and equitable allocation.

SSGA recognizes and rewards outstanding performance by:

•

Promoting employee ownership to connect employees directly to the company’s success.

•

Using rewards to reinforce mission, vision, values and business strategy.

•

Seeking to recognize and preserve the firm’s unique culture and team orientation.

•

Providing all employees the opportunity to share in the success of SSGA.

BROKERAGE ALLOCATION AND OTHER PRACTICES

•

Prompt and reliable execution;

•

The competitiveness of commission rates and spreads, if applicable;

•

The financial strength, stability and/or reputation of the trading counterparty;

•

The willingness and ability of the executing trading counterparty to execute transactions (and commit capital) of size in liquid and illiquid markets without disrupting the market for the security;

•

Local laws, regulations or restrictions;

•

The ability of the trading counterparty to maintain confidentiality;

•

The availability and capability of execution venues, including electronic communications networks for trading and execution management systems made available to Adviser;

•

Market share;

•

Liquidity;

•

Price;

•

Execution related costs;

•

History of execution of orders;

•

Likelihood of execution and settlement;

•

Order size and nature;

•

Clearing and settlement capabilities, especially in high volatility market environments;

•

Availability of lendable securities;

•

Sophistication of the trading counterparty’s trading capabilities and infrastructure/facilities;

•

The operational efficiency with which transactions are processed and cleared, taking into account the order size and complexity;

•

Speed and responsiveness to the Adviser;

•

Access to secondary markets;

•

Counterparty exposure; and

•

Any other consideration the Adviser believes is relevant to the execution of the order.

(i) The nature and characteristics of the order or transaction. For example, size of order, market impact of order, limits, or other instructions relating to the order;

(iii) The characteristics of the execution venues to which that order can be directed, if relevant. For example, availability and capabilities of electronic trading systems;

(v) Any other circumstances relevant the Adviser believes is relevant at the time.

The brokerage commissions paid by the Portfolios for the last three fiscal years are shown below:


Portfolio	Fiscal year ended December 31 2016		Fiscal year ended December 31 2017		Fiscal year ended December 31 2018
Equity 500 Index II Portfolio	$	40,301	$	91,884	$	56,546
Aggregate Bond Index Portfolio		—		—		—
Global Equity ex-U.S. Index Portfolio	$	152,651	$	310,966	$	185,330
Small/Mid Cap Equity Index Portfolio ⁽¹⁾	$	16,649	$	52,601	$	58,356

The increase in brokerage commissions paid by the Equity 500 Index II Portfolio, Global Equity ex-U.S. Index Portfolio and Small/Mid Cap Equity Index Portfolio for the fiscal year ended December 31, 2017 as compared to the fiscal year ended December 31, 2016 was generally due to an increase in trading activity caused by an increase in assets during the year.

The brokerage commissions paid by the Ultra Short Term Bond Portfolio have been omitted because the Portfolio had not commenced investment operations as of December 31, 2018.

Securities of “Regular Broker-Dealer.” Each Portfolio is required to identify any securities of its “regular brokers and dealers” (as such term is defined in the 1940 Act) which it may hold at the close of its most recent fiscal year. “Regular brokers or dealers” of the Trust are the ten brokers or dealers that, during the most recent fiscal year: (i) received the greatest dollar amounts of brokerage commissions from the Trust’s portfolio transactions; (ii) engaged as principal in the largest dollar amounts of portfolio transactions of the Trust; or (iii) sold the largest dollar amounts of the Trust’s shares.

Holdings in Securities of Regular Broker-Dealers as of December 31, 2018.


JPMorgan Chase & Co.	$	45,010,592
Bank of America Corp	$	31,567,811
Citigroup, Inc.	$	19,341,527
HSBC Holdings PLC	$	18,486,996
Goldman Sachs & Co.	$	11,665,741
Morgan Stanley	$	10,829,479
UBS Securities LLC	$	8,766,056
Barclays Capital	$	4,301,255
Credit Suisse	$	3,676,640
Virtu Financial	$	141,680

For the fiscal year ending December 31, 2018, the Equity 500 Index II Portfolio experienced an increase in portfolio turnover, compared to the previous period, due to a rebalancing of constituent securities in the underlying index which it tracks.

DECLARATION OF TRUST, CAPITAL STOCK AND OTHER INFORMATION

Capitalization

Under the Declaration of Trust, the Trustees are authorized to issue an unlimited number of shares of each Portfolio. Upon liquidation or dissolution of a Portfolio, investors are entitled to share pro rata in the Portfolio’s net assets available for distribution to its investors. Investments in a Portfolio have no preference, preemptive, conversion or similar rights, except as determined by the Trustees or as set forth in the Bylaws, and are fully paid and non-assessable, except as set forth below.

Declaration of Trust

The Declaration of Trust of the Trust provides that the Trust may redeem shares of a Portfolio at the redemption price that would apply if the share redemption were initiated by a shareholder. It is the policy of the Trust that, except upon such conditions as may from time to time be set forth in the then current prospectus of the Trust or to facilitate the Trust’s or a Portfolio’s compliance with applicable law or regulation, the Trust would not initiate a redemption of shares unless it were to determine that failing to do so may have a substantial adverse consequence for the Portfolio or the Trust.

The Trust’s Declaration of Trust provides that a Trustee who is not an “interested person” (as defined in the 1940 Act) of the Trust will be deemed independent and disinterested with respect to any demand made in connection with a derivative action or proceeding. It is the policy of the Trust that it will not assert that provision to preclude a shareholder from claiming that a trustee is not independent or disinterested with respect to any demand made in connection with a derivative action or proceeding; provided, however, that the foregoing policy will not prevent the Trust from asserting applicable law (including Section 2B of Chapter 182 of the Massachusetts General Laws) to preclude a shareholder from claiming that a trustee is not independent or disinterested with respect to any demand made in connection with a derivative action or proceeding.

The Trust will not deviate from the foregoing policies in a manner that adversely affects the rights of shareholders of a Portfolio without the approval of “a vote of a majority of the outstanding voting securities” (as defined in the 1940 Act) of such Portfolio.

Voting

Each investor is entitled to a vote in proportion to the number of Portfolio shares it owns. Shares do not have cumulative voting rights in the election of Trustees, and investors holding more than 50% of the aggregate outstanding shares in the Trust may elect all of the Trustees if they choose to do so. The Trust is not required and has no current intention to hold annual meetings of investors but the Trust will hold special meetings of shareholders when in the judgment of the Trustees it is necessary or desirable to submit matters for a shareholder vote.

Massachusetts Business Trust

Under Massachusetts law, shareholders in a Massachusetts business trust could, under certain circumstances, be held personally liable for the obligations of the trust. However, the Declaration of Trust disclaims shareholder liability for acts or obligations of the Trust and provides for indemnification out of the property of the applicable series of the Trust for any loss to which the shareholder may become subject by reason of being or having been a shareholder of that series and for reimbursement of the shareholder for all expense arising from such liability. Thus the risk of a shareholder incurring financial loss on account of shareholder liability should be limited to circumstances in which the series would be unable to meet its obligations.

PRICING OF SHARES

Pricing of shares of the Portfolios does not occur on New York Stock Exchange (“NYSE”) holidays. The NYSE is open for trading every weekday except for: (a) the following holidays: New Year’s Day, Martin Luther King, Jr.’s Birthday, Washington’s Birthday (the third Monday in February), Good Friday, Memorial Day, Independence Day, Labor Day, Thanksgiving Day and Christmas; and (b) the preceding Friday or the subsequent Monday when one of the calendar-determined holidays falls on a Saturday or Sunday, respectively. Purchases and withdrawals will be effected at the time of determination of NAV next following the receipt of any purchase or withdrawal order which is determined to be in good order.

The Portfolios’ securities will be valued pursuant to guidelines established by the Board of Trustees.

TAXATION OF THE PORTFOLIOS

The following discussion of U.S. federal income tax consequences of an investment in the Portfolios is based on the Code, U.S. Treasury regulations, and other applicable authority, as of the date of this SAI. These authorities are subject to change by legislative or administrative action, possibly with retroactive effect. The following discussion is only a summary of some of the important U.S. federal income tax considerations generally applicable to investments in the Portfolios. There may be other tax considerations applicable to particular shareholders. Shareholders should consult their own tax advisors regarding their particular situation and the possible application of foreign, state and local tax laws.

Special tax rules apply to investments through defined contribution plans and other tax-qualified plans or tax-advantaged arrangements. Shareholders should consult their tax advisers to determine the suitability of shares of a Portfolio as an investment through such plans and arrangements and the precise effect of an investment on their particular tax situations.

Qualification as a Regulated Investment Company

Each Portfolio has elected or intends to elect to be treated as a regulated investment company (“RIC”) under Subchapter M of the Code and intends each year to qualify and be eligible to be treated as such. In order to qualify for the special tax treatment accorded RICs and their shareholders, each Portfolio must, among other things, (a) derive at least 90% of its gross income for each taxable year from (i) dividends, interest, payments with respect to certain securities loans, gains from the sale of securities or foreign currencies, or other income (including but not limited to gains from options, futures or forward contracts) derived with respect to its business of investing in such stock, securities or currencies and (ii) net income derived from interests in “qualified publicly traded partnerships” (as defined below); (b) diversify its holdings so that, at the end of each quarter of the Portfolio’s taxable year, (i) at least 50% of the value of the Portfolio’s total assets consists of cash and cash items, U.S. Government securities, securities of other RICs, and other securities limited in respect of any one issuer to a value not greater than 5% of the value of the Portfolio’s total assets and no more than 10% of the outstanding voting securities of such issuer, and (ii) no more than 25% of its assets are invested, including through corporations in which the Portfolio owns a 20% or more voting stock interest, (x) in the securities (other than those of the U.S. Government or other RICs) of any one issuer or of two or more issuers which the Portfolio controls and which are engaged in the same, similar or related trades and businesses, or (y) in the securities of one or more qualified publicly traded partnerships (as defined below); and (c) distribute with respect to each taxable year at least 90% of the sum of its investment company taxable income (as that term is defined in the Code without regard to the deduction for dividends paid — generally taxable ordinary income and the excess, if any, of net short-term capital gains over net long-term capital losses) and net tax-exempt income, for such year.

In general, for purposes of the 90% gross income requirement described in (a) above, income derived from a partnership will be treated as qualifying income only to the extent such income is attributable to items of income of the partnership which would be qualifying income if realized directly by the RIC. However, 100% of the net income derived from an interest in a “qualified publicly traded partnership” (a partnership (x) the interests in which are traded on an established securities market or readily tradable on a secondary market or the substantial equivalent thereof, and (y) that derives less than 90% of its income from the qualifying income described in section (a)(i) of the preceding paragraph), will be treated as qualifying income. In general, such entities will be treated as partnerships for federal income tax purposes, because they meet the passive income requirement under Code section 7704(c)(2). Further, although in general the passive loss rules of the Code do not apply to RICs, such rules do apply to a RIC with respect to items attributable to an interest in a qualified publicly traded partnership.

For purposes of the diversification test in (b) above, the term “outstanding voting securities of such issuer” will include the equity securities of a qualified publicly traded partnership. Also, for purposes of the diversification test in (b) above, the identification of the issuer (or, in some cases, issuers) of a particular Portfolio investment can depend on the terms and conditions of that investment. In some cases, identification of the issuer (or issuers) is uncertain under current law, and an adverse determination or future guidance by the Internal Revenue Service (“IRS”) with respect to issuer identification for a particular type of investment may adversely affect a Portfolio’s ability to meet the diversification test in (b) above.

If a Portfolio qualifies as a RIC that is accorded special tax treatment, the Portfolio will not be subject to federal income tax on income or gains distributed in a timely manner to its shareholders in the form of dividends (including Capital Gain Dividends, as defined below). If a Portfolio were to fail to meet the income, diversification or distribution test described above, the Portfolio could in some cases cure such failure, including by paying a Portfolio-level tax, paying interest or disposing of certain assets. If such Portfolio were ineligible to or otherwise did not cure such failure for any year, or if such Portfolio were otherwise to fail to qualify as a RIC accorded special tax treatment in any taxable year, the Portfolio would be subject to tax at the Portfolio level on its taxable income at corporate rates, and all distributions from earnings and profits, including any distributions of net tax-exempt income and net capital gains (each as defined below), would be taxable to shareholders as ordinary income. Some portions of such distributions may be eligible for the dividends-received deduction in the case of corporate shareholders and may be eligible to be treated as “qualified dividend income” in the case of shareholders taxed as individuals, provided, in both cases, the shareholder meets certain holding period and other requirements in respect of a Portfolio’s shares (each as described below). In addition, a Portfolio could be required to recognize unrealized gains, pay substantial taxes and interest and make substantial distributions before re-qualifying as a RIC that is accorded special tax treatment.

Each Portfolio intends to distribute at least annually to its shareholders all or substantially all of its investment company taxable income (computed without regard to the dividends-paid deduction) and its net tax-exempt income (if any), and may distribute its net capital gain (that is, the excess of net long-term capital gain over net short-term capital loss, in each case determined with reference to any loss carryforwards). Any taxable income retained by a Portfolio will be subject to tax at the Portfolio level at regular corporate rates. If a Portfolio retains any net capital gain, it will be subject to tax at regular corporate rates on the amount retained, but is permitted to designate the retained amount as undistributed capital gain in a timely notice to its shareholders who (a) will be required to include in income for federal income tax purposes, as long-term capital gain, their shares of such undistributed amount, and (b) will be entitled to credit their proportionate shares of the tax paid by the Portfolio on such undistributed amount against their federal income tax liabilities, if any, and to claim refunds on a properly-filed U.S. tax return to the extent the credit exceeds such liabilities. If a Portfolio makes this designation, for U.S. federal income tax purposes, the tax basis of shares owned by a shareholder of the Portfolio will be increased by an amount equal to the difference between the amount of undistributed capital gains included in the shareholder’s gross income under clause (a) of the preceding sentence and the tax deemed paid by the shareholder under clause (b) of the preceding sentence. The Portfolios are not required to, and there can be no assurance a Portfolio will, make this designation if it retains all or a portion of its net capital gain in a taxable year.

If a Portfolio were to fail to distribute in a calendar year at least an amount equal, in general, to the sum of 98% of its ordinary income for such year and 98.2% of its capital gain net income for the one-year period ending October 31 of such year (or November 30 or December 31, if the Portfolio is eligible to elect and so elects), plus any such amounts retained from the prior year, the Portfolio would be subject to a nondeductible 4% excise tax on the undistributed amounts. For purposes of the required excise tax distribution, a RIC’s ordinary gains and losses from the sale, exchange or other taxable disposition of property that would otherwise be taken into account after October 31 of a calendar year (or November 30, if the Portfolio makes the election referred to above) generally are treated as arising on January 1 of the following calendar year in the case of a Portfolio with a December 31 year end that makes the election described above, no such gains or losses will be so treated. Also, for these purposes, a Portfolio will be treated as having distributed any amount on which it is subject to corporate income tax for the taxable year ending within the calendar year. Each Portfolio intends generally to make distributions sufficient to avoid imposition of the excise tax, although there can be no assurance that it will be able to do so. Distributions declared by a Portfolio during October, November and December to shareholders of record on a date in any such month and paid by the Portfolio during the following January will be treated for federal tax purposes as paid by the Portfolio and received by shareholders on December 31 of the year in which declared.

Capital losses in excess of capital gains (“net capital losses”) are not permitted to be deducted against a Portfolio’s net investment income. Instead, potentially subject to certain limitations, a Portfolio may carry net capital losses from any taxable year forward to subsequent taxable years to offset capital gains, if any, realized during such subsequent taxable years. Distributions from capital gains are generally made after applying any available capital loss carryforwards. Capital loss carryforwards are reduced to the extent they offset current-year net realized capital gains, whether the Portfolio retains or distributes such gains. A Portfolio may carry net capital losses forward to one or more subsequent taxable years without expiration; any such carryforward losses will retain their character as short-term or long-term. The Portfolio must apply such carryforwards first against gains of the same character. See a Portfolio’s most recent annual shareholder report for the Portfolio’s available capital loss carryovers as of the end of its most recently ended fiscal year.

Taxation of Distributions Received by Shareholders

For U.S. federal income tax purposes, distributions of investment income are generally taxable to shareholders as ordinary income. Taxes on distributions of capital gains are determined by how long the Portfolio owned (or is deemed to have owned) the investments that generated them, rather than how long a shareholder has owned his or her Portfolio shares. In general, a Portfolio will recognize long-term capital gain or loss on the disposition of assets the Portfolio has owned (or is deemed to have owned) for more than one year, and short-term capital gain or loss on the disposition of investments the Portfolio has owned (or is deemed to have owned) for one year or less. Distributions of net-capital gain (that is, the excess of net long-term capital gain over net short-term capital loss) that are properly reported by a Portfolio as capital gain dividends (“Capital Gain Dividends”) generally will be taxable to a shareholder receiving such distributions as long-term capital gains includible in net capital gain and taxed to individuals at reduced rates relative to ordinary income. Distributions from capital gains are generally made after applying any available capital loss carryovers. The Aggregate Bond Index Portfolio generally does not expect a significant portion of its distributions to be Capital Gain Dividends. Distributions of net short-term capital gain (as reduced by any net long-term capital loss for the taxable year) will be taxable to shareholders as ordinary income. Distributions of investment income properly reported by a Portfolio as derived from “qualified dividend income” will be taxed in the hands of individuals at the rates applicable to net capital gain, provided holding period and other requirements are met at both the shareholder and Portfolio level. The Aggregate Bond Index Portfolio does not expect its distributions to be derived from qualified dividend income.

The Code generally imposes a 3.8% Medicare contribution tax on the net investment income of certain individuals, trusts and estates to the extent their income exceeds certain threshold amounts. For these purposes, “net investment income” generally includes, among other things, (i) distributions paid by a Portfolio of net investment income and capital gains, and (ii) any net gain from the sale, redemption, exchange or other taxable disposition of Portfolio shares. Shareholders are advised to consult their tax advisors regarding the possible implications of this additional tax on their investment in a Portfolio.

If a Portfolio makes a distribution to a shareholder in excess of the Portfolio’s current and accumulated earnings and profits in any taxable year, the excess distribution will be treated as a return of capital to the extent of such shareholder’s tax basis in its shares, and thereafter as capital gain. A return of capital is not taxable, but it reduces a shareholder’s tax basis in its shares, thus reducing any loss or increasing any gain on a subsequent taxable disposition by the shareholder of its shares.

Shareholders of a Portfolio will be subject to federal income taxes as described herein on distributions made by the Portfolio whether received in cash or reinvested in additional shares of the Portfolio.

Distributions with respect to a Portfolio’s shares are generally subject to U.S. federal income tax as described herein to the extent they do not exceed the Portfolio’s realized income and gains, even though such distributions may economically represent a return of a particular shareholder’s investment. Such distributions are likely to occur in respect of shares purchased at a time when a Portfolio’s net asset value includes either unrealized gains, or realized but undistributed income or gains, that were therefore included in the price the shareholder paid. Such distributions may reduce the fair market value of the Portfolio’s shares below the shareholder’s cost basis in those shares. As described above, a Portfolio is required to distribute realized income and gains regardless of whether the Portfolio’s net asset value also reflects unrealized losses.

In order for some portion of the dividends received by a Portfolio shareholder to be “qualified dividend income,” the Portfolio must meet holding period and other requirements with respect to the dividend-paying stocks held by the Portfolio, and the shareholder must meet holding period and other requirements with respect to the Portfolio’s shares. In general, a dividend will not be treated as qualified dividend income (at either the Portfolio or shareholder level) (a) if the dividend is received with respect to any share of stock held for fewer than 61 days during the 121-day period beginning on the date which is 60 days before the date on which such share becomes ex-dividend with respect to such dividend (or, in the case of certain preferred stock, 91 days during the 181-day period beginning 90 days before such date), (b) to the extent that the recipient is under an obligation (whether pursuant to a short sale or otherwise) to make related payments with respect to positions in substantially similar or related property, (c) if the recipient elects to have the dividend income treated as investment income for purposes of the limitation on deductibility of investment interest, or (d) if the dividend is received from a foreign corporation that is (i) not eligible for the benefits of a comprehensive income tax treaty with the United States (with the exception of dividends paid on stock of such a foreign corporation readily tradable on an established securities market in the United States) or (ii) treated as a passive foreign investment company.

In general, distributions of investment income properly reported by a Portfolio as derived from qualified dividend income will be treated as qualified dividend income in the hands of a shareholder taxed as an individual, provided the shareholder meets the holding period and other requirements described above with respect to the Portfolio’s shares. If the aggregate qualified dividends received by a Portfolio during any taxable year are 95% or more of the Portfolio’s gross income (excluding net long-term capital gain over net short-term capital loss), then 100% of the Portfolio’s dividends (other than dividends properly reported as Capital Gain Dividends) will be eligible to be treated as qualified dividend income.

In general, dividends of net investment income received by corporate shareholders of a Portfolio will qualify for the dividends-received deduction generally available to corporations to the extent of the amount of eligible dividends received by a Portfolio from domestic corporations for the taxable year. A dividend will not be treated as a dividend eligible for the dividends-received deduction (a) if it has been received with respect to any share of stock that the Portfolio has held for less than 46 days (91 days in the case of certain preferred stock) during the 91-day period beginning on the date which is 45 days before the date on which such share becomes ex-dividend with respect to such dividend (during the 181-day period beginning 90 days before such date in the case of certain preferred stock) or (b) to the extent that the Portfolio is under an obligation (pursuant to a short sale or otherwise) to make related payments with respect to positions in substantially similar or related property. Moreover, the dividends-received deduction may otherwise be disallowed or reduced (x) if the corporate shareholder fails to satisfy the foregoing requirements with respect to its shares of the Portfolio or (y) by application of various provisions of the Code (for instance, the dividends-received deduction is reduced in the case of a dividend received on debt-financed portfolio stock (generally, stock acquired with borrowed funds)). The Aggregate Bond Index Portfolio does not expect Portfolio distributions to be eligible for the dividends-received deduction.

Any distribution of income that is attributable to (a) income received by a Portfolio in lieu of dividends with respect to securities on loan pursuant to a securities lending transaction or (b) dividend income received by a Portfolio on securities it temporarily purchased from a counterparty pursuant to a repurchase agreement that is treated for U.S. federal income tax purposes as a loan by the Portfolio, will not constitute qualified dividend income to individual shareholders and will not be eligible for the dividends-received deduction for corporate shareholders.

Pursuant to proposed regulations on which the Portfolios may rely, distributions by a Portfolio to its shareholders that the Portfolio properly reports as “section 199A dividends,” as defined and subject to certain conditions described below, are treated as qualified REIT dividends in the hands of non-corporate shareholders. Non-corporate shareholders are permitted a federal income tax deduction equal to 20% of qualified REIT dividends received by them, subject to certain limitations. Very generally, a “section 199A dividend” is any dividend or portion thereof that is attributable to certain dividends received by a RIC from REITs (as defined below), to the extent such dividends are properly reported as such by the RIC in a written notice to its shareholders. A section 199A dividend is treated as a qualified REIT dividend only if the shareholder receiving such dividend holds the dividend-paying RIC shares for at least 46 days of the 91-day period beginning 45 days before the shares become ex-dividend, and is not under an obligation to make related payments with respect to a position in substantially similar or related property. A Portfolio is permitted to report such part of its dividends as section 199A dividends as are eligible, but is not required to do so.

If a Portfolio holds, directly or indirectly, one or more “tax credit bonds,” issued on or before December 31, 2018, on one or more applicable dates during a taxable year, the Portfolio may elect to permit its shareholders to claim a tax credit on their income tax returns equal to each shareholder’s proportionate share of tax credits from the bond otherwise allowed to the Portfolio. In such a case, shareholders must include in gross income (as interest) their proportionate share of the income attributable to the tax credits. A shareholder’s ability to claim a tax credit associated with one or more tax credit bonds may be subject to certain limitations imposed by the Code, and the amount of the tax credits may not exceed the amount reported by the Portfolio in a written notice to shareholders. Even if a Portfolio is eligible to pass through tax credits to shareholders, the Portfolio may choose not to do so.

As required by federal law, detailed federal tax information with respect to each calendar year will be furnished to each shareholder early in the succeeding year.

The Code’s wash sale rule may also apply to certain redemptions and exchanges by non-U.S. shareholders. See “Non-U.S. Shareholders” below.

Tax Implications of Certain Portfolio Investments

Special Rules for Debt Obligations . Some debt obligations with a fixed maturity date of more than one year from the date of issuance (and zero-coupon debt obligations with a fixed maturity date of more than one year from the date of issuance) will be treated as debt obligations that are issued originally at a discount. Generally, original issue discount (“OID”) is treated as interest income and is included in a Portfolio’s income and required to be distributed by the Portfolio over the term of the debt obligation, even though payment of that amount is not received until a later time, upon partial or full repayment or disposition of the debt obligation. In addition, payment-in-kind securities will give rise to income which is required to be distributed and is taxable even though the Portfolio holding the security receives no interest payment in cash on the obligation during the year.

Some debt obligations with a fixed maturity date of more than one year from the date of issuance that are acquired in the secondary market by a Portfolio may be treated as having “market discount.” Very generally, market discount is the excess of the stated redemption price of a debt obligation (or in the case of an obligation issued with OID, its “revised issue price”) over the purchase price of such obligation. Subject to the discussion below regarding Section 451 of the Code, (i) generally, any gain recognized on the disposition of, and any partial payment of principal on, a debt security having market discount is treated as ordinary income to the extent the gain, or principal payment, does not exceed the “accrued market discount” on such debt security, (ii) alternatively, a Portfolio may elect to accrue market discount currently, in which case the Portfolio will be required to include the accrued market discount in income (as ordinary income) and thus distribute it over the term of the debt security, even though payment of that amount is not received until a later time, upon partial or full repayment or disposition of the debt security, and (iii) the rate at which the market discount accrues, and thus is included in a Portfolio’s income, will depend upon which of the permitted accrual methods the Portfolio elects. Notwithstanding the foregoing, effective for taxable years beginning after 2017, Section 451 of the Code generally requires any accrual method taxpayer to take into account items of gross income no later than the time at which such items are taken into account as revenue in the taxpayer’s financial statements. The IRS and the Department of Treasury have announced their intent to issue proposed regulations providing that Section 451 does not apply to accrued market discount. If Section 451 were to apply to the accrual of market discount, each Portfolio would be required to include in income any market discount as it takes the same into account on its financial statements, even if the Portfolio does not otherwise elect to accrue market discount currently for federal income tax purposes.

If a Portfolio holds the foregoing kinds of obligations, or other obligations subject to special rules under the Code, the Portfolio may be required to pay out as an income distribution each year an amount which is greater than the total amount of cash interest the Portfolio actually received. Such distributions may be made from the cash assets of the Portfolio or, if necessary, by disposition of portfolio securities including at a time when it may not be advantageous to do so. These dispositions may cause a Portfolio to realize higher amounts of short-term capital gains (generally taxed to shareholders at ordinary income tax rates) and, in the event the Portfolio realizes net capital gains from such transactions, its shareholders may receive a larger Capital Gain Dividend than they would have if the Portfolio had not held such obligations.

Securities Purchased at a Premium . Very generally, where a Portfolio purchases a bond at a price that exceeds the redemption price at maturity – that is, at a premium — the premium is amortizable over the remaining term of the bond. In the case of a taxable bond, if a Portfolio makes an election applicable to all such bonds it purchases, which election is irrevocable without consent of the IRS, the Portfolio reduces the current taxable income from the bond by the amortized premium and reduces its tax basis in the bond by the amount of such offset; upon the disposition or maturity of such bonds acquired on or after January 4, 2013, the Portfolio is permitted to deduct any remaining premium allocable to a prior period.

A portion of the OID accrued on certain high yield discount obligations may not be deductible to the issuer and will instead be treated as a dividend paid by the issuer for purposes of the dividends-received deduction. In such cases, if the issuer of the high yield discount obligations is a domestic corporation, dividend payments by a Portfolio may be eligible for the dividends-received deduction to the extent attributable to the deemed dividend portion of such OID.

At-risk or Defaulted Securities . Investments in debt obligations that are at risk of or in default present special tax issues for the Portfolios. Tax rules are not entirely clear about issues such as when a Portfolio may cease to accrue interest, OID or market discount; whether, when or to what extent the Portfolio should recognize market discount on a debt obligation; when and to what extent a Portfolio may take deductions for bad debts or worthless securities; and how a Portfolio should allocate payments received on obligations in default between principal and income. These and other related issues will be addressed by a Portfolio when, as and if it invests in such securities, in order to seek to ensure that it distributes sufficient income to preserve its status as a RIC and does not become subject to U.S. federal income or excise tax.

Certain Investments in REITs . Any investment by a Portfolio in equity securities of real estate investment trusts qualifying as such under Subchapter M of the Code (“REITs”) may result in the Portfolio’s receipt of cash in excess of the REIT’s earnings; if the Portfolio distributes these amounts, these distributions could constitute a return of capital to Portfolio shareholders for U.S. federal income tax purposes. Dividends received by a Portfolio from a REIT will not qualify for the corporate dividends-received deduction and generally will not constitute qualified dividend income.

Certain Investments in Mortgage Pooling Vehicles . Certain Portfolios may invest directly or indirectly in residual interests in real estate mortgage investment conduits (“REMICs”) (including by investing in residual interests in collateralized mortgage obligations (“CMOs”) with respect to which an election to be treated as a REMIC is in effect) or equity interests in taxable mortgage pools (“TMPs”). Under a notice issued by the IRS in October 2006 and Treasury regulations that have yet to be issued but may apply retroactively, a portion of a Portfolio’s income (including income allocated to the Portfolio from certain pass-through entities) that is attributable to a residual interest in a REMIC or an equity interest in a TMP (referred to in the Code as an “excess inclusion”) will be subject to U.S. federal income tax in all events. This notice also provides, and the regulations are expected to provide, that excess inclusion income of a RIC, such as a Portfolio, will be allocated to shareholders of the RIC in proportion to the dividends received by such shareholders, with the same consequences as if the shareholders held the related interest directly. As a result, a RIC investing in such securities may not be a suitable investment for charitable remainder trusts, as noted below.

In general, excess inclusion income allocated to shareholders (i) cannot be offset by net operating losses (subject to a limited exception for certain thrift institutions), (ii) will constitute unrelated business taxable income (“UBTI”) to entities (including a qualified pension plan, an individual retirement account, a 401(k) plan, a Keogh plan or other tax-exempt entity) subject to tax on UBTI, thereby potentially requiring such an entity that is allocated excess inclusion income, and that otherwise might not be required to file a tax return, to file a tax return and pay tax on such income, and (iii) in the case of a foreign shareholder will not qualify for any reduction in U.S. federal withholding tax. A shareholder will be subject to U.S. federal income tax on such inclusions notwithstanding any exemption from such income tax otherwise available under the Code.

Foreign Currency Transactions . Any transaction by a Portfolio in foreign currencies, foreign currency-denominated debt obligations or certain foreign currency options, futures contracts or forward contracts (or similar instruments) may give rise to ordinary income or loss to the extent such income or loss results from fluctuations in the value of the foreign currency concerned. Any such net gains could require a larger dividend toward the end of the calendar year. Any such net losses will generally reduce and potentially require the recharacterization of prior ordinary income distributions. Such ordinary income treatment may accelerate a Portfolio’s distributions to shareholders and increase the distributions taxed to shareholders as ordinary income. Any net ordinary losses so created cannot be carried forward by the Portfolio to offset income or gains earned in subsequent taxable years.

Passive Foreign Investment Companies . Equity investments by a Portfolio in certain “passive foreign investment companies” (“PFICs”) could potentially subject the Portfolio to a U.S. federal income tax (including interest charges) on distributions received from the company or on proceeds received from the disposition of shares in the company. This tax cannot be eliminated by making distributions to Portfolio shareholders. However, a Portfolio may elect to avoid the imposition of that tax. For example, a Portfolio may elect to treat a PFIC as a “qualified electing fund” ( i.e. , make a “QEF election”), in which case the Portfolio will be required to include its share of the PFIC’s income and net capital gains annually, regardless of whether it receives any distribution from the PFIC. A Portfolio also may make an election to mark the gains (and to a limited extent losses) in such holdings “to the market” as though it had sold (and, solely for purposes of this mark-to-market election, repurchased) its holdings in those PFICs on the last day of the Portfolio’s taxable year. Such gains and losses are treated as ordinary income and loss. The QEF and mark-to-market elections may accelerate the recognition of income (without the receipt of cash) and increase the amount required to be distributed by the Portfolio to avoid taxation. Either of these elections therefore may require a Portfolio to liquidate other investments (including when it is not advantageous to do so) to meet its distribution requirement, which also may accelerate the recognition of gain and affect the Portfolio’s total return. Dividends paid by PFICs will not be eligible to be treated as “qualified dividend income.”

Because it is not always possible to identify a foreign corporation as a PFIC, a Portfolio may incur the tax and interest charges described above in some instances.

Options and Futures . In general, option premiums received by a Portfolio are not immediately included in the income of the Portfolio. Instead, the premiums are recognized when the option contract expires, the option is exercised by the holder, or the Portfolio transfers or otherwise terminates the option ( e.g. , through a closing transaction). If a call option written by a Portfolio is exercised and the Portfolio sells or delivers the underlying stock, the Portfolio generally will recognize capital gain or loss equal to (a) the sum of the strike price and the option premium received by the Portfolio minus (b) the Portfolio’s basis in the stock. Such gain or loss generally will be short-term or long-term depending upon the holding period of the underlying stock. If securities are purchased by a Portfolio pursuant to the exercise of a put option written by it, the Portfolio generally will subtract the premium received for purposes of computing its cost basis in the securities purchased. Gain or loss arising in respect of a termination of a Portfolio’s obligation under an option other than through the exercise of the option will be short-term gain or loss depending on whether the premium income received by the Portfolio is greater or less than the amount paid by the Portfolio (if any) in terminating the transaction. Thus, for example, if an option written by a Portfolio expires unexercised, the Portfolio generally will recognize short-term gain equal to the premium received.

A Portfolio’s options activities may include transactions constituting straddles for U.S. federal income tax purposes, that is, that trigger the U.S. federal income tax straddle rules contained primarily in Section 1092 of the Code. Such straddles include, for example, positions in a particular security, or an index of securities, and one or more options that offset the former position, including options that are “covered” by a Portfolio’s long position in the subject security. Very generally, where applicable, Section 1092 requires (i) that losses be deferred on positions deemed to be offsetting positions with respect to “substantially similar or related property,” to the extent of unrealized gain in the latter, and (ii) that the holding period of such a straddle position that has not already been held for the long-term holding period be terminated and begin anew once the position is no longer part of a straddle. Options on single stocks that are not “deep in the money” may constitute qualified covered calls, which generally are not subject to the straddle rules; the holding period on stock underlying qualified covered calls that are “in the money” although not “deep in the money” will be suspended during the period that such calls are outstanding. Thus, the straddle rules and the rules governing qualified covered calls could cause gains that would otherwise constitute long-term capital gains to be treated as short-term capital gains, and distributions that would otherwise constitute “qualified dividend income” or qualify for the dividends-received deduction to fail to satisfy the holding period requirements and therefore to be taxed as ordinary income or fail to qualify for the dividends-received deduction, as the case may be.

The tax treatment of certain positions entered into by a Portfolio, including regulated futures contracts, certain foreign currency positions and certain listed non-equity options, will be governed by section 1256 of the Code (“section 1256 contracts”). Gains or losses on section 1256 contracts generally are considered 60% long-term and 40% short-term capital gains or losses (“60/40”), although certain foreign currency gains and losses from such contracts may be treated as ordinary in character. Also, section 1256 contracts held by a Portfolio at the end of each taxable year (and, for purposes of the 4% excise tax, on certain other dates as prescribed under the Code) are “marked to market” with the result that unrealized gains or losses are treated as though they were realized and the resulting gain or loss is treated as ordinary or 60/40 gain or loss, as applicable.

Derivatives, Hedging, and Related Transactions . In addition to the special rules described above in respect of futures and options transactions, a Portfolio’s transactions in other derivative instruments ( e.g. , forward contracts and swap agreements), as well as any of its hedging, short sale, securities loan or similar transactions, may be subject to one or more special tax rules ( e.g. , notional principal contract, straddle, constructive sale, wash sale and short sale rules). These rules may affect whether gains and losses recognized by a Portfolio are treated as ordinary or capital, accelerate the recognition of income or gains to the Portfolio, defer losses to the Portfolio, and cause adjustments in the holding periods of the Portfolio’s securities, thereby affecting whether capital gains and losses are treated as short-term or long-term. These rules could therefore affect the amount, timing and/or character of distributions to shareholders.

Because these and other tax rules applicable to these types of transactions are in some cases uncertain under current law, an adverse determination or future guidance by the IRS with respect to these rules (which determination or guidance could be retroactive) may affect whether a Portfolio has made sufficient distributions, and otherwise satisfied the relevant requirements, to maintain its qualification as a RIC and avoid a Portfolio-level tax. Commodity-Linked Instruments . A Portfolio’s direct or indirect investments in commodities and commodity-linked instruments can be limited by the Portfolio’s intention to qualify as a RIC, and can bear on the Portfolio’s ability to so qualify. Income and gains from commodities and certain commodity-linked instruments does not constitute qualifying income to a RIC for purposes of the 90% gross income test described above. The tax treatment of some other commodity-linked instruments in which a Portfolio might invest is not certain, in particular with respect to whether income or gains from such instruments constitute qualifying income to a RIC. If a Portfolio were to treat income or gain from a particular instrument as qualifying income and the income or gain were later determined not to constitute qualifying income and, together with any other nonqualifying income, caused the Portfolio’s nonqualifying income to exceed 10% of its gross income in any taxable year, the Portfolio would fail to qualify as a RIC unless it is eligible to and does pay a tax at the Portfolio level.

Book-Tax Differences . Certain of a Portfolio’s investments in derivative instruments and foreign currency-denominated instruments, and any of the Portfolio’s transactions in foreign currencies and hedging activities, are likely to produce a difference between its book income and the sum of its taxable income and net tax-exempt income (if any). If such a difference arises, and a Portfolio’s book income is less than the sum of its taxable income and net tax-exempt income, the Portfolio could be required to make distributions exceeding book income to qualify as a RIC that is accorded special tax treatment and to avoid an entity-level tax. In the alternative, if a Portfolio’s book income exceeds the sum of its taxable income (including realized capital gains) and net tax-exempt income, the distribution (if any) of such excess generally will be treated as (i) a dividend to the extent of the Portfolio’s remaining earnings and profits (including earnings and profits arising from tax-exempt income), (ii) thereafter, as a return of capital to the extent of the recipient’s basis in its shares, and (iii) thereafter as gain from the sale or exchange of a capital asset.

Investments in Other RICs . If a Portfolio receives dividends from underlying RICs (an “underlying RIC”) and the underlying RIC reports such dividends as qualified dividend income, then the Portfolio is permitted, in turn, to report a portion of its distributions as “qualified dividend income,” provided the Portfolio meets the holding period and other requirements with respect to shares of the underlying RIC.

If a Portfolio receives dividends from an underlying RIC, and the underlying RIC reports such dividends as eligible for the dividends-received deduction, then the Portfolio is permitted, in turn, to report a portion of its distributions as eligible for the dividends-received deduction, provided the Portfolio meets the holding period and other requirements with respect to shares of the underlying RIC.

Foreign Taxation

A Portfolio’s income, proceeds and gains from sources within foreign countries may be subject to non-U.S. withholding or other taxes, which will reduce the yield on those investments. Tax conventions between certain countries and the United States may reduce or eliminate such taxes. If, at the close of a Portfolio’s taxable year, more than 50% of the assets of the Portfolio consists of the securities of foreign corporations, the Portfolio may elect to permit shareholders to claim a credit or deduction on their income tax returns for their pro rata portions of qualified taxes paid by a Portfolio to foreign countries in respect of foreign securities that the Portfolio has held for at least the minimum period specified in the Code. In such a case, shareholders will include in gross income from foreign sources their pro rata shares of such taxes paid by such Portfolio. A shareholder’s ability to claim an offsetting foreign tax credit or deduction in respect of foreign taxes paid by a Portfolio is subject to certain limitations imposed by the Code, which may result in the shareholder’s not receiving a full credit or deduction (if any) for the amount of such taxes. Shareholders who do not itemize on their U.S. federal income tax returns may claim a credit (but not a deduction) for such foreign taxes. Even if a Portfolio were eligible to make such an election for a given year, it may determine not to do so.

Backup Withholding

A Portfolio generally is required to withhold and remit to the U.S. Treasury a percentage of the taxable distributions and redemption proceeds paid to any individual shareholder who fails to properly furnish the Portfolio with a correct taxpayer identification number (“TIN”), who has under- reported dividend or interest income, or who fails to certify to the Portfolio that he or she is not subject to such withholding.

Tax-Exempt Shareholders

Income of a RIC that would be unrelated business taxable income (“UBTI”) if earned directly by a tax-exempt entity will not generally constitute UBTI when distributed to a tax-exempt shareholder of the RIC. Notwithstanding this “blocking” effect, a tax-exempt shareholder could realize UBTI by virtue of its investment in a Portfolio if shares in the Portfolio constitute debt-financed property in the hands of the tax-exempt shareholder within the meaning of Code Section 514(b).

A tax-exempt shareholder may also recognize UBTI if a Portfolio recognizes “excess inclusion income” derived from direct or indirect investments in residual interests in REMICS or equity interests in TMPs if the amount of such income recognized by the Portfolio exceeds the Portfolio’s investment company taxable income (after taking into account deductions for dividends paid by the Portfolio).

In addition, special tax consequences apply to charitable remainder trusts (“CRTs”) that invest in RICs that invest directly or indirectly in residual interests in REMICs or equity interests in TMPs. Under legislation enacted in December 2006, a CRT (as defined in section 664 of the Code) that realizes any UBTI for a taxable year must pay an excise tax annually of an amount equal to such UBTI. Under IRS guidance issued in October 2006, a CRT will not recognize UBTI as a result of investing in a RIC that recognizes “excess inclusion income.” Rather, if at any time during any taxable year a CRT (or one of certain other tax-exempt shareholders, such as the United States, a state or political subdivision, or an agency or instrumentality thereof, and certain energy cooperatives) is a record holder of a share in a RIC that recognizes “excess inclusion income,” then the RIC will be subject to a tax on that portion of its “excess inclusion income” for the taxable year that is allocable to such shareholders at the highest federal corporate income tax rate. The extent to which this IRS guidance remains applicable in light of the December 2006 legislation is unclear. To the extent permitted under the 1940 Act, each Portfolio may elect to specially allocate any such tax to the applicable CRT, or other shareholder, and thus reduce such shareholder’s distributions for the year by the amount of the tax that relates to such shareholder’s interest in a Portfolio. CRTs are urged to consult their tax advisors concerning the consequences of investing in each Portfolio.

Redemptions and Exchanges

Redemptions and exchanges of each Portfolio’s shares are taxable events and, accordingly, shareholders may realize gain or loss on these transactions. In general, any gain or loss realized upon a taxable disposition of shares will be treated as long-term capital gain or loss if the shares have been held for more than 12 months. Otherwise, the gain or loss on the taxable disposition of Portfolio shares will be treated as short-term capital gain or loss. However, any loss realized upon a taxable disposition of Portfolio shares held by a shareholder for six months or less will be treated as long-term, rather than short-term, to the extent of any Capital Gain Dividends received (or deemed received) by the shareholder with respect to the shares. Further, subject to the discussion below regarding money market funds, all or a portion of any loss realized upon a taxable disposition of Portfolio shares generally will be disallowed under the Code’s “ wash sale” rule if other substantially identical shares are purchased, including by means of dividend reinvestment, within 30 days before or after the disposition. In such a case, the basis of the newly purchased shares will be adjusted to reflect the disallowed loss.

The IRS permits a simplified method of accounting for gains and losses realized upon the disposition of shares of a regulated investment company that is a money market fund. Very generally, rather than realizing gain or loss upon each redemption of a share, a shareholder of a Portfolio using such method of accounting will recognize gain or loss with respect to such a Portfolio’s shares for a given computation period (the shareholder’s taxable year or shorter period selected by the shareholder) equal to the value of all the Portfolio shares held by the shareholder on the last day of the computation period, less the value of all Portfolio shares held by the shareholder on the last day of the preceding computation period, less the shareholder’s net investment in the Portfolio (generally, purchases minus redemptions) made during the computation period. Shareholders of a Portfolio are urged to consult their own tax advisors regarding their investment in the Portfolio.

Upon the redemption or exchange of shares of a Portfolio, the Portfolio or, in the case of shares purchased through a financial intermediary, the financial intermediary may be required to provide you and the IRS with cost basis and certain other related tax information about the Portfolio shares you redeemed or exchanged. See the Portfolio’ prospectuses for more information.

Tax Shelter Reporting

Non-U.S. Shareholders

Non-U.S. shareholders in a Portfolio should consult their tax advisors concerning the tax consequences of ownership of shares in the Portfolio. Distributions by a Portfolio to shareholders that are not “U.S. persons” within the meaning of the Code (“foreign shareholders”) properly reported by the Portfolio as (1) Capital Gain Dividends, (2) short-term capital gain dividends and (3) interest-related dividends, each as defined and subject to certain conditions described below, generally are not subject to withholding of U.S. federal income tax.

The exceptions to withholding for Capital Gain Dividends and short-term capital gain dividends do not apply to (A) distributions to an individual foreign shareholder who is present in the United States for a period or periods aggregating 183 days or more during the year of the distribution and (B) distributions attributable to gain that is treated as effectively connected with the conduct by the foreign shareholder of a trade or business within the United States, under special rules regarding the disposition of U.S. real property interests as described below. If a Portfolio invests in a RIC that pays such distributions to the Portfolio, such distributions retain their character as not subject to withholding if properly reported when paid by the Portfolio to foreign shareholders. The exception to withholding for interest-related dividends does not apply to distributions to a foreign shareholder (i) that has not provided a satisfactory statement that the beneficial owner is not a U.S. person, (ii) to the extent that the dividend is attributable to certain interest on an obligation if the foreign shareholder is the issuer or is a 10% shareholder of the issuer, (iii) that is within certain foreign countries that have inadequate information exchange with the United States, or (iv) to the extent the dividend is attributable to interest paid by a person that is a related person of the foreign shareholder and the foreign shareholder is a controlled foreign corporation). A RIC is permitted to report such parts of its dividends as are eligible to be treated as interest-related or short-term capital gain dividends, but is not required to do so. In the case of shares held through an intermediary, the intermediary may withhold even if a Portfolio reports all or a portion of a payment as an interest-related or short-term capital gain dividend to shareholders.

Foreign shareholders should contact their intermediaries regarding the application of withholding rules to their accounts.

Distributions by a Portfolio to foreign shareholders other than Capital Gain Dividends, short-term capital gain dividends and interest-related dividends (e.g., dividends attributable to dividend and foreign-source interest income or to short-term capital gains or U.S. source interest income to which the exception from withholding described above does not apply) are generally subject to withholding of U.S. federal income tax at a rate of 30% (or lower applicable treaty rate).

A foreign shareholder is not, in general, subject to U.S. federal income tax on gains (and is not allowed a deduction for losses) realized on the sale of shares of a Portfolio unless (a) such gain is effectively connected with the conduct of a trade or business carried on by such holder within the United States, (b) in the case of an individual holder, the holder is present in the United States for a period or periods aggregating 183 days or more during the year of the sale and certain other conditions are met, or (c) the special rules relating to gain attributable to the sale or exchange of “U.S. real property interests” (“USRPIs”) apply to the foreign shareholder’s sale of shares of the Portfolio (as described below).

Foreign shareholders with respect to whom income from a Portfolio is effectively connected with a trade or business conducted by the foreign person within the United States will in general be subject to U.S. federal income tax on the income derived from the Portfolio at the graduated rates applicable to U.S. citizens, residents or domestic corporations, whether such income is received in cash or reinvested in shares of the Portfolio and, in the case of a foreign corporation, may also be subject to a branch profits tax. If a foreign shareholder is eligible for the benefits of a tax treaty, any effectively connected income or gain will generally be subject to U.S. federal income tax on a net basis only if it is also attributable to a permanent establishment maintained by the shareholder in the United States. More generally, foreign shareholders who are residents in a country with an income tax treaty with the United States may obtain different tax results than those described herein, and are urged to consult their tax advisors.

Special rules would apply if a Portfolio were a qualified investment entity (“QIE”) because it is either a “U.S. real property holding corporation” (“USRPHC”) or would be a USRPHC but for the operation of certain exceptions to the definition thereof. Very generally, a USRPHC is a domestic corporation that holds USRPIs the fair market value of which equals or exceeds 50% of the sum of the fair market values of the corporation’s USRPIs, interests in real property located outside the United States, and other trade or business assets. USRPIs are generally defined as any interest in U.S. real property and any interest (other than solely as a creditor) in a USRPHC or, very generally, an entity that has been a USRPHC in the last five years. A Portfolio that holds, directly or indirectly, significant interests in REITs may be a USRPHC. Interests in domestically controlled QIEs, including REITs and RICs that are QIEs, not-greater-than-10% interests in publicly traded classes of stock in REITs and not-greater-than-5% interests in publicly traded classes of stock in RICs generally are not USRPIs, but these exceptions do not apply for purposes of determining whether a Portfolio is a QIE. If an interest in a Portfolio were a USRPI, the Portfolio would be required to withhold U.S. tax on the proceeds of a share redemption by a greater-than-5% foreign shareholder, in which case such foreign shareholder generally would also be required to file U.S. tax returns and pay any additional taxes due in connection with the redemption.

If a Portfolio were a QIE under a special “look-through” rule, any distributions by the Portfolio to a foreign shareholder attributable directly or indirectly to (i) distributions received by the Portfolio from a lower-tier REIT that the Portfolio is required to treat as USRPI gain in its hands and (ii) gains realized on the disposition of USRPIs by the Portfolio, would retain their character as gains realized from USRPIs in the hands of the Portfolio’s foreign shareholders and would be subject to U.S. tax withholding. In addition,

such distributions could result in the foreign shareholder being required to file a U.S. tax return and pay tax on the distributions at regular U.S. federal income tax rates. The consequences to a foreign shareholder, including the rate of such withholding and character of such distributions (e.g., as ordinary income or USRPI gain), would vary depending upon the extent of the foreign shareholder’s current and past ownership of the Portfolio. Each Portfolio generally does not expect that it will be a QIE.

Foreign shareholders of a Portfolio also may be subject to “wash sale” rules to prevent the avoidance of the tax-filing and –payment obligations discussed above through the sale and repurchase of Portfolio shares.

Foreign shareholders should consult their tax advisers and, if holding shares through intermediaries, their intermediaries, concerning the application of these rules to their investment in a Portfolio.

In order for a foreign shareholder to qualify for any exemptions from withholding described above or from lower withholding tax rates under income tax treaties, or to establish an exemption from back back-up withholding, the foreign shareholder must comply with special certification and filing requirements relating to its non-U.S. status (including, in general, furnishing an IRS Form W-8BEN, IRS Form W-8BEN-E or substitute form). Non-U.S. investors in a Portfolio should consult their tax advisers in this regard.

Special rules (including withholding and reporting requirements) apply to foreign partnerships and those holding Portfolio shares through foreign partnerships. Additional considerations may apply to foreign trusts and estates. Investors holding Portfolio shares through foreign entities should consult their tax advisers about their particular situation.

A foreign shareholder may be subject to state and local tax and to the U.S. federal estate tax in addition to the U.S. federal income tax on income referred to above.

Shareholder Reporting Obligations With Respect To Foreign Bank and Financial Accounts

Shareholders that are U.S. persons and own, directly or indirectly, more than 50% of a Portfolio by vote or value could be required to report annually their “financial interest” in the Portfolio’s “foreign financial accounts,” if any, on FinCEN Form 114, Report of Foreign Bank and Financial Accounts (“FBAR”). Shareholders should consult a tax advisor, and persons investing in a Portfolio through an intermediary should contact their intermediary, regarding the applicability to them of this reporting requirement.

Other Reporting and Withholding Requirements

Sections 1471-1474 of the Code and the U.S. Treasury and IRS guidance issued thereunder (collectively, “FATCA”) generally require a Portfolio to obtain information sufficient to identify the status of each of its shareholders under FATCA or under an applicable intergovernmental agreement (an “IGA”) between the United States and a foreign government. If a shareholder fails to provide the requested information or otherwise fails to comply with FATCA or an IGA, the Portfolio may be required to withhold under FATCA at a rate of 30% with respect to that shareholder on ordinary dividends it pays. .The IRS and the Department of Treasury have issued proposed regulations providing that these withholding rules will not apply to the gross proceeds of share redemptions or Capital Gain Dividends a Portfolio pays. If a payment by a Portfolio is subject to FATCA withholding, the Portfolio is required to withhold even if such payment would otherwise be exempt from withholding under the rules applicable to foreign shareholders described above ( e.g. ,short-term capital gain dividends and interest-related dividends).

General Considerations

The U.S. federal income tax discussion set forth above is for general information only. Prospective investors should consult their tax advisers regarding the specific U.S. federal income tax consequences of purchasing, holding, and disposing of shares of the Portfolios, as well as the effects of state, local, foreign, and other tax laws and any proposed tax law changes.

UNDERWRITER

Investment companies, common and commingled trust funds and similar organizations and entities may continuously invest in the Portfolios.

FINANCIAL STATEMENTS

The audited financial statements for the fiscal year ended December 31, 2018 for the Portfolios in operation at that date are included in the Annual Report of the Trust (the “Annual Report”), which was filed with the SEC on March 6, 2019 as part of the Trust’s filing on Form N-CSR (SEC Accession No. 0001193125-19-065518) and are incorporated into this SAI by reference. The Annual Report is available, without charge, upon request, by calling (866) 392-0869.