As filed with the Securities and Exchange Commission on November 23, 2020

Securities Act File No. 33-26305

Investment Company Act File No. 811-05742

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

☒

Pre-Effective Amendment No.

□

Post-Effective Amendment No. 1055

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and/or

REGISTRATION STATEMENT UNDER THE

INVESTMENT COMPANY ACT OF 1940

☒

Amendment No. 1057

☒

(Check appropriate box or boxes)

BLACKROCK FUNDS^SM

(Exact Name of Registrant as Specified in Charter)

100 Bellevue Parkway, Wilmington, Delaware 19809
United States of America

(Address of Principal Executive Offices)

Registrant’s Telephone Number, including Area Code: (800) 441-7762

If appropriate, check the following box:

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

Title of Securities Being Registered: Shares of beneficial interest, par value $0.001 per share.

NOVEMBER 27, 2020

Prospectus

BlackRock Funds^SM  |  Investor A and Institutional Shares

•	iShares Russell Mid-Cap Index Fund
	Investor A: BRMAX • Institutional: BRMIX

This Prospectus contains information you should know before investing, including information about risks. Please read it before you invest and keep it for future reference.

The 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.

Not FDIC Insured • May Lose Value • No Bank Guarantee

    

    

Account Information	Information about account services, sales charges and waivers, shareholder transactions, and distribution and other payments
	How to Choose the Share Class that Best Suits Your Needs	16
	Details About the Share Classes	19
	Distribution and Shareholder Servicing Payments	20
	How to Buy, Sell, Exchange and Transfer Shares	21
	Account Services and Privileges	26
	Fund’s Rights	27
	Participation in Fee-Based Programs	27
	Short-Term Trading Policy	28

    

Management of the Fund	Information about BlackRock and the Portfolio Managers
	BlackRock	30
	Portfolio Manager Information	31
	Conflicts of Interest	32
	Valuation of Fund Investments	33
	Dividends, Distributions and Taxes	34

    

Financial Highlights	Financial Performance of the Fund	36

    

General Information	Shareholder Documents	38
	Certain Fund Policies	38
	Statement of Additional Information	39

    

Glossary	Glossary of Investment Terms	40

    

For More Information	Fund and Service Providers	Inside Back Cover
	Additional Information	Back Cover

Key Facts About iShares Russell Mid-Cap Index Fund

  

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As described in the “Management of the Fund” section of the Fund’s prospectus beginning on page 30, BlackRock Advisors, LLC (“BlackRock”) has contractually agreed to waive the management fee with respect to any portion of the Fund’s assets estimated to be attributable to investments in other equity and fixed-income mutual funds and exchange-traded funds managed by BlackRock or its affiliates that have a contractual management fee, through November 30, 2021. In addition, BlackRock has contractually agreed to waive its management fees by the amount of investment advisory fees the Fund pays to BlackRock indirectly through its investment in money market funds managed by BlackRock or its affiliates, through November 30, 2021. The contractual agreements may be terminated upon 90 days’ notice by a majority of the non-interested trustees of the Trust or by a vote of a majority of the outstanding voting securities of the Fund.

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As described in the “Management of the Fund” section of the Fund’s prospectus beginning on page 30, BlackRock has contractually agreed to waive and/or reimburse fees or expenses in order to limit Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses) to 0.37% of average daily net assets (for Investor A Shares) and 0.12% of average daily net assets (for Institutional Shares) through November 30, 2021. The Fund may have to repay some of these waivers and/or reimbursements to BlackRock in the following two years, and such repayment arrangement will terminate on May 13, 2022. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested trustees of the Trust or by a vote of a majority of the outstanding voting securities of the Fund.

	1 Year	3 Years	5 Years	10 Years
Investor A Shares	$37	$116	$202	$456
Institutional Shares	$10	$32	$56	$128

  

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■	Management Risk — As the Fund may not fully replicate the Underlying Index, it is subject to the risk that BlackRock’s investment strategy may not produce the intended results.
■	Market Risk and Selection Risk — Market risk is the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. The value of a security or other asset may decline due to changes in general market conditions, economic trends or events that are not specifically related to the issuer of the security or other asset, or factors that affect a particular issuer or issuers, exchange, country, group of countries, region, market, industry, group of industries, sector or asset class. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues like pandemics or epidemics, recessions, or other events could have a significant impact on the Fund and its investments. Selection risk is the risk that the securities selected by Fund management will underperform the markets, the relevant indices or the securities selected by other funds with similar investment objectives and investment strategies. This means you may lose money.
	A recent outbreak of an infectious coronavirus has developed into a global pandemic that has resulted in numerous disruptions in the market and has had significant economic impact leaving general concern and uncertainty. The impact of this coronavirus, and other epidemics and pandemics that may arise in the future, could affect the economies of many nations, individual companies and the market in general ways that cannot necessarily be foreseen at the present time.
■	Mid Cap Securities Risk — The securities of mid cap companies generally trade in lower volumes and are generally subject to greater and less predictable price changes than the securities of larger capitalization companies.
■	Passive Investment Risk — Because BlackRock does not select individual companies in the index that the Fund tracks, the Fund may hold securities of companies that present risks that an investment adviser researching individual securities might seek to avoid.
■	Technology Sector Risk — Technology companies, including information technology companies, may have limited product lines, markets, financial resources or personnel. Technology companies typically face intense competition and potentially rapid product obsolescence. They are also heavily dependent on intellectual property rights and may be adversely affected by the loss or impairment of those rights. Companies in the technology sector are facing increased government and regulatory scrutiny and may be subject to adverse government or regulatory action.

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iShares Russell Mid-Cap Index Fund
Investor A Shares

  

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. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Investor A Shares only, and the after-tax returns for Institutional Shares will vary.

Investment Manager

The Fund’s investment manager is BlackRock Advisors, LLC (previously defined as “BlackRock”). The Fund’s sub-adviser is BlackRock Fund Advisors (the “Sub-Adviser”). Where applicable, “BlackRock” refers also to the Sub-Adviser.

  

Purchase and Sale of Fund Shares

You may purchase or redeem shares of the Fund each day the New York Stock Exchange is open. To purchase or sell shares you should contact your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock and its affiliates) (each a “Financial Intermediary”), or, if

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you hold your shares through the Fund, you should contact the Fund by phone at (800) 441-7762, by mail (c/o BlackRock Funds, P.O. Box 9819, Providence, Rhode Island 02940-8019) or by the Internet at www.blackrock.com. The Fund’s initial and subsequent investment minimums generally are as follows, although the Fund may reduce or waive the minimums in some cases:

  

Tax Information

The Fund’s dividends and distributions may be subject to U.S. federal income taxes and may be taxed as ordinary income or capital gains, unless you are a tax-exempt investor or are investing through a qualified tax-exempt plan described in section 401(a) of the Internal Revenue Code of 1986, as amended, in which case you may be subject to U.S. federal income tax when distributions are received from such tax-deferred arrangements.

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Payments to Broker/Dealers and Other Financial Intermediaries

If you purchase shares of the Fund through a Financial Intermediary, the Fund and BlackRock Investments, LLC, the Fund’s distributor, or its affiliates may pay the Financial Intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the Financial Intermediary and your individual financial professional to recommend the Fund over another investment.

Ask your individual financial professional or visit your Financial Intermediary’s website for more information.

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Details About the Fund

Included in this prospectus are sections that tell you about buying and selling shares, management information, shareholder features of iShares Russell Mid-Cap Index Fund (the “Fund”), a series of BlackRock Funds^SM (the “Trust”), and your rights as a shareholder.

How the Fund Invests

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	subscriptions, to maintain liquidity in the event of redemptions and to keep trading costs low. The Fund may use derivatives for hedging purposes, including anticipatory hedges, and to seek to enhance returns.
■	Illiquid Investments — The Fund may invest up to an aggregate amount of 15% of its net assets in illiquid investments. An illiquid investment is any investment that the 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.
■	Investment Companies — The Fund has the ability to invest in other investment companies, such as exchange-traded funds (“ETFs”), unit investment trusts, and open-end and closed-end funds. The Fund may invest in affiliated investment companies, including affiliated money market funds and affiliated ETFs.
■	Securities Lending — The Fund may lend securities with a value up to 33 1⁄3% of its total assets to financial institutions that provide cash or securities issued or guaranteed by the U.S. Government as collateral.

    

Investment Risks

This section contains a discussion of the general risks of investing in the Fund. The “Investment Objective and Policies” section in the Statement of Additional Information (the “SAI”) also includes more information about the Fund, its investments and the related risks. As with any fund, there can be no guarantee that the Fund will meet its investment objective or that the Fund’s performance will be positive for any period of time. An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or by any bank or governmental agency. The order of the below risk factors does not indicate the significance of any particular risk factor.

Principal Risks of Investing in the Fund

■	Asset Class Risk — The securities or other assets in the Underlying Index or in the Fund’s portfolio may underperform in comparison to other securities or indexes that track other countries, groups of countries, regions, industries, groups of industries, markets, asset classes or sectors. Various types of securities, currencies and indexes or assets may experience cycles of outperformance and underperformance in comparison to the general financial markets depending upon a number of factors including, among other things, inflation, interest rates, productivity, global demand for local products or resources, and regulation and governmental controls. This may cause the Fund to underperform other investment vehicles that invest in different asset classes.
■	Concentration Risk — The Fund reserves the right to concentrate its investments (i.e., invest 25% or more of its total assets in securities of issuers in a particular industry) to approximately the same extent that the Underlying Index concentrates in a particular industry. To the extent the Fund concentrates in a particular industry, it may be more susceptible to economic conditions and risks affecting that industry.
■	Consumer Discretionary Sector Risk — The success of consumer product manufacturers and retailers is tied closely to the performance of domestic and international economies, interest rates, exchange rates, competition, consumer confidence, changes in demographics and consumer preferences. Companies in the consumer discretionary sector depend heavily on disposable household income and consumer spending, and may be strongly affected by social trends and marketing campaigns. These companies may be subject to severe competition, which may have an adverse impact on their profitability.
■	Equity Securities Risk — Common and preferred stocks represent equity ownership in a company. Stock markets are volatile. The price of equity securities will fluctuate and can decline and reduce the value of a portfolio investing in equities. The value of equity securities purchased by the Fund could decline if the financial condition of the companies the Fund invests in declines or if overall market and economic conditions deteriorate. The value of equity securities may also decline due to factors that affect a particular industry or industries, such as labor shortages or an increase in production costs and competitive conditions within an industry. In addition, the value may decline due to general market conditions that are not specifically related to a company or industry, such as real or

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	perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates or generally adverse investor sentiment.
■	Index Fund Risk — An index fund has operating and other expenses while an index does not. As a result, while the Fund will attempt to track the Underlying Index as closely as possible, it will tend to underperform the Underlying Index to some degree over time. If an index fund is properly correlated to its stated index, the fund will perform poorly when the index performs poorly.
■	Index-Related Risk — The Fund seeks to achieve a return that corresponds generally to the price and yield performance, before fees and expenses, of the Underlying Index as published by the Index Provider. There is no assurance that the Index Provider or any agents that may act on its behalf will compile the Underlying Index accurately, or that the Underlying Index will be determined, composed or calculated accurately. While the Index Provider provides descriptions of what the Underlying Index is designed to achieve, neither the Index Provider nor its agents provide any warranty or accept any liability in relation to the quality, accuracy or completeness of the Underlying Index or its related data, and they do not guarantee that the Underlying Index will be in line with the Index Provider’s methodology. BlackRock’s mandate as described in this prospectus is to manage the Fund consistently with the Underlying Index provided by the Index Provider to BlackRock. BlackRock does not provide any warranty or guarantee against the Index Provider’s or any agent’s errors. Errors in respect of the quality, accuracy and completeness of the data used to compile the Underlying Index may occur from time to time and may not be identified and corrected by the Index Provider for a period of time or at all, particularly where the indices are less commonly used as benchmarks by funds or managers. Such errors may negatively or positively impact the Fund and its shareholders. For example, during a period where the Underlying Index contains incorrect constituents, the Fund would have market exposure to such constituents and would be underexposed to the Underlying Index’s other constituents. Shareholders should understand that any gains from Index Provider errors will be kept by the Fund and its shareholders and any losses or costs resulting from Index Provider errors will be borne by the Fund and its shareholders.
	Unusual market conditions may cause the Index Provider to postpone a scheduled rebalance, which could cause the Underlying Index to vary from its normal or expected composition. The postponement of a scheduled rebalance in a time of market volatility could mean that constituents that would otherwise be removed at rebalance due to changes in market capitalizations, issuer credit ratings, or other reasons may remain, causing the performance and constituents of the Underlying Index to vary from those expected under normal conditions. Apart from scheduled rebalances, the Index Provider or its agents may carry out additional ad hoc rebalances to the Underlying Index due to reaching certain weighting constraints, unusual market conditions or in order, for example, to correct an error in the selection of index constituents. When the Underlying Index is rebalanced and the Fund in turn rebalances its portfolio to attempt to increase the correlation between the Fund’s portfolio and the Underlying Index, any transaction costs and market exposure arising from such portfolio rebalancing will be borne directly by the Fund and its shareholders. Therefore, errors and additional ad hoc rebalances carried out by the Index Provider or its agents to the Underlying Index may increase the costs to and the tracking error risk of the Fund.
■	Industrials Sector Risk — The value of securities issued by companies in the industrials sector may be adversely affected by supply and demand changes related to their specific products or services and industrials sector products in general. The products of manufacturing companies may face obsolescence due to rapid technological developments and frequent new product introduction. Global events, trade disputes and changes in government regulations, economic conditions and exchange rates may adversely affect the performance of companies in the industrials sector. Companies in the industrials sector may be adversely affected by liability for environmental damage and product liability claims. The industrials sector may also be adversely affected by changes or trends in commodity prices, which may be influenced by unpredictable factors. Aerospace and defense companies, a component of the industrials sector, can be significantly affected by government spending policies because companies involved in this industry rely, to a significant extent, on government demand for their products and services. Thus, the financial condition of, and investor interest in, aerospace and defense companies are heavily influenced by governmental defense spending policies, which are typically under pressure from efforts to control government budgets. Transportation stocks, a component of the industrials sector, are cyclical and can be significantly affected by economic changes, fuel prices, labor relations and insurance costs. Transportation companies in certain countries may also be subject to significant government regulation and oversight, which may adversely affect their businesses. Companies in the industrials sector, particularly aerospace and defense companies, may also be adversely affected by government spending policies because companies in this sector tend to rely to a significant extent on government demand for their products and services.
■	Issuer Risk — The performance of the Fund depends on the performance of individual securities to which the Fund has exposure. Any issuer of these securities may perform poorly, causing the value of its securities to decline. Poor performance may be caused by poor management decisions, competitive pressures, changes in technology, expiration of patent protection, disruptions in supply, labor problems or shortages, corporate restructurings,

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	fraudulent disclosures, credit deterioration of the issuer or other factors. Issuers may, in times of distress or at their own discretion, decide to reduce or eliminate dividends, which may also cause their stock prices to decline.
■	Management Risk — The Fund may not fully replicate the Underlying Index and may hold securities not included in the Underlying Index. As a result, the Fund is subject to the risk that BlackRock’s investment strategy, the implementation of which is subject to a number of constraints, may not produce the intended results.
■	Market Risk and Selection Risk — Market risk is the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. The value of a security or other asset may decline due to changes in general market conditions, economic trends or events that are not specifically related to the issuer of the security or other asset, or factors that affect a particular issuer or issuers, exchange, country, group of countries, region, market, industry, group of industries, sector or asset class. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues like pandemics or epidemics, recessions, or other events could have a significant impact on the Fund and its investments. Selection risk is the risk that the securities selected by Fund management will underperform the markets, the relevant indices or the securities selected by other funds with similar investment objectives and investment strategies. This means you may lose money.
	A recent outbreak of an infectious coronavirus has developed into a global pandemic that has resulted in numerous disruptions in the market and has had significant economic impact leaving general concern and uncertainty. The impact of this coronavirus, and other epidemics and pandemics that may arise in the future, could affect the economies of many nations, individual companies and the market in general ways that cannot necessarily be foreseen at the present time.
■	Mid Cap Securities Risk — The securities of mid cap companies generally trade in lower volumes and are generally subject to greater and less predictable price changes than the securities of larger capitalization companies.
■	Passive Investment Risk — Because BlackRock does not select individual companies in the index that the Fund tracks, the Fund may hold securities of companies that present risks that an investment adviser researching individual securities might seek to avoid.
■	Technology Sector Risk — Technology companies, including information technology companies, face intense competition, both domestically and internationally, which may have an adverse effect on a company’s profit margins. Technology companies may have limited product lines, markets, financial resources or personnel. The products of technology companies may face obsolescence due to rapid technological developments, frequent new product introduction, unpredictable changes in growth rates, aggressive pricing, changes in demand, and competition for the services of qualified personnel. Companies in the technology sector are heavily dependent on patent and other intellectual property rights. A technology company’s loss or impairment of these rights may adversely affect the company’s profitability. Companies in the technology sector are facing increased government and regulatory scrutiny and may be subject to adverse government or regulatory action. The technology sector may also be adversely affected by changes or trends in commodity prices, which may be influenced or characterized by unpredictable factors.

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	period. A risk of the Fund’s use of derivatives is that the fluctuations in their values may not correlate with the overall securities markets.
	Counterparty Risk — Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will not fulfill its contractual obligation.
	Market and Illiquidity Risk — Some derivatives are more sensitive to interest rate changes and market price fluctuations than other securities. The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately. The Fund could also suffer losses related to its derivatives positions as a result of unanticipated market movements, which losses are potentially unlimited. Finally, BlackRock may not be able to predict correctly the direction of securities prices, interest rates and other economic factors, which could cause the Fund’s derivatives positions to lose value.
	Valuation Risk — Valuation may be more difficult in times of market turmoil since many investors and market makers may be reluctant to purchase complex instruments or quote prices for them. Derivatives may also expose the Fund to greater risk and increase its costs. Certain transactions in derivatives involve substantial leverage risk and may expose the Fund to potential losses that exceed the amount originally invested by the Fund.
	Hedging Risk — When a derivative is used as a hedge against a position that the Fund holds, any loss generated by the derivative 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 derivative and the underlying security, and there can be no assurance that the Fund’s hedging transactions will be effective. The use of hedging may result in certain adverse tax consequences noted below.
	Tax Risk — The federal income tax treatment of a derivative may not be as favorable as a direct investment in an underlying asset and may adversely affect the timing, character and amount of income the Fund realizes from its investments. As a result, a larger portion of the Fund’s distributions may be treated as ordinary income rather than capital gains. In addition, certain derivatives are subject to mark-to-market or straddle provisions of the Internal Revenue Code of 1986, as amended. If such provisions are applicable, there could be an increase (or decrease) in the amount of taxable dividends paid by the Fund. In addition, the tax treatment of certain derivatives, such as swaps, is unsettled and may be subject to future legislation, regulation or administrative pronouncements issued by the Internal Revenue Service (the “IRS”).
	Regulatory Risk — Derivative contracts, including, without limitation, swaps, currency forwards and non-deliverable forwards, are subject to regulation under the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”) in the United States and under comparable regimes in Europe, Asia and other non-U.S. jurisdictions. Under the Dodd-Frank Act, certain derivatives are subject to margin requirements and swap dealers are required to collect margin from the Fund with respect to such derivatives. Specifically, regulations are now in effect that require swap dealers to post and collect variation margin (comprised of specified liquid instruments and subject to a required haircut) in connection with trading of over-the-counter (“OTC”) swaps with the Fund. Shares of investment companies (other than certain money market funds) may not be posted as collateral under these regulations. Requirements for posting of initial margin in connection with OTC swaps will be phased-in through at least 2021. In addition, regulations adopted by global prudential regulators that are now in effect require certain bank-regulated counterparties and certain of their affiliates to include in certain financial contracts, including many derivatives contracts, terms that delay or restrict the rights of counterparties, such as the Fund, to terminate such contracts, foreclose upon collateral, exercise other default rights or restrict transfers of credit support in the event that the counterparty and/or its affiliates are subject to certain types of resolution or insolvency proceedings. The implementation of these requirements with respect to derivatives, as well as regulations under the Dodd-Frank Act regarding clearing, mandatory trading and margining of other derivatives, may increase the costs and risks to the Fund of trading in these instruments and, as a result, may affect returns to investors in the Fund.
	On October 28, 2020, the Securities and Exchange Commission (the “SEC”) adopted new regulations governing the use of derivatives by registered investment companies (“Rule 18f-4”). The Fund will be required to implement and comply with Rule 18f-4 by the third quarter of 2022. Once implemented, Rule 18f-4 will impose limits on the amount of derivatives a fund can enter into, eliminate the asset segregation framework currently used by funds to comply with Section 18 of the Investment Company Act, treat derivatives as senior securities so that a failure to comply with the limits would result in a statutory violation and require funds whose use of derivatives is more than a limited specified exposure amount to establish and maintain a comprehensive derivatives risk management program and appoint a derivatives risk manager.
	In addition, other future regulatory developments may impact the Fund’s ability to invest or remain invested in

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certain derivatives. Legislation or regulation may also change the way in which the Fund itself is regulated. BlackRock cannot predict the effects of any new governmental regulation that may be implemented on the ability of the Fund to use swaps or any other financial derivative product, and there can be no assurance that any new governmental regulation will not adversely affect the Fund’s ability to achieve its investment objective.

Risks Specific to Certain Derivatives Used by the Fund

Swaps — Swap agreements, including total return swaps that may be referred to as contracts for difference, are two-party contracts entered into for periods ranging from a few weeks to more than one year. In a standard “swap” transaction, two parties agree to exchange the returns (or differentials in rates of return) earned or realized on particular predetermined investments or instruments, which can be adjusted for an interest factor. Swap agreements involve the risk that the party with whom the Fund has entered into the swap will default on its obligation to pay the Fund and the risk that the Fund will not be able to meet its obligations to pay the other party to the agreement. Swap agreements may also involve the risk that there is an imperfect correlation between the return on the Fund’s obligation to its counterparty and the return on the referenced asset. In addition, swap agreements are subject to market and illiquidity risk, leverage risk and hedging risk.

Futures — Futures are standardized, exchange-traded contracts that obligate a purchaser to take delivery, and a seller to make delivery, of a specific amount of an asset at a specified future date at a specified price. The primary risks associated with the use of futures contracts and options are: (a) the imperfect correlation between the change in market value of the instruments held by the Fund and the price of the futures contract or option; (b) the possible lack of a liquid secondary market for a futures contract and the resulting inability to close a futures contract when desired; (c) losses caused by unanticipated market movements, which are potentially unlimited; (d) the investment adviser’s inability to predict correctly the direction of securities prices, interest rates, currency exchange rates and other economic factors; and (e) the possibility that the counterparty will default in the performance of its obligations.

■	Expense Risk — Fund expenses are subject to a variety of factors, including fluctuations in the Fund’s net assets. Accordingly, actual expenses may be greater or less than those indicated. For example, to the extent that the Fund’s net assets decrease due to market declines or redemptions, the Fund’s expenses will increase as a percentage of Fund net assets. During periods of high market volatility, these increases in the Fund’s expense ratio could be significant.
■	Financials Sector Risk — Companies in the financials sector of an economy are subject to extensive governmental regulation and intervention, which may adversely affect the scope of their activities, the prices they can charge, the amount of capital they must maintain and, potentially, their size. The extent to which the Fund may invest in a company that engages in securities-related activities or banking is limited by applicable law. Governmental regulation may change frequently and may have significant adverse consequences for companies in the financials sector, including effects not intended by such regulation. Recently enacted legislation in the United States has relaxed capital requirements and other regulatory burdens on certain U.S. banks. While the effect of the legislation may benefit certain companies in the financials sector, including non-U.S. financials sector companies, increased risk taking by affected banks may also result in greater overall risk in the United States and global financials sector. The impact of changes in capital requirements, or recent or future regulation in various countries, on any individual financial company or on the financials sector as a whole cannot be predicted. Certain risks may impact the value of investments in the financials sector more severely than those of investments outside this sector, including the risks associated with companies that operate with substantial financial leverage. Companies in the financials sector may also be adversely affected by increases in interest rates and loan losses, decreases in the availability of money or asset valuations, credit rating downgrades and adverse conditions in other related markets. Insurance companies, in particular, may be subject to severe price competition and/or rate regulation, which may have an adverse impact on their profitability. The financials sector is particularly sensitive to fluctuations in interest rates. The financials sector is also a target for cyberattacks, and may experience technology malfunctions and disruptions. In recent years, cyberattacks and technology malfunctions and failures have become increasingly frequent in this sector and have reportedly caused losses to companies in this sector, which may negatively impact the Fund.
■	Healthcare Sector Risk — The profitability of companies in the healthcare sector may be adversely affected by the following factors, among others: extensive government regulations, restrictions on government reimbursement for medical expenses, rising costs of medical products and services, pricing pressure, an increased emphasis on outpatient services, changes in the demand for medical products and services, a limited number of products, industry innovation, changes in technologies and other market developments. A number of issuers in the healthcare sector have recently merged or otherwise experienced consolidation. The effects of this trend toward consolidation are unknown and may be far-reaching. Many healthcare companies are heavily dependent on patent protection. The expiration of a company’s patents may adversely affect that company’s profitability. Many healthcare companies are subject to extensive litigation based on product liability and similar claims. Healthcare companies are subject to

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	competitive forces that may make it difficult to raise prices and, in fact, may result in price discounting. Many new products in the healthcare sector may be subject to regulatory approvals. The process of obtaining such approvals may be long and costly, and such efforts ultimately may be unsuccessful. Companies in the healthcare sector may be thinly capitalized and may be susceptible to product obsolescence. In addition, a number of legislative proposals concerning healthcare have been considered by the U.S. Congress in recent years. It is unclear what proposals will ultimately be enacted, if any, and what effect they may have on companies in the healthcare sector.
■	Illiquid Investments Risk — The Fund’s illiquid investments may reduce the returns of the Fund because it may be difficult to sell the illiquid investments at an advantageous time or price. An investment may be illiquid due to, among other things, the lack of an active trading market. To the extent that the Fund’s principal investment strategies involve derivatives or securities with substantial market and/or credit risk, the Fund will tend to have the greatest exposure to the risks associated with illiquid investments. Liquid investments may become illiquid after purchase by the Fund, particularly during periods of market turmoil. Illiquid investments may be harder to value, especially in changing markets, and if the Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss. In addition, when there is illiquidity in the market for certain securities, the Fund, due to limitations on illiquid investments, may be subject to purchase and sale restrictions.
■	Investment in Other Investment Companies Risk — As with other investments, investments in other investment companies, including ETFs, are subject to market and selection risk. In addition, if the Fund acquires shares of investment companies, including ones affiliated with the Fund, shareholders bear both their proportionate share of expenses in the Fund (including management and advisory fees) and, indirectly, the expenses of the investment companies (to the extent not offset by BlackRock through waivers). To the extent the Fund is held by an affiliated fund, the ability of the Fund itself to hold other investment companies may be limited.
■	Leverage Risk — Some transactions may give rise to a form of economic leverage. These transactions may include, among others, derivatives, and may expose the Fund to greater risk and increase its costs. As an open-end investment company registered with the SEC, the Fund is subject to the federal securities laws, including the Investment Company Act, the rules thereunder, and various SEC and SEC staff interpretive positions. In accordance with these laws, rules and positions, the Fund must “set aside” liquid assets (often referred to as “asset segregation”), or engage in other SEC- or staff-approved measures, to “cover” open positions with respect to certain kinds of instruments. The use of leverage may cause the Fund to liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet any required asset segregation requirements. Increases and decreases in the value of the Fund’s portfolio will be magnified when the Fund uses leverage.
■	Securities Lending Risk — Securities lending involves the risk that the borrower may fail to return the securities in a timely manner or at all. As a result, the Fund may lose money and there may be a delay in recovering the loaned securities. The Fund could also lose money if it does not recover the securities and/or the value of the collateral falls, including the value of investments made with cash collateral. These events could trigger adverse tax consequences for the Fund.
■	Valuation Risk — The price the Fund could receive upon the sale of any particular portfolio investment may differ from the Fund’s valuation of the investment, particularly for securities that trade in thin or volatile markets or that are valued using a fair valuation methodology or a price provided by an independent pricing service. As a result, the price received upon the sale of an investment may be less than the value ascribed by the Fund, and the Fund could realize a greater than expected loss or lesser than expected gain upon the sale of the investment. Pricing services that value fixed-income securities generally utilize a range of market-based and security-specific inputs and assumptions, as well as considerations about general market conditions, to establish a price. Pricing services generally value fixed-income securities assuming orderly transactions of an institutional round lot size, but may be held or transactions may be conducted in such securities in smaller, odd lot sizes. Odd lots may trade at lower prices than institutional round lots. The Fund’s ability to value its investments may also be impacted by technological issues and/or errors by pricing services or other third-party service providers.

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Account Information

How to Choose the Share Class that Best Suits Your Needs

The Fund currently offers multiple share classes (Investor A and Institutional Shares in this prospectus), each with its own expense structure, allowing you to invest in the way that best suits your needs. Each share class represents an ownership interest in the same investment portfolio of the Fund. When you choose your class of shares, you should consider the size of your investment and how long you plan to hold your shares. Only certain investors are eligible to buy Institutional Shares. Either your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock and its affiliates) (each a “Financial Intermediary”) can help you determine which share class is best suited to your personal financial goals.

The Fund’s shares are distributed by BlackRock Investments, LLC (the “Distributor”), an affiliate of BlackRock.

The table on the following pages summarizes key features of each of the share classes offered by this prospectus.

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1	Please see “Details About the Share Classes” for more information about each share class.

The following pages will cover the additional details of each share class, including the eligibility requirements to purchase Institutional Shares.

More information about existing sales charge reductions and waivers is available free of charge in a clear and prominent format via hyperlink at www.blackrock.com and in the SAI, which is available on the website or on request.

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Details About the Share Classes

Investor A Shares

Investor A Shares of the Fund pay an ongoing service fee of 0.25% per year. The Distributor normally pays the annual 0.25% Investor A Shares service fee to dealers on a monthly basis.

Institutional Shares

Institutional Shares are not subject to any sales charge. Only certain investors are eligible to buy Institutional Shares. Your Financial Intermediary can help you determine whether you are eligible to buy Institutional Shares. The Fund may permit a lower initial investment for certain investors if their purchase, combined with purchases by other investors received together by the Fund, meets the minimum investment requirement.

Institutional Shares may also be available on certain brokerage platforms. An investor transacting in Institutional Shares on such brokerage platforms through a broker acting as an agent for the investor may be required to pay a commission and/or other forms of compensation to the broker. Shares of the Fund are available in other share classes that have different fees and expenses.

Eligible Institutional Share investors include the following:

■	Individuals and “Institutional Investors” with a minimum initial investment of $2 million who may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Distributor to purchase such shares;
■	Clients of Financial Intermediaries that: (i) charge such clients a fee for advisory, investment consulting, or similar services or (ii) have entered into an agreement with the Distributor to offer Institutional Shares through a no-load program or investment platform, in each case, with no minimum initial investment;
■	Clients investing through Financial Intermediaries that have entered into an agreement with the Distributor to offer such shares on a platform that charges a transaction based sales commission outside of the Fund, with a minimum initial investment of $1,000;
■	Employer-sponsored retirement plans (not including SEP IRAs, SIMPLE IRAs or SARSEPs), state sponsored 529 college savings plans, collective trust funds, investment companies or other pooled investment vehicles, unaffiliated thrifts and unaffiliated banks and trust companies, each of which is not subject to any minimum initial investment and may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Distributor to purchase such shares;
■	Trust department clients of Bank of America, N.A. and its affiliates for whom they (i) act in a fiduciary capacity (excluding participant directed employee benefit plans); (ii) otherwise have investment discretion; or (iii) act as custodian for at least $2 million in assets, who are not subject to any minimum initial investment;
■	Holders of certain Bank of America Corporation (“BofA Corp.”) sponsored unit investment trusts (“UITs”) who reinvest dividends received from such UITs in shares of the Fund, who are not subject to any minimum initial investment;
■	Employees, officers and directors/trustees of BlackRock, Inc., mutual funds sponsored and advised by BlackRock or its affiliates (“BlackRock Funds”), BofA Corp., Barclays PLC or their respective affiliates and immediate family members of such persons, if they open an account directly with BlackRock, who are not subject to any minimum initial investment;
■	Tax-qualified accounts for insurance agents that are registered representatives of an insurance company’s broker-dealer that has entered into an agreement with the Distributor to offer Institutional Shares, and the family members of such persons; and
■	Clients investing through a self-directed IRA brokerage account program sponsored by a retirement plan record-keeper, provided that such program offers only mutual fund options and that the program maintains an account with the Fund on an omnibus basis.

The Fund reserves the right to modify or waive the above-stated policies at any time.

Right of Accumulation

Investors have a “right of accumulation” under which any of the following may be combined with the amount of the current purchase in determining whether an investor qualifies for a breakpoint and a reduced front-end sales charge:

i.	The current value of an investor’s existing Investor A and A1, Investor C, Investor P, Institutional, Class K and Premier Shares in most BlackRock Funds,

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ii.	The current value of an investor’s existing shares of certain unlisted closed-end management investment companies sponsored and advised by BlackRock or its affiliates and
iii.	The investment in the BlackRock CollegeAdvantage 529 Program by the investor or by or on behalf of the investor’s spouse and children.

Financial Intermediaries may value current holdings of their customers differently for purposes of determining whether an investor qualifies for a breakpoint and a reduced front-end sales charge, although customers of the same Financial Intermediary will be treated similarly. In order to use this right, the investor must alert BlackRock to the existence of any previously purchased shares.

Distribution and Shareholder Servicing Payments

Plan Payments

The Trust, on behalf of the Fund, has adopted a plan (the “Plan”) pursuant to Rule 12b-1 under the Investment Company Act with respect to the Investor Shares that allows the Fund to pay distribution fees for the sale of its shares and/or shareholder servicing fees for certain services provided to its shareholders.

Under the Plan, the Fund pays shareholder servicing fees (also referred to as general shareholder liaison services fees) to Financial Intermediaries for providing support services to their customers who own Investor Shares of the Fund. The shareholder servicing fee payment is calculated as a percentage of the average daily net asset value of Investor Shares of the Fund. All Investor Shares pay this shareholder servicing fee. Institutional Shares do not pay a shareholder servicing fee.

In return for the shareholder servicing fee, Financial Intermediaries (including BlackRock) may provide one or more of the following services to their customers who own Investor Shares:

■	Answering customer inquiries regarding account status and history, the manner in which purchases, exchanges and redemptions or repurchases of shares may be effected and certain other matters pertaining to the customers’ investments;
■	Assisting customers in designating and changing dividend options, account designations and addresses; and
■	Providing other similar shareholder liaison services.

The shareholder servicing fees payable pursuant to the Plan are paid to compensate Financial Intermediaries for the administration and servicing of shareholder accounts and are not costs which are primarily intended to result in the sale of the Fund’s shares.

Because the fees paid by the Fund under the Plan are paid out of Fund assets on an ongoing basis, over time these fees will increase the cost of your investment and may cost you more than paying other types of sales charges. For more information on the Plan, including a complete list of services provided thereunder, see the SAI.

Other Payments by the Fund

In addition to fees that the Fund may pay to a Financial Intermediary pursuant to the Plan and fees the Fund pays to its transfer agent, BNY Mellon Investment Servicing (US) Inc. (the “Transfer Agent”), BlackRock, on behalf of the Fund, may enter into non-Plan agreements with affiliated and unaffiliated Financial Intermediaries pursuant to which the Fund will pay a Financial Intermediary for administrative, networking, recordkeeping, sub-transfer agency, sub-accounting and/or shareholder services. These non-Plan payments are generally based on either (1) a percentage of the average daily net assets of Fund shareholders serviced by a Financial Intermediary or (2) a fixed dollar amount for each account serviced by a Financial Intermediary. The aggregate amount of these payments may be substantial.

Other Payments by BlackRock

From time to time, BlackRock, the Distributor or their affiliates also may pay a portion of the fees for administrative, networking, recordkeeping, sub-transfer agency, sub-accounting and shareholder services described above at its or their own expense and out of its or their profits. BlackRock, the Distributor and their affiliates may also compensate affiliated and unaffiliated Financial Intermediaries for the sale and distribution of shares of the Fund. These payments would be in addition to the Fund payments described in this prospectus and may be a fixed dollar amount, may be based on the number of customer accounts maintained by the Financial Intermediary, may be based on a percentage of the value of shares sold to, or held by, customers of the Financial Intermediary or may be calculated on another basis. The aggregate amount of these payments by BlackRock, the Distributor and their affiliates may be substantial and, in some circumstances, may create an incentive for a Financial Intermediary, its employees or associated persons to recommend or sell shares of the Fund to you.

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Please contact your Financial Intermediary for details about payments it may receive from the Fund or from BlackRock, the Distributor or their affiliates. For more information, see the SAI.

How to Buy, Sell, Exchange and Transfer Shares

The chart on the following pages summarizes how to buy, sell, exchange and transfer shares through your Financial Intermediary. You may also buy, sell, exchange and transfer shares through BlackRock if your account is held directly with BlackRock. To learn more about buying, selling, exchanging or transferring shares through BlackRock, call (800) 441-7762. Because the selection of a mutual fund involves many considerations, your Financial Intermediary may help you with this decision.

With certain limited exceptions, the Fund is generally available only to investors residing in the United States and may not be distributed by a foreign Financial Intermediary. Under this policy, in order to accept new accounts or additional investments (including by way of exchange from another BlackRock Fund) into existing accounts, the Fund generally requires that (i) a shareholder that is a natural person be a U.S. citizen or resident alien, in each case residing within the United States or a U.S. territory (including APO/FPO/DPO addresses), and have a valid U.S. taxpayer identification number, and (ii) a Financial Intermediary or a shareholder that is an entity be domiciled in the United States and have a valid U.S. taxpayer identification number or be domiciled in a U.S. territory and have a valid U.S. taxpayer identification number or IRS Form W-8. Any existing account that is updated to reflect a non-U.S. address will also be restricted from making additional investments.

The Fund may reject any purchase order, modify or waive the minimum initial or subsequent investment requirements for any shareholders and suspend and resume the sale of any share class of the Fund at any time, for any reason. In addition, the Fund may waive certain requirements regarding the purchase, sale, exchange or transfer of shares described below.

Under certain circumstances, if no activity occurs in an account within a time period specified by state law, a shareholder’s shares in the Fund may be transferred to that state.

How to Buy Shares

	Your Choices	Important Information for You to Know
Initial Purchase	First, select the share class appropriate for you	Refer to the “Share Classes at a Glance” table in this prospectus (be sure to read this prospectus carefully). When you place your initial order, you must indicate which share class you select (if you do not specify a share class and do not qualify to purchase Institutional Shares, you will receive Investor A Shares). Certain factors, such as the amount of your investment, your time frame for investing and your financial goals, may affect which share class you choose. Your Financial Intermediary can help you determine which share class is appropriate for you.
	Next, determine the amount of your investment	Refer to the minimum initial investment in the “Share Classes at a Glance” table of this prospectus.
	Have your Financial Intermediary submit your purchase order	The price of your shares is based on the next calculation of the Fund’s net asset value after your order is placed. Any purchase orders placed prior to the close of business on the New York Stock Exchange (the “NYSE”) (generally 4:00 p.m. Eastern time) will be priced at the net asset value determined that day. Certain Financial Intermediaries, however, may require submission of orders prior to that time. Purchase orders placed after that time will be priced at the net asset value determined on the next business day. A broker-dealer or financial institution maintaining the account in which you hold shares may charge a separate account, service or transaction fee on the purchase or sale of Fund shares that would be in addition to the fees and expenses shown in the Fund’s “Fees and Expenses” table. The Fund may reject any order to buy shares and may suspend the sale of shares at any time. Certain Financial Intermediaries may charge a processing fee to confirm a purchase.

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	Your Choices	Important Information for You to Know
Initial Purchase (continued)	Or contact BlackRock (for accounts held directly with BlackRock)	To purchase shares directly from BlackRock, call (800) 441-7762 and request a new account application. Mail the completed application along with a check payable to “BlackRock Funds” to the Transfer Agent at the address on the application.
Add to Your Investment	Purchase additional shares	For Investor A Shares, the minimum investment for additional purchases is generally $50 for all accounts (with the exception of certain employer-sponsored retirement plans which may have a lower minimum for additional purchases). The minimums for additional purchases may be waived under certain circumstances. Institutional Shares have no minimum for additional purchases.
	Have your Financial Intermediary submit your purchase order for additional shares	To purchase additional shares, you may contact your Financial Intermediary.
	Or contact BlackRock (for accounts held directly with BlackRock)	Purchase by Telephone: Call (800) 441-7762 and speak with one of our representatives. The Fund has the right to reject any telephone request for any reason. Purchase in Writing: You may send a written request to BlackRock at the address on the back cover of this prospectus. Purchase by VRU: Investor A Shares may also be purchased by use of the Fund’s automated voice response unit (“VRU”) service at (800) 441-7762. Purchase by Internet: You may purchase your shares and view activity in your account by logging onto the BlackRock website at www.blackrock.com. Purchases made on the Internet using the Automated Clearing House (“ACH”) will have a trade date that is the day after the purchase is made. Certain institutional clients’ purchase orders of Institutional Shares placed by wire prior to the close of business on the NYSE will be priced at the net asset value determined that day. Contact your Financial Intermediary or BlackRock for further information. The Fund limits Internet purchases in shares of the Fund to $25,000 per trade. Different maximums may apply to certain institutional investors. Please read the On-Line Services Disclosure Statement and User Agreement, the Terms and Conditions page and the Consent to Electronic Delivery Agreement (if you consent to electronic delivery), before attempting to transact online. The Fund employs reasonable procedures to confirm that transactions entered over the Internet are genuine. By entering into the User Agreement with the Fund in order to open an account through the website, the shareholder waives any right to reclaim any losses from the Fund or any of its affiliates incurred through fraudulent activity.
	Acquire additional shares by reinvesting dividends and capital gains	All dividends and capital gains distributions are automatically reinvested in shares of the Fund at net asset value. To make any changes to your dividend and/or capital gains distributions options, please call BlackRock at (800) 441-7762 or contact your Financial Intermediary (if your account is not held directly with BlackRock).
	Participate in the AIP	BlackRock’s AIP allows you to invest a specific amount on a periodic basis from your checking or savings account into your investment account. Refer to the “Account Services and Privileges” section of this prospectus for additional information.
How to Pay for Shares	Making payment for purchases	Payment for an order must be made in Federal funds or other immediately available funds by the time specified by your Financial Intermediary, but in no event later than 4:00 p.m. (Eastern time) on the first business day following BlackRock’s receipt of the order. If payment is not received by this time, the order will be canceled and you and your Financial Intermediary will be responsible for any loss to the Fund. For shares purchased directly from the Fund, a check payable to BlackRock Funds which bears the name of the Fund must accompany a completed purchase application. There is a $20 fee for each purchase check that is returned due to insufficient funds. The Fund does not

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How to Exchange Shares or Transfer Your Account

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EZ Trader (continued)	Allows an investor to purchase or sell Investor A Shares by telephone or over the Internet through ACH. (continued)	complete an application, making sure to include the appropriate bank information, and return the application to the address listed on the form. Prior to placing a telephone or Internet purchase or sale order, please call (800) 441-7762 to confirm that your bank information has been updated on your account. Once this is established, you may place your request to sell shares with the Fund by telephone or Internet. Proceeds will be sent to your pre-designated bank account.
Systematic Exchange Plan	This feature can be used by investors to systematically exchange money from one fund to up to four other funds.	A minimum of $10,000 in the initial BlackRock Fund is required, and investments in any additional funds must meet minimum initial investment requirements.
Systematic Withdrawal Plan (“SWP”)	This feature can be used by investors who want to receive regular distributions from their accounts.	To start an SWP, a shareholder must have a current investment of $10,000 or more in a BlackRock Fund. Shareholders can elect to receive cash payments of $50 or more at any interval they choose. Shareholders may sign up by completing the SWP Application Form, which may be obtained from BlackRock. Shareholders should realize that if withdrawals exceed income the invested principal in their account will be depleted. To participate in the SWP, shareholders must have their dividends reinvested. Shareholders may change or cancel the SWP at any time, with a minimum of 24 hours’ notice. If a shareholder purchases additional Investor A Shares of a fund at the same time he or she redeems shares through the SWP, that investor may lose money because of any applicable sales charge. Ask your Financial Intermediary for details.

  

Fund’s Rights

The Fund may:

■	Suspend the right of redemption if trading is halted or restricted on the NYSE or under other emergency conditions described in the Investment Company Act;
■	Postpone the date of payment upon redemption if trading is halted or restricted on the NYSE or under other emergency conditions described in the Investment Company Act or if a redemption request is made before the Fund has collected payment for the purchase of shares;
■	Redeem shares for property other than cash as may be permitted under the Investment Company Act; and
■	Redeem shares involuntarily in certain cases, such as when the value of a shareholder account falls below a specified level.

Note on Low Balance Accounts. Because of the high cost of maintaining smaller shareholder accounts, BlackRock has set a minimum balance of $500 in each Fund position you hold within your account (“Fund Minimum”), and may redeem the shares in your account if the net asset value of those shares in your account falls below $500 for any reason, including market fluctuation.

You will be notified that the value of your account is less than the Fund Minimum before the Fund makes any involuntary redemption. This notification will provide you with a 90 calendar day period to make an additional investment in order to bring the value of your account to at least $500 before the Fund makes an involuntary redemption. This involuntary redemption will not charge any deferred sales charge, and may not apply to accounts of certain employer-sponsored retirement plans (not including IRAs), qualified state tuition plan (529 Plan) accounts, and select fee-based programs at your Financial Intermediary.

Participation in Fee-Based Programs

If you participate in certain fee-based programs offered by BlackRock or an affiliate of BlackRock, or by Financial Intermediaries that have agreements with the Distributor or in certain fee-based programs in which BlackRock participates, you may be able to buy Institutional Shares, including by exchanges from other share classes. Sales charges on the shares being exchanged may be reduced or waived under certain circumstances. You generally cannot transfer shares held through a fee-based program into another account. Instead, if you choose to leave the fee-based program, you may have to redeem your shares held through the program and purchase shares of another class, which

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may be subject to distribution and service fees. This may be a taxable event and you may pay any applicable sales charges or redemption fee. Please speak to your Financial Intermediary for information about specific policies and procedures applicable to your account.

Generally, upon termination of a fee-based program, the shares may be liquidated or the shares can be held in an account. In certain instances, when a shareholder chooses to continue to hold the shares, whatever share class was held in the program can be held after termination. Shares that have been held for less than specified periods within the program may be subject to a fee upon redemption. Shareholders that held Investor A or Institutional Shares in the program may be eligible to purchase additional shares of the respective share class of the Fund, but may be subject to upfront sales charges with respect to Investor A Shares. Additional purchases of Institutional Shares are permitted only if you have an existing position at the time of purchase or are otherwise eligible to purchase Institutional Shares. Please speak to your Financial Intermediary for more information.

Certain Financial Intermediaries may, in connection with a change in account type (for example, due to leaving a fee-based program or upon termination of the fee-based program) or otherwise in accordance with the Financial Intermediary’s policies and procedures, exchange the share class held in the program for another share class of the same fund, provided that the exchanged shares are not subject to a sales charge and the shareholder meets the eligibility requirements of the new share class. Please speak to your Financial Intermediary for information about specific policies and procedures applicable to your account.

Details about the features of each fee-based program and the relevant charges, terms and conditions are included in the client agreement for each fee-based program and are available from your Financial Intermediary. Please speak to your Financial Intermediary for more information.

Short-Term Trading Policy

The Board has determined that the interests of long-term shareholders and the Fund’s ability to manage its investments may be adversely affected when shares are repeatedly bought, sold or exchanged in response to short-term market fluctuations — also known as “market timing.” The Fund is not designed for market timing organizations or other entities using programmed or frequent purchases and sales or exchanges. The exchange privilege is not intended as a vehicle for short-term trading. Excessive purchase and sale or exchange activity may interfere with portfolio management, increase expenses and taxes and may have an adverse effect on the performance of the Fund and its returns to shareholders. For example, large flows of cash into and out of the Fund may require the management team to allocate a significant amount of assets to cash or other short-term investments or sell securities, rather than maintaining such assets in securities selected to achieve the Fund’s investment objective. Frequent trading may cause the Fund to sell securities at less favorable prices, and transaction costs, such as brokerage commissions, can reduce the Fund’s performance.

A fund’s investment in non-U.S. securities is subject to the risk that an investor may seek to take advantage of a delay between the change in value of the fund’s portfolio securities and the determination of the fund’s net asset value as a result of different closing times of U.S. and non-U.S. markets by buying or selling fund shares at a price that does not reflect their true value. A similar risk exists for funds that invest in securities of small capitalization companies, securities of issuers located in emerging markets or high yield securities (“junk bonds”) that are thinly traded and therefore may have actual values that differ from their market prices. This short-term arbitrage activity can reduce the return received by long-term shareholders. The Fund will seek to eliminate these opportunities by using fair value pricing, as described in “Management of the Fund — Valuation of Fund Investments” below.

The Fund discourages market timing and seeks to prevent frequent purchases and sales or exchanges of Fund shares that it determines may be detrimental to the Fund or long-term shareholders. The Board has approved the policies discussed below to seek to deter market timing activity. The Board has not adopted any specific numerical restrictions on purchases, sales and exchanges of Fund shares because certain legitimate strategies will not result in harm to the Fund or its shareholders.

If as a result of its own investigation, information provided by a Financial Intermediary or other third-party, or otherwise, the Fund believes, in its sole discretion, that your short-term trading is excessive or that you are engaging in market timing activity, it reserves the right to reject any specific purchase or exchange order. If the Fund rejects your purchase or exchange order, you will not be able to execute that transaction, and the Fund will not be responsible for any losses you therefore may suffer. For transactions placed directly with the Fund, the Fund may consider the trading history of accounts under common ownership or control for the purpose of enforcing these policies. Transactions placed through the same Financial Intermediary on an omnibus basis may be deemed part of a group for the purpose of this policy and may be rejected in whole or in part by the Fund. Certain accounts, such as omnibus accounts and accounts at Financial Intermediaries, however, include multiple investors and such accounts typically provide the Fund

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with net purchase or redemption and exchange requests on any given day where purchases, redemptions and exchanges of shares are netted against one another and the identity of individual purchasers, redeemers and exchangers whose orders are aggregated may not be known by the Fund. While the Fund monitors for market timing activity, the Fund may be unable to identify such activities because the netting effect in omnibus accounts often makes it more difficult to locate and eliminate market timers from the Fund. The Distributor has entered into agreements with respect to Financial Intermediaries that maintain omnibus accounts with the Fund pursuant to which such Financial Intermediaries undertake to cooperate with the Distributor in monitoring purchase, exchange and redemption orders by their customers in order to detect and prevent short-term or excessive trading in the Fund’s shares through such accounts. Identification of market timers may also be limited by operational systems and technical limitations. In the event that a Financial Intermediary is determined by the Fund to be engaged in market timing or other improper trading activity, the Distributor may terminate such Financial Intermediary’s agreement with the Distributor, suspend such Financial Intermediary’s trading privileges or take other appropriate actions.

There is no assurance that the methods described above will prevent market timing or other trading that may be deemed abusive.

The Fund may from time to time use other methods that it believes are appropriate to deter market timing or other trading activity that may be detrimental to the Fund or long-term shareholders.

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The amount of the contractual waivers and/or reimbursements of fees and expenses made pursuant to the contractual caps on net expenses will be reduced by the amount of the affiliated money market fund waiver.

With respect to the contractual agreement to cap net expenses, if during the Fund’s fiscal year the operating expenses of a share class, that at any time during the prior two fiscal years received a waiver or reimbursement from BlackRock, are less than the current expense limit for that share class, the share class is required to repay BlackRock up to the lesser of (a) the amount of fees waived or expenses reimbursed during those prior two fiscal years under the agreement and (b) an amount not to exceed either (x) the current expense limit of that share class or (y) the expense limit of the share class in effect at the time that the share class received the applicable waiver and/or reimbursement, provided that: (i) the Fund has more than $50 million in assets and (ii) BlackRock or an affiliate serves as the Fund’s manager or administrator. This repayment arrangement will terminate on May 13, 2022, and applies only to the contractual caps on net expenses and does not apply to the contractual management fee waivers described above or any voluntary waivers that may be in effect from time to time.

For the fiscal year ended July 31, 2020, BlackRock received management fees, net of any applicable waivers, at the annual rate of 0.02% of the Fund’s average daily net assets.

BlackRock has entered into a sub-advisory agreement with BFA, with respect to the Fund, under which BlackRock pays BFA for services it provides for that portion of the Fund for which BFA acts as sub-adviser a fee equal to a percentage of the management fee paid to BlackRock under the Management Agreement.

A discussion of the basis for the approval by the Board of the Management Agreement with BlackRock and the sub-advisory agreement between BlackRock and BFA is included in the Fund’s annual shareholder report for the period ended July 31, 2020.

From time to time, a manager, analyst, or other employee of BlackRock or its affiliates may express views regarding a particular asset class, company, security, industry, or market sector. The views expressed by any such person are the views of only that individual as of the time expressed and do not necessarily represent the views of BlackRock or any other person within the BlackRock organization. Any such views are subject to change at any time based upon market or other conditions and BlackRock disclaims any responsibility to update such views. These views may not be relied on as investment advice and, because investment decisions for the Fund are based on numerous factors, may not be relied on as an indication of trading intent on behalf of the Fund.

Legal Proceedings. On May 27, 2014, certain investors in the BlackRock Global Allocation Fund, Inc. (“Global Allocation”) and the BlackRock Equity Dividend Fund (“Equity Dividend”) filed a consolidated complaint in the United States District Court for the District of New Jersey against BlackRock Advisors, LLC, BlackRock Investment Management, LLC and BlackRock International Limited (collectively, the “Defendants”) under the caption In re BlackRock Mutual Funds Advisory Fee Litigation. In the lawsuit, which purports to be brought derivatively on behalf of Global Allocation and Equity Dividend, the plaintiffs allege that the Defendants violated Section 36(b) of the Investment Company Act by receiving allegedly excessive investment advisory fees from Global Allocation and Equity Dividend. On June 13, 2018, the court granted in part and denied in part the Defendants’ motion for summary judgment. On July 25, 2018, the plaintiffs served a pleading that supplemented the time period of their alleged damages to run through the date of trial. The lawsuit seeks, among other things, to recover on behalf of Global Allocation and Equity Dividend all allegedly excessive advisory fees received by the Defendants beginning twelve months preceding the start of the lawsuit with respect to each of Global Allocation and Equity Dividend and ending on the date of judgment, along with purported lost investment returns on those amounts, plus interest. The trial on the remaining issues was completed on August 29, 2018. On February 8, 2019, the court issued an order dismissing the claims in their entirety. On March 8, 2019, the plaintiffs provided notice that they were appealing both the February 8, 2019 post-trial order and the June 13, 2018 order partially granting Defendants’ motion for summary judgment. On May 28, 2020, the appellate court affirmed the trial court’s orders. On June 26, 2020, the plaintiffs petitioned the appeals court for a rehearing, which was denied on July 9, 2020. Plaintiffs’ deadline to seek further appeal has passed; consequently, this matter is now closed.

Portfolio Manager Information

Information regarding the portfolio managers of the Fund is set forth below. Further information regarding the portfolio managers, including other accounts managed, compensation, ownership of Fund shares, and possible conflicts of interest, is available in the Fund’s SAI.

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Conflicts of Interest

The investment activities of BlackRock and its affiliates (including BlackRock, Inc. and its subsidiaries (collectively, the “Affiliates”)), and their respective directors, officers or employees, in the management of, or their interest in, their own accounts and other accounts they manage, may present conflicts of interest that could disadvantage the Fund and its shareholders.

BlackRock and its Affiliates provide investment management services to other funds and discretionary managed accounts that may follow investment programs similar to that of the Fund. BlackRock and its Affiliates are involved worldwide with a broad spectrum of financial services and asset management activities and may engage in the ordinary course of business in activities in which their interests or the interests of their clients may conflict with those of the Fund. BlackRock or one or more Affiliates act or may act as an investor, research provider, investment manager, commodity pool operator, commodity trading advisor, financier, underwriter, adviser, trader, lender, index provider, agent and/or principal, and have other direct and indirect interests in securities, currencies, commodities, derivatives and other instruments in which the Fund may directly or indirectly invest. The Fund may invest in securities of, or engage in other transactions with, companies with which an Affiliate has significant debt or equity investments or other interests. The Fund may also invest in issuances (such as structured notes) by entities for which an Affiliate provides and is compensated for cash management services relating to the proceeds from the sale of such issuances. The Fund also may invest in securities of, or engage in other transactions with, companies for which an Affiliate provides or may in the future provide research coverage. An Affiliate may have business relationships with, and purchase, or distribute or sell services or products from or to, distributors, consultants or others who recommend the Fund or who engage in transactions with or for the Fund, and may receive compensation for such services. BlackRock or one or more Affiliates may engage in proprietary trading and advise accounts and funds that have investment objectives similar to those of the Fund and/or that engage in and compete for transactions in the same types of securities, currencies and other instruments as the Fund. This may include transactions in securities issued by other open-end and closed-end investment companies (which may include investment companies that are affiliated with the Fund and BlackRock, to the extent permitted under the Investment Company Act). The trading activities of BlackRock and these Affiliates are carried out without reference to positions held directly or indirectly by the Fund and may result in

32

BlackRock or an Affiliate having positions in certain securities that are senior or junior to, or have interests different from or adverse to, the securities that are owned by the Fund.

Neither BlackRock nor any Affiliate is under any obligation to share any investment opportunity, idea or strategy with the Fund. As a result, an Affiliate may compete with the Fund for appropriate investment opportunities. The results of the Fund’s investment activities, therefore, may differ from those of an Affiliate and of other accounts managed by BlackRock or an Affiliate, and it is possible that the Fund could sustain losses during periods in which one or more Affiliates and other accounts achieve profits on their trading for proprietary or other accounts. The opposite result is also possible.

In addition, the Fund may, from time to time, enter into transactions in which BlackRock or an Affiliate or their directors, officers or employees or other clients have an adverse interest. Furthermore, transactions undertaken by clients advised or managed by BlackRock or its Affiliates may adversely impact the Fund. Transactions by one or more clients or BlackRock or its Affiliates or their directors, officers or employees, may have the effect of diluting or otherwise disadvantaging the values, prices or investment strategies of the Fund. The Fund’s activities may be limited because of regulatory restrictions applicable to BlackRock or one or more Affiliates and/or their internal policies designed to comply with such restrictions.

Under a securities lending program approved by the Board, the Trust, on behalf of the Fund, has retained BlackRock Institutional Trust Company, N.A., an Affiliate of BlackRock, to serve as the securities lending agent for the Fund to the extent that the Fund participates in the securities lending program. For these services, the securities lending agent will receive a fee from the Fund, including a fee based on the returns earned on the Fund’s investment of the cash received as collateral for the loaned securities. In addition, one or more Affiliates may be among the entities to which the Fund may lend its portfolio securities under the securities lending program.

The activities of BlackRock and its Affiliates and their respective directors, officers or employees, may give rise to other conflicts of interest that could disadvantage the Fund and its shareholders. BlackRock has adopted policies and procedures designed to address these potential conflicts of interest. See the SAI for further information.

Valuation of Fund Investments

When you buy shares, you pay the net asset value. This is the offering price. Shares are also redeemed at their net asset value. The Fund calculates the net asset value of each class of its shares each day the NYSE is open generally as of the close of regular trading hours on the NYSE, based on prices at the time of closing. The NYSE generally closes at 4:00 p.m. (Eastern time). The net asset value used in determining your share price is the next one calculated after your purchase or redemption order is received.

Equity securities and other instruments for which market quotations are readily available are valued at market value, which is generally determined using the last reported closing price or, if a reported closing price is not available, the last traded price on the exchange or market on which the security or instrument is primarily traded at the time of valuation. The Fund values fixed-income portfolio securities and non-exchange traded derivatives using last available bid prices or current market quotations provided by dealers or prices (including evaluated prices) supplied by the Fund’s approved independent third-party pricing services, each in accordance with valuation procedures approved by the Board. Pricing services may use matrix pricing or valuation models that utilize certain inputs and assumptions to derive values. Pricing services generally value fixed-income securities assuming orderly transactions of institutional round lot size, but the Fund may hold or transact in such securities in smaller, odd lot sizes. Odd lots may trade at lower prices than institutional round lots. Short-term debt securities with remaining maturities of 60 days or less may be valued on the basis of amortized cost.

Foreign currency exchange rates are generally determined as of the close of business on the NYSE. Foreign securities owned by the Fund may trade on weekends or other days when the Fund does not price its shares. As a result, the Fund’s net asset value may change on days when you will not be able to purchase or redeem the Fund’s shares.

Generally, trading in foreign securities, U.S. Government securities, money market instruments and certain fixed-income securities is substantially completed each day at various times prior to the close of business on the NYSE. The values of such securities used in computing the net asset value of the Fund’s shares are determined as of such times.

When market quotations are not readily available or are not believed by BlackRock to be reliable, the Fund’s investments are valued at fair value. Fair value determinations are made by BlackRock in accordance with procedures approved by the Board. BlackRock may conclude that a market quotation is not readily available or is unreliable if a security or other asset or liability does not have a price source due to its lack of liquidity, if BlackRock believes a market quotation from a broker-dealer or other source is unreliable, where the security or other asset or other liability

33

is thinly traded (e.g., municipal securities, certain small cap and emerging growth companies and certain non-U.S. securities) or where there is a significant event subsequent to the most recent market quotation. For this purpose, a “significant event” is deemed to occur if BlackRock determines, in its business judgment prior to or at the time of pricing the Fund’s assets or liabilities, that it is likely that the event will cause a material change to the last closing market price of one or more assets or liabilities held by the Fund. For instance, significant events may occur between the foreign market close and the close of business on the NYSE that may not be reflected in the computation of the Fund’s net assets. If such event occurs, those instruments may be fair valued. Similarly, foreign securities whose values are affected by volatility that occurs in U.S. markets on a trading day after the close of foreign securities markets may be fair valued.

For certain foreign securities, a third-party vendor supplies evaluated, systematic fair value pricing based upon the movement of a proprietary multi-factor model after the relevant foreign markets have closed. This systematic fair value pricing methodology is designed to correlate the prices of foreign securities following the close of the local markets to the price that might have prevailed as of the Fund’s pricing time.

Fair value represents a good faith approximation of the value of a security. The fair value of one or more securities may not, in retrospect, be the price at which those assets could have been sold during the period in which the particular fair values were used in determining the Fund’s net asset value.

The Fund may accept orders from certain authorized Financial Intermediaries or their designees. The Fund will be deemed to receive an order when accepted by the Financial Intermediary or designee and the order will receive the net asset value next computed by the Fund after such acceptance. If the payment for a purchase order is not made by a designated later time, the order will be canceled and the Financial Intermediary could be held liable for any losses.

Dividends, Distributions and Taxes

The Fund will distribute net investment income, if any, quarterly, and net realized capital gains, if any, at least annually. The Fund may also pay a special distribution at the end of the calendar year to comply with federal tax requirements. Dividends may be reinvested automatically in shares of the Fund at net asset value or may be taken in cash. If you would like to receive dividends in cash, contact your Financial Intermediary or the Fund. Although this cannot be predicted with any certainty, the Fund anticipates that a significant amount of its dividends, if any, will consist of ordinary income. Capital gains may be taxable to you at different rates depending on how long the Fund held the assets sold.

You will pay tax on dividends from the Fund whether you receive them in cash or additional shares. If you redeem Fund shares or exchange them for shares of another fund, you generally will be treated as having sold your shares and any gain on the transaction may be subject to tax. Fund distributions derived from qualified dividend income, which consists of dividends received from U.S. corporations and qualifying foreign corporations, and from long-term capital gains are eligible for taxation at a maximum rate of 15% or 20% for individuals, depending on whether their income exceeds certain threshold amounts, which are adjusted annually for inflation.

A 3.8% Medicare tax is imposed on the net investment income (which includes, but is not limited to, interest, dividends and net gain from investments) of U.S. individuals with income exceeding $200,000, or $250,000 if married filing jointly, and of trusts and estates.

Your dividends and redemption proceeds will be subject to backup withholding tax if you have not provided a taxpayer identification number or social security number or the number you have provided is incorrect.

If you are neither a tax resident nor a citizen of the United States or if you are a foreign entity (other than a pass-through entity to the extent owned by U.S. persons), the Fund’s ordinary income dividends will generally be subject to a 30% U.S. withholding tax, unless a lower treaty rate applies. However, certain distributions reported by the Fund as capital gain dividends, interest-related dividends or short-term capital gain dividends and paid to a foreign shareholder may be eligible for an exemption from U.S. withholding tax.

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Separately, a 30% withholding tax is currently imposed on U.S.-source dividends, interest and other income items paid to (i) certain foreign financial institutions and investment funds, and (ii) certain other foreign entities. To avoid withholding, foreign financial institutions and investment funds will generally either need to (a) collect and report to the IRS detailed information identifying their U.S. accounts and U.S. account holders, comply with due diligence procedures for identifying U.S. accounts and withhold tax on certain payments made to noncomplying foreign entities and account holders or (b) if an intergovernmental agreement is entered into and implementing legislation is adopted, comply with the agreement and legislation. Other foreign entities will generally either need to provide detailed information identifying each substantial U.S. owner or certify there are no such owners.

This section summarizes some of the consequences under current federal tax law of an investment in the Fund. It is not a substitute for individualized tax advice. Consult your tax adviser about the potential tax consequences of an investment in the Fund under all applicable tax laws.

35

General Information

Shareholder Documents

Electronic Access to Annual Reports, Semi-Annual Reports and Prospectuses

Electronic copies of most financial reports and prospectuses are available on BlackRock’s website. Shareholders can sign up for e-mail notifications of annual and semi-annual reports and prospectuses by enrolling in the Fund’s electronic delivery program. To enroll:

Shareholders Who Hold Accounts with Investment Advisers, Banks or Brokerages: Please contact your Financial Intermediary. Please note that not all investment advisers, banks or brokerages may offer this service.

Shareholders Who Hold Accounts Directly With BlackRock:

■	Access the BlackRock website at http://www.blackrock.com/edelivery; and
■	Log into your account.

Delivery of Shareholder Documents

The Fund delivers only one copy of shareholder documents, including prospectuses, shareholder reports and proxy statements, to shareholders with multiple accounts at the same address. This practice is known as “householding” and is intended to eliminate duplicate mailings and reduce expenses. Mailings of your shareholder documents may be householded indefinitely unless you instruct us otherwise. If you do not want the mailing of these documents to be combined with those for other members of your household, please contact the Fund at (800) 441-7762.

Certain Fund Policies

Anti-Money Laundering Requirements

The Fund is subject to the USA PATRIOT Act (the “Patriot Act”). The Patriot Act is intended to prevent the use of the U.S. financial system in furtherance of money laundering, terrorism or other illicit activities. Pursuant to requirements under the Patriot Act, the Fund is required to obtain sufficient information from shareholders to enable it to form a reasonable belief that it knows the true identity of its shareholders. This information will be used to verify the identity of investors or, in some cases, the status of Financial Intermediaries . Such information may be verified using third-party sources. This information will be used only for compliance with the Patriot Act or other applicable laws, regulations and rules in connection with money laundering, terrorism or economic sanctions.

The Fund reserves the right to reject purchase orders from persons who have not submitted information sufficient to allow the Fund to verify their identity. The Fund also reserves the right to redeem any amounts in the Fund from persons whose identity it is unable to verify on a timely basis. It is the Fund’s policy to cooperate fully with appropriate regulators in any investigations conducted with respect to potential money laundering, terrorism or other illicit activities.

BlackRock Privacy Principles

BlackRock is committed to maintaining the privacy of its current and former fund investors and individual clients (collectively, “Clients”) and to safeguarding their non-public personal information. The following information is provided to help you understand what personal information BlackRock collects, how we protect that information and why in certain cases we share such information with select parties.

If you are located in a jurisdiction where specific laws, rules or regulations require BlackRock to provide you with additional or different privacy-related rights beyond what is set forth below, then BlackRock will comply with those specific laws, rules or regulations.

BlackRock obtains or verifies personal non-public information from and about you from different sources, including the following: (i) information we receive from you or, if applicable, your Financial Intermediary, on applications, forms or other documents; (ii) information about your transactions with us, our affiliates, or others; (iii) information we receive from a consumer reporting agency; and (iv) from visits to our website.

38

BlackRock does not sell or disclose to non-affiliated third parties any non-public personal information about its Clients, except as permitted by law, or as is necessary to respond to regulatory requests or to service Client accounts. These non-affiliated third parties are required to protect the confidentiality and security of this information and to use it only for its intended purpose.

We may share information with our affiliates to service your account or to provide you with information about other BlackRock products or services that may be of interest to you. In addition, BlackRock restricts access to non-public personal information about its Clients to those BlackRock employees with a legitimate business need for the information. BlackRock maintains physical, electronic and procedural safeguards that are designed to protect the non-public personal information of its Clients, including procedures relating to the proper storage and disposal of such information.

Statement of Additional Information

If you would like further information about the Fund, including how it invests, please see the SAI.

For a discussion of the Fund’s policies and procedures regarding the selective disclosure of its portfolio holdings, please see the SAI. The Fund makes its top ten holdings available on a monthly basis at www.blackrock.com generally within 5 business days after the end of the month to which the information applies.

39

Glossary

This glossary contains an explanation of some of the common terms used in this prospectus. For additional information about the Fund, please see the SAI.

Acquired Fund Fees and Expenses — fees and expenses charged by other investment companies in which the Fund invests a portion of its assets.

Annual Fund Operating Expenses — expenses that cover the costs of operating the Fund.

Distribution Fees — fees used to support the Fund’s marketing and distribution efforts, such as compensating Financial Intermediaries, advertising and promotion.

Interest Expense — the cost of borrowing money to buy additional securities.

Management Fee — a fee paid to BlackRock for managing the Fund.

Other Expenses — include accounting, transfer agency, custody, professional and registration fees.

Russell Midcap^® Index — an index that measures the performance of the 800 smallest companies in the Russell 1000^® Index, which represent approximately 31% of the total market capitalization of the Russell 1000^® Index.

Russell 1000^® Index — an index that measures the performance of the large-cap segment of the U.S. equity universe. It is a subset of the Russell 3000^® Index and includes approximately 1,000 of the largest securities based on a combination of their market cap and current index membership. The Russell 1000^® represents approximately 92% of the U.S. market.

Service Fees — fees used to compensate Financial Intermediaries for certain shareholder servicing activities.

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For More Information

Fund and Service Providers

NOVEMBER 27, 2020

Prospectus

BlackRock Funds^SM  |  Class K Shares

•	iShares Russell Mid-Cap Index Fund
	Class K: BRMKX

This Prospectus contains information you should know before investing, including information about risks. Please read it before you invest and keep it for future reference.

The 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.

Not FDIC Insured • May Lose Value • No Bank Guarantee

    

Details About the Fund	Information about how the Fund invests, including investment objective, investment process, principal strategies and risk factors
	How the Fund Invests	8
	Investment Risks	9

    

Account Information	Information about account services, sales charges and waivers, shareholder transactions, and distribution and other payments
	Details About the Share Class	15
	How to Buy, Sell, Exchange and Transfer Shares	16
	Fund’s Rights	21
	Short-Term Trading Policy	21

    

Management of the Fund	Information about BlackRock and the Portfolio Managers
	BlackRock	23
	Portfolio Manager Information	24
	Conflicts of Interest	25
	Valuation of Fund Investments	26
	Dividends, Distributions and Taxes	27

    

Financial Highlights	Financial Performance of the Fund	29

    

General Information	Shareholder Documents	30
	Certain Fund Policies	30
	Statement of Additional Information	31

    

Glossary	Glossary of Investment Terms	32

    

For More Information	Fund and Service Providers	Inside Back Cover
	Additional Information	Back Cover

Key Facts About iShares Russell Mid-Cap Index Fund

  

1

As described in the “Management of the Fund” section of the Fund’s prospectus beginning on page 23, BlackRock Advisors, LLC (“BlackRock”) has contractually agreed to waive the management fee with respect to any portion of the Fund’s assets estimated to be attributable to investments in other equity and fixed-income mutual funds and exchange-traded funds managed by BlackRock or its affiliates that have a contractual management fee, through November 30, 2021. In addition, BlackRock has contractually agreed to waive its management fees by the amount of investment advisory fees the Fund pays to BlackRock indirectly through its investment in money market funds managed by BlackRock or its affiliates, through November 30, 2021. The contractual agreements may be terminated upon 90 days’ notice by a majority of the non-interested trustees of the Trust or by a vote of a majority of the outstanding voting securities of the Fund.

2

As described in the “Management of the Fund” section of the Fund’s prospectus beginning on page 23, BlackRock has contractually agreed to waive and/or reimburse fees or expenses in order to limit Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses) to 0.07% of average daily net assets through November 30, 2021. The Fund may have to repay some of these waivers and/or reimbursements to BlackRock in the following two years, and such repayment arrangement will terminate on May 13, 2022. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested trustees of the Trust or by a vote of a majority of the outstanding voting securities of the Fund.

	1 Year	3 Years	5 Years	10 Years
Class K Shares	$7	$25	$44	$102

  

3

■	Management Risk — As the Fund may not fully replicate the Underlying Index, it is subject to the risk that BlackRock’s investment strategy may not produce the intended results.
■	Market Risk and Selection Risk — Market risk is the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. The value of a security or other asset may decline due to changes in general market conditions, economic trends or events that are not specifically related to the issuer of the security or other asset, or factors that affect a particular issuer or issuers, exchange, country, group of countries, region, market, industry, group of industries, sector or asset class. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues like pandemics or epidemics, recessions, or other events could have a significant impact on the Fund and its investments. Selection risk is the risk that the securities selected by Fund management will underperform the markets, the relevant indices or the securities selected by other funds with similar investment objectives and investment strategies. This means you may lose money.
	A recent outbreak of an infectious coronavirus has developed into a global pandemic that has resulted in numerous disruptions in the market and has had significant economic impact leaving general concern and uncertainty. The impact of this coronavirus, and other epidemics and pandemics that may arise in the future, could affect the economies of many nations, individual companies and the market in general ways that cannot necessarily be foreseen at the present time.
■	Mid Cap Securities Risk — The securities of mid cap companies generally trade in lower volumes and are generally subject to greater and less predictable price changes than the securities of larger capitalization companies.
■	Passive Investment Risk — Because BlackRock does not select individual companies in the index that the Fund tracks, the Fund may hold securities of companies that present risks that an investment adviser researching individual securities might seek to avoid.
■	Technology Sector Risk — Technology companies, including information technology companies, may have limited product lines, markets, financial resources or personnel. Technology companies typically face intense competition and potentially rapid product obsolescence. They are also heavily dependent on intellectual property rights and may be adversely affected by the loss or impairment of those rights. Companies in the technology sector are facing increased government and regulatory scrutiny and may be subject to adverse government or regulatory action.

5

iShares Russell Mid-Cap Index Fund
Class K Shares

  

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. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

Investment Manager

The Fund’s investment manager is BlackRock Advisors, LLC (previously defined as “BlackRock”). The Fund’s sub-adviser is BlackRock Fund Advisors (the “Sub-Adviser”). Where applicable, “BlackRock” refers also to the Sub-Adviser.

  

Purchase and Sale of Fund Shares

Class K Shares of the Fund are available only to (i) certain employee benefit plans, such as health savings accounts, and certain employer-sponsored retirement plans (not including SEP IRAs, SIMPLE IRAs and SARSEPs) (collectively, “Employer-Sponsored Retirement Plans”), (ii) collective trust funds, investment companies and other pooled investment vehicles, each of which may purchase shares of the Fund through a Financial Intermediary (as defined below) that has entered into an agreement with the Fund’s distributor to purchase such shares, (iii) “Institutional Investors,” which include, but are not limited to, endowments, foundations, family offices, banks and bank trusts,

6

local, city, and state governmental institutions, corporations and insurance company separate accounts, each of which may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Fund’s distributor to purchase such shares, (iv) clients of private banks that purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Fund’s distributor to sell such shares; (v) fee-based advisory platforms of a Financial Intermediary that (a) has specifically acknowledged in a written agreement with the Fund’s distributor and/or its affiliate(s) that the Financial Intermediary shall offer such shares to fee-based advisory clients through an omnibus account held at the Fund or (b) transacts in the Fund’s shares through another intermediary that has executed such an agreement and (vi) any other investors who met the eligibility criteria for BlackRock Shares or Class K Shares prior to August 15, 2016 and have continually held Class K Shares of the Fund in the same account since August 15, 2016.

You may purchase or redeem shares of the Fund each day the New York Stock Exchange is open. Purchase orders may also be placed by calling (800) 537-4942, by mail (c/o BlackRock, P.O. Box 9819, Providence, Rhode Island 02940-8019), or online at www.blackrock.com. Institutional Investors are subject to a $5 million minimum initial investment requirement. Other investors, including Employer-Sponsored Retirement Plans, have no minimum initial investment requirement. There is no minimum investment amount for additional purchases.

Tax Information

Different income tax rules apply depending on whether you are invested through a qualified tax-exempt plan described in section 401(a) of the Internal Revenue Code of 1986, as amended. If you are invested through such a plan (and Fund shares are not “debt-financed property” to the plan), then the dividends paid by the Fund and the gain realized from a redemption or exchange of Fund shares will generally not be subject to U.S. federal income taxes until you withdraw or receive distributions from the plan. If you are not invested through such a plan, then the Fund’s dividends and gain from a redemption or exchange may be subject to U.S. federal income taxes and may be taxed as ordinary income or capital gains, unless you are a tax-exempt investor.

Payments to Broker/Dealers and Other Financial Intermediaries

If you purchase shares of the Fund through a financial professional or selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock and its affiliates) (each a “Financial Intermediary”), the Fund and BlackRock Investments, LLC, the Fund’s distributor, or its affiliates may pay the Financial Intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the Financial Intermediary and your individual financial professional to recommend the Fund over another investment.

Class K Shares are only available through a Financial Intermediary if the Financial Intermediary will not receive from Fund assets, or the Fund’s distributor’s or an affiliate’s resources, any commission payments, shareholder servicing fees (including sub-transfer agent and networking fees), or distribution fees (including Rule 12b-1 fees) with respect to assets invested in Class K Shares.

Ask your individual financial professional or visit your Financial Intermediary’s website for more information.

7

Details About the Fund

Included in this prospectus are sections that tell you about buying and selling shares, management information, shareholder features of iShares Russell Mid-Cap Index Fund (the “Fund”), a series of BlackRock Funds^SM (the “Trust”), and your rights as a shareholder.

How the Fund Invests

8

	subscriptions, to maintain liquidity in the event of redemptions and to keep trading costs low. The Fund may use derivatives for hedging purposes, including anticipatory hedges, and to seek to enhance returns.
■	Illiquid Investments — The Fund may invest up to an aggregate amount of 15% of its net assets in illiquid investments. An illiquid investment is any investment that the 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.
■	Investment Companies — The Fund has the ability to invest in other investment companies, such as exchange-traded funds (“ETFs”), unit investment trusts, and open-end and closed-end funds. The Fund may invest in affiliated investment companies, including affiliated money market funds and affiliated ETFs.
■	Securities Lending — The Fund may lend securities with a value up to 33 1⁄3% of its total assets to financial institutions that provide cash or securities issued or guaranteed by the U.S. Government as collateral.

    

Investment Risks

This section contains a discussion of the general risks of investing in the Fund. The “Investment Objective and Policies” section in the Statement of Additional Information (the “SAI”) also includes more information about the Fund, its investments and the related risks. As with any fund, there can be no guarantee that the Fund will meet its investment objective or that the Fund’s performance will be positive for any period of time. An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or by any bank or governmental agency. The order of the below risk factors does not indicate the significance of any particular risk factor.

Principal Risks of Investing in the Fund

■	Asset Class Risk — The securities or other assets in the Underlying Index or in the Fund’s portfolio may underperform in comparison to other securities or indexes that track other countries, groups of countries, regions, industries, groups of industries, markets, asset classes or sectors. Various types of securities, currencies and indexes or assets may experience cycles of outperformance and underperformance in comparison to the general financial markets depending upon a number of factors including, among other things, inflation, interest rates, productivity, global demand for local products or resources, and regulation and governmental controls. This may cause the Fund to underperform other investment vehicles that invest in different asset classes.
■	Concentration Risk — The Fund reserves the right to concentrate its investments (i.e., invest 25% or more of its total assets in securities of issuers in a particular industry) to approximately the same extent that the Underlying Index concentrates in a particular industry. To the extent the Fund concentrates in a particular industry, it may be more susceptible to economic conditions and risks affecting that industry.
■	Consumer Discretionary Sector Risk — The success of consumer product manufacturers and retailers is tied closely to the performance of domestic and international economies, interest rates, exchange rates, competition, consumer confidence, changes in demographics and consumer preferences. Companies in the consumer discretionary sector depend heavily on disposable household income and consumer spending, and may be strongly affected by social trends and marketing campaigns. These companies may be subject to severe competition, which may have an adverse impact on their profitability.
■	Equity Securities Risk — Common and preferred stocks represent equity ownership in a company. Stock markets are volatile. The price of equity securities will fluctuate and can decline and reduce the value of a portfolio investing in equities. The value of equity securities purchased by the Fund could decline if the financial condition of the companies the Fund invests in declines or if overall market and economic conditions deteriorate. The value of equity securities may also decline due to factors that affect a particular industry or industries, such as labor shortages or an increase in production costs and competitive conditions within an industry. In addition, the value may decline due to general market conditions that are not specifically related to a company or industry, such as real or

9

	perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates or generally adverse investor sentiment.
■	Index Fund Risk — An index fund has operating and other expenses while an index does not. As a result, while the Fund will attempt to track the Underlying Index as closely as possible, it will tend to underperform the Underlying Index to some degree over time. If an index fund is properly correlated to its stated index, the fund will perform poorly when the index performs poorly.
■	Index-Related Risk — The Fund seeks to achieve a return that corresponds generally to the price and yield performance, before fees and expenses, of the Underlying Index as published by the Index Provider. There is no assurance that the Index Provider or any agents that may act on its behalf will compile the Underlying Index accurately, or that the Underlying Index will be determined, composed or calculated accurately. While the Index Provider provides descriptions of what the Underlying Index is designed to achieve, neither the Index Provider nor its agents provide any warranty or accept any liability in relation to the quality, accuracy or completeness of the Underlying Index or its related data, and they do not guarantee that the Underlying Index will be in line with the Index Provider’s methodology. BlackRock’s mandate as described in this prospectus is to manage the Fund consistently with the Underlying Index provided by the Index Provider to BlackRock. BlackRock does not provide any warranty or guarantee against the Index Provider’s or any agent’s errors. Errors in respect of the quality, accuracy and completeness of the data used to compile the Underlying Index may occur from time to time and may not be identified and corrected by the Index Provider for a period of time or at all, particularly where the indices are less commonly used as benchmarks by funds or managers. Such errors may negatively or positively impact the Fund and its shareholders. For example, during a period where the Underlying Index contains incorrect constituents, the Fund would have market exposure to such constituents and would be underexposed to the Underlying Index’s other constituents. Shareholders should understand that any gains from Index Provider errors will be kept by the Fund and its shareholders and any losses or costs resulting from Index Provider errors will be borne by the Fund and its shareholders.
	Unusual market conditions may cause the Index Provider to postpone a scheduled rebalance, which could cause the Underlying Index to vary from its normal or expected composition. The postponement of a scheduled rebalance in a time of market volatility could mean that constituents that would otherwise be removed at rebalance due to changes in market capitalizations, issuer credit ratings, or other reasons may remain, causing the performance and constituents of the Underlying Index to vary from those expected under normal conditions. Apart from scheduled rebalances, the Index Provider or its agents may carry out additional ad hoc rebalances to the Underlying Index due to reaching certain weighting constraints, unusual market conditions or in order, for example, to correct an error in the selection of index constituents. When the Underlying Index is rebalanced and the Fund in turn rebalances its portfolio to attempt to increase the correlation between the Fund’s portfolio and the Underlying Index, any transaction costs and market exposure arising from such portfolio rebalancing will be borne directly by the Fund and its shareholders. Therefore, errors and additional ad hoc rebalances carried out by the Index Provider or its agents to the Underlying Index may increase the costs to and the tracking error risk of the Fund.
■	Industrials Sector Risk — The value of securities issued by companies in the industrials sector may be adversely affected by supply and demand changes related to their specific products or services and industrials sector products in general. The products of manufacturing companies may face obsolescence due to rapid technological developments and frequent new product introduction. Global events, trade disputes and changes in government regulations, economic conditions and exchange rates may adversely affect the performance of companies in the industrials sector. Companies in the industrials sector may be adversely affected by liability for environmental damage and product liability claims. The industrials sector may also be adversely affected by changes or trends in commodity prices, which may be influenced by unpredictable factors. Aerospace and defense companies, a component of the industrials sector, can be significantly affected by government spending policies because companies involved in this industry rely, to a significant extent, on government demand for their products and services. Thus, the financial condition of, and investor interest in, aerospace and defense companies are heavily influenced by governmental defense spending policies, which are typically under pressure from efforts to control government budgets. Transportation stocks, a component of the industrials sector, are cyclical and can be significantly affected by economic changes, fuel prices, labor relations and insurance costs. Transportation companies in certain countries may also be subject to significant government regulation and oversight, which may adversely affect their businesses. Companies in the industrials sector, particularly aerospace and defense companies, may also be adversely affected by government spending policies because companies in this sector tend to rely to a significant extent on government demand for their products and services.
■	Issuer Risk — The performance of the Fund depends on the performance of individual securities to which the Fund has exposure. Any issuer of these securities may perform poorly, causing the value of its securities to decline. Poor performance may be caused by poor management decisions, competitive pressures, changes in technology, expiration of patent protection, disruptions in supply, labor problems or shortages, corporate restructurings,

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	fraudulent disclosures, credit deterioration of the issuer or other factors. Issuers may, in times of distress or at their own discretion, decide to reduce or eliminate dividends, which may also cause their stock prices to decline.
■	Management Risk — The Fund may not fully replicate the Underlying Index and may hold securities not included in the Underlying Index. As a result, the Fund is subject to the risk that BlackRock’s investment strategy, the implementation of which is subject to a number of constraints, may not produce the intended results.
■	Market Risk and Selection Risk — Market risk is the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. The value of a security or other asset may decline due to changes in general market conditions, economic trends or events that are not specifically related to the issuer of the security or other asset, or factors that affect a particular issuer or issuers, exchange, country, group of countries, region, market, industry, group of industries, sector or asset class. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues like pandemics or epidemics, recessions, or other events could have a significant impact on the Fund and its investments. Selection risk is the risk that the securities selected by Fund management will underperform the markets, the relevant indices or the securities selected by other funds with similar investment objectives and investment strategies. This means you may lose money.
	A recent outbreak of an infectious coronavirus has developed into a global pandemic that has resulted in numerous disruptions in the market and has had significant economic impact leaving general concern and uncertainty. The impact of this coronavirus, and other epidemics and pandemics that may arise in the future, could affect the economies of many nations, individual companies and the market in general ways that cannot necessarily be foreseen at the present time.
■	Mid Cap Securities Risk — The securities of mid cap companies generally trade in lower volumes and are generally subject to greater and less predictable price changes than the securities of larger capitalization companies.
■	Passive Investment Risk — Because BlackRock does not select individual companies in the index that the Fund tracks, the Fund may hold securities of companies that present risks that an investment adviser researching individual securities might seek to avoid.
■	Technology Sector Risk — Technology companies, including information technology companies, face intense competition, both domestically and internationally, which may have an adverse effect on a company’s profit margins. Technology companies may have limited product lines, markets, financial resources or personnel. The products of technology companies may face obsolescence due to rapid technological developments, frequent new product introduction, unpredictable changes in growth rates, aggressive pricing, changes in demand, and competition for the services of qualified personnel. Companies in the technology sector are heavily dependent on patent and other intellectual property rights. A technology company’s loss or impairment of these rights may adversely affect the company’s profitability. Companies in the technology sector are facing increased government and regulatory scrutiny and may be subject to adverse government or regulatory action. The technology sector may also be adversely affected by changes or trends in commodity prices, which may be influenced or characterized by unpredictable factors.

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	period. A risk of the Fund’s use of derivatives is that the fluctuations in their values may not correlate with the overall securities markets.
	Counterparty Risk — Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will not fulfill its contractual obligation.
	Market and Illiquidity Risk — Some derivatives are more sensitive to interest rate changes and market price fluctuations than other securities. The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately. The Fund could also suffer losses related to its derivatives positions as a result of unanticipated market movements, which losses are potentially unlimited. Finally, BlackRock may not be able to predict correctly the direction of securities prices, interest rates and other economic factors, which could cause the Fund’s derivatives positions to lose value.
	Valuation Risk — Valuation may be more difficult in times of market turmoil since many investors and market makers may be reluctant to purchase complex instruments or quote prices for them. Derivatives may also expose the Fund to greater risk and increase its costs. Certain transactions in derivatives involve substantial leverage risk and may expose the Fund to potential losses that exceed the amount originally invested by the Fund.
	Hedging Risk — When a derivative is used as a hedge against a position that the Fund holds, any loss generated by the derivative 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 derivative and the underlying security, and there can be no assurance that the Fund’s hedging transactions will be effective. The use of hedging may result in certain adverse tax consequences noted below.
	Tax Risk — The federal income tax treatment of a derivative may not be as favorable as a direct investment in an underlying asset and may adversely affect the timing, character and amount of income the Fund realizes from its investments. As a result, a larger portion of the Fund’s distributions may be treated as ordinary income rather than capital gains. In addition, certain derivatives are subject to mark-to-market or straddle provisions of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code”). If such provisions are applicable, there could be an increase (or decrease) in the amount of taxable dividends paid by the Fund. In addition, the tax treatment of certain derivatives, such as swaps, is unsettled and may be subject to future legislation, regulation or administrative pronouncements issued by the Internal Revenue Service (the “IRS”).
	Regulatory Risk — Derivative contracts, including, without limitation, swaps, currency forwards and non-deliverable forwards, are subject to regulation under the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”) in the United States and under comparable regimes in Europe, Asia and other non-U.S. jurisdictions. Under the Dodd-Frank Act, certain derivatives are subject to margin requirements and swap dealers are required to collect margin from the Fund with respect to such derivatives. Specifically, regulations are now in effect that require swap dealers to post and collect variation margin (comprised of specified liquid instruments and subject to a required haircut) in connection with trading of over-the-counter (“OTC”) swaps with the Fund. Shares of investment companies (other than certain money market funds) may not be posted as collateral under these regulations. Requirements for posting of initial margin in connection with OTC swaps will be phased-in through at least 2021. In addition, regulations adopted by global prudential regulators that are now in effect require certain bank-regulated counterparties and certain of their affiliates to include in certain financial contracts, including many derivatives contracts, terms that delay or restrict the rights of counterparties, such as the Fund, to terminate such contracts, foreclose upon collateral, exercise other default rights or restrict transfers of credit support in the event that the counterparty and/or its affiliates are subject to certain types of resolution or insolvency proceedings. The implementation of these requirements with respect to derivatives, as well as regulations under the Dodd-Frank Act regarding clearing, mandatory trading and margining of other derivatives, may increase the costs and risks to the Fund of trading in these instruments and, as a result, may affect returns to investors in the Fund.
	On October 28, 2020, the Securities and Exchange Commission (the “SEC”) adopted new regulations governing the use of derivatives by registered investment companies (“Rule 18f-4”). The Fund will be required to implement and comply with Rule 18f-4 by the third quarter of 2022. Once implemented, Rule 18f-4 will impose limits on the amount of derivatives a fund can enter into, eliminate the asset segregation framework currently used by funds to comply with Section 18 of the Investment Company Act, treat derivatives as senior securities so that a failure to comply with the limits would result in a statutory violation and require funds whose use of derivatives is more than a limited specified exposure amount to establish and maintain a comprehensive derivatives risk management program and appoint a derivatives risk manager.
	In addition, other future regulatory developments may impact the Fund’s ability to invest or remain invested in

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certain derivatives. Legislation or regulation may also change the way in which the Fund itself is regulated. BlackRock cannot predict the effects of any new governmental regulation that may be implemented on the ability of the Fund to use swaps or any other financial derivative product, and there can be no assurance that any new governmental regulation will not adversely affect the Fund’s ability to achieve its investment objective.

Risks Specific to Certain Derivatives Used by the Fund

Swaps — Swap agreements, including total return swaps that may be referred to as contracts for difference, are two-party contracts entered into for periods ranging from a few weeks to more than one year. In a standard “swap” transaction, two parties agree to exchange the returns (or differentials in rates of return) earned or realized on particular predetermined investments or instruments, which can be adjusted for an interest factor. Swap agreements involve the risk that the party with whom the Fund has entered into the swap will default on its obligation to pay the Fund and the risk that the Fund will not be able to meet its obligations to pay the other party to the agreement. Swap agreements may also involve the risk that there is an imperfect correlation between the return on the Fund’s obligation to its counterparty and the return on the referenced asset. In addition, swap agreements are subject to market and illiquidity risk, leverage risk and hedging risk.

Futures — Futures are standardized, exchange-traded contracts that obligate a purchaser to take delivery, and a seller to make delivery, of a specific amount of an asset at a specified future date at a specified price. The primary risks associated with the use of futures contracts and options are: (a) the imperfect correlation between the change in market value of the instruments held by the Fund and the price of the futures contract or option; (b) the possible lack of a liquid secondary market for a futures contract and the resulting inability to close a futures contract when desired; (c) losses caused by unanticipated market movements, which are potentially unlimited; (d) the investment adviser’s inability to predict correctly the direction of securities prices, interest rates, currency exchange rates and other economic factors; and (e) the possibility that the counterparty will default in the performance of its obligations.

■	Expense Risk — Fund expenses are subject to a variety of factors, including fluctuations in the Fund’s net assets. Accordingly, actual expenses may be greater or less than those indicated. For example, to the extent that the Fund’s net assets decrease due to market declines or redemptions, the Fund’s expenses will increase as a percentage of Fund net assets. During periods of high market volatility, these increases in the Fund’s expense ratio could be significant.
■	Financials Sector Risk — Companies in the financials sector of an economy are subject to extensive governmental regulation and intervention, which may adversely affect the scope of their activities, the prices they can charge, the amount of capital they must maintain and, potentially, their size. The extent to which the Fund may invest in a company that engages in securities-related activities or banking is limited by applicable law. Governmental regulation may change frequently and may have significant adverse consequences for companies in the financials sector, including effects not intended by such regulation. Recently enacted legislation in the United States has relaxed capital requirements and other regulatory burdens on certain U.S. banks. While the effect of the legislation may benefit certain companies in the financials sector, including non-U.S. financials sector companies, increased risk taking by affected banks may also result in greater overall risk in the United States and global financials sector. The impact of changes in capital requirements, or recent or future regulation in various countries, on any individual financial company or on the financials sector as a whole cannot be predicted. Certain risks may impact the value of investments in the financials sector more severely than those of investments outside this sector, including the risks associated with companies that operate with substantial financial leverage. Companies in the financials sector may also be adversely affected by increases in interest rates and loan losses, decreases in the availability of money or asset valuations, credit rating downgrades and adverse conditions in other related markets. Insurance companies, in particular, may be subject to severe price competition and/or rate regulation, which may have an adverse impact on their profitability. The financials sector is particularly sensitive to fluctuations in interest rates. The financials sector is also a target for cyberattacks, and may experience technology malfunctions and disruptions. In recent years, cyberattacks and technology malfunctions and failures have become increasingly frequent in this sector and have reportedly caused losses to companies in this sector, which may negatively impact the Fund.
■	Healthcare Sector Risk — The profitability of companies in the healthcare sector may be adversely affected by the following factors, among others: extensive government regulations, restrictions on government reimbursement for medical expenses, rising costs of medical products and services, pricing pressure, an increased emphasis on outpatient services, changes in the demand for medical products and services, a limited number of products, industry innovation, changes in technologies and other market developments. A number of issuers in the healthcare sector have recently merged or otherwise experienced consolidation. The effects of this trend toward consolidation are unknown and may be far-reaching. Many healthcare companies are heavily dependent on patent protection. The expiration of a company’s patents may adversely affect that company’s profitability. Many healthcare companies are subject to extensive litigation based on product liability and similar claims. Healthcare companies are subject to

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	competitive forces that may make it difficult to raise prices and, in fact, may result in price discounting. Many new products in the healthcare sector may be subject to regulatory approvals. The process of obtaining such approvals may be long and costly, and such efforts ultimately may be unsuccessful. Companies in the healthcare sector may be thinly capitalized and may be susceptible to product obsolescence. In addition, a number of legislative proposals concerning healthcare have been considered by the U.S. Congress in recent years. It is unclear what proposals will ultimately be enacted, if any, and what effect they may have on companies in the healthcare sector.
■	Illiquid Investments Risk — The Fund’s illiquid investments may reduce the returns of the Fund because it may be difficult to sell the illiquid investments at an advantageous time or price. An investment may be illiquid due to, among other things, the lack of an active trading market. To the extent that the Fund’s principal investment strategies involve derivatives or securities with substantial market and/or credit risk, the Fund will tend to have the greatest exposure to the risks associated with illiquid investments. Liquid investments may become illiquid after purchase by the Fund, particularly during periods of market turmoil. Illiquid investments may be harder to value, especially in changing markets, and if the Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss. In addition, when there is illiquidity in the market for certain securities, the Fund, due to limitations on illiquid investments, may be subject to purchase and sale restrictions.
■	Investment in Other Investment Companies Risk — As with other investments, investments in other investment companies, including ETFs, are subject to market and selection risk. In addition, if the Fund acquires shares of investment companies, including ones affiliated with the Fund, shareholders bear both their proportionate share of expenses in the Fund (including management and advisory fees) and, indirectly, the expenses of the investment companies (to the extent not offset by BlackRock through waivers). To the extent the Fund is held by an affiliated fund, the ability of the Fund itself to hold other investment companies may be limited.
■	Leverage Risk — Some transactions may give rise to a form of economic leverage. These transactions may include, among others, derivatives, and may expose the Fund to greater risk and increase its costs. As an open-end investment company registered with the SEC, the Fund is subject to the federal securities laws, including the Investment Company Act, the rules thereunder, and various SEC and SEC staff interpretive positions. In accordance with these laws, rules and positions, the Fund must “set aside” liquid assets (often referred to as “asset segregation”), or engage in other SEC- or staff-approved measures, to “cover” open positions with respect to certain kinds of instruments. The use of leverage may cause the Fund to liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet any required asset segregation requirements. Increases and decreases in the value of the Fund’s portfolio will be magnified when the Fund uses leverage.
■	Securities Lending Risk — Securities lending involves the risk that the borrower may fail to return the securities in a timely manner or at all. As a result, the Fund may lose money and there may be a delay in recovering the loaned securities. The Fund could also lose money if it does not recover the securities and/or the value of the collateral falls, including the value of investments made with cash collateral. These events could trigger adverse tax consequences for the Fund.
■	Valuation Risk — The price the Fund could receive upon the sale of any particular portfolio investment may differ from the Fund’s valuation of the investment, particularly for securities that trade in thin or volatile markets or that are valued using a fair valuation methodology or a price provided by an independent pricing service. As a result, the price received upon the sale of an investment may be less than the value ascribed by the Fund, and the Fund could realize a greater than expected loss or lesser than expected gain upon the sale of the investment. Pricing services that value fixed-income securities generally utilize a range of market-based and security-specific inputs and assumptions, as well as considerations about general market conditions, to establish a price. Pricing services generally value fixed-income securities assuming orderly transactions of an institutional round lot size, but may be held or transactions may be conducted in such securities in smaller, odd lot sizes. Odd lots may trade at lower prices than institutional round lots. The Fund’s ability to value its investments may also be impacted by technological issues and/or errors by pricing services or other third-party service providers.

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Account Information

Details About the Share Class

The Fund currently offers multiple share classes (Class K Shares in this prospectus), each with its own expense structure, allowing you to invest in the way that best suits your needs. Each share class represents an ownership interest in the same investment portfolio of the Fund. When you choose your class of shares, you should consider the size of your investment and how long you plan to hold your shares. Only certain investors are eligible to buy Class K Shares. Either your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock and its affiliates) (each a “Financial Intermediary”) can help you determine whether you are eligible to buy Class K Shares.

The Fund’s shares are distributed by BlackRock Investments, LLC (the “Distributor”), an affiliate of BlackRock.

The table below summarizes key features of Class K Shares of the Fund.

  

The Fund reserves the right to modify or waive the above-stated policies at any time.

When Class K Shares are purchased through a customer’s account in an Employer-Sponsored Retirement Plan through procedures established by the Employer-Sponsored Retirement Plan, confirmation of share purchases and redemptions will be sent to the Employer-Sponsored Retirement Plan. A customer’s ownership of shares will be recorded by the Employer-Sponsored Retirement Plan and reflected in the account statements provided by the Employer-Sponsored Retirement Plan to its participants.

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If you purchased your shares through an Employer-Sponsored Retirement Plan and you transfer your investment from an Employer-Sponsored Retirement Plan to a type of account, such as an individual retirement account, that is not an eligible Class K Share investor in the Fund, you must liquidate your investment in Class K Shares of the Fund and purchase a share class of the Fund or another fund advised by BlackRock or its affiliates that is available for purchase by that type of account.

For investors not purchasing shares through an Employer-Sponsored Retirement Plan, please see below for information on how to buy, sell, exchange and transfer shares.

Right of Accumulation

Investors have a “right of accumulation” under which any of the following may be combined with the amount of the current purchase in determining whether an investor qualifies for a breakpoint and a reduced front-end sales charge:

i.	The current value of an investor’s existing Investor A and A1, Investor C, Investor P, Institutional, Class K and Premier Shares in most mutual funds sponsored and advised by BlackRock or its affiliates (“BlackRock Funds”),
ii.	The current value of an investor’s existing shares of certain unlisted closed-end management investment companies sponsored and advised by BlackRock or its affiliates and
iii.	The investment in the BlackRock CollegeAdvantage 529 Program by the investor or by or on behalf of the investor’s spouse and children.

Financial Intermediaries may value current holdings of their customers differently for purposes of determining whether an investor qualifies for a breakpoint and a reduced front-end sales charge, although customers of the same Financial Intermediary will be treated similarly. In order to use this right, the investor must alert BlackRock to the existence of any previously purchased shares.

How to Buy, Sell, Exchange and Transfer Shares

The chart on the following pages summarizes how to buy, sell, exchange and transfer shares through your Financial Intermediary. If you are not purchasing shares through an Employer-Sponsored Retirement Plan, you may also buy, sell, exchange and transfer shares through BlackRock if your account is held directly with BlackRock. To learn more about buying, selling, exchanging or transferring shares through BlackRock, call (800) 537-4942. Because the selection of a mutual fund involves many considerations, your Financial Intermediary may help you with this decision.

With certain limited exceptions, the Fund is generally available only to investors residing in the United States and may not be distributed by a foreign Financial Intermediary. Under this policy, in order to accept new accounts or additional investments (including by way of exchange from another BlackRock Fund) into existing accounts, the Fund generally requires that (i) a shareholder that is a natural person be a U.S. citizen or resident alien, in each case residing within the United States or a U.S. territory (including APO/FPO/DPO addresses), and have a valid U.S. taxpayer identification number, and (ii) a Financial Intermediary or a shareholder that is an entity be domiciled in the United States and have a valid U.S. taxpayer identification number or be domiciled in a U.S. territory and have a valid U.S. taxpayer identification number or IRS Form W-8. Any existing account that is updated to reflect a non-U.S. address will also be restricted from making additional investments.

The Fund may reject any purchase order, modify or waive the minimum initial or subsequent investment requirements for any shareholders and suspend and resume the sale of any share class of the Fund at any time for any reason. In addition, the Fund may waive certain requirements regarding the purchase, sale, exchange or transfer of shares described below.

Under certain circumstances, if no activity occurs in an account within a time period specified by state law, a shareholder’s shares in the Fund may be transferred to that state.

How to Buy Shares

	Your Choices	Important Information for You to Know
Initial Purchase	Determine the amount of your investment	There is no minimum initial investment for any Employer-Sponsored Retirement Plans or any other investors other than Institutional Investors. For Institutional Investors, there is a $5 million minimum initial investment for all accounts.

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	Your Choices	Important Information for You to Know
How to Pay for Shares	Making payment for purchases	If you are purchasing shares through an Employer-Sponsored Retirement Plan, payment for an order must be made in Federal funds or other immediately available funds by the time specified by your Financial Intermediary, but in no event later than 4:00 p.m. (Eastern time) on the first business day following the receipt of the order. If payment is not received by this time, the order will be canceled and you and your Financial Intermediary will be responsible for any loss to the Fund. If you are not purchasing shares through an Employer-Sponsored Retirement Plan, payment for shares must normally be made in Federal funds or other immediately available funds by the time specified by your Financial Intermediary but in no event later than 4:00 p.m. (Eastern time) on the first business day following the receipt of the order. Payment may also, at the discretion of the Fund, be made in the form of securities that are permissible investments for the Fund. If payment is not received by this time, the order will be canceled and you and your Financial Intermediary will be responsible for any loss to the Fund.

  

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How to Exchange Shares or Transfer Your Account

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	Your Choices	Important Information for You to Know
Transfer Shares to Another Financial Intermediary (continued)	Transfer to a non-participating Financial Intermediary (continued)	Please contact your Financial Intermediary to accomplish the transfer of your Class K Shares.

  

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result of different closing times of U.S. and non-U.S. markets by buying or selling fund shares at a price that does not reflect their true value. A similar risk exists for funds that invest in securities of small capitalization companies, securities of issuers located in emerging markets or high yield securities (“junk bonds”) that are thinly traded and therefore may have actual values that differ from their market prices. This short-term arbitrage activity can reduce the return received by long-term shareholders. The Fund will seek to eliminate these opportunities by using fair value pricing, as described in “Management of the Fund — Valuation of Fund Investments” below.

The Fund discourages market timing and seeks to prevent frequent purchases and sales or exchanges of Fund shares that it determines may be detrimental to the Fund or long-term shareholders. The Board has approved the policies discussed below to seek to deter market timing activity. The Board has not adopted any specific numerical restrictions on purchases, sales and exchanges of Fund shares because certain legitimate strategies will not result in harm to the Fund or its shareholders.

If as a result of its own investigation, information provided by a Financial Intermediary or other third-party, or otherwise, the Fund believes, in its sole discretion, that your short-term trading is excessive or that you are engaging in market timing activity, it reserves the right to reject any specific purchase or exchange order. If the Fund rejects your purchase or exchange order, you will not be able to execute that transaction, and the Fund will not be responsible for any losses you therefore may suffer. For transactions placed directly with the Fund, the Fund may consider the trading history of accounts under common ownership or control for the purpose of enforcing these policies. Transactions placed through the same Financial Intermediary on an omnibus basis may be deemed part of a group for the purpose of this policy and may be rejected in whole or in part by the Fund. Certain accounts, such as omnibus accounts and accounts at Financial Intermediaries, however, include multiple investors and such accounts typically provide the Fund with net purchase or redemption and exchange requests on any given day where purchases, redemptions and exchanges of shares are netted against one another and the identity of individual purchasers, redeemers and exchangers whose orders are aggregated may not be known by the Fund. While the Fund monitors for market timing activity, the Fund may be unable to identify such activities because the netting effect in omnibus accounts often makes it more difficult to locate and eliminate market timers from the Fund. The Distributor has entered into agreements with respect to Financial Intermediaries that maintain omnibus accounts with the Fund pursuant to which such Financial Intermediaries undertake to cooperate with the Distributor in monitoring purchase, exchange and redemption orders by their customers in order to detect and prevent short-term or excessive trading in the Fund’s shares through such accounts. Identification of market timers may also be limited by operational systems and technical limitations. In the event that a Financial Intermediary is determined by the Fund to be engaged in market timing or other improper trading activity, the Distributor may terminate such Financial Intermediary’s agreement with the Distributor, suspend such Financial Intermediary’s trading privileges or take other appropriate actions.

There is no assurance that the methods described above will prevent market timing or other trading that may be deemed abusive.

The Fund may from time to time use other methods that it believes are appropriate to deter market timing or other trading activity that may be detrimental to the Fund or long-term shareholders.

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are less than the current expense limit for that share class, the share class is required to repay BlackRock up to the lesser of (a) the amount of fees waived or expenses reimbursed during those prior two fiscal years under the agreement and (b) an amount not to exceed either (x) the current expense limit of that share class or (y) the expense limit of the share class in effect at the time that the share class received the applicable waiver and/or reimbursement, provided that: (i) the Fund has more than $50 million in assets and (ii) BlackRock or an affiliate serves as the Fund’s manager or administrator. This repayment arrangement will terminate on May 13, 2022, and applies only to the contractual cap on net expenses and does not apply to the contractual management fee waivers described above or any voluntary waivers that may be in effect from time to time.

For the fiscal year ended July 31, 2020, BlackRock received management fees, net of any applicable waivers, at the annual rate of 0.02% of the Fund’s average daily net assets.

BlackRock has entered into a sub-advisory agreement with BFA, with respect to the Fund, under which BlackRock pays BFA for services it provides for that portion of the Fund for which BFA acts as sub-adviser a fee equal to a percentage of the management fee paid to BlackRock under the Management Agreement.

A discussion of the basis for the approval by the Board of the Management Agreement with BlackRock and the sub-advisory agreement between BlackRock and BFA is included in the Fund’s annual shareholder report for the period ended July 31, 2020.

From time to time, a manager, analyst, or other employee of BlackRock or its affiliates may express views regarding a particular asset class, company, security, industry, or market sector. The views expressed by any such person are the views of only that individual as of the time expressed and do not necessarily represent the views of BlackRock or any other person within the BlackRock organization. Any such views are subject to change at any time based upon market or other conditions and BlackRock disclaims any responsibility to update such views. These views may not be relied on as investment advice and, because investment decisions for the Fund are based on numerous factors, may not be relied on as an indication of trading intent on behalf of the Fund.

Legal Proceedings. On May 27, 2014, certain investors in the BlackRock Global Allocation Fund, Inc. (“Global Allocation”) and the BlackRock Equity Dividend Fund (“Equity Dividend”) filed a consolidated complaint in the United States District Court for the District of New Jersey against BlackRock Advisors, LLC, BlackRock Investment Management, LLC and BlackRock International Limited (collectively, the “Defendants”) under the caption In re BlackRock Mutual Funds Advisory Fee Litigation. In the lawsuit, which purports to be brought derivatively on behalf of Global Allocation and Equity Dividend, the plaintiffs allege that the Defendants violated Section 36(b) of the Investment Company Act by receiving allegedly excessive investment advisory fees from Global Allocation and Equity Dividend. On June 13, 2018, the court granted in part and denied in part the Defendants’ motion for summary judgment. On July 25, 2018, the plaintiffs served a pleading that supplemented the time period of their alleged damages to run through the date of trial. The lawsuit seeks, among other things, to recover on behalf of Global Allocation and Equity Dividend all allegedly excessive advisory fees received by the Defendants beginning twelve months preceding the start of the lawsuit with respect to each of Global Allocation and Equity Dividend and ending on the date of judgment, along with purported lost investment returns on those amounts, plus interest. The trial on the remaining issues was completed on August 29, 2018. On February 8, 2019, the court issued an order dismissing the claims in their entirety. On March 8, 2019, the plaintiffs provided notice that they were appealing both the February 8, 2019 post-trial order and the June 13, 2018 order partially granting Defendants’ motion for summary judgment. On May 28, 2020, the appellate court affirmed the trial court’s orders. On June 26, 2020, the plaintiffs petitioned the appeals court for a rehearing, which was denied on July 9, 2020. Plaintiffs’ deadline to seek further appeal has passed; consequently, this matter is now closed.

Portfolio Manager Information

Information regarding the portfolio managers of the Fund is set forth below. Further information regarding the portfolio managers, including other accounts managed, compensation, ownership of Fund shares, and possible conflicts of interest, is available in the Fund’s SAI.

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Portfolio Manager	Primary Role	Since	Title and Recent Biography
Suzanne Henige, CFA	Jointly and primarily responsible for the day-to-day management of the Fund’s portfolio, including setting the Fund’s overall investment strategy and overseeing the management of the Fund.	2020	Director of BlackRock, Inc. since 2016; Vice President of BlackRock, Inc. from 2011 to 2015.
Jennifer Hsui, CFA	Jointly and primarily responsible for the day-to-day management of the Fund’s portfolio, including setting the Fund’s overall investment strategy and overseeing the management of the Fund.	2016	Managing Director of BlackRock, Inc. since 2011; Director of BlackRock, Inc. from 2009 to 2011; Principal of BGI from 2006 to 2009.
Amy Whitelaw	Jointly and primarily responsible for the day-to-day management of the Fund’s portfolio, including setting the Fund’s overall investment strategy and overseeing the management of the Fund.	2019	Managing Director of BlackRock, Inc. since 2013; Director of BlackRock, Inc. from 2009 to 2012; Principal of BGI from 2000 to 2009.
Rachel Aguirre	Jointly and primarily responsible for the day-to-day management of the Fund’s portfolio, including setting the Fund’s overall investment strategy and overseeing the management of the Fund.	2016	Managing Director of BlackRock, Inc. since 2018; Director of BlackRock, Inc. from 2012 to 2017; Vice President of BlackRock, Inc. from 2009 to 2011; Principal and Portfolio Manager of BGI from 2005 to 2009.

  

Conflicts of Interest

The investment activities of BlackRock and its affiliates (including BlackRock, Inc. and its subsidiaries (collectively, the “Affiliates”)), and their respective directors, officers or employees, in the management of, or their interest in, their own accounts and other accounts they manage, may present conflicts of interest that could disadvantage the Fund and its shareholders.

BlackRock and its Affiliates provide investment management services to other funds and discretionary managed accounts that may follow investment programs similar to that of the Fund. BlackRock and its Affiliates are involved worldwide with a broad spectrum of financial services and asset management activities and may engage in the ordinary course of business in activities in which their interests or the interests of their clients may conflict with those of the Fund. BlackRock or one or more Affiliates act or may act as an investor, research provider, investment manager, commodity pool operator, commodity trading advisor, financier, underwriter, adviser, trader, lender, index provider, agent and/or principal, and have other direct and indirect interests in securities, currencies, commodities, derivatives and other instruments in which the Fund may directly or indirectly invest. The Fund may invest in securities of, or engage in other transactions with, companies with which an Affiliate has significant debt or equity investments or other interests. The Fund may also invest in issuances (such as structured notes) by entities for which an Affiliate provides and is compensated for cash management services relating to the proceeds from the sale of such issuances. The Fund also may invest in securities of, or engage in other transactions with, companies for which an Affiliate provides or may in the future provide research coverage. An Affiliate may have business relationships with, and purchase, or distribute or sell services or products from or to, distributors, consultants or others who recommend the Fund or who engage in transactions with or for the Fund, and may receive compensation for such services. BlackRock or one or more Affiliates may engage in proprietary trading and advise accounts and funds that have investment objectives similar to those of the Fund and/or that engage in and compete for transactions in the same types of securities, currencies and other instruments as the Fund. This may include transactions in securities issued by other open-end and closed-end investment companies (which may include investment companies that are affiliated with the Fund and BlackRock, to the extent permitted under the Investment Company Act). The trading activities of BlackRock and these Affiliates are carried out without reference to positions held directly or indirectly by the Fund and may result in BlackRock or an Affiliate having positions in certain securities that are senior or junior to, or have interests different from or adverse to, the securities that are owned by the Fund.

Neither BlackRock nor any Affiliate is under any obligation to share any investment opportunity, idea or strategy with the Fund. As a result, an Affiliate may compete with the Fund for appropriate investment opportunities. The results of the Fund’s investment activities, therefore, may differ from those of an Affiliate and of other accounts managed by

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BlackRock or an Affiliate, and it is possible that the Fund could sustain losses during periods in which one or more Affiliates and other accounts achieve profits on their trading for proprietary or other accounts. The opposite result is also possible.

In addition, the Fund may, from time to time, enter into transactions in which BlackRock or an Affiliate or their directors, officers or employees or other clients have an adverse interest. Furthermore, transactions undertaken by clients advised or managed by BlackRock or its Affiliates may adversely impact the Fund. Transactions by one or more clients or BlackRock or its Affiliates or their directors, officers or employees, may have the effect of diluting or otherwise disadvantaging the values, prices or investment strategies of the Fund. The Fund’s activities may be limited because of regulatory restrictions applicable to BlackRock or one or more Affiliates and/or their internal policies designed to comply with such restrictions.

Under a securities lending program approved by the Board, the Trust, on behalf of the Fund, has retained BlackRock Institutional Trust Company, N.A., an Affiliate of BlackRock, to serve as the securities lending agent for the Fund to the extent that the Fund participates in the securities lending program. For these services, the securities lending agent will receive a fee from the Fund, including a fee based on the returns earned on the Fund’s investment of the cash received as collateral for the loaned securities. In addition, one or more Affiliates may be among the entities to which the Fund may lend its portfolio securities under the securities lending program.

The activities of BlackRock and its Affiliates and their respective directors, officers or employees, may give rise to other conflicts of interest that could disadvantage the Fund and its shareholders. BlackRock has adopted policies and procedures designed to address these potential conflicts of interest. See the SAI for further information.

Valuation of Fund Investments

When you buy shares, you pay the net asset value. This is the offering price. Shares are also redeemed at their net asset value. The Fund calculates the net asset value of each class of its shares each day the NYSE is open generally as of the close of regular trading hours on the NYSE, based on prices at the time of closing. The NYSE generally closes at 4:00 p.m. (Eastern time). The net asset value used in determining your share price is the next one calculated after your purchase or redemption order is received.

Equity securities and other instruments for which market quotations are readily available are valued at market value, which is generally determined using the last reported closing price or, if a reported closing price is not available, the last traded price on the exchange or market on which the security or instrument is primarily traded at the time of valuation. The Fund values fixed-income portfolio securities and non-exchange traded derivatives using last available bid prices or current market quotations provided by dealers or prices (including evaluated prices) supplied by the Fund’s approved independent third-party pricing services, each in accordance with valuation procedures approved by the Board. Pricing services may use matrix pricing or valuation models that utilize certain inputs and assumptions to derive values. Pricing services generally value fixed-income securities assuming orderly transactions of institutional round lot size, but the Fund may hold or transact in such securities in smaller, odd lot sizes. Odd lots may trade at lower prices than institutional round lots. Short-term debt securities with remaining maturities of 60 days or less may be valued on the basis of amortized cost.

Foreign currency exchange rates are generally determined as of the close of business on the NYSE. Foreign securities owned by the Fund may trade on weekends or other days when the Fund does not price its shares. As a result, the Fund’s net asset value may change on days when you will not be able to purchase or redeem the Fund’s shares.

Generally, trading in foreign securities, U.S. Government securities, money market instruments and certain fixed-income securities is substantially completed each day at various times prior to the close of business on the NYSE. The values of such securities used in computing the net asset value of the Fund’s shares are determined as of such times.

When market quotations are not readily available or are not believed by BlackRock to be reliable, the Fund’s investments are valued at fair value. Fair value determinations are made by BlackRock in accordance with procedures approved by the Board. BlackRock may conclude that a market quotation is not readily available or is unreliable if a security or other asset or liability does not have a price source due to its lack of liquidity, if BlackRock believes a market quotation from a broker-dealer or other source is unreliable, where the security or other asset or other liability is thinly traded (e.g., municipal securities, certain small cap and emerging growth companies and certain non-U.S. securities) or where there is a significant event subsequent to the most recent market quotation. For this purpose, a “significant event” is deemed to occur if BlackRock determines, in its business judgment prior to or at the time of pricing the Fund’s assets or liabilities, that it is likely that the event will cause a material change to the last closing market price of one or more assets or liabilities held by the Fund. For instance, significant events may occur between

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the foreign market close and the close of business on the NYSE that may not be reflected in the computation of the Fund’s net assets. If such event occurs, those instruments may be fair valued. Similarly, foreign securities whose values are affected by volatility that occurs in U.S. markets on a trading day after the close of foreign securities markets may be fair valued.

For certain foreign securities, a third-party vendor supplies evaluated, systematic fair value pricing based upon the movement of a proprietary multi-factor model after the relevant foreign markets have closed. This systematic fair value pricing methodology is designed to correlate the prices of foreign securities following the close of the local markets to the price that might have prevailed as of the Fund’s pricing time.

Fair value represents a good faith approximation of the value of a security. The fair value of one or more securities may not, in retrospect, be the price at which those assets could have been sold during the period in which the particular fair values were used in determining the Fund’s net asset value.

The Fund may accept orders from certain authorized Financial Intermediaries or their designees. The Fund will be deemed to receive an order when accepted by the Financial Intermediary or designee and the order will receive the net asset value next computed by the Fund after such acceptance. If the payment for a purchase order is not made by a designated later time, the order will be canceled and the Financial Intermediary could be held liable for any losses.

Dividends, Distributions and Taxes

The Fund will distribute net investment income, if any, quarterly, and net realized capital gains, if any, at least annually. The Fund may also pay a special distribution at the end of the calendar year to comply with federal tax requirements. Dividends may be reinvested automatically in shares of the Fund at net asset value or may be taken in cash. If you would like to receive dividends in cash, contact your Financial Intermediary or the Fund.

Your tax consequences from an investment in the Fund will depend on whether you have invested through a qualified tax-exempt plan described in section 401(a) of the Internal Revenue Code (a “Qualified Plan”).

Investments Through a Qualified Plan

Special tax rules apply to investments made through Qualified Plans. If you are invested through a Qualified Plan (and Fund shares are not “debt-financed property” to the plan), then you will not be subject to U.S. federal income tax on the dividends paid by the Fund or the gain realized from a redemption or exchange of Fund shares until you withdraw or receive distributions from the plan. Distributions you receive from the Qualified Plan may be subject to U.S. federal withholding tax depending on the kind of payment you receive.

Investments Not Made Through Qualified Plans

If you are not invested through a Qualified Plan, you will generally pay tax on dividends from the Fund whether you receive them in cash or additional shares. If you redeem Fund shares or exchange them for shares of another fund, you generally will be treated as having sold your shares and any gain on the transaction may be subject to tax. Fund distributions derived from qualified dividend income, which consists of dividends received from U.S. corporations and qualifying foreign corporations, and long-term capital gains, are eligible for taxation at a maximum rate of 15% or 20% for individuals, depending on whether their income exceeds certain threshold amounts, which are adjusted annually for inflation.

A 3.8% Medicare tax is imposed on the net investment income (which includes, but is not limited to, interest, dividends and net gain from investments) of U.S. individuals with income exceeding $200,000, or $250,000 if married filing jointly, and of trusts and estates.

Your dividends and redemption proceeds will be subject to backup withholding tax if you have not provided a taxpayer identification number or social security number or the number you have provided is incorrect.

Special Considerations for Non-U.S. Persons

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If you are not invested through a Qualified Plan and you are neither a tax resident nor a citizen of the United States or if you are a foreign entity (other than a pass-through entity to the extent owned by U.S. persons), the Fund’s ordinary income dividends will generally be subject to a 30% U.S. withholding tax, unless a lower treaty rate applies. However, certain distributions paid to a foreign shareholder and reported by the Fund as capital gain dividends, interest-related dividends or short-term capital gain dividends may be eligible for an exemption from U.S. withholding tax.

Separately, a 30% withholding tax is currently imposed on U.S.-source dividends, interest and other income items paid to (i) certain foreign financial institutions and investment funds, and (ii) certain other foreign entities. To avoid withholding, foreign financial institutions and investment funds will generally either need to (a) collect and report to the IRS detailed information identifying their U.S. accounts and U.S. account holders, comply with due diligence procedures for identifying U.S. accounts and withhold tax on certain payments made to noncomplying foreign entities and account holders or (b) if an intergovernmental agreement is entered into and implementing legislation is adopted, comply with the agreement and legislation. Other foreign entities will generally either need to provide detailed information identifying each substantial U.S. owner or certify there are no such owners.

This section summarizes some of the consequences under current federal tax law of an investment in the Fund. It is not a substitute for individualized tax advice. Consult your tax adviser about the potential tax consequences of an investment in the Fund under all applicable tax laws.

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General Information

Shareholder Documents

Electronic Access to Annual Reports, Semi-Annual Reports and Prospectuses

Electronic copies of most financial reports and prospectuses are available on BlackRock’s website. Shareholders can sign up for e-mail notifications of annual and semi-annual reports and prospectuses by enrolling in the Fund’s electronic delivery program. To enroll:

Shareholders Who Hold Accounts with Investment Advisers, Banks or Brokerages: Please contact your Financial Intermediary. Please note that not all investment advisers, banks or brokerages may offer this service.

Shareholders Who Hold Accounts Directly With BlackRock:

■	Access the BlackRock website at http://www.blackrock.com/edelivery; and
■	Log into your account.

Delivery of Shareholder Documents

The Fund delivers only one copy of shareholder documents, including prospectuses, shareholder reports and proxy statements, to shareholders with multiple accounts at the same address. This practice is known as “householding” and is intended to eliminate duplicate mailings and reduce expenses. Mailings of your shareholder documents may be householded indefinitely unless you instruct us otherwise. If you do not want the mailing of these documents to be combined with those for other members of your household, please contact the Fund at (800) 537-4942.

Certain Fund Policies

Anti-Money Laundering Requirements

The Fund is subject to the USA PATRIOT Act (the “Patriot Act”). The Patriot Act is intended to prevent the use of the U.S. financial system in furtherance of money laundering, terrorism or other illicit activities. Pursuant to requirements under the Patriot Act, the Fund is required to obtain sufficient information from shareholders to enable it to form a reasonable belief that it knows the true identity of its shareholders. This information will be used to verify the identity of investors or, in some cases, the status of Financial Intermediaries . Such information may be verified using third-party sources. This information will be used only for compliance with the Patriot Act or other applicable laws, regulations and rules in connection with money laundering, terrorism or economic sanctions.

The Fund reserves the right to reject purchase orders from persons who have not submitted information sufficient to allow the Fund to verify their identity. The Fund also reserves the right to redeem any amounts in the Fund from persons whose identity it is unable to verify on a timely basis. It is the Fund’s policy to cooperate fully with appropriate regulators in any investigations conducted with respect to potential money laundering, terrorism or other illicit activities.

BlackRock Privacy Principles

BlackRock is committed to maintaining the privacy of its current and former fund investors and individual clients (collectively, “Clients”) and to safeguarding their non-public personal information. The following information is provided to help you understand what personal information BlackRock collects, how we protect that information and why in certain cases we share such information with select parties.

If you are located in a jurisdiction where specific laws, rules or regulations require BlackRock to provide you with additional or different privacy-related rights beyond what is set forth below, then BlackRock will comply with those specific laws, rules or regulations.

BlackRock obtains or verifies personal non-public information from and about you from different sources, including the following: (i) information we receive from you or, if applicable, your Financial Intermediary, on applications, forms or other documents; (ii) information about your transactions with us, our affiliates, or others; (iii) information we receive from a consumer reporting agency; and (iv) from visits to our website.

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BlackRock does not sell or disclose to non-affiliated third parties any non-public personal information about its Clients, except as permitted by law, or as is necessary to respond to regulatory requests or to service Client accounts. These non-affiliated third parties are required to protect the confidentiality and security of this information and to use it only for its intended purpose.

We may share information with our affiliates to service your account or to provide you with information about other BlackRock products or services that may be of interest to you. In addition, BlackRock restricts access to non-public personal information about its Clients to those BlackRock employees with a legitimate business need for the information. BlackRock maintains physical, electronic and procedural safeguards that are designed to protect the non-public personal information of its Clients, including procedures relating to the proper storage and disposal of such information.

Statement of Additional Information

If you would like further information about the Fund, including how it invests, please see the SAI.

For a discussion of the Fund’s policies and procedures regarding the selective disclosure of its portfolio holdings, please see the SAI. The Fund makes its top ten holdings available on a monthly basis at www.blackrock.com generally within 5 business days after the end of the month to which the information applies.

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Glossary

This glossary contains an explanation of some of the common terms used in this prospectus. For additional information about the Fund, please see the SAI.

Acquired Fund Fees and Expenses — fees and expenses charged by other investment companies in which the Fund invests a portion of its assets.

Annual Fund Operating Expenses — expenses that cover the costs of operating the Fund.

Distribution Fees — fees used to support the Fund’s marketing and distribution efforts, such as compensating Financial Intermediaries, advertising and promotion.

Interest Expense — the cost of borrowing money to buy additional securities.

Management Fee — a fee paid to BlackRock for managing the Fund.

Other Expenses — include accounting, transfer agency, custody, professional and registration fees.

Russell Midcap^® Index — an index that measures the performance of the 800 smallest companies in the Russell 1000^® Index, which represent approximately 31% of the total market capitalization of the Russell 1000^® Index.

Russell 1000^® Index — an index that measures the performance of the large-cap segment of the U.S. equity universe. It is a subset of the Russell 3000^® Index and includes approximately 1,000 of the largest securities based on a combination of their market cap and current index membership. The Russell 1000^® represents approximately 92% of the U.S. market.

Service Fees — fees used to compensate Financial Intermediaries for certain shareholder servicing activities.

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