Management

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

Subadviser: Royce & Associates, LP

Portfolio managers : George Necakov, CFA, has been the Portfolio Manager of the fund since its inception. Michael Connors has been the Assistant Portfolio Manager of the fund since its inception.

Purchase and sale of fund shares

The fund is an 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 net asset value, shares may trade at a price greater than net asset value (a premium) or less than net asset value (a discount). The fund will only issue or redeem shares that have been aggregated into blocks of 50,000 shares or multiples thereof (“Creation Units”) to Authorized Participants who have entered into agreements with the fund’s distributor. The fund generally will issue or redeem Creation Units in return for a designated portfolio of securities (and an amount of 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 exchange-traded fund (“ETF”), and the 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 NAV.

ETFs are funds that trade like other publicly traded securities. The fund is designed to track an index. Similar to shares of an index mutual fund, each share of the fund represents an ownership interest in an underlying portfolio of securities intended to track a market index. Unlike shares of a mutual fund, which can be bought and redeemed from the issuing fund by all shareholders at a price based on net asset value, shares of the fund may be purchased or redeemed directly from the fund at net asset value 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.

An index is a financial calculation, based on a grouping of financial instruments, that is not an investment product, while the fund is an actual investment portfolio. The performance of the fund and its Underlying Index may vary for a number of reasons, including transaction costs, non-U.S. currency valuations, asset valuations, corporate actions (such as mergers and spin-offs), timing variances and differences between the fund’s portfolio and its Underlying Index resulting from the fund’s use of representative sampling or from legal restrictions (such as diversification requirements) that apply to the fund but not to its Underlying Index. “Tracking error” is the divergence of the performance (return) of the fund’s portfolio from that of its Underlying Index. Royce expects that, over time, the fund’s tracking error will not exceed 5%. To the extent the fund uses a representative sampling indexing strategy, it may have a larger tracking error than if it used a replication indexing strategy. “Replication” is an indexing strategy in which the fund invests in substantially all of the securities in its underlying index in approximately the same proportions as in the underlying index.

Investment objective

The fund seeks to track the investment results of an index composed of equity securities of small-capitalization companies that are traded in the United States.

Principal investment strategies

The fund seeks to track the investment results of the Royce Small-Cap Quality Value Index (the “Underlying Index”). The Underlying Index utilizes a proprietary methodology created and sponsored by Royce, the fund’s subadviser. Royce is affiliated with both LMPFA and the fund. The fund will invest at least 80% of its net assets, plus borrowings for investment purposes, if any, in securities that compose its Underlying Index.

The Underlying Index is composed of equity securities that meet certain criteria. Using Royce’s methodology, the Underlying Index will generally favor stocks with lower than average valuation, higher than average profitability, and higher than average debt coverage (i.e. , available cash flow to pay current debt obligations) as compared with other stocks included in the investment universe while maintaining a comparable risk profile.

The investment universe includes common stocks of U.S. headquartered companies listed on U.S. exchanges, and excludes royalty companies, American depository receipts and global depository receipts, master limited partnerships, stocks with a share price less than or equal to $1.00, and stocks deemed by Royce to have insufficient trading volume. The universe is then refined to include stocks with market capitalizations that are between the 1001st and 3000th largest companies based on descending market capitalization at time of rebalance. From that universe, real estate investment trusts (REITs) are excluded.

Underlying Index constituents are selected using Royce’s proprietary, rules-based multi-factor scoring system, with all factors measured by Royce, in order to seek to identify companies which combine favorable attributes of quality and value, as defined by Royce, compared with companies within the same market sector. For quality factors, the Underlying Index focuses on a company’s profitability (as measured by return on invested capital), the historic stability of its profitability (as measured by variance of return on company assets), and debt coverage (as measured by cash flow relative to debt). The debt coverage ratio is used in an attempt to limit Underlying Index exposure to companies that Royce believes may have higher financial risk. For value factors, the Underlying Index focuses on the free cash flow of a company compared to its enterprise value. After the securities are scored by quality and value factors, each security’s momentum score, which is based on the price performance over the most recent 30 days, is used to determine the timing of the addition or deletion of the security into the Underlying Index. Underlying Index position weights are then calculated using a composite score based on company fundamentals that include book value, revenue, free cash flow, and dividends paid. By using fundamental factors to weight stocks rather than market capitalization, the Underlying Index seeks to have lower exposure to overvalued companies, while still maintaining broad diversification. Concentration limits are also implemented in the construction process of the Underlying Index.

As initially constituted and balanced, the Underlying Index is designed to seek to maintain diversification by limiting the weighting of individual constituents as well as sectors. No individual security in the Underlying Index will exceed 3%, and there is no minimum weighting for an individual security and no sector will exceed 25% of the Underlying Index.

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The Underlying Index’s constituents are reconstituted quarterly, on the second Friday of March, June, September, and December. If that day is a New York Stock Exchange (“NYSE”) holiday or the NYSE is closed, however, reconstitution will take place on the next business day. Any changes to or deviations from this methodology ( e.g. , to limit portfolio turnover) are made in the sole judgment and discretion of Royce so that the Underlying Index continues to achieve its objectives. The fund’s securities portfolio is rebalanced when the Underlying Index is reconstituted. The composition of the Underlying Index and the fund after reconstitution and rebalancing may fluctuate and exceed the above Underlying Index limitations due to market movements and other factors. The components of the Underlying Index, and the degree to which these components represent certain sectors and industries, may change over time.

The fund may invest up to 20% of its net assets in cash and cash equivalents; other investment companies, including exchange-traded funds; exchange-traded notes; depository receipts; and in securities and other instruments not included in its Underlying Index but which Royce believes will help the fund track its Underlying Index.

Industry concentration policy. The fund will concentrate its investments ( i.e. , hold 25% or more of its total assets) in a particular industry to approximately the same extent that the Underlying Index is concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities) and repurchase agreements collateralized by U.S. government securities are not considered to be issued by members of any industry.

Important information

The fund’s investment objective may be changed by the Board of Trustees (the “Board”) without shareholder approval and on notice to shareholders.

There is no assurance that the fund will meet its investment objective.

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 the fund’s investments

Cash management

The fund may hold cash pending investment, and may invest in money market instruments for cash management purposes.

Percentage and other limitations

The fund’s compliance with its investment limitations 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.

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 an Underlying Index or 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 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 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, in either of these cases, fund shares may trade at a discount to NAV and possibly face trading halts and/or delisting.

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

Calculation methodology risk. The Underlying Index relies on various sources of information to assess the criteria of issuers, including information that may be based on assumptions and estimates. Neither the fund, LMPFA nor Royce can offer assurances that an Underlying Index’s calculation methodology will accurately assess criteria of included issuers.

Cash management risk. The value of the investments held by the fund for cash management purposes may be affected by changing interest rates and by changes in credit ratings of the investments. If the fund holds cash uninvested it will be subject to the credit risk of the depository institution holding the cash. If a significant amount of the fund’s assets are used for cash management purposes, it may not achieve its investment objective. The fund’s investments in money market instruments will likely cause the fund’s returns to differ from those of the Underlying Index.

Concentration risk. The fund may be susceptible to an increased risk of loss, including losses due to events that affect the fund’s investments more than the market as a whole, to the extent that the fund’s investments are concentrated in the securities of a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class.

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, any subadviser, Authorized Participants, the relevant listing exchange and/or the fund’s service providers (including, but not limited to, fund accountants, custodians, sub-custodians, transfer agents and financial intermediaries) to suffer data breaches, data corruption or lose operational functionality.

Index-related risk. Royce serves as the index administrator for the Underlying Index. Solactive AG serves as the calculation agent for the Underlying Index. The fund seeks to achieve a return which corresponds generally to the price and yield performance, before fees and expenses, of its Underlying Index as published by Solactive AG. There is no assurance that Solactive AG or any agents that may act on its behalf will compile the Underlying Index accurately, or that the Underlying Index will be determined, composed or calculated accurately. Consequently, Royce does not provide any warranty or guarantee against the calculation agent’s or others’ errors. Errors in respect of the quality, accuracy and completeness of the data used to compile each Underlying Index may occur from time to time and may not be identified and corrected by the index administrator for a period of time or at all, particularly where the indices are less commonly used as benchmarks by funds or managers. Therefore, gains, losses or costs associated with errors of the index administrator or its agents will generally be borne by the fund and its shareholders. For example, during a period where the fund’s Underlying Index contains incorrect constituents, the fund would have market exposure to such constituents and would be underexposed to the Underlying Index’s other constituents. Such errors may negatively or positively impact the fund and its shareholders. Any gains due to the index administrator’s or others’ errors will be kept by the fund and its shareholders and any losses resulting from the index administrator’s or others’ errors will be borne by the fund and its shareholders.

If the Underlying Index includes the securities of the listed parent company of the manager or the subadviser or another issuer that is affiliated with the manager or the subadviser, or the securities of an issuer that the fund may not hold for other legal or regulatory reasons, the fund will not be able to purchase that security. The exclusion of such security may cause performance to vary from that of the Underlying Index.

Index sampling risk. The fund may not fully replicate its Underlying Index and may hold securities not included in the Underlying Index. As a result, the fund is subject to the risk that Royce’s investment strategy, the implementation of which is subject to a number of constraints, may not produce the intended results.

Information technology sector risk. Information technology companies face intense competition, both domestically and internationally, which may have an adverse effect on profit margins. Like other technology companies, information technology companies may have limited product lines, markets, financial resources or personnel. The products of information technology companies may face obsolescence due to rapid technological developments, frequent new product introduction, unpredictable changes in growth rates and competition for the services of qualified personnel. Companies in the information technology sector are heavily dependent on patent and intellectual property rights. The loss or impairment of these rights may adversely affect the profitability of these companies.

Issuer risk. The value of a security can be more volatile than the market as a whole and can perform differently from the value of the market as a whole. The value of a company’s securities may deteriorate because of a variety of factors, including disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. The fund may experience a substantial or complete loss on an individual security.

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

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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.

Market events risk. In the past several years financial markets, such as those in the United States, Europe, Asia and elsewhere, 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.

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 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. 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.

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

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.

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 net asset value. The net asset value 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 net asset value. As a result, the trading prices of the fund’s shares may deviate significantly from net asset value during periods of market volatility, including during periods of high 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 NET ASSET VALUE. However, because shares can be created and redeemed in Creation Units at net asset value, Royce believes that large discounts or premiums to the net asset value 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 net asset values). 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 net asset value, exchange prices are not expected to correlate exactly with the fund’s net asset value 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 market participants, or during periods of significant market volatility, may result in trading prices for shares of the fund that differ significantly from its net asset value. 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 net asset value.

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 increased 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 trading in fund shares.

Model risk. The fund, LMPFA, and Royce cannot offer any assurance that the allocation methodology used to determine the components of the Underlying Index will achieve its intended results or maximize returns or minimize risks.

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.

Passive investment risk. The fund uses an indexing strategy. It does not attempt to use defensive strategies or reduce the effects of any long-term periods of poor stock performance. The fund’s expenses, changes in securities markets, changes in the composition of the Underlying Index, and the timing of purchases and redemptions of fund shares may affect the correlation between fund and Underlying Index performance. The fund may not perform as well as other investments if, among other things, the Underlying Index declines or performs poorly relative to other related indexes or individual securities or the securities issued by companies that comprise the Underlying Index fall out of favor with investors. Market disruptions and regulatory restrictions could have an adverse effect on the fund’s ability to adjust its exposure to the required levels in order to track the Underlying Index. The Underlying Index is relatively new and has limited performance history.

Quality stocks risk. The Fund invests in stocks that are deemed by Royce to be of high quality based on a number of factors. There is no guarantee, however, that the past performance of these stocks will continue, and Royce may be unsuccessful in creating an Underlying Index that reflects the quality of individual stocks. Profitability and other measures of a stock’s quality can be adversely affected by market, regulatory, political, environmental and other factors, and the degree to which these factors affect a stock’s performance can be difficult to predict. The price of a stock also may be affected by factors other than those factors considered by Royce.

Redemptions by other funds and by other significant investors risk. Redemptions by other funds and by other significant investors risk. The fund may be an investment option for other Legg Mason, Inc. (“Legg Mason”) 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.

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Risk of investing in the United States. The fund has significant exposure to U.S. issuers. A decrease in imports or exports, changes in trade regulations and/or an economic recession in the United States may have a material adverse effect on the U.S. economy and the securities listed on U.S. exchanges. Policy and legislative changes in the United States are changing many aspects of financial and other regulation and may have a significant effect on the U.S. markets generally, as well as the value of certain securities. In addition, a continued rise in the U.S. public debt level or U.S. austerity measures may adversely affect U.S. economic growth and the securities to which the fund has exposure.

Small capitalization company risk. The fund will be exposed to additional risks as a result of its investments in the securities of small capitalization companies. Small capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small capitalization companies may underperform large capitalization companies and may offer greater potential for losses.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. The value of a particular security may decline due to factors that affect a particular industry or industries, such as an increase in production costs, competitive conditions or labor shortages; or due to general market conditions, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates or generally adverse investor sentiment. If the market prices of the securities owned by the fund fall, the value of your investment in the fund will decline.

Tracking error risk. Tracking error is the divergence of the fund’s performance from that of its Underlying Index. The fund’s portfolio composition and performance may not match, and may vary substantially from, that of the Underlying Index for any period of time, in part because there may be a delay in the fund’s implementation of any changes to the composition of the Underlying Index. Tracking error may also occur because of pricing differences, transaction costs, differences in accrual of distributions, tax gains or losses, or the need to meet new or existing regulatory requirements. Unlike the fund, the returns of an Underlying Index are not reduced by investment and other operating expenses, including the trading costs associated with implementing changes to its portfolio of investments. Tracking error risk may be heightened during times of market volatility or other unusual market conditions. Because the Underlying Index is not subject to the tax diversification requirements to which the fund must adhere, the fund may be required to deviate its investments from the securities and relative weightings of the Underlying Index. For tax efficiency purposes, the fund may sell certain securities to realize losses, which will result in a deviation from the Underlying Index.

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.

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 net asset value. 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.

Value investing risk. The value approach to investing involves the risk that value stocks may remain undervalued. Value stocks as a group may be out of favor and underperform the overall equity market for a long period of time, while the market concentrates on growth stocks. To the extent the Underlying Index is concentrated in a particular industry or industries, like many value funds, the fund’s exposure to factors adversely affecting issuers within those industries would be increased.

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

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

affecting individual securities or sectors may increase the volatility of the fund. 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 the identities and quantities of the fund’s portfolio holdings as of the end of the previous 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.

Tax advantaged product structure

Unlike many conventional mutual funds which are only bought and sold at closing NAVs, the shares of the fund have been designed to be created and redeemed principally in-kind (although under some circumstances its shares are created and redeemed partially for cash) in Creation Units at each day’s market close. These in-kind arrangements are designed to mitigate adverse effects on the fund’s portfolio that could arise from frequent cash purchase and redemption transactions that affect the NAV of the fund. Moreover, in contrast to conventional mutual funds, where frequent redemptions can have an adverse tax impact on taxable shareholders because of the need to sell portfolio securities—which, in turn, may generate taxable gain—the in-kind redemption mechanism of the fund, to the extent used, generally is not expected to lead to a tax event for shareholders whose shares are not being redeemed or sold.

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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 March 31, 2017, LMPFA’s total assets under management were approximately $192.5 billion.

Royce & Associates, LP (“Royce” or the “subadviser”) provides the day-to-day portfolio management of the fund, except for any portion of the fund’s cash and short-term instruments that is allocated to Western Asset Management Company (“Western Asset”). Royce, with offices at 745 Fifth Avenue, New York, NY 10151, has been investing in small- and mid-capitalization securities with a value approach for more than 40 years. As of March 31, 2017, Royce’s total assets under management were approximately $17.8 billion.

Western Asset manages the portion of the fund’s cash and short-term instruments allocated to it. 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 acts as investment adviser to institutional accounts, such as corporate pension plans, mutual funds and endowment funds. As of March 31, 2017, the total assets under management of Western Asset and its supervised affiliates were approximately $426.9 billion.

LMPFA and Western Asset are wholly-owned subsidiaries of Legg Mason, and Royce is a majority-owned subsidiary 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 March 31, 2017, Legg Mason’s asset management operations had aggregate assets under management of approximately $728.4 billion.

Portfolio managers

George Necakov, CFA, has been the Portfolio Manager, and Michael Connors has been the Assistant Portfolio Manager of the fund since its inception.

George Necakov, CFA, is a Portfolio Manager, Principal, and Director of Quantitative Strategies of Royce. Mr. Necakov joined Royce in 1994 and has been involved in portfolio management since 1998. He holds a bachelor’s degree from New York University and is a CFA ^® charterholder.

Michael Connors is an Assistant Portfolio Manager and Director of Portfolio Analytics of Royce. Mr. Connors joined Royce in 2003 and has been involved in quantitative research since 2014. He holds a bachelor’s degree from Mount Saint Mary College and a Masters of Business Administration from Zicklin School of Business—Baruch College.

The SAI provides information about the compensation of the portfolio managers, other accounts managed by the portfolio managers and any fund shares held by the portfolio managers.

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 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 first shareholder report.

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.

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More on fund management cont’d

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: 888-386-5535 or visiting our website at www.leggmason.com.

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 net asset value per share only in Creation Units or Creation Unit aggregations.

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 net asset value. 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 net asset value 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 net asset value, 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 or make any representation or warranty as to its accuracy.

Calculation of net asset value

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

The fund calculates its net asset value every day the New York Stock Exchange (the “NYSE”) is open. The fund generally values its securities and other assets and calculates its net asset value 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 net asset value 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, in turn, 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 a 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 net asset value.

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Dividends, other distributions and taxes

Dividends and other distributions

The fund generally distributes long-term capital gain, if any, once a year, typically in December and at such other times as are necessary.

The fund generally pays dividends, if any, as follows:

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 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

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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 at a 28% rate 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.

A creation transaction, which is subject to acceptance by LMIS, generally takes 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.

Similarly, shares can be redeemed only in Creation Units, generally 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 net asset value 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 June 30, 2017 the approximate value of one Creation Unit of the fund, standard fees and maximum additional charges for creations and redemptions (as described above):

Index

The Underlying Index is created and sponsored by Royce, the fund’s subadviser and an affiliated person of the manager and the fund. The Underlying Index is the exclusive property of Royce. The Trust has entered into a license agreement with Royce to use the Underlying Index at no charge. Royce has retained Solactive AG, an unaffiliated third party, to calculate the Underlying Index. Solactive AG publishes information regarding the market value of the Underlying Index.

Disclaimers

The fund is not sponsored, promoted, sold or supported in any other manner by Solactive AG nor does Solactive AG offer any express or implicit guarantee or assurance either with regard to the results of using the Underlying Index and/or Underlying Index trade marks or the Underlying Index Price at any time or in any other respect. The Underlying Index is calculated and published by Solactive AG. Solactive AG uses its best efforts to ensure that the Underlying Index is calculated correctly. Irrespective of its obligations towards the fund, Solactive AG has no obligation to point out errors in the Underlying Index to third parties including but not limited to investors and/or financial intermediaries of the fund. Neither publication of the Underlying Index by Solactive AG nor the licensing of the Underlying Index or Underlying Index trade marks for the purpose of use in connection with the fund constitutes a recommendation by Solactive AG to invest capital in the fund nor does it in any way represent an assurance or opinion of Solactive AG with regard to any investment in the fund.

Royce does not guarantee the accuracy and/or the completeness of the Underlying Index or any data included therein, and Royce shall not have any liability for any errors, omissions or interruptions therein. Royce makes no warranty, express or implied, as to results to be obtained by the fund, owners of the shares of the fund or any other person or entity from the use of the Underlying Index or any data included therein, either in connection with the fund or for any other use. Royce makes no express or implied warranties, and expressly disclaims all warranties of merchantability or fitness for a particular purpose or use with respect to the Underlying Index or any data included therein. Without limiting any of the foregoing, in no event shall Royce have any liability for any special, punitive, direct, indirect or consequential damages (including lost profits) arising out of matters relating to the use of the Underlying Index, even if notified of the possibility of such damages.

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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 contain audited financial statements.

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Legg Mason Equity

ETFs

Legg Mason Small-Cap Quality Value 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 the broker-dealer through which you hold your shares 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 calling the fund at 888-386-5535 or by writing to the fund at www.leggmason.com .

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)

ETFF387009ST 07/17

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July 11, 2017

LEGG MASON ETF INVESTMENT TRUST

LEGG MASON SMALL-CAP QUALITY VALUE ETF (“Small-Cap Quality Value ETF”)

NASDAQ (Ticker Symbol): SQLV

620 Eighth Avenue

New York, New York 10018

1-888-386-5535