Management

Investment manager: Legg Mason Partners Fund Advisor, LLC (“LMPFA” or the “manager”)

Subadviser: Western Asset Management Company, LLC (formerly known as Western Asset Management Company) (“Western Asset”)

Sub-subadviser: Western Asset Management Company Limited in London (“Western Asset London”), Western Asset Management Company Pte. Ltd. in Singapore (“Western Asset Singapore”) and Western Asset Management Company Ltd in Japan (“Western Asset Japan”). References to “the subadviser” include the subadviser and each applicable sub-subadviser.

Portfolio managers: S. Kenneth Leech (Chief Investment Officer), Mark S. Lindbloom (Portfolio Manager), Julien A. Scholnick (Portfolio Manager), Frederick R. Marki (Portfolio Manager) and John L. Bellows (Portfolio Manager/Research Analyst). Each of Mr. Leech, Mr. Lindbloom, Mr. Scholnick, Mr. Marki and Mr. Bellows has been part of the portfolio management team for the fund since [month] 2018. These investment professionals, all of whom are employed by Western Asset, work together with a broader investment management team.

Purchase and sale of fund shares

The fund is an actively managed exchange-traded fund (commonly referred to as an “ETF”). Individual shares of the fund are listed on a national securities exchange and are redeemable only by Authorized Participants in Creation Units (as defined in this section). Most investors will buy and sell shares of the fund through a broker-dealer. The price of fund shares is based on market price, and because ETF shares trade at market prices rather than at NAV, shares may trade at a price greater than NAV (a premium) or less than NAV (a discount). The fund will only issue or redeem shares that have been aggregated into blocks of 100,000 shares or multiples thereof (“Creation Units”) to Authorized Participants who have entered into agreements with the fund’s distributor. The fund will issue or redeem Creation Units in return for a designated portfolio of securities and/or cash that the fund specifies each day.

Tax information

The fund’s distributions are taxable, and will be taxed as ordinary income and/or capital gains, unless you are investing through a tax-deferred arrangement, such as a 401(k) plan or individual retirement account. Withdrawals from such tax-deferred arrangements may be subject to tax at a later date.

Payments to broker-dealers and other financial intermediaries

If you purchase shares of the fund through a broker-dealer or other financial intermediary (such as a bank), LMPFA or other related companies may pay the intermediary for marketing activities and presentations, educational training programs, conferences, the development of technology platforms and reporting systems or other services related to the sale or promotion of the fund. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

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More on the fund’s investment strategies, investments and risks

Introduction

The fund is an actively managed exchange-traded fund (“ETF”) and shares of the fund are listed for trading on NASDAQ. The market price for a share of the fund may be different from the fund’s most recent net asset value (“NAV”).

ETFs are funds that trade like other publicly traded securities. Unlike shares of a mutual fund, which can be bought and redeemed from the issuing fund by all shareholders at a price based on NAV, shares of the fund may be purchased or redeemed directly from the fund at NAV solely by Authorized Participants (as defined in the “Creations and redemptions” section of this Prospectus). Also unlike shares of a mutual fund, shares of the fund are listed on a national securities exchange and trade in the secondary market at market prices that change throughout the day.

Investment objective

The fund seeks to maximize total return, consistent with prudent investment management and liquidity needs.

Principal investment strategies

Under normal market conditions, the fund will seek its investment objective by investing at least 80% of its assets in a portfolio comprised of fixed income securities, debt instruments, derivatives, equity securities of any type acquired in reorganizations of issuers of fixed income securities or debt instruments (“work out securities”), non-convertible preferred securities, warrants, cash and cash equivalents, foreign currencies, and exchange-traded funds (“ETFs”) that provide exposure to these investments (“Principal Investments”).

As part of its 80% policy, the fund intends to invest in derivatives that (i) provide exposure to the Principal Investments, (ii) are used to risk manage the fund’s holdings, and/or (iii) are used to enhance returns, such as through covered call strategies. The risk management uses of derivatives will include managing (i) investment-related risks, (ii) risks due to fluctuations in securities prices, interest rates, or currency exchanges rates, (iii) risks due to the credit-worthiness of an issuer, and (iv) the effective duration of the fund’s portfolio. The types of derivatives in which the fund will invest include swaps and security-based swaps, futures and options on futures, currency forwards, and currency options and swaps. As a result of the fund’s use of derivatives and to serve as collateral, the fund may also hold significant amounts of U.S. Treasury securities and foreign currencies in which certain derivatives are denominated.

The types of fixed income securities and debt instruments in which the fund may invest include corporate debt securities, U.S. government securities, asset-backed securities (“ABS”), mortgage-backed securities (“MBS”) (including commercial MBS (“CMBS”), residential MBS (“RMBS”) and non-agency collateralized mortgage obligations (“CMOs”)), collateralized debt obligations (“CDOs”) and mortgage dollar rolls. The fixed income securities in which the fund may invest may pay fixed, variable or floating rates of interest. The fund will not invest more than 20% of its portfolio in non-agency, non-government sponsored enterprise and privately-issued MBS and ABS.

Although the fund may invest in securities and debt instruments of any maturity, the fund will normally maintain an average effective duration within 35% of the average duration of the U.S. bond market as a whole as estimated by the fund’s subadviser. As of the date of this Prospectus, the fund expects the normal range of the fund’s effective duration to be approximately 1.5 to 9.5 years. The subadviser uses the historic duration range of Bloomberg Barclays U.S. Aggregate Index, a widely accepted broad U.S. market index. As of the date of this Prospectus, the duration for the Bloomberg Barclays U.S. Aggregate Index was approximately 6 years. The subadviser may change the index from which it measures historic duration from time to time. Effective duration seeks to measure the expected sensitivity of market price to changes in interest rates, taking into account the anticipated effects of structural complexities (for example, some bonds can be prepaid by the issuer).

The fund may invest up to 30% of its assets in below investment grade fixed income securities or debt instruments. For these purposes, “investment grade” is defined as investments with a rating at the time of purchase in one of the four highest categories of at least one nationally recognized statistical rating organization (“NRSRO”) (e.g., BBB- or higher or Baa3 or higher) or, if unrated, securities of comparable quality at the time of purchase (as determined by the subadviser). Securities rated below investment grade (e.g., BB+ to D or Baa1 to C) or, if unrated, securities of comparable quality at the time of purchase (as determined by the subadviser) are commonly known as “junk bonds” or “high yield securities.”

The fund may invest in securities issued by both U.S. and non-U.S. issuers (including issuers in emerging markets), but the fund will not invest more than 30% of its total assets in securities or debt instruments of non-U.S. issuers or more than 25% of its total assets directly in non-U.S. dollar denominated securities or debt instruments. For purposes of these limitations only, derivatives, warrants and U.S.-listed ETFs that provide indirect exposure to the investments described above will not be counted by the fund in calculating its holdings in non-U.S. issuers or in non-U.S. dollar denominated securities or debt instruments.

Investment Professionals and Security Selection. Western Asset’s investment process combines top-down and bottom-up analyses. Western Asset’s US Broad Strategy Committee, which is chaired by the Chief Investment Officer, leads the investment process by considering macro-economic and securities-specific insights and ideas covering all major bond market segments from all of its macro-economic and credit research teams around the globe, and formulates the broad top-down investment outlook, including a set of strategies around duration, yield curve, country, currency and sector.

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The US Broad Market portfolios team is ultimately responsible for the fund’s portfolio construction, making sure that allocations are consistent with Western Asset’s overall investment themes while adhering to strategy risk/return profiles and specific guidelines. This includes duration, curve, country, currency and sector positioning. The portfolio managers of the fund are S. Kenneth Leech, Mark S. Lindbloom, Julien A. Scholnick, Frederick R. Marki and John L. Bellows. These investment professionals, all of whom are employed by Western Asset, work together with a broader investment management team (collectively, the “Investment Professionals”).

The Investment Professionals conduct bottom-up fundamental research and provide input into the top-down perspectives. “A top-down view” incorporates macro-economic views on growth, inflation, and fiscal and monetary policy, as well as views on sectors (such as corporates which trade at spreads over U.S. Treasuries) and current general market conditions and valuation levels. This top-down view translates into a set of strategies regarding duration, yield curve, country, currency and sector. The Investment Professionals provide fundamental analysis at sector and subsector levels. Incorporating the macro-economic views of the US Broad Strategy Committee and the risk profile of the fund’s portfolio, the Investment Professionals balance these inputs with their industry/issuer insights in setting sector overweights and underweights. “Bottom up fundamental research” involves detailed analysis of individual securities, issuers, sectors and sub-sectors. The Investment Professionals use a security-specific process in order to assess whether securities are mispriced or undervalued in their opinion and select securities for the fund’s portfolio. The Investment Professionals conduct an ongoing assessment of changing credit characteristics and of securities with characteristics such as assets perceived to be overlooked or under-appreciated, floating or fixed interest rates, credit quality and securities issued in mergers, as well as newly-issued securities. Using sector and issue analyses, the Investment Professionals select issues opportunistically in order to exploit perceived mispricings versus long-term fundamental value that exist in the market.

The subadviser monitors a broad set of factors that may prompt it to consider selling or reducing a position focused on the risk/reward characteristics of a credit. Factors include the following: whether total return and/or valuation targets have been realized, whether there have been significant changes in macro/micro economic analyses indicating that sector emphasis should be changed, whether industry conditions have deteriorated, whether the issuer has changed its business strategy, whether credit fundamentals have deteriorated and whether the subadviser finds better relative value elsewhere in the bond market.

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Maturity and duration

The fund may invest in securities of any maturity. The maturity of a fixed income security is a measure of the time remaining until the final payment on the security is due.

The fund will normally maintain an average effective duration within 35% of the average duration of the U.S. bond market as a whole as estimated by the fund’s subadviser. The average effective duration of the fund may fall outside of its expected range due to market movements. If this happens, the fund’s subadviser will take action to bring the fund’s average effective duration back within its expected range within a reasonable period of time.

Effective duration seeks to measure the expected sensitivity of market price to changes in interest rates, taking into account the anticipated effects of structural complexities (for example, some bonds can be prepaid by the issuer). The assumptions that are made about a security’s features and options when calculating effective duration may prove to be incorrect. As a result, investors should be aware that effective duration is not an exact measurement and may not reliably predict a security’s price sensitivity to changes in yield or interest rates.

Generally, the longer a portfolio’s duration, the more sensitive it will be to changes in interest rates. For example, if interest rates rise by 1%, a fund with a two year effective duration would expect the value of its portfolio to decrease by 2% and a fund with a ten year effective duration would expect the value of its portfolio to decrease by 10%, all other factors being equal.

Credit quality

The continued holding of a security downgraded below its rating at the time of purchase will be evaluated on a case by case basis. As a result, the fund may from time to time hold debt securities that are rated below investment grade in excess of the amounts described in its investment limitations. Securities rated below investment grade are commonly known as “junk bonds” or “high yield securities.” To the extent not addressed above, in the event that NRSROs assign different ratings to the same security, the subadviser will treat the security as being rated in the highest rating category received from any one NRSRO. Rating categories may include sub-categories or gradations indicating relative standing.

Derivatives

The fund may engage in a variety of transactions using derivatives, such as swaps and security-based swaps, futures and options on futures, currency forwards, currency options and swaps, swaptions and other synthetic instruments. Derivatives are financial instruments whose value

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depends upon, or is derived from, the value of something else, such as one or more underlying investments, indexes or currencies. Derivatives may be used by the fund for any of the following purposes:

The fund from time to time may sell protection on debt securities by entering into credit default swaps. In these transactions, the fund is generally required to pay the par (or other agreed-upon) value of a referenced debt security to the counterparty in the event of a default on or downgrade of the debt security and/or a similar credit event. In return, the fund receives from the counterparty a periodic stream of payments over the term of the contract. If no default occurs, the fund keeps the stream of payments and has no payment obligations. As the seller, the fund would effectively add leverage to its portfolio because, in addition to its net assets, the fund would be subject to loss on the par (or other agreed-upon) value it had undertaken to pay. Credit default swaps may also be structured based on an index or the debt of a basket of issuers, rather than a single issuer, and may be customized with respect to the default event that triggers purchase or other factors (for example, a particular number of defaults within a basket, or defaults by a particular combination of issuers within the basket, may trigger a payment obligation).

The fund may buy credit default swaps to hedge against the risk of default of debt securities held in its portfolio or for other reasons. As the buyer of a credit default swap, the fund would make the stream of payments described in the preceding paragraph to the seller of the credit default swap and would expect to receive from the seller a payment in the event of a default on the underlying debt security or other specified event.

Using derivatives, especially for non-hedging purposes, may involve greater risks to the fund than investing directly in securities, particularly as these instruments may be very complex and may not behave in the manner anticipated by the fund. Certain derivative transactions may have a leveraging effect on the fund.

Use of derivatives or similar instruments may have different tax consequences for the fund than an investment in the underlying security, and those differences may affect the amount, timing and character of income distributed to shareholders.

When the fund enters into derivative transactions, it may be required to segregate assets, or enter into offsetting positions, in accordance with applicable regulations. Such segregation will not limit the fund’s exposure to loss, however, and the fund will have investment risk with respect to both the derivative itself and the assets that have been segregated to cover the fund’s derivative exposure. If the segregated assets represent a large portion of the fund’s portfolio, this may impede portfolio management or the fund’s ability to meet redemption requests or other current obligations.

Instead of, and/or in addition to, investing directly in particular securities, the fund may use derivatives and other synthetic instruments that are intended to provide economic exposure to securities, issuers or other measures of market or economic value. The fund may use one or more types of these instruments to the extent consistent with its 80% policy.

The fund’s subadviser may choose not to make use of derivatives.

Fixed income securities

Fixed income securities represent obligations of corporations, governments and other entities to repay money borrowed, usually at the maturity of the security. These securities may pay fixed, variable or floating rates of interest. However, some fixed income securities, such as zero coupon bonds, do not pay current interest but are issued at a discount from their face values. Other debt instruments, such as certain MBS and ABS (as further described under “Mortgage-backed and asset-backed securities”), make periodic payments of interest and/or principal. Some debt instruments are partially or fully secured by collateral supporting the payment of interest and principal. “Fixed income securities” are commonly referred to as “notes,” “debt,” “debt obligations,” “debt securities,” “corporate debt,” “bonds” and “corporate bonds,” and these terms are used in this Prospectus interchangeably, and, where used, are not intended to be limiting.

Variable and floating rate securities

Variable rate securities reset at specified intervals, while floating rate securities reset whenever there is a change in a specified index rate. In most cases, these reset provisions reduce the impact of changes in market interest rates on the value of the security. However, the value of these securities may decline if their interest rates do not rise as much, or as quickly, as other interest rates. Conversely, these securities will not generally increase in value if interest rates decline. The fund may also invest in inverse floating rate debt instruments (“inverse floaters”). Interest payments on inverse floaters vary inversely with changes in interest rates. Inverse floaters pay higher interest (and therefore generally increase in value) when interest rates decline, and vice versa. An inverse floater may exhibit greater price volatility than a fixed rate obligation of similar credit quality.

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Stripped securities

Certain fixed income securities, called stripped securities, represent the right to receive either payments of principal (“POs”) or payments of interest (“IOs”) on underlying pools of mortgages or on government securities. The value of these types of instruments may change more drastically than debt securities that pay both principal and interest during periods of changing interest rates. Interest-only and principal-only MBS are especially sensitive to interest rate changes, which can affect not only their prices but can also change the prepayment assumptions about those investments and income flows the fund receives from them.

Corporate debt

Corporate debt securities are fixed income securities usually issued by businesses to finance their operations. Various types of business entities may issue these securities, including corporations, trusts, limited partnerships, limited liability companies and other types of non-governmental legal entities. Notes, bonds, debentures and commercial paper are the most common types of corporate debt securities, with the primary difference being their maturities and secured or unsecured status. Commercial paper has the shortest term and is usually unsecured. The broad category of corporate debt securities includes debt issued by U.S. or foreign companies of all kinds, including those with small, mid and large capitalizations. Corporate debt may be rated investment grade or below investment grade and may carry variable or floating rates of interest.

Loans

The primary risk in an investment in loans is that borrowers may be unable to meet their interest and/or principal payment obligations. Loans in which the fund invests may be made to finance highly leveraged borrowers which may make such loans especially vulnerable to adverse changes in economic or market conditions. Loans in which the fund may invest may be either collateralized or uncollateralized and senior or subordinate. Investments in uncollateralized and/or subordinate loans entail a greater risk of nonpayment than do investments in loans that hold a more senior position in the borrower’s capital structure and/or are secured with collateral. In addition, loans are generally subject to liquidity risk. The fund may acquire an interest in loans by purchasing participations in and/or assignments of portions of loans from third parties or by investing in pools of loans, such as collateralized debt obligations as further described under “Collateralized debt obligations.” Transactions in loans may settle on a delayed basis. As a result, the proceeds from the sale of a loan may not be available to make additional investments or to meet the fund’s redemption obligations. Bank loans may not be considered securities and therefore, the fund may not have the protections afforded by U.S. federal securities laws with respect to such investments.

Government securities

U.S. government securities are obligations of, or guaranteed by, the U.S. government, its agencies or government-sponsored entities. U.S. government securities include issues by non-governmental entities (like financial institutions) that carry direct guarantees from U.S. government agencies as part of government initiatives in response to the market crisis or otherwise. Although the U.S. government guarantees principal and interest payments on securities issued by the U.S. government and some of its agencies, such as securities issued by the Government National Mortgage Association (“Ginnie Mae”), this guarantee does not apply to losses resulting from declines in the market value of these securities. Some of the U.S. government securities that the fund may hold are not guaranteed or backed by the full faith and credit of the U.S. government, such as those issued by Fannie Mae (formally known as the Federal National Mortgage Association) and Freddie Mac (formally known as the Federal Home Loan Mortgage Corporation).

Mortgage-backed and asset-backed securities

MBS represent direct or indirect participations in, or are collateralized by and payable from, mortgage loans secured by real property. MBS may be issued by private issuers, by government-sponsored entities such as Fannie Mae or Freddie Mac or issued or guaranteed by agencies of the U.S. government, such as Ginnie Mae.

Unlike MBS issued or guaranteed by agencies of the U.S. government or government-sponsored entities, MBS issued by private issuers do not have a government or government-sponsored entity guarantee (but may have other credit enhancement), and may, and frequently do, have less favorable collateral, credit risk or other underwriting characteristics.

A RMBS is comprised of a pool of mortgage loans created by banks and other financial institutions. CMBS are a type of MBS backed by commercial mortgages rather than residential real estate.

CMOs are debt obligations collateralized by mortgage loans or mortgage pass-through securities. CMOs are a type of MBS. Typically, CMOs are collateralized by Ginnie Mae, Fannie Mae or Freddie Mac Certificates, but may also be collateralized by whole loans or private pass-throughs (referred to as “Mortgage Assets”). Payments of principal and of interest on the Mortgage Assets, and any reinvestment income thereon, provide the funds to pay debt service on the CMOs. In a CMO, a series of bonds or certificates is issued in multiple classes. Each class of CMOs, often referred to as a “tranche,” is issued at a specified fixed or floating coupon rate and has a stated maturity or final distribution date. Principal prepayments on

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the Mortgage Assets may cause the CMOs to be retired substantially earlier than their stated maturities or final distribution dates. Interest is paid or accrues on all classes of the CMOs on a monthly, quarterly or semi-annual basis. The principal of and interest on the Mortgage Assets may be allocated among the several classes of a series of a CMO in innumerable ways. As market conditions change, and particularly during periods of rapid or unanticipated changes in market interest rates, the attractiveness of the CMO classes and the ability of the structure to provide the anticipated investment characteristics may be significantly reduced. Such changes can result in volatility in the market value, and in some instances reduced liquidity, of the CMO class.

ABS are securities backed by consumer-related (e.g., credit card receivables, student loans and automobile loans) and commercial loans made by non-bank lenders and participations in such loans, which are unsecured or secured by payments from installment sales, leases, credit card receivables, and other categories of receivables other than real estate and government and corporate debt. ABS exclude CDOs and fixed income securities issued by securitization vehicles backed by bank loans and participations in such loans.

Collateralized debt obligations

Collateralized debt obligations (“CDOs”) include collateralized bond obligations (“CBOs”), collateralized loan obligations (“CLOs”) and other similarly structured securities. CBOs are securities issued by a trust or other special purpose entity that are backed by a diversified pool of fixed income securities issued by U.S. or foreign governmental entities or fixed income securities issued by U.S. or corporate issuers. CDOs are distinguishable from ABS because they are collateralized by bank loans or by corporate or government fixed income securities and not by consumer, and other loans made by non-bank lenders, including student loans. Like CMOs, CDOs generally issue separate series or “tranches” which vary with respect to risk and yield. These tranches can experience substantial losses due to actual defaults, increased sensitivity to defaults due to collateral default and disappearance of subordinate tranches, market anticipation of defaults, as well as investor aversion to CDO securities as a class. Interest on certain tranches of a CDO may be paid in kind (paid in the form of obligations of the same type rather than cash), which involves continued exposure to default risk with respect to such payments.

Municipal securities

Municipal securities include general obligation bonds, revenue bonds, housing authority bonds, private activity bonds, industrial development bonds, residual interest bonds, tender option bonds, tax and revenue anticipation notes, bond anticipation notes, tax-exempt commercial paper, municipal leases, participation certificates and custodial receipts. General obligation bonds are backed by the full faith and credit of the issuing entity. Revenue bonds are typically used to fund public works projects, such as toll roads, airports and transportation facilities, that are expected to produce income sufficient to make the payments on the bonds, since they are not backed by the full taxing power of the municipality. Housing authority bonds are used primarily to fund low to middle income residential projects and may be backed by the payments made on the underlying mortgages. Tax and revenue anticipation notes are generally issued in order to finance short-term cash needs or, occasionally, to finance construction. Tax and revenue anticipation notes are expected to be repaid from taxes or designated revenues in the related fiscal period, and they may or may not be general obligations of the issuing entity. Bond anticipation notes are issued with the expectation that their principal and interest will be paid out of proceeds from renewal notes or bonds and may be issued to finance such items as land acquisition, facility acquisition and/or construction and capital improvement projects.

Foreign and emerging markets securities

The fund may invest its assets in securities of foreign issuers, including MBS and ABS issued by foreign entities. The value of the fund’s foreign securities may decline because of unfavorable government actions, political instability or the more limited availability of accurate information about foreign issuers. The fund may invest in foreign securities issued by issuers located in emerging market countries. To the extent the fund invests in these securities, the risks associated with investments in foreign issuers will generally be more pronounced.

The fund considers a country to be an emerging market country, if, at the time of investment, it is represented in the J.P. Morgan Emerging Market Bond Index Global or the J.P. Morgan Corporate Emerging Market Bond Index Broad or categorized by the World Bank in its annual categorization as middle- or low-income.

Preferred stock and convertible securities

The fund may invest in preferred stock and convertible securities. Preferred stock represents an interest in a company that generally entitles the holder to receive, in preference to the holders of common stock, dividends and a fixed share of the proceeds resulting from a liquidation of the company. Preferred stocks may pay fixed or adjustable rates of return. Convertible fixed income securities convert into shares of common stock of their issuer. Preferred stock and convertible fixed income securities share investment characteristics of both fixed income and equity securities. However, the value of these securities tends to vary more with fluctuations in the underlying common stock and less with fluctuations in interest rates and tends to exhibit greater volatility.

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Equity securities

Although the fund invests principally in fixed income securities and related investments, the fund may from time to time invest in or receive equity securities and equity-like securities, which include warrants, rights, exchange traded and over-the-counter common stocks, baskets of equity securities such as exchange traded funds, depositary receipts, trust certificates, limited partnership interests and shares of other investment companies and real estate investment trusts.

Equity securities represent an ownership interest in the issuing company. Holders of equity securities are not creditors of the company, and in the event of the liquidation of the company, would be entitled to their pro rata share of the company’s assets, if any, after creditors, including the holders of fixed income securities, and holders of any senior equity securities are paid. Equity securities generally have greater price volatility than fixed income securities.

Warrants and rights permit, but do not obligate, their holders to subscribe for other securities. Warrants and rights are subject to the same market risks as stocks, but may be more volatile in price. An investment in warrants or rights may be considered speculative. In addition, the value of a warrant or right does not necessarily change with the value of the underlying securities and a warrant or right ceases to have value if it is not exercised prior to its expiration date.

Securities of other investment companies

The fund may invest in securities of other investment companies to the extent permitted under the Investment Company Act of 1940, as amended (the “1940 Act”). The return on investments in other registered investment companies will be reduced by the operating expenses, including investment advisory expenses, of such companies, and by any sales loads or other distribution and/or service fees or charges incurred in purchasing or selling shares of such companies, in addition to the fund’s own fees and expenses. As such, there is a layering of fees and expenses.

Investments by other funds

The fund may be an investment option for other funds, including affiliated funds.

Credit downgrades and other credit events

Credit rating or credit quality of a security is determined at the time of purchase. If, after purchase, the credit rating on a security is downgraded or the credit quality deteriorates, or if the duration of a security is extended, the subadviser will decide whether the security should be held or sold. Upon the occurrence of certain triggering events or defaults on a security held by the fund, or if an obligor of such a security has difficulty meeting its obligations, the fund may obtain a new or restructured security or underlying assets. In that case, the fund may become the holder of securities or other assets that it could not purchase or might not otherwise hold (for example, because they are of lower quality or are subordinated to other obligations of the issuer) at a time when those assets may be difficult to sell or can be sold only at a loss. In addition, the fund may incur expenses in an effort to protect the fund’s interest in securities experiencing these events.

Zero coupon, pay-in-kind and deferred interest securities

Zero coupon, pay-in-kind and deferred interest securities may be used by issuers to manage cash flow and maintain liquidity. Zero coupon securities pay no interest during the life of the obligation but are issued at prices below their stated maturity value. Because zero coupon securities pay no interest until maturity, their prices may fluctuate more than other types of securities with the same maturity in the secondary market. However, zero coupon bonds may act as a useful tool for managing duration.

Pay-in-kind securities have a stated coupon, but the interest is generally paid in the form of obligations of the same type as the underlying pay-in-kind securities ( e.g. , bonds) rather than in cash. These securities are more sensitive to the credit quality of the underlying issuer and their secondary market prices may fluctuate more than other types of securities with the same maturity.

Deferred interest securities are obligations that generally provide for a period of delay before the regular payment of interest begins and are issued at a significant discount from face value.

Certain zero coupon, pay-in-kind and deferred interest securities are subject to tax rules applicable to debt obligations acquired with “original issue discount.” The fund would generally have to accrue income on these securities for federal income tax purposes before it receives corresponding cash payments. Because the fund intends to make sufficient annual distributions of its taxable income, including accrued non-cash income, in order to maintain its federal income tax status and avoid fund-level income and excise taxes, the fund might be required to liquidate portfolio securities at a disadvantageous time, or borrow cash, to make these distributions. The fund also accrues income on these securities prior to receipt for accounting purposes. To the extent it is deemed collectible, accrued income is taken into account when calculating the value of these securities and the fund’s NAV per share, in accordance with the fund’s valuation policies.

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When-issued securities, delayed delivery, to be announced and forward commitment transactions

The fund may purchase securities under arrangements (called when-issued, delayed delivery, to be announced or forward commitment basis) where the securities will not be delivered or paid for immediately. The fund will set aside assets to pay for these securities at the time of the agreement. Such transactions involve a risk of loss, for example, if the value of the securities declines prior to the settlement date or if the assets set aside to pay for these securities decline in value prior to the settlement date. Therefore, these transactions may have a leveraging effect on the fund, making the value of an investment in the fund more volatile and increasing the fund’s overall investment exposure. Typically, no income accrues on securities the fund has committed to purchase prior to the time delivery of the securities is made, although the fund may earn income on securities it has set aside to cover these positions.

Mortgage dollar roll transactions

In a mortgage dollar roll transaction, the fund sells a MBS while simultaneously agreeing to purchase a similar security from the same party (the counterparty) on a specified future date at a lower fixed price. During the roll period, the fund forgoes principal and interest paid on the securities. The fund is compensated by the difference between the current sales price and the forward price for the future purchase as well as by the interest earned on the cash proceeds of the initial sale. The fund may enter into a mortgage dollar roll transaction with the intention of entering into an offsetting transaction whereby, rather than accepting delivery of the security on the specified date, the fund sells the security and agrees to repurchase a similar security at a later time.

Investments in mortgage dollar roll transactions involve a risk of loss if the value of the securities that the fund is obligated to purchase declines below the purchase price prior to the repurchase date. Mortgage dollar roll transactions may have a leveraging effect on the fund (see “When-issued securities, delayed delivery, to be announced and forward commitment transactions”).

Short-term investments

The fund may invest in cash, money market instruments and short-term securities, including repurchase agreements, U.S. government securities, bank obligations and commercial paper. A repurchase agreement is a transaction in which the fund purchases a security from a seller, subject to the obligation of the seller to repurchase that security from the fund at a higher price. The repurchase agreement thereby determines the yield during the fund’s holding period, while the seller’s obligation to repurchase is secured by the value of the underlying security held by the fund.

Borrowings and reverse repurchase agreements

The fund may enter into borrowing transactions. Borrowing may make the value of an investment in the fund more volatile and increase the fund’s overall investment exposure. The fund may be required to liquidate portfolio securities at a time when it would be disadvantageous to do so in order to make payments with respect to any borrowings. Interest on any borrowings will be a fund expense and will reduce the value of the fund’s shares.

The fund may enter into reverse repurchase agreements, which have characteristics like borrowings. In a reverse repurchase agreement, the fund sells securities to a counterparty, in return for cash, and the fund agrees to repurchase the securities at a later date and for a higher price, representing the cost to the fund for the cash received.

Restricted and illiquid securities

Restricted securities are securities subject to legal or contractual restrictions on their resale. An “illiquid security” is any security which may not reasonably be expected to 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. Such conditions might prevent the sale of such securities at a time when the sale would otherwise be desirable. The fund will not acquire “illiquid securities” if immediately after the acquisition the value of illiquid securities held by the fund would exceed 15% of the fund’s net assets. The fund may determine that some restricted securities can be more readily sold, for example to qualified institutional buyers pursuant to SEC Rule 144A, and therefore may treat certain such securities as “liquid” for purposes of limitations on the amount of illiquid securities it may own. Investing in these restricted securities could have the effect of increasing the fund’s illiquidity if qualified buyers become, for a time, uninterested in buying these securities. These securities may be difficult to value, and the fund may have difficulty disposing of such securities promptly. The fund does not consider non-U.S. securities to be restricted if they can be freely sold in the principal markets in which they are traded, even if they are not registered for sale in the United States.

Structured notes and indexed securities

The fund may invest in various types of structured instruments, including securities that have demand, tender or put features, or interest rate reset features. These may include instruments issued by structured investment or special purpose vehicles or conduits, and may be ABS or MBS. Structured instruments may take the form of participation interests or receipts in underlying securities or other assets, and in some cases are backed by a financial institution serving as a liquidity provider. The interest rate or principal amount payable at maturity on a structured instrument may vary

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based on changes in one or more specified reference factors, such as currencies, interest rates, commodities, indices or other financial indicators. Changes in the underlying reference factors may result in disproportionate changes in amounts payable under a structured instrument. Some of these instruments may have an interest rate swap feature which substitutes a floating or variable interest rate for the fixed interest rate on an underlying security. Structured instruments are a type of derivative instrument and the payment and credit qualities of these instruments derive from the assets embedded in the structure. For structured securities that have embedded leverage features, small changes in interest or prepayment rates may cause large and sudden price movements. Structured instruments are often subject to heightened liquidity risk.

Non-U.S. currency transactions

The fund may engage in non-U.S. currency exchange transactions in an effort to protect against uncertainty in the level of future exchange rates or to enhance returns based on expected changes in exchange rates. Non-U.S. currency exchange transactions may take the form of options, futures, options on futures, swaps, warrants, structured notes, forwards or spot (cash) transactions. The value of these non-U.S. currency transactions depends on, and will vary based on fluctuations in, the value of the underlying currency relative to the U.S. dollar.

Inflation-indexed, inflation-protected and related securities

Inflation-indexed and inflation-protected securities are fixed income securities that are structured to provide protection against inflation and whose principal value or coupon (interest payment) is periodically adjusted according to the rate of inflation. If the index measuring inflation falls, the principal value or coupon of these securities will be adjusted downward. Consequently, the interest payable on these securities will be reduced. Also, if the principal value of these securities is adjusted according to the rate of inflation, the adjusted principal value repaid at maturity may be less than the original principal.

Inflation-protected securities denominated in the U.S. dollar include U.S. Treasury Inflation Protected Securities (“U.S. TIPS”), as well as other bonds issued by U.S. and non-U.S. government agencies and instrumentalities or corporations and derivatives related to these securities. U.S. TIPS are inflation-protected securities issued by the U.S. Department of the Treasury the principal amounts of which are adjusted daily based upon changes in the rate of inflation (as currently represented by the non-seasonally adjusted Consumer Price Index for All Urban Consumers, calculated with a three-month lag). U.S. TIPS pay interest semiannually, equal to a fixed percentage of the inflation-adjusted principal amount. The interest rate on these bonds is fixed at issuance, but over the life of the bond, this interest may be paid on an increasing or decreasing principal amount that has been adjusted for inflation. The current market value of U.S. TIPS is not guaranteed and will fluctuate.

The value of inflation-indexed and inflation-protected securities held by the fund fluctuates in response to changes in real interest rates. In addition, if nominal interest rates increase at a faster rate than inflation, causing real interest rates to rise, it will lead to a decrease in the value of inflation-indexed or inflation-protected securities.

The fund may invest in other fixed-income securities that the subadviser believes will provide protection against inflation, including floating rate and other short duration securities. Floating rate securities bear interest at rates that are not fixed but vary with changes in specified market rates or indices, such as the prime rate, and at specified intervals.

Exchange-traded funds (ETFs)

The fund may invest in ETFs. Typically, an ETF seeks to track (positively or negatively) the performance of an index by holding in its portfolio either the same securities that comprise the index or a representative sample of the index. Investing in an ETF gives the fund exposure to the securities comprising the index on which the ETF is based and the fund will gain or lose value depending on the performance of the index. The fund will indirectly bear its proportionate share of the management fees and other expenses that are charged by the ETF in addition to the management fees and other expenses paid by the fund. The fund will also pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Covered calls

The fund’s covered call strategy focuses on options on U.S. Treasury futures. In entering an options contract, the buyer is purchasing the right to buy (called a call option) or to sell (called a put option) the underlying futures contract. For example, a call option on 10-year U.S. Treasury Note, gives the buyer the right to assume a long position on it while the seller is obligated to take a short position if the buyer chooses to exercise the option. In the case of a put option, the buyer has the right to a short position in the 10-year U.S. Treasury Note futures contract while the seller in this case must assume a long position in the futures contract. An option is said to be covered if the option writer (seller) holds an offsetting position in the underlying futures contract. For example, a writer of a 10-year U.S Treasury Note futures contract would be called covered if the seller either owns cash market U.S. Treasury Notes or is long on the 10-year U.S. Treasury Note futures contract. The seller’s risk in selling a covered call is limited as the obligation towards the buyer can be met either by the ownership of the futures position or the cash security tied to the underlying futures contract.

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More on the fund’s investment strategies, investments and risks cont’d

Defensive investing

The fund may depart from its principal investment strategies in response to adverse market, economic or political conditions by taking temporary defensive positions, including by investing in any type of money market instruments and short-term debt securities or holding cash without regard to any percentage limitations. Although the subadvisers have the ability to take defensive positions, they may choose not to do so for a variety of reasons, even during volatile market conditions.

Other investments

The fund may also use other strategies and invest in other investments that are described, along with their risks, in the SAI. However, the fund might not use all of the strategies and techniques or invest in all of the types of investments described in this Prospectus or in the SAI.

Percentage and other limitations

The fund’s compliance with its investment limitations (other than the limitation on borrowing) and requirements described in this Prospectus is usually determined at the time of investment. If such a percentage limitation is complied with at the time of an investment, any subsequent change resulting from a change in asset values or characteristics will not constitute a violation of that limitation.

Important information

The fund’s investment objective may be changed by the Board of Trustees (the “Board”) without shareholder approval and on 60 days’ notice to shareholders. There is no assurance that the fund will meet its investment objective.

The fund will consider an issuer to be a “non-U.S. issuer” if the issuer is a non-U.S. government (including any sub-division, agency or instrumentality of a non-U.S. government), a supranational entity or any other issuer (including corporate issuers) organized under the laws of a country outside of the United States and having a principal place of business outside of the United States. The fund will consider all other issuers to be “U.S. issuers.”

The fund will consider the entity that issues the security backed by the pool of assets supporting a MBS or ABS to be the “issuer” for purposes of its investment limitations set forth above.

The fund’s 80% investment policy may be changed by the Board without shareholder approval upon 60 days’ prior notice to shareholders.

The fund’s other investment strategies and policies may be changed from time to time without shareholder approval, unless specifically stated otherwise in this Prospectus or in the SAI.

More on risks of investing in the fund

Below are descriptions of the main factors that may play a role in shaping the fund’s overall risk profile. The descriptions appear in alphabetical order, not in order of importance.

Asset class risk. Securities or other assets in the fund’s portfolio may underperform in comparison to the general financial markets, a particular financial market or other asset classes. This may cause the fund to underperform other investment vehicles that invest in different asset classes.

Assets under management (AUM) risk. From time to time a third party, LMPFA and/or affiliates of LMPFA or the fund may invest in the fund and hold its investment for a specific period of time in order for the fund to achieve size or scale. There can be no assurance that any such entity would not redeem its investment or that the size of the fund would be maintained at such levels.

Authorized Participant concentration risk. Only an Authorized Participant may engage in creation or redemption transactions directly with the fund. The fund has a limited number of institutions that act as Authorized Participants. To the extent that these institutions exit the business, elect not to transact with the fund, or are unable to proceed with creation and/or redemption orders with respect to the fund and no other Authorized Participant is able to step forward to create or redeem, fund shares may trade at a discount to NAV and possibly face trading halts and/or delisting.

Cash management and defensive investing risk. The value of the investments held by the fund for cash management or defensive investing purposes can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If a significant amount of the fund’s assets are used for cash management or defensive investing purposes, it may not achieve its investment objective.

Cash transactions risk. Unlike many ETFs, the fund may effect its creations and redemptions primarily for cash, rather than in-kind securities. Other more conventional ETFs generally are able to make in-kind redemptions and avoid realizing gains in connection with transactions designed to meet

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redemption requests. Effecting all redemptions for cash may cause the fund to sell portfolio securities in order to obtain the cash needed to distribute redemption proceeds. Such dispositions may occur at an inopportune time resulting in potential losses to the fund and involve transaction costs. If the fund recognizes a capital loss on these sales, the loss will offset capital gains and may result in smaller capital gain distributions from the fund. If the fund recognizes gain on these sales, this generally will cause the fund to recognize gain it might not otherwise have recognized if it were to distribute portfolio securities in-kind or to recognize such gain sooner than would otherwise be required. The fund generally intends to distribute these gains to shareholders to avoid being taxed on this gain at the fund level and otherwise comply with the special tax rules that apply to it. This strategy may cause shareholders to be subject to tax on gains they would not otherwise be subject to, or at an earlier date than, if they had made an investment in a more conventional ETF.

In addition, cash transactions may have to be carried out over several days if the securities market is relatively illiquid and may involve considerable brokerage fees and taxes. These brokerage fees and taxes, which will be higher than if the fund sold and redeemed its shares primarily in-kind, will generally be passed on to purchasers and redeemers of Creation Units in the form of creation and redemption transaction fees. To the extent transaction and other costs associated with a redemption exceed the redemption fee, those transaction costs might be borne by the fund’s remaining shareholders. In addition, these factors may result in wider spreads between the bid and the offered prices of the fund’s shares than for more conventional ETFs. As a practical matter, only institutions and large investors, such as market makers or other large broker-dealers, purchase or redeem Creation Units. Most investors will buy and sell shares of the fund on an exchange.

Collateralized debt obligations risk. In addition to the typical risks associated with fixed-income securities and ABS, CDOs carry additional risks including, but not limited to: (i) the possibility that distributions from collateral securities will not be adequate to make interest or other payments; (ii) the risk that the collateral may default or decline in value or be downgraded, if rated by a NRSRO; (iii) the fund may invest in tranches of CDOs that are subordinate to other tranches; (iv) the structure and complexity of the transaction and the legal documents could lead to disputes among investors regarding the characterization of proceeds; (v) the investment returns achieved by the fund could be significantly different than those predicted by financial models; (vi) the lack of a readily available secondary market for CDOs; (vii) the risk of forced “fire sale” liquidation due to technical defaults such as coverage test failures; and (viii) the CDO’s manager may perform poorly. CDOs are subject to heightened liquidity risk and the liquidity of CDOs may change over time.

Covered call risk. Covered call risk is the risk that the issuer of the call option will forgo any profit from increases in the market value of the underlying security or futures contract covering the call option above the sum of the premium and the strike price of the call but retain the risk of loss if the underlying security or futures contract declines in value. The fund will have no control over the exercise of the option by the option holder and may lose the benefit from any capital appreciation on the underlying security or futures contract. A number of factors may influence the option holder’s decision to exercise the option, including the value of the underlying security or futures contract, price volatility, dividend yield and interest rates. To the extent that these factors increase the value of the call option, the option holder is more likely to exercise the option, which may negatively affect the fund.

Credit risk. If an obligor (such as the issuer itself or a party offering credit enhancement) for a security held by the fund fails to pay, otherwise defaults, is perceived to be less creditworthy, becomes insolvent or files for bankruptcy, a security’s credit rating is downgraded or the credit quality or value of any underlying assets declines, the value of your investment in the fund could decline. If the fund enters into financial contracts (such as certain derivatives, repurchase agreements, reverse repurchase agreements, and when-issued, delayed delivery and forward commitment transactions), the fund will be subject to the credit risk presented by the counterparty. In addition, the fund may incur expenses in an effort to protect the fund’s interests or to enforce its rights. Credit risk is broadly gauged by the credit ratings of the securities in which the fund invests. However, ratings are only the opinions of the companies issuing them and are not guarantees as to quality. Securities rated in the lowest category of investment grade BBB-/Baa3 may possess certain speculative characteristics. Credit risk is typically greatest for the fund’s high yield debt securities, which are rated below the BBB-/Baa3 categories or unrated securities of comparable quality (“junk bonds”).

The fund may invest in securities which are subordinated to more senior securities of the issuer, or which represent interests in pools of such subordinated securities. The fund is more likely to suffer a credit loss on subordinated securities than on non-subordinated securities of the same issuer. If there is a default, bankruptcy or liquidation of the issuer, most subordinated securities are paid only if sufficient assets remain after payment of the issuer’s non-subordinated securities. In addition, any recovery of interest or principal may take more time. As a result, even a perceived decline in creditworthiness of the issuer is likely to have a greater impact on subordinated securities.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

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More on the fund’s investment strategies, investments and risks cont’d

Cybersecurity risk. Cybersecurity incidents may allow an unauthorized party to gain access to fund assets, customer data (including private shareholder information), or proprietary information, or cause the fund, the manager, the subadviser, Authorized Participants, the relevant listing exchange and/or their service providers (including, but not limited to, fund accountants, custodians, sub-custodians, transfer agents and financial intermediaries) to suffer data breaches, data corruption or loss of operational functionality.

Derivatives risk. Derivatives involve special risks and costs and may result in losses to the fund, even when used for hedging purposes. Using derivatives can increase losses and reduce opportunities for gains when market prices, interest rates, currencies or the derivatives themselves behave in a way not anticipated by the fund, especially in abnormal market conditions. Using derivatives also can have a leveraging effect (which may increase investment losses) and increase the fund’s volatility, which is the degree to which the fund’s share price may fluctuate within a short time period. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. The other parties to certain derivatives transactions present the same types of credit risk as issuers of fixed income securities. Derivatives also tend to involve greater liquidity risk and they may be difficult to value. The fund may be unable to terminate or sell its derivative positions. In fact, many over-the-counter derivatives will not have liquidity beyond the counterparty to the instrument. Derivatives are generally subject to the risks applicable to the assets, rates, indices or other indicators underlying the derivative. The value of a derivative may fluctuate more than the underlying assets, rates, indices or other indicators to which it relates. Use of derivatives or similar instruments may have different tax consequences for the fund than an investment in the underlying security, and those differences may affect the amount, timing and character of income distributed to shareholders. The fund’s use of derivatives may also increase the amount of taxes payable by shareholders. The U.S. government and foreign governments are in the process of adopting and implementing regulations governing derivatives markets, including mandatory clearing of certain derivatives, margin, and reporting requirements. The ultimate impact of the regulations remains unclear. Additional regulation of derivatives may make derivatives more costly, limit their availability or utility, otherwise adversely affect their performance or disrupt markets. The fund may be exposed to additional risks as a result of the additional regulations. The extent and impact of the additional regulations are not yet fully known and may not be for some time.

Investments by the fund in structured securities, a type of derivative, raise certain tax, legal, regulatory and accounting issues that may not be presented by direct investments in securities. These issues could be resolved in a manner that could hurt the performance of the fund.

Swap agreements tend to shift the fund’s investment exposure from one type of investment to another. For example, the fund may enter into interest rate swaps, which involve the exchange of interest payments by the fund with another party, such as an exchange of floating rate payments for fixed interest rate payments with respect to a notional amount of principal. If an interest rate swap intended to be used as a hedge negates a favorable interest rate movement, the investment performance of the fund would be less than what it would have been if the fund had not entered into the interest rate swap.

Credit default swap contracts involve heightened risks and may result in losses to the fund. Credit default swaps may be illiquid and difficult to value. If the fund buys a credit default swap, it will be subject to the risk that the credit default swap may expire worthless, as the credit default swap would only generate income in the event of a default on the underlying debt security or other specified event. As a buyer, the fund would also be subject to credit risk relating to the seller’s payment of its obligations in the event of a default (or similar event). If the fund sells a credit default swap, it will be exposed to the credit risk of the issuer of the obligation to which the credit default swap relates. As a seller, the fund would also be subject to leverage risk, because it would be liable for the full notional amount of the swap in the event of a default (or similar event).

The absence of a central exchange or market for swap transactions may lead, in some instances, to difficulties in trading and valuation, especially in the event of market disruptions. Recent legislation requires certain swaps to be executed through a centralized exchange or regulated facility and be cleared through a regulated clearinghouse. Although this clearing mechanism is generally expected to reduce counterparty credit risk, it may disrupt or limit the swap market and may not result in swaps being easier to trade or value. As swaps become more standardized, the fund may not be able to enter into swaps that meet its investment needs. The fund also may not be able to find a clearinghouse willing to accept a swap for clearing. In a cleared swap, a central clearing organization will be the counterparty to the transaction. The fund will assume the risk that the clearinghouse may be unable to perform its obligations.

The fund will be required to maintain its positions with a clearing organization through one or more clearing brokers. The clearing organization will require the fund to post margin and the broker may require the fund to post additional margin to secure the fund’s obligations. The amount of margin required may change from time to time. In addition, cleared transactions may be more expensive to maintain than over-the-counter transactions and may require the fund to deposit larger amounts of margin. The fund may not be able to recover margin amounts if the broker has financial difficulties. Also, the broker may require the fund to terminate a derivatives position under certain circumstances. This may cause the fund to lose money.

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 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; (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

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market movements, which are potentially unlimited; (d) the subadviser’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.

An option is an agreement that, for a premium payment or fee, gives the option holder (the purchaser) the right but not the obligation to buy (a “call option”) or sell (a “put option”) the underlying asset (or settle for cash in an amount based on an underlying asset, rate, or index) at a specified price (the “exercise price”) during a period of time or on a specified date. The fund may write a call or put option where it (i) owns or is short the underlying security in the case of a call or put option, respectively (sometimes referred to as a “covered option”), or (ii) does not own or is not short such security (sometimes referred to as a “naked option”). When the fund purchases an option, it may lose the total premium paid for it if the price of the underlying security or other assets decreased, remained the same or failed to increase to a level at or beyond the exercise price (in the case of a call option) or increased, remained the same or failed to decrease to a level at or below the exercise price (in the case of a put option). If a put or call option purchased by the fund were permitted to expire without being sold or exercised, its premium would represent a loss to the fund. To the extent that the fund writes or sells an option, in particular a naked option, if the decline or increase in the underlying asset is significantly below or above the exercise price of the written option, the fund could experience a substantial loss.

Risks associated with the use of derivatives are magnified to the extent that an increased portion of the fund’s assets are committed to derivatives in general or are invested in just one or a few types of derivatives.

ETFs risk. Unlike shares of typical mutual funds or unit investment trusts, shares of ETFs are traded on an exchange and may trade throughout a trading day. ETFs are bought and sold based on market values and not at NAV, and therefore may trade at either a premium or discount to NAV and may experience volatility in certain market conditions.

Extension risk. When interest rates rise, repayments of fixed income securities, particularly ABS and MBS, may occur more slowly than anticipated, extending the effective duration of these fixed income securities at below market interest rates and causing their market prices to decline more than they would have declined due to the rise in interest rates alone. This may cause the fund’s share price to be more volatile.

Foreign custody risk. Foreign custody risk refers to the risks inherent in the process of clearing and settling trades and to the holding of securities, cash and other assets by banks, agents and depositories in securities markets that are less developed than those in the United States. Low trading volumes and volatile prices in less developed markets make trades harder to complete and settle, and governments or trade groups may compel non-U.S. agents to hold securities in designated depositories that may not be subject to independent evaluation. The laws of certain countries may place limitations on the ability to recover assets if a non-U.S. bank, agent or depository becomes insolvent or enters bankruptcy. Non-U.S. agents are held only to the standards of care of their local markets, and thus may be subject to limited or no government oversight. In general, the less developed a country’s securities market is, or the more difficult communication is with that location, the greater the likelihood of custody problems.

Foreign investments and emerging market risk. The fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable or unsuccessful government actions, reduction of government or central bank support and political or financial instability. Lack of information may also affect the value of these securities. To the extent the fund focuses its investments in a single country or only a few countries in a particular geographic region, economic, political, regulatory or other conditions affecting such country or region may have a greater impact on fund performance relative to a more geographically diversified fund.

The value of the fund’s foreign investments may also be affected by foreign tax laws, special U.S. tax considerations and restrictions on receiving the investment proceeds from a foreign country. Dividends or interest on, or proceeds from the sale or disposition of, foreign securities may be subject to non-U.S. withholding or other taxes.

In some foreign countries, less information is available about issuers and markets because of less rigorous accounting and regulatory standards than in the United States. It may be difficult for the fund to pursue claims against a foreign issuer in the courts of a foreign country. Some securities issued by non-U.S. governments or their subdivisions, agencies and instrumentalities may not be backed by the full faith and credit of such governments. Even where a security is backed by the full faith and credit of a government, it may be difficult for the fund to pursue its rights against the government. Some non-U.S. governments have defaulted on principal and interest payments, and more may do so. In certain foreign markets, settlement and clearance procedures may result in delays in payment for or delivery of securities not typically associated with settlement and clearance of U.S. investments.

The risks of foreign investments are heightened when investing in issuers in emerging market countries. Emerging market countries tend to have economic, political and legal systems that are less fully developed and are less stable than those of more developed countries. They are often particularly sensitive to market movements because their market prices tend to reflect speculative expectations. Low trading volumes may result in a

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More on the fund’s investment strategies, investments and risks cont’d

lack of liquidity and in extreme price volatility. Investors should be able to tolerate sudden, sometimes substantial, fluctuations in the value of their investments. Emerging market countries may have policies that restrict investment by foreigners or that prevent foreign investors from withdrawing their money at will. Economies and financial markets throughout the world are becoming increasingly interconnected, which increases the likelihood that events or conditions in one country or region will adversely impact markets or issuers in other countries or regions.

Hedging risk. The decision as to whether and to what extent the fund will engage in hedging transactions to hedge against such risks as credit risk, currency risk and interest rate risk will depend on a number of factors, including prevailing market conditions, the composition of the fund and the availability of suitable transactions. Accordingly, there can be no assurance that the fund will engage in hedging transactions at any given time or from time to time, even under volatile market environments, or that any such strategies, if used, will be successful. Hedging transactions involve costs and may reduce gains or result in losses.

High yield (“junk”) bonds risk. High yield bonds, often called “junk” bonds, have a higher risk of issuer default or may be in default and are considered speculative. Changes in economic conditions or developments regarding the individual issuer are more likely to cause price volatility and weaken the capacity of such securities to make principal and interest payments than is the case for higher grade debt securities. The value of lower-quality debt securities often fluctuates in response to company, political, or economic developments and can decline significantly over short as well as long periods of time or during periods of general or regional economic difficulty. High yield bonds may also be less liquid than higher-rated securities, which means the fund may have difficulty selling them at times, and it may have to apply a greater degree of judgment in establishing a price for purposes of valuing fund shares. High yield bonds generally are issued by less creditworthy issuers. Issuers of high yield bonds may have a larger amount of outstanding debt relative to their assets than issuers of investment grade bonds. In the event of an issuer’s bankruptcy, claims of other creditors may have priority over the claims of high yield bond holders, leaving few or no assets available to repay high yield bond holders. The fund may incur expenses to the extent necessary to seek recovery upon default or to negotiate new terms with a defaulting issuer. High yield bonds frequently have redemption features that permit an issuer to repurchase the security from the fund before it matures. If the issuer redeems high yield bonds, the fund may have to invest the proceeds in bonds with lower yields and may lose income.

Leveraging risk. The value of your investment may be more volatile if the fund borrows or uses derivatives or other investments that have a leveraging effect on the fund’s portfolio. Other risks also will be compounded. This is because leverage generally magnifies the effect of a change in the value of an asset and creates a risk of loss of value on a larger pool of assets than the fund would otherwise have had. The fund may also have to sell assets at inopportune times to satisfy its obligations. The use of leverage is considered to be a speculative investment practice and may result in the loss of a substantial amount, and possibly all, of the fund’s assets.

Liquidity risk. Liquidity risk exists when particular investments are impossible or difficult to sell. Although most of the fund’s investments must be liquid at the time of investment, investments may become illiquid after purchase by the fund, particularly during periods of market turmoil. Markets may become illiquid when, for instance, there are few, if any, interested buyers or sellers or when dealers are unwilling or unable to make a market for certain securities. As a general matter, dealers recently have been less willing to make markets for fixed income securities. When the fund holds illiquid investments, the portfolio 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 management needs, the fund may suffer a loss. The fund may experience heavy redemptions that could cause the fund to liquidate its assets at inopportune times or at a loss or depressed value, which could cause the value of your investment to decline. In addition, when there is illiquidity in the market for certain investments, the fund, due to limitations on illiquid investments, may be unable to achieve its desired level of exposure to a certain sector. The liquidity of certain assets, particularly of privately-issued and non-investment grade MBS, ABS and CDOs, may be difficult to ascertain and may change over time.

Market events risk. In the past decade financial markets throughout the world have experienced increased volatility, depressed valuations, decreased liquidity and heightened uncertainty. Governmental and non-governmental issuers have defaulted on, or been forced to restructure, their debts. These conditions may continue, recur, worsen or spread. Events that have contributed to these market conditions include, but are not limited to major cybersecurity events; measures to address U.S. federal and state budget deficits; downgrading of U.S. long-term sovereign debt; declines in oil and commodity prices; dramatic changes in currency exchange rates; and public sentiment.

The U.S. government and the Federal Reserve, as well as certain foreign governments and central banks, have taken steps to support financial markets, including by keeping interest rates at historically low levels. This and other government intervention may not work as intended, particularly if the efforts are perceived by investors as being unlikely to achieve the desired results. The Federal Reserve has reduced its market support activities and recently has begun raising interest rates. Certain foreign governments and central banks are implementing or discussing so-called negative interest rates (e.g., charging depositors who keep their cash at a bank) to spur economic growth. Further Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, could negatively affect financial markets generally, increase market volatility and reduce the value and liquidity of securities in which the fund invests.

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Policy and legislative changes in the United States and in other countries are affecting many aspects of financial regulation, and may in some instances contribute to decreased liquidity and increased volatility in the financial markets. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Economies and financial markets throughout the world are increasingly interconnected. Economic, financial or political events, trading and tariff arrangements, terrorism, natural disasters and other circumstances in one country or region could have profound impacts on global economies or markets. As a result, whether or not the fund invests in securities of issuers located in or with significant exposure to the countries directly affected, the value and liquidity of the fund’s investments may be negatively affected.

Market and interest rate risk. The market prices of fixed income and other securities owned by the fund may go up or down, sometimes rapidly or unpredictably. If the market prices of the securities owned by the fund fall, the value of your investment in the fund will decline. The value of a security may fall due to general market conditions, such as real or perceived adverse economic or political conditions, inflation, changes in interest or currency rates, lack of liquidity in the bond markets or adverse investor sentiment. Changes in market conditions will not typically have the same impact on all types of securities. The value of a security may also fall due to specific conditions that affect a particular sector of the securities market or a particular issuer.

The market prices of securities may fluctuate significantly when interest rates change. When interest rates rise, the value of fixed income securities, and therefore the value of your investment in the fund, generally goes down. Interest rates have been historically low, so the fund faces a heightened risk that interest rates may rise. Generally, the longer the maturity or duration of a fixed income security, the greater the impact of a rise in interest rates on the security’s value. However, calculations of duration and maturity may be based on estimates and may not reliably predict a security’s price sensitivity to changes in interest rates. Moreover, securities can change in value in response to other factors, such as credit risk. In addition, different interest rate measures (such as short- and long-term interest rates and U.S. and foreign interest rates), or interest rates on different types of securities or securities of different issuers, may not necessarily change in the same amount or in the same direction. When interest rates go down, the fund’s yield will decline. Also, when interest rates decline, investments made by the fund may pay a lower interest rate, which would reduce the income received by the fund.

Market sector risk. The fund may be significantly overweight or underweight in certain companies, industries or market sectors, which may cause the fund’s performance to be more sensitive to developments affecting those companies, industries or market sectors.

Market trading risk.

Absence of active market. Although shares of the fund are listed for trading on one or more stock exchanges, there can be no assurance that an active trading market for such shares will develop or be maintained by market makers or Authorized Participants. Authorized Participants are not obligated to execute purchase or redemption orders for Creation Units. In periods of market volatility, market makers and/or Authorized Participants may be less willing to transact in fund shares. The absence of an active market for the fund’s shares may contribute to the fund’s shares trading at a premium or discount to NAV.

Risk of secondary listings. The fund’s shares may be listed or traded on U.S. and non-U.S. stock exchanges other than the U.S. stock exchange where the fund’s primary listing is maintained, and may otherwise be made available to non-U.S. investors through funds or structured investment vehicles similar to depositary receipts. There can be no assurance that the fund’s shares will continue to trade on any such stock exchange or in any market or that the fund’s shares will continue to meet the requirements for listing or trading on any exchange or in any market. The fund’s shares may be less actively traded in certain markets than in others, and investors are subject to the execution and settlement risks and market standards of the market where they or their broker direct their trades for execution. Certain information available to investors who trade fund shares on a U.S. stock exchange during regular U.S. market hours may not be available to investors who trade in other markets, which may result in secondary market prices in such markets being less efficient.

Secondary market trading risk. Shares of the fund may trade in the secondary market at times when the fund does not accept orders to purchase or redeem shares. At such times, shares may trade in the secondary market with more significant premiums or discounts than might be experienced at times when the fund accepts purchase and redemption orders.

Secondary market trading in fund shares may be halted by a stock exchange because of market conditions or for other reasons. In addition, trading in fund shares on a stock exchange or in any market may be subject to trading halts caused by extraordinary market volatility pursuant to “circuit breaker” rules on the stock exchange or market.

Shares of the fund, similar to shares of other issuers listed on a stock exchange, may be sold short and are therefore subject to the risk of increased volatility and price decreases associated with being sold short.

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Shares of the fund may trade at prices other than NAV. Shares of the fund trade on stock exchanges at prices at, above or below the fund’s most recent NAV. The NAV of the fund is calculated at the end of each business day and fluctuates with changes in the market value of the fund’s holdings. The trading price of the fund’s shares fluctuates continuously throughout trading hours based on both market supply of and demand for fund shares and the underlying value of the fund’s portfolio holdings or NAV. As a result, the trading prices of the fund’s shares may deviate significantly from NAV during periods of market volatility, including during periods of significant redemption requests or other unusual market conditions. ANY OF THESE FACTORS, AMONG OTHERS, MAY LEAD TO THE FUND’S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV . However, because shares can be created and redeemed in Creation Units at NAV, the subadviser believes that large discounts or premiums to the NAV of the fund are not likely to be sustained over the long term (unlike shares of many closed-end funds, which frequently trade at appreciable discounts from, and sometimes at premiums to, their NAVs). While the creation/redemption feature is designed to make it more likely that the fund’s shares normally will trade on stock exchanges at prices close to the fund’s next calculated NAV, exchange prices are not expected to correlate exactly with the fund’s NAV due to timing reasons, supply and demand imbalances and other factors. In addition, disruptions to creations and redemptions, including disruptions at market makers, Authorized Participants, or other market participants, and during periods of significant market volatility, may result in trading prices for shares of the fund that differ significantly from its NAV. Authorized Participants may be less willing to create or redeem fund shares if there is a lack of an active market for such shares or its underlying investments, which may contribute to the fund’s shares trading at a discount to NAV.

Costs of buying or selling fund shares. Buying or selling fund shares on an exchange involves two types of costs that apply to all securities transactions. When buying or selling shares of the fund through a broker, you will likely incur a brokerage commission and other charges. In addition, you may incur the cost of the “spread”; that is, the difference between what investors are willing to pay for fund shares (the “bid” price) and the price at which they are willing to sell fund shares (the “ask” price). There may also be regulatory and other charges that are incurred as a result of trading activity. The spread varies over time for shares of the fund based on trading volume and market liquidity, and is generally narrower if the fund has more trading volume and market liquidity and wider if the fund has less trading volume and market liquidity. In addition, increased market volatility may cause wider spreads. Because of the costs inherent in buying or selling fund shares, frequent trading may detract significantly from investment results and an investment in fund shares may not be advisable for investors who anticipate regularly making small investments through a brokerage account.

Mortgage-backed and asset-backed securities risk. Although asset-backed and CMBS generally experience less prepayment than RMBS; MBS and ABS, like traditional fixed-income securities, are subject to credit, interest rate, prepayment and extension risks.

Small movements in interest rates (both increases and decreases) may quickly and significantly reduce the value of certain MBS. The fund’s investments in ABS are subject to risks similar to those associated with mortgage-related securities, as well as additional risks associated with the nature of the assets and the servicing of those assets. These securities also are subject to the risk of default on the underlying mortgage or assets, particularly during periods of economic downturn. The risk of loss due to default on private MBS and ABS is historically higher because neither the U.S. government nor an agency or instrumentality has guaranteed them. Certain CMBS are issued in several classes with different levels of yield and credit protection. The fund’s investments in CMBS with several classes may be in the lower classes that have greater risks than the higher classes, including greater interest rate, credit and prepayment risks. MBS and ABS are subject to heightened liquidity risk and the liquidity of MBS and ABS may change over time.

MBS may be either pass-through securities or CMOs. Pass-through securities represent a right to receive principal and interest payments collected on a pool of mortgages, which are passed through to security holders. CMOs are created by dividing the principal and interest payments collected on a pool of mortgages into several revenue streams (tranches) with different priority rights to portions of the underlying mortgage payments. Certain CMO tranches may represent a right to receive interest only (“IOs”), principal only (“POs”) or an amount that remains after floating-rate tranches are paid (an inverse floater). These securities are frequently referred to as “mortgage derivatives” and may be extremely sensitive to changes in interest rates. Interest rates on inverse floaters, for example, vary inversely with a short-term floating rate (which may be reset periodically). Interest rates on inverse floaters will decrease when short-term rates increase, and will increase when short-term rates decrease. These securities have the effect of providing a degree of investment leverage. In response to changes in market interest rates or other market conditions, the value of an inverse floater may increase or decrease at a multiple of the increase or decrease in the value of the underlying securities. If the fund invests in CMO tranches (including CMO tranches issued by government agencies) and interest rates move in a manner not anticipated by fund management, it is possible that the fund could lose all or substantially all of its investment. Certain MBS in which the fund may invest may also provide a degree of investment leverage, which could cause the fund to lose all or substantially all of its investment.

The mortgage market in the United States has experienced difficulties that may adversely affect the performance and market value of certain of the fund’s mortgage-related investments. Delinquencies and losses on mortgage loans (including subprime and second-lien mortgage loans) generally have increased and may continue to increase, and a decline in or flattening of real-estate values (as has been experienced and may continue to be experienced in many housing markets) may exacerbate such delinquencies and losses. Also, a number of mortgage loan originators have experienced

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serious financial difficulties or bankruptcy. Reduced investor demand for mortgage loans and mortgage-related securities and increased investor yield requirements have caused limited liquidity in the secondary market for mortgage-related securities, which can adversely affect the market value of mortgage-related securities. It is possible that such limited liquidity in such secondary markets could continue or worsen.

ABS entail certain risks not presented by MBS, including the risk that in certain states it may be difficult to perfect the liens securing the collateral backing certain asset-backed securities. In addition, certain ABS are based on loans that are unsecured, which means that there is no collateral to seize if the underlying borrower defaults.

Mortgage dollar rolls risk. Mortgage dollar rolls are transactions in which the fund sells MBS to a dealer and simultaneously agrees to repurchase similar securities in the future at a predetermined price. The fund’s mortgage dollar rolls could lose money if the price of the mortgage-backed securities sold falls below the agreed upon repurchase price, or if the counterparty is unable to honor the agreement. Mortgage dollar roll transactions may have a leveraging effect on the fund, making the value of an investment in the fund more volatile and magnifying any change in the fund’s net asset value.

National closed market trading risk. Where the underlying securities held by the fund trade on foreign exchanges that are closed when the securities exchange on which the fund’s shares trade is open, there are likely to be deviations between the current price of such an underlying security (i.e., during the ETF’s domestic trading day) and the last quoted price for the underlying security (i.e., the fund’s quote from the closed foreign market), which in turn could lead to a difference between the price at which the fund has valued the security and the value of the underlying security. This could also result in premiums or discounts to the fund’s NAV that may be greater than those experienced by other ETFs.

Operational risk. Your ability to transact with the fund or the valuation of your investment may be negatively impacted because of the operational risks arising from factors such as processing errors and human errors, inadequate or failed internal or external processes, failures in systems and technology, changes in personnel, and errors caused by third party service providers or trading counterparties. It is not possible to identify all of the operational risks that may affect the fund or to develop processes and controls that completely eliminate or mitigate the occurrence of such failures. The fund and its shareholders could be negatively impacted as a result.

Portfolio management risk. The value of your investment may decrease if the subadviser’s judgment about the attractiveness or value of, or market trends affecting a particular security, industry, sector or region, or about market movements is incorrect, or if there are imperfections, errors or limitations in the tools and data used by the subadviser. In addition, the fund’s investment strategies or policies may change from time to time. Those changes may not lead to the results intended by the subadviser and could have an adverse effect on the value or performance of the fund.

Furthermore, the implementation of the fund’s investment strategies is subject to a number of constraints, which could also adversely affect the fund’s value or performance.

Preferred stock risk. Preferred stock is subject to many of the risks associated with debt securities, including interest rate risk. In addition, preferred stock may not pay a dividend, an issuer may suspend payment of dividends on preferred stock at any time, and in certain situations an issuer may call or redeem its preferred stock or convert it to common stock.

Prepayment or call risk. Many fixed income securities give the issuer the option to repay or call the security prior to its maturity date. Issuers often exercise this right when interest rates fall. Accordingly, if the fund holds a fixed income security subject to prepayment or call risk, it will not benefit fully from the increase in value that other fixed income securities generally experience when interest rates fall. Upon prepayment of the security, the fund would also be forced to reinvest the proceeds at then current yields, which would be lower than the yield of the security that was paid off. In addition, if the fund purchases a fixed income security at a premium (at a price that exceeds its stated par or principal value), the fund may lose the amount of the premium paid in the event of prepayment.

Redemptions by other funds and by other significant investors risk. The fund may be an investment option for other Legg Mason, Inc. sponsored mutual funds and ETFs that are managed as “funds of funds,” unaffiliated mutual funds and ETFs and other investors with substantial investments in the fund. As a result, from time to time, the fund may experience relatively large redemptions and could be required to liquidate its assets at inopportune times or at a loss or depressed value, which could cause the value of your investment to decline.

Risk of investing in fewer issuers. To the extent the fund invests its assets in a small number of issuers, the fund will be more susceptible to negative events affecting those issuers.

Risks relating to inflation-indexed securities. The value of inflation-indexed fixed income securities generally fluctuates in response to changes in real interest rates, which are in turn tied to the relationship between nominal interest rates and the rate of inflation. Therefore, if inflation were to rise at a faster rate than nominal interest rates, real interest rates might decline, leading to an increase in value of inflation-indexed securities. In contrast, if nominal interest rates increased at a faster rate than inflation, real interest rates might rise, leading to a decrease in value of inflation-indexed securities.

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The principal value of inflation-indexed securities declines in periods of deflation, and holders of such securities may experience a loss. Although the holders of U.S. TIPS receive no less than the par value of the security maturity, if the fund purchases U.S. TIPS in the secondary market whose principal values have been adjusted upward due to inflation since issuance, it may experience a loss if there is a subsequent period of deflation. If inflation is lower than expected during the period the fund holds an inflation-indexed security, the fund may earn less on the security than on a conventional bond.

Any increase in principal value caused by an increase in the index the inflation-indexed securities are tied to is taxable in the year the increase occurs, even though the fund will not receive cash representing the increase at that time. As a result, the fund could be required at times to liquidate other investments, including when it is not advantageous to do so, in order to satisfy its distribution requirements as a regulated investment company under the Code. See “Taxes” in the SAI.

If real interest rates rise (i.e., if interest rates rise for reasons other than inflation, for example, due to changes in currency exchange rates), the value of inflation-indexed securities held by the fund will decline. Moreover, because the principal amount of inflation-indexed securities would be adjusted downward during a period of deflation, the fund will be subject to deflation risk with respect to its investments in these securities. Inflation-indexed securities are tied to indices that are calculated based on rates of inflation for prior periods. There can be no assurance that such indices will accurately measure the actual rate of inflation in the prices of goods and services.

Trading issues risk. Trading in shares of the fund on NASDAQ may be halted due to market conditions or for reasons that, in the view of NASDAQ, make trading in shares inadvisable. In addition, trading in shares on NASDAQ is subject to trading halts caused by extraordinary market volatility pursuant to NASDAQ’s “circuit breaker” rules. There can be no assurance that the requirements of NASDAQ necessary to maintain the listing of the fund will continue to be met or will remain unchanged.

U.S. government securities risk. Although the U.S. government guarantees principal and interest payments on securities issued by the U.S. government and some of its agencies, such as securities issued by the Ginnie Mae, this guarantee does not apply to losses resulting from declines in the market value of these securities.

Valuation risk. Many factors may influence the price at which the fund could sell any particular portfolio investment. The sales price may well differ—higher or lower—from the fund’s last valuation, and such differences could be significant, particularly for illiquid securities and securities that trade in relatively thin markets and/or markets that experience extreme volatility. If market conditions make it difficult to value some investments, the fund may value these investments using more subjective methods, such as fair value methodologies. Valuation methodologies may be further impacted by technological issues and/or errors by pricing vendors or their personnel. Authorized Participants who purchase or redeem fund shares on days when the fund is holding fair-valued securities may receive fewer or more shares, or lower or higher redemption proceeds, than they would have received if the fund had not fair-valued securities or had used a different valuation methodology. The value of foreign securities, certain fixed income securities and currencies, as applicable, may be materially affected by events after the close of the markets on which they are traded, but before the fund determines its NAV. The fund’s ability to value its investments may be impacted by technological issues and/or errors by pricing services or other third party service providers.

Volatility risk. The value of the securities and other assets in the fund’s portfolio may fluctuate, sometimes rapidly and unpredictably. The value of a security or other asset may fluctuate due to factors affecting markets generally or particular industries. The value of a security may also be more volatile than the market as a whole. This volatility may affect the fund’s NAV. Securities or other assets in the fund’s portfolio may be subject to price volatility and the prices may not be any less volatile than the market as a whole and could be more volatile. Events or financial circumstances affecting individual securities or sectors may increase the volatility of the fund.

Warrants and rights risk. Warrants and rights can provide a greater potential for profit or loss than an equivalent investment in the underlying security. Prices of warrants and rights do not necessarily move in tandem with the prices of the underlying securities and therefore are highly volatile and speculative investments. They have no voting rights, pay no dividends and have no rights with respect to the assets of the issuer other than a purchase option. If a warrant or right held by the fund is not exercised by the date of its expiration, the fund would lose the entire purchase price of the warrant or right.

Please note that there are other factors that could adversely affect your investment and that could prevent the fund from achieving its investment objective. More information about risks appears in the SAI. Before investing, you should carefully consider the risks that you will assume.

Portfolio holdings

On each business day, the fund will disclose on www.leggmason.com/etfproducts (click on the name of the fund) the identities and quantities of the fund’s portfolio holdings and other assets held by the fund that will form the basis for the fund’s calculation of its net asset value per share at the end of the business day. A description of the fund’s policies and procedures with respect to the disclosure of its portfolio holdings is available in the SAI.

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More on fund management

Legg Mason Partners Fund Advisor, LLC (“LMPFA” or the “manager”) is the fund’s investment manager. LMPFA, with offices at 620 Eighth Avenue, New York, New York 10018, also serves as the investment manager of other Legg Mason-sponsored funds. LMPFA provides administrative and certain oversight services to the fund. As of June 30, 2018, LMPFA’s total assets under management were approximately $179.1 billion.

Western Asset Management Company, LLC (formerly known as Western Asset Management Company) (“Western Asset”) provides the day-to-day portfolio management of the fund as subadviser. Western Asset Management Company Limited (“Western Asset London”), Western Asset Management Company Pte. Ltd. (“Western Asset Singapore”) and Western Asset Management Company Ltd (“Western Asset Japan” and, collectively with Western Asset London and Western Asset Singapore, the “sub-subadvisers”) serve as sub-subadvisers to the fund. References to “the subadviser” include the subadviser and each applicable sub-subadviser.

Western Asset, established in 1971, has offices at 385 East Colorado Boulevard, Pasadena, California 91101 and 620 Eighth Avenue, New York, New York 10018. Western Asset London was founded in 1984 and has offices at 10 Exchange Square, Primrose Street, London EC2A 2EN. Western Asset Singapore was established in 2000 and has offices at 1 George Street #23-01, Singapore 049145. Western Asset Japan was founded in 1991 and has offices at 36F Shin-Marunouchi Building, 5-1 Marunouchi 1-Chome Chiyoda-Ku, Tokyo 100-6536, Japan.

Western Asset London, Western Asset Singapore and Western Asset Japan provide certain sub-subadvisory services relating to currency transactions and investments in non-U.S. dollar-denominated securities and related foreign currency instruments. Western Asset London generally manages global and non-U.S. dollar fixed income mandates, Western Asset Singapore generally manages Asian (other than Japan) fixed income mandates and Western Asset Japan generally manages Japanese fixed income mandates. Each office provides services relating to relevant portions of Western Asset’s broader portfolios as appropriate.

Western Asset London, Western Asset Singapore and Western Asset Japan undertake investment-related activities including investment management, research and analysis, and securities settlement.

Western Asset employs a team approach to investment management that utilizes relevant staff in multiple offices around the world. Expertise from Western Asset investment professionals in those offices add local sector investment experience as well as the ability to trade in local markets. Although the investment professionals at Western Asset London, Western Asset Singapore, and Western Asset Japan are responsible for the management of the investments in their local sectors, Western Asset provides overall supervision of their activities for the fund to maintain a cohesive investment management approach.

Western Asset, Western Asset London, Western Asset Singapore and Western Asset Japan act as investment advisers to institutional accounts, such as corporate pension plans, mutual funds and endowment funds. As of June 30, 2018, the total assets under management of Western Asset and its supervised affiliates, including Western Asset London, Western Asset Singapore and Western Asset Japan, were approximately $415.1 billion.

LMPFA, Western Asset, Western Asset London, Western Asset Singapore and Western Asset Japan are wholly-owned subsidiaries of Legg Mason. Legg Mason, whose principal executive offices are at 100 International Drive, Baltimore, Maryland 21202, is a global asset management company. As of June 30, 2018, Legg Mason’s asset management operations, including Western Asset and its supervised affiliates, had aggregate assets under management of approximately $744.6 billion.

Investment professionals

The fund is managed by a broad team of investment professionals. The particular mix of investment professionals involved in developing and implementing investment strategies for the fund depends on the asset classes in which the fund invests. Senior members of the portfolio management team are responsible for the development of investment strategy and oversight for the fund and coordination of other relevant investment team members. They work together with the broader Western Asset investment management team on portfolio structure, duration weighting and term structure decisions.

The individuals responsible for day-to-day portfolio management, development of investment strategy, oversight and coordination of the fund are S. Kenneth Leech (Chief Investment Officer), Mark S. Lindbloom (Portfolio Manager), Julien A. Scholnick (Portfolio Manager), Frederick R. Marki (Portfolio Manager) and John L. Bellows (Portfolio Manager/Research Analyst). Messrs. Leech, Lindbloom, Scholnick, Marki and Bellows have each been employed by Western Asset as an investment professional for at least the past five years. Each of Mr. Leech, Mr. Lindbloom, Mr. Scholnick, Mr. Marki and Mr. Bellows has been part of the portfolio management team for the fund since [month] 2018.

The SAI provides information about the investment professionals’ compensation, other accounts managed by the investment professionals and any fund shares held by the investment professionals.

Management fees

Pursuant to the Management Agreement and subject to the general supervision of the Board, LMPFA provides or causes to be furnished all investment management, supervisory, administrative and other services reasonably necessary for the operation of the fund, including certain

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distribution services (provided pursuant to a separate distribution agreement) and investment advisory services (provided pursuant to separate subadvisory agreements) under a unitary fee structure. The fund is responsible for paying interest expenses, taxes, brokerage expenses, future 12b-1 fees (if any), acquired fund fees and expenses, extraordinary expenses and the management fee payable to LMPFA under the Management Agreement.

The fund pays management fees as follows:

A discussion regarding the basis for the Board’s approval of the fund’s management agreement and subadvisory agreements will be available in the fund’s annual report for the year ending December 31, 2018.

Expense limitation

The manager has agreed to waive and/or reimburse management fees so that the ratio of total annual fund operating expenses will not exceed 0.45% (subject to the same exclusions as the Management Agreement). This arrangement cannot be terminated prior to December 31, 2019 without the Board of Trustees’ consent.

Additional information

The fund enters into contractual arrangements with various parties, including, among others, the fund’s investment manager and the subadvisers, who provide services to the fund. Shareholders are not parties to, or intended (or “third-party”) beneficiaries of, those contractual arrangements.

This Prospectus and the SAI provide information concerning the fund that you should consider in determining whether to purchase shares of the fund. The fund may make changes to this information from time to time. Neither this Prospectus nor the SAI is intended to give rise to any contract rights or other rights in any shareholder, other than any rights conferred explicitly by federal or state securities laws that may not be waived.

Distribution

Legg Mason Investor Services, LLC (“LMIS”), 100 International Drive, Baltimore, Maryland 21202, serves as the distributor of Creation Units for the fund on an agency basis. LMIS does not maintain a secondary market in the fund’s shares. LMIS has no role in determining the fund’s policies or the securities that are purchased or sold by the fund.

The Board has adopted a distribution and service plan (“Plan”) pursuant to Rule 12b-1 under the 1940 Act. Under the Plan, the fund is authorized to pay distribution fees in connection with the sale and distribution of its shares and pay service fees in connection with the provision of ongoing services to shareholders of the fund and the maintenance of shareholder accounts in an amount up to 0.25% of its average daily net assets each year. No Rule 12b-1 fees are currently paid by the fund, and there are no current plans to impose these fees.

Additional payments

Legg Mason or its affiliates make payments to broker-dealers, registered investment advisers, banks or other intermediaries (together, “intermediaries”) related to marketing activities and presentations, educational training programs, conferences, the development of technology platforms and reporting systems, or their making shares of the fund available to their customers generally and in certain investment programs. Such payments, which may be significant to the intermediary, are not made by the fund. Rather, such payments are made by Legg Mason or its affiliates from their own resources, which come directly or indirectly in part from fees paid by the fund. A financial intermediary may make decisions about which investment options it recommends or makes available, or the level of services provided, to its customers based on the payments it is eligible to receive. Therefore, such payments to an intermediary create conflicts of interest between the intermediary and its customers and may cause the intermediary to recommend the fund over another investment. More information regarding these payments is contained in the fund’s SAI. Please contact your salesperson or other investment professional for more information regarding any such payments his or her firm may receive from Legg Mason or its affiliates.

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Shareholder information

Additional shareholder information, including how to buy and sell shares of the fund, is available free of charge by calling toll-free: 877-721-1926 or visiting our website at www.leggmason.com/etfliterature.

Purchasing and selling shares

Shares of the fund may be acquired or redeemed directly from the fund only in Creation Units or multiples thereof, as discussed in the “Creations and redemptions” section of this Prospectus. Only an Authorized Participant (as defined in the “Creations and redemptions” section) may engage in creation or redemption transactions directly with the fund. Once created, shares of the fund generally trade in the secondary market in amounts less than a Creation Unit.

Shares of the fund are listed for trading on the secondary market on NASDAQ. Shares can be bought and sold throughout the trading day like other publicly traded shares. There is no minimum investment. Although shares are generally purchased and sold in “round lots” of 100 shares, brokerage firms typically permit investors to purchase or sell shares in smaller “odd lots” at no per-share price differential. The fund’s shares trade on NASDAQ as follows:

Share prices are reported in dollars and cents per share.

Buying or selling fund shares on an exchange or other secondary market involves two types of costs that may apply to all securities transactions. When buying or selling shares of the fund through a broker, you may incur a brokerage commission and other charges. The commission is frequently a fixed amount and may be a significant proportional cost for investors seeking to buy or sell small amounts of shares. In addition, you may incur the cost of the “spread,” that is, any difference between the bid price and the ask price. The spread varies over time for shares of the fund based on the fund’s trading volume and market liquidity, and is generally lower if the fund has high trading volume and market liquidity, and higher if the fund has little trading volume and market liquidity (which is often the case for funds that are newly launched or small in size). The fund’s spread may also be impacted by the liquidity of the underlying securities held by the fund, particularly for newly launched or smaller funds or in instances of significant volatility of the underlying securities.

Authorized Participants may acquire shares directly from the fund and may tender their shares for redemption directly to the fund, at NAV per share only in Creation Units.

The fund’s primary listing exchange is NASDAQ. NASDAQ is open for trading Monday through Friday and is closed on weekends and the following holidays: New Year’s Day, Martin Luther King, Jr. Day, Presidents’ Day, Good Friday, Memorial Day, Independence Day, Labor Day, Thanksgiving Day and Christmas Day.

Section 12(d)(1) of the 1940 Act restricts investments by investment companies in the securities of other investment companies. Registered investment companies are permitted to invest in the fund beyond the limits set forth in Section 12(d)(1), subject to certain terms and conditions set forth in SEC rules or in an SEC exemptive order issued to the fund. In order for a registered investment company to invest in shares of the fund beyond the limitations of Section 12(d)(1) pursuant to the exemptive relief obtained by the fund, the registered investment company (outside the Legg Mason fund family) must enter into an agreement with the fund.

Frequent purchases and redemptions of fund shares

The Board has evaluated the risks of frequent purchases and redemptions of fund shares (“market timing”) activities by the fund’s shareholders. The Board noted that the fund’s shares can only be purchased and redeemed directly from the fund in Creation Units by Authorized Participants and that the vast majority of trading in the fund’s shares occurs on the secondary market. Because the secondary market trades do not involve the fund directly, it is unlikely those trades would cause many of the harmful effects of market timing, including dilution, disruption of portfolio management, increases in the fund’s trading costs and the realization of capital gains.

With respect to trades directly with the fund, to the extent effected in-kind, those trades do not cause any of the harmful effects (as previously noted) that may result from frequent cash trades. To the extent that the fund permits or requires trades to be effected in whole or in part in cash, the Board noted that those trades could result in dilution to the fund and increased transaction costs, which could negatively impact the fund’s ability to achieve its investment objective. However, the Board noted that direct trading by Authorized Participants is critical to ensuring that the fund’s shares trade at or close to NAV. The fund also employs fair valuation pricing to minimize potential dilution from market timing. The fund imposes transaction fees on in-kind purchases and redemptions of fund shares to cover the custodial and other costs incurred by the fund in effecting in-kind trades. These fees may increase if an investor substitutes cash in part or in whole for securities, reflecting the fact that the fund’s trading costs increase in those circumstances. Given this structure, the Board determined that it is not necessary to apply policies and procedures to the fund to detect and deter market timing.

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Shareholder information cont’d

Book entry

Shares are held in book-entry form, which means that no stock certificates are issued. The Depository Trust Company (“DTC”) or its nominee is the record owner of all outstanding shares of the fund and is recognized as the owner of all shares for all purposes.

Investors owning shares are beneficial owners as shown on the records of DTC or its participants. DTC serves as the securities depository for all shares. Participants in DTC include securities brokers and dealers, banks, trust companies, clearing corporations and other institutions that directly or indirectly maintain a custodial relationship with DTC. As a beneficial owner of shares, you are not entitled to receive physical delivery of stock certificates or to have shares registered in your name, and you are not considered a registered owner of shares. Therefore, to exercise any right as an owner of shares, you must rely upon the procedures of DTC and its participants. These procedures are the same as those that apply to any other stocks that you hold in book entry or “street name” form.

Fund share trading prices

The trading prices of the fund’s shares in the secondary market generally differ from the fund’s daily NAV and are affected by market forces such as the supply of and demand for ETF shares and underlying securities held by the fund, economic conditions and other factors. Information regarding the intraday value of shares of the fund, also known as the “intra-day indicative value” (“IIV”), is disseminated every 15 seconds throughout each trading day by the national securities exchange on which the fund’s shares are listed or by market data vendors or other information providers. The IIV is based on the current market value of the securities and/or cash required to be deposited in exchange for a Creation Unit but does not include a reduction for the fees, operating expenses or transaction costs incurred by the fund. The IIV does not necessarily reflect the precise composition of the current portfolio of securities held by the fund at a particular point in time or the best possible valuation of the current portfolio. Therefore, the IIV should not be viewed as a “real-time” update of the fund’s NAV, which is computed only once a day. The IIV is generally determined by using both current market quotations and/or price quotations obtained from broker-dealers and other market intermediaries that may trade in the portfolio securities held by the fund. The quotations of certain fund holdings may not be updated during U.S. trading hours if such holdings do not trade in the United States and thus may not reflect the current fair value of those securities. The fund is not involved in, or responsible for, the calculation or dissemination of the IIV nor makes any representation or warranty as to its accuracy.

Calculation of net asset value

The fund’s NAV per share is the value of its assets minus its liabilities divided by the number of shares outstanding.

The fund calculates its NAV every day the New York Stock Exchange (the “NYSE”) is open. The fund generally values its securities and other assets and calculates its NAV as of the scheduled close of regular trading on the NYSE, normally at 4:00 p.m. (Eastern time). If the NYSE closes at a time other than the scheduled closing time, the fund will calculate its NAV as of the scheduled closing time. The NYSE is closed on certain holidays listed in the SAI.

Valuation of the fund’s securities and other assets is performed in accordance with procedures approved by the Board. These procedures delegate most valuation functions to the manager, which generally, uses independent third party pricing services approved by the Board. Under the procedures, assets are valued as follows:

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Many factors may influence the price at which the fund could sell any particular portfolio investment. The sales price may well differ—higher or lower—from the fund’s last valuation, and such differences could be significant, particularly for securities that trade in relatively thin markets and/or markets that experience extreme volatility. Moreover, valuing securities using fair value methodologies involves greater reliance on judgment than valuing securities based on market quotations. A fund that uses fair value methodologies may value those securities higher or lower than another fund using market quotations or its own fair value methodologies to price the same securities. There can be no assurance that the fund could obtain the value assigned to a security if it were to sell the security at approximately the time at which the fund determines its NAV.

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Dividends, other distributions and taxes

Dividends and other distributions

The fund pays dividends from any net investment income monthly. Shares will generally begin to earn dividends on the settlement date of purchase. The fund generally distributes capital gain, if any, once a year, typically in December. The fund may pay additional distributions and dividends in order to avoid a federal tax.

Dividends and other distributions on shares of the fund are distributed on a pro rata basis to beneficial owners of such shares. Dividend payments are made through DTC participants and indirect participants to beneficial owners then of record with proceeds received from the fund.

The Board reserves the right to revise the dividend policy or postpone the payment of dividends if warranted in the Board’s judgment due to unusual circumstances.

Reinvestment of distributions

Distributions are paid by the fund in cash. No dividend reinvestment service is provided by the fund. Broker-dealers may make available the DTC book-entry Dividend Reinvestment Service for use by beneficial owners of the fund for reinvestment of their dividend distributions. Beneficial owners should contact their broker to determine the availability and costs of the service and the details of participation therein. Brokers may require beneficial owners to adhere to specific procedures and timetables. If this service is available and used, dividend distributions of both income and realized gains will be automatically reinvested in additional whole shares of the fund purchased in the secondary market.

Taxes

The following discussion is very general, applies only to shareholders who are U.S. persons, and does not address shareholders subject to special rules, such as those who hold fund shares through an IRA, 401(k) plan or other tax-advantaged account. Except as specifically noted, the discussion is limited to federal income tax matters, and does not address state, local, foreign or non-income taxes. Further information regarding taxes, including certain federal income tax considerations relevant to non-U.S. persons, is included in the SAI. Because each shareholder’s circumstances are different and special tax rules may apply, you should consult your tax adviser about federal, state, local and/or foreign tax considerations that may be relevant to your particular situation.

Taxes on distributions

In general, dividends and distributions are all taxable events. Distributions of investment income that the fund reports as “qualified dividend income” may be eligible to be taxed to noncorporate shareholders at the reduced rates applicable to long-term capital gain if certain requirements are satisfied. Distributions of net capital gain reported by the fund as capital gain dividends are taxable to you as long-term capital gain regardless of how long you have owned your shares. Noncorporate shareholders ordinarily pay tax at reduced rates on long-term capital gain. Substitute payments received on fund shares that are lent out will be ineligible for being reported as qualified dividend income and for other potentially beneficial tax treatment.

You may want to avoid buying shares when the fund is about to declare a dividend or capital gain distribution because it will be taxable to you even though it may economically represent a return of a portion of your investment.

A Medicare contribution tax is imposed at the rate of 3.8% on the net investment income of U.S. individuals with income exceeding specified thresholds, and on undistributed net investment income of certain estates and trusts. Net investment income generally includes for this purpose dividends and capital gain distributions paid by the fund and gain on the redemption or exchange of fund shares.

A dividend declared by the fund in October, November or December and paid during January of the following year will, in certain circumstances, be treated as paid in December for tax purposes.

Interest received by the fund with respect to non-U.S. securities may give rise to withholding and other taxes imposed by non-U.S. countries. Tax conventions between certain countries and the U.S. may reduce or eliminate such taxes. If more than 50% of the total assets of the fund at the close of a year consists of securities of non-U.S. corporations, the fund may “pass through” to you certain non-U.S. income taxes (including withholding taxes) paid by the fund. This means that you would be considered to have received as an additional dividend your share of such non-U.S. taxes, but you may be entitled to either a corresponding tax deduction in calculating your U.S. federal taxable income, or, subject to certain limitations, a credit in calculating your U.S. federal income tax.

If you are neither a resident nor a citizen of the United States or if you are a non-U.S. entity, the fund’s ordinary income dividends (which include distributions of net short-term capital gains) will generally be subject to a 30% U.S. federal withholding tax, unless a lower treaty rate applies.

A 30% withholding tax is currently imposed on U.S.-source dividends, interest and other income items and will be imposed on proceeds from the sale of property producing U.S.-source dividends and interest paid after December 31, 2018, to (i) foreign financial institutions, including non-U.S. investment funds, unless they agree to collect and disclose to the U.S. Internal Revenue Service (“IRS”) information regarding their direct and

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indirect U.S. account holders and (ii) certain other foreign entities, unless they certify certain information regarding their direct and indirect U.S. owners. To avoid withholding, foreign financial institutions will need to (i) enter into agreements with the IRS that state that they will provide the IRS information, including the names, addresses and taxpayer identification numbers of direct and indirect U.S. account holders; comply with due diligence procedures with respect to the identification of U.S. accounts; report to the IRS certain information with respect to U.S. accounts maintained, agree to withhold tax on certain payments made to non-compliant foreign financial institutions or to account holders who fail to provide the required information; and determine certain other information concerning their account holders, or (ii) in the event that an applicable intergovernmental agreement and implementing legislation are adopted, provide local revenue authorities with similar account holder information. Other foreign entities may need to report the name, address, and taxpayer identification number of each substantial U.S. owner or provide certifications of no substantial U.S. ownership, unless certain exceptions apply.

If you are a resident or a citizen of the United States, by law, back-up withholding will apply to your distributions and proceeds if you have not provided a taxpayer identification number or social security number and made other required certifications.

Taxes when shares are sold

Capital gain or loss realized upon a sale of fund shares is generally treated as a long-term gain or loss if the shares have been held for more than one year. Any capital gain or loss realized upon a sale of fund shares held for one year or less is generally treated as short-term gain or loss, except that any capital loss on the sale of shares held for six months or less is treated as long-term capital loss to the extent that capital gain dividends were paid with respect to such shares. Any such capital gains, including from sales of fund shares or from capital gain dividends, are included in “net investment income” for purposes of the 3.8% U.S. federal Medicare contribution tax mentioned above.

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Creations and redemptions

Prior to trading in the secondary market, shares of the fund are “created” at NAV by market makers, large investors and institutions only in block-size Creation Units or multiples thereof. The following table sets forth the number of shares of the fund that constitute a Creation Unit:

Each “creator” or “Authorized Participant” enters into an authorized participant agreement with LMIS, the fund’s distributor. Only an Authorized Participant may create or redeem Creation Units directly with the fund.

The fund generally only accepts cash to purchase Creation Units. The purchaser must transfer cash in an amount equal to the value of the Creation Unit(s) purchased and the applicable transaction fee. However, a creation transaction, which is subject to acceptance by LMIS, may also take place when an Authorized Participant deposits into the fund a designated portfolio of securities (including any portion of such securities for which cash may be substituted) and a specified amount of cash approximating the holdings of the fund in exchange for a specified number of Creation Units (a “Creation Basket”). Except in limited circumstances, the composition of such portfolio will correspond pro rata to the positions in the fund’s portfolio.

Redemption proceeds will generally be paid in cash. However, shares may also be redeemed in Creation Units for a designated portfolio of securities (including any portion of such securities for which cash may be substituted) held by the fund (“Fund Securities”) and a specified amount of cash. Except in limited circumstances, the composition of such portfolio will correspond pro rata to the positions in the fund’s portfolio. Except when aggregated in Creation Units, shares are not redeemable by the fund.

The prices at which creations and redemptions occur are based on the next calculation of NAV after a creation or redemption order is received in an acceptable form under the authorized participant agreement.

In the event of a system failure or other interruption, including disruptions at market makers or Authorized Participants, orders to purchase or redeem Creation Units either may not be executed according to the fund’s instructions or may not be executed at all, or the fund may not be able to place or change orders.

To the extent the fund engages in in-kind transactions, the fund intends to comply with the U.S. federal securities laws in accepting securities for deposit and satisfying redemptions with redemption securities by, among other means, assuring that any securities accepted for deposit and any securities used to satisfy redemption requests will be sold in transactions that would be exempt from registration under the Securities Act of 1933 (the “1933 Act”). Further, an Authorized Participant that is not a “qualified institutional buyer,” as such term is defined in Rule 144A under the 1933 Act, will not be able to receive restricted securities eligible for resale under Rule 144A.

Information about the procedures regarding creation and redemption of Creation Units (including the cut-off times for receipt of creation and redemption orders) is included in the fund’s SAI.

Because new shares may be created and issued on an ongoing basis, at any point during the life of the fund a “distribution,” as such term is used in the 1933 Act, may be occurring. Broker-dealers and other persons are cautioned that some activities on their part may, depending on the circumstances, result in their being deemed participants in a distribution in a manner that could render them statutory underwriters subject to the prospectus delivery and liability provisions of the 1933 Act. Any determination of whether one is an underwriter must take into account all the relevant facts and circumstances of each particular case.

Broker-dealers should also note that dealers who are not “underwriters” but are participating in a distribution (as contrasted to ordinary secondary transactions), and thus dealing with shares that are part of an “unsold allotment” within the meaning of Section 4(a)(3)(C) of the 1933 Act, would be unable to take advantage of the prospectus delivery exemption provided by Section 4(a)(3) of the 1933 Act. For delivery of prospectuses to exchange members, the prospectus delivery mechanism of Rule 153 under the 1933 Act is available only with respect to transactions on a national securities exchange.

Costs associated with creations and redemptions. Authorized Participants are charged standard creation and redemption transaction fees to offset transfer and other transaction costs associated with the issuance and redemption of Creation Units. The standard creation and redemption transaction fees are set forth in the table below. The standard creation transaction fee is charged to the Authorized Participant on the day such Authorized Participant creates a Creation Unit, and is the same regardless of the number of Creation Units purchased by the Authorized Participant on the applicable business day. Similarly, the standard redemption transaction fee is charged to the Authorized Participant on the day such Authorized Participant redeems a Creation Unit, and is the same regardless of the number of Creation Units redeemed by the Authorized Participant on the applicable business day. Creations and redemptions for cash (when cash creations and redemptions (in whole or in part) are available or specified) are also subject to an additional charge (up to the maximum amounts shown in the table below). This charge is intended to compensate for brokerage, tax, foreign exchange, execution, market impact and other costs and expenses related to cash transactions. Investors who use the services of a broker or other financial intermediary to acquire or dispose of fund shares may pay fees for such services.

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The following table shows, as of July 30, 2018, the approximate value of one Creation Unit of the fund, standard fees and maximum additional charges for creations and redemptions (as described above):

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Financial highlights

As the fund has not commenced operations as of the date of this Prospectus, no financial information is available. The Prospectus will include financial information for the fund once it has issued its first annual report to shareholders that contains audited financial statements.

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Legg Mason Fixed Income

ETFs

Western Asset Total Return ETF

You may visit www.leggmason.com/etfliterature for a free copy of a Prospectus, Statement of Additional Information (“SAI”) or an Annual or Semi-Annual Report.

Shareholder reports Additional information about the fund’s investments will be available in the fund’s Annual and Semi-Annual Reports to shareholders. In the fund’s Annual Report, you will find a discussion of the market conditions and investment strategies that significantly affected the fund’s performance during its last fiscal year.

The fund sends only one report to a household if more than one account has the same last name and same address. Contact your Service Agent or the fund if you do not want this policy to apply to you.

Statement of additional information The SAI provides more detailed information about the fund and is incorporated by reference into (is legally a part of) this Prospectus.

You can make inquiries about the fund or obtain shareholder reports or the SAI (without charge) by contacting your Service Agent, by calling the fund at 1-877-721-1926 or by writing to the fund at 100 First Stamford Place, Attn: Shareholder Services – 5th Floor, Stamford, Connecticut 06902.

Information about the fund (including the SAI) can be reviewed and copied at the SEC’s Public Reference Room in Washington, D.C. Information on the operation of the Public Reference Room may be obtained by calling the SEC at 1-202-551-8090. Reports and other information about the fund are available on the EDGAR Database on the SEC’s Internet site at http://www.sec.gov . Copies of this information may be obtained for a duplicating fee by electronic request at the following E-mail address: publicinfo@sec.gov , or by writing the SEC’s Public Reference Room, Washington, D.C. 20549-1520.

If someone makes a statement about the fund that is not in this Prospectus, you should not rely upon that information. Neither the fund nor the distributor is offering to sell shares of the fund to any person to whom the fund may not lawfully sell its shares.

(Investment Company Act

file no. 811-23096)

ETFF411564ST [    ]/18

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The information in this Statement of Additional Information is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This Statement of Additional Information is not an offer to sell these securities and is not soliciting an offer to buy these securities in any state where the offer or sale is not permitted.

Subject to completion, [    ], 2018

[            ], 2018

LEGG MASON ETF INVESTMENT TRUST

WESTERN ASSET TOTAL RETURN ETF

NASDAQ (Ticker Symbol): WBND

620 Eighth Avenue

New York, New York 10018

1-877-721-1926