Mutual Fund Summary Prospectus (497k)

Rule 497(k)

File No. 333-176976

First Trust Exchange-Traded Fund III

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SUMMARY PROSPECTUS

First Trust Merger Arbitrage ETF

Ticker Symbol:	MARB
Exchange:	NYSE Arca, Inc.

Before you invest, you may want to review the Fund’s prospectus, which contains more information about the Fund and its risks. You can find the Fund’s statutory prospectus and other information about the Fund, including the statement of additional information and most recent reports to shareholders, online at www.ftportfolios.com/retail/ETF/ETFfundnews.aspx?Ticker=MARB.  You can also get this information at no cost by calling [phone] or by sending an e-mail request to [e-mail].  The Fund’s  prospectus and statement of additional information, both dated February 3, 2020, are all incorporated by reference into this Summary Prospectus.

February 5, 2020

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Investment Objective

The First Trust Merger Arbitrage ETF's (the "Fund") investment objective is to seek to provide investors with capital appreciation.

Fees and Expenses of the Fund

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees
(fees paid directly from your investment)

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)

None

    

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

Management Fees	1.25%
Distribution and Service (12b-1) Fees	0.00%
Other Expenses(1)	0.69%
Total Annual Fund Operating Expenses	1.94%

(1)	“Other Expenses” is an estimate based on the expenses the Fund expects to incur for the current fiscal year.

Example

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain at current levels. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

1 Year	3 Years
$197	$609

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance.

Principal Investment Strategies

Under normal market conditions, the Fund seeks to achieve its investment objective by establishing long and short positions in the equity securities of companies that are involved in a publicly-announced significant corporate event, such as a merger or acquisition. The Fund’s portfolio may include equity securities issued by U.S. and non-U.S. companies, including American Depositary Receipts (“ADRs”), and derivatives, including total return swaps. The Fund may invest in securities issued by small, mid and large capitalization issuers.

The Fund’s investment sub-advisor, Vivaldi Asset Management, LLC (“Vivaldi” or the “Sub-Advisor”), generally seeks to take advantage of the return opportunity presented by the natural deal spread that emerges after the announcement of a merger or acquisition by purchasing the stock of the company being acquired (the “target company”), while shorting the stock of the company acquiring the target company’s stock (the “acquiring company”). The profit which may be realized is the “spread,” or difference in price between the trading price of the target company’s stock following the announcement of the corporate event and the contractual price to be paid for the target company stock in the future when the transaction closes. Such a spread typically exists due to the uncertainty regarding whether the announced merger, acquisition or other corporate event will close, and if it closes, that such transaction will be at the initially proposed economic terms. Only the securities of companies involved in publicly-announced transactions are eligible for inclusion in the Fund’s portfolio. Merger arbitrage, when executed well, has the potential to produce a differentiated and robust absolute return stream.

In deciding upon which opportunities to invest in, the Sub-Advisor assesses a number of factors, including, but not limited to, the probability that the merger will be completed, the attractiveness of a transaction relative to others in the arbitrage universe, and any unique risks which may decrease the likelihood that a transaction will close. Every transaction has its unique set of elements, and the

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Sub-Advisor’s investment process relies on real-time quantitative-based research to evaluate how attractive each transaction is relative to other deals in the arbitrage universe. The Fund adheres to that quantitative criteria to separate which deals to invest in and which to avoid. In the event that the Sub-Advisor cannot find enough securities that satisfy its investment criteria, the Fund may hold a significant amount of cash or cash equivalents.

The Sub-Advisor intends to engage in short selling. Short selling is a technique that allows an investor (such as the Fund) to profit from the falling price of a security. It involves selling a security that has been borrowed from a third-party with the intention of buying an identical security back at a later date to return to that third-party. The Fund’s short positions may be significant, however, the Fund will at all times comply with the regulatory requirements of the Securities and Exchange Commission with respect to coverage of the Fund’s short positions. The Fund intends to invest the proceeds from a sale of a borrowed security in cash or cash equivalents, including money market funds. The Fund’s investment strategy may include active and frequent trading.

The Fund is classified as “non-diversified” under the Investment Company Act of 1940, as amended (the “1940 Act”).

Principal Risks

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund’s investment objective will be achieved. The order of the below risk factors does not indicate the significance of any particular risk factor.

AUTHORIZED PARTICIPANT CONCENTRATION RISK. Only an authorized participant may engage in creation or redemption transactions directly with the Fund. A limited number of institutions act as authorized participants for the Fund. To the extent that these institutions exit the business or are unable to proceed with creation and/or redemption orders and no other authorized participant steps forward to create or redeem, the Fund’s shares may trade at a premium or discount to the Fund’s net asset value and possibly face delisting.

COUNTERPARTY RISK. Fund transactions involving a counterparty are subject to the risk that the counterparty will not fulfill its obligation to the Fund. Counterparty risk may arise because of the counterparty’s financial condition (i.e., financial difficulties, bankruptcy, or insolvency), market activities and developments, or other reasons, whether foreseen or not. A counterparty’s inability to fulfill its obligation may result in significant financial loss to the Fund. The Fund may be unable to recover its investment from the counterparty or may obtain a limited recovery, and/or recovery may be delayed.

CURRENCY RISK. Changes in currency exchange rates affect the value of investments denominated in a foreign currency, and therefore the value of such investments in the Fund’s portfolio. The Fund’s net asset value could decline if a currency to which the Fund has exposure depreciates against the U.S. dollar or if there are delays or limits on repatriation of such currency. Currency exchange rates can be very volatile and can change quickly and unpredictably. As a result, the value of an investment in the Fund may change quickly and without warning.

CYBER SECURITY RISK. The Fund is susceptible to operational risks through breaches in cyber security. A breach in cyber security refers to both intentional and unintentional events that may cause the Fund to lose proprietary information, suffer data corruption or lose operational capacity. Such events could cause the Fund to incur regulatory penalties, reputational damage, additional compliance costs associated with corrective measures and/or financial loss. Cyber security breaches may involve unauthorized access to the Fund’s digital information systems through “hacking” or malicious software coding but may also result from outside attacks such as denial-of-service attacks through efforts to make network services unavailable to intended users. In addition, cyber security breaches of the issuers of securities in which the Fund invests or the Fund’s third-party service providers, such as its administrator, transfer agent, custodian, or sub-advisor, as applicable, can also subject the Fund to many of the same risks associated with direct cyber security breaches. Although the Fund has established risk management systems designed to reduce the risks associated with cyber security, there is no guarantee that such efforts will succeed, especially because the Fund does not directly control the cyber security systems of issuers or third-party service providers.

DEPOSITARY RECEIPTS RISK. Depositary receipts may be less liquid than the underlying shares in their primary trading market. Any distributions paid to the holders of depositary receipts are usually subject to a fee charged by the depositary. Holders of depositary receipts may have limited voting rights, and investment restrictions in certain countries may adversely impact the value of depositary receipts because such restrictions may limit the ability to convert the equity shares into depositary receipts and vice versa. Such restrictions may cause the equity shares of the underlying issuer to trade at a discount or premium to the market price of the depositary receipts.

DERIVATIVES RISK. The use of derivative instruments involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other traditional investments. These risks include: (i) the risk that the counterparty to a derivative transaction may not fulfill its contractual obligations; (ii) risk of mispricing or improper valuation; and (iii) the risk that changes in the value of the derivative may not correlate perfectly with the underlying asset. Derivative prices are highly volatile and may fluctuate substantially during a short period of time. Such prices are influenced by numerous factors that affect the markets, including, but not limited to: changing supply and demand relationships; government programs and policies; national and international political and economic events, changes in interest rates, inflation and deflation and changes in supply and demand relationships. Trading derivative

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instruments involves risks different from, or possibly greater than, the risks associated with investing directly in securities. Derivative contracts ordinarily have leverage inherent in their terms. The low margin deposits normally required in trading derivatives, including futures contracts, permit a high degree of leverage. Accordingly, a relatively small price movement may result in an immediate and substantial loss. The use of leverage may also cause the Fund to liquidate portfolio positions when it would not be advantageous to do so in order to satisfy its obligations or to meet collateral segregation requirements. The use of leveraged derivatives can magnify potential for gain or loss and, therefore, amplify the effects of market volatility on share price.

EQUITY SECURITIES RISK. The value of the Fund’s shares will fluctuate with changes in the value of the equity securities in which it invests. Equity securities prices fluctuate for several reasons, including changes in investors’ perceptions of the financial condition of an issuer or the general condition of the relevant equity market, such as market volatility, or when political or economic events affecting an issuer occur. Common stock prices may be particularly sensitive to rising interest rates, as the cost of capital rises and borrowing costs increase. Equity securities may decline significantly in price over short or extended periods of time, and such declines may occur in the equity market as a whole, or they may occur in only a particular country, company, industry or sector of the market.

INDEX CONSTITUENT RISK. The Fund may be a constituent of one or more indices. As a result, the Fund may be included in one or more index-tracking exchange-traded funds or mutual funds. Being a component security of such a vehicle could greatly affect the trading activity involving the Fund’s shares, the size of the Fund and the market volatility of the Fund. Inclusion in an index could increase demand for the Fund and removal from an index could result in outsized selling activity in a relatively short period of time. As a result, the Fund’s net asset value could be negatively impacted and the Fund’s market price may be below the Fund’s net asset value during certain periods. In addition, index rebalances may potentially result in increased trading activity in the Fund’s shares.

LEVERAGE RISK. Leverage may result in losses that exceed the amount originally invested and may accelerate the rates of losses. Leverage tends to magnify, sometimes significantly, the effect of any increase or decrease in the Fund’s exposure to an asset or class of assets and may cause the value of the Fund’s shares to be volatile and sensitive to market swings.

LIQUIDITY RISK. The Fund may hold certain investments that may be subject to restrictions on resale, trade over-the-counter or in limited volume, or lack an active trading market. Accordingly, the Fund may not be able to sell or close out of such investments at favorable times or prices (or at all), or at the prices approximating those at which the Fund currently values them. Illiquid securities may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value.

MANAGEMENT RISK. The Fund is subject to management risk because it is an actively managed portfolio. In managing the Fund’s investment portfolio, the portfolio managers will apply investment techniques and risk analyses that may not produce the desired result. There can be no guarantee that the Fund will meet its investment objective.

MARKET MAKER RISK. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares due to a limited number of market markers. Decisions by market makers or authorized participants to reduce their role or step away from these activities in times of market stress could inhibit the effectiveness of the arbitrage process in maintaining the relationship between the underlying values of the Fund’s portfolio securities and the Fund’s market price. The Fund may rely on a small number of third-party market makers to provide a market for the purchase and sale of shares. Any trading halt or other problem relating to the trading activity of these market makers could result in a dramatic change in the spread between the Fund’s net asset value and the price at which the Fund’s shares are trading on the Exchange, which could result in a decrease in value of the Fund’s shares. This reduced effectiveness could result in Fund shares trading at a discount to net asset value and also in greater than normal intraday bid-ask spreads for Fund shares.

MARKET RISK. Market risk is the risk that a particular security, or shares of the Fund in general, may fall in value. Securities are subject to market fluctuations caused by such factors as economic, political, regulatory or market developments, changes in interest rates and perceived trends in securities prices. Shares of the Fund could decline in value or underperform other investments.

MERGER ARBITRAGE RISK. Investments in companies that are the subject of a publicly-announced transaction carry the risk the transaction is renegotiated, takes longer to complete than originally planned and that the transaction is never completed. Any such event could cause the Fund to incur a loss. In the case of an investment in a potential target company, if the proposed transaction appears likely not to be consummated, in fact is not consummated, or is delayed, the market price of the security will usually decline sharply, resulting in a loss to the Fund. The risk/reward payout of merger arbitrage strategies typically is asymmetric, with the losses in failed transactions often far exceeding the gains in successful transactions.

MONEY MARKET/SHORT-TERM SECURITIES RISK. To the extent the Fund holds cash or invests in money market or short-term securities, the Fund may be less likely to achieve its investment objective. In addition, it is possible that the Fund’s investments in these instruments could lose money.

NEW FUND RISK. As of the date of this prospectus, the Fund has no operating history and currently has fewer assets than larger funds. Like other new funds, large inflows and outflows may impact the Fund’s market exposure for limited periods of time. This impact may be positive or negative, depending on the direction of market movement during the period affected.

NON-DIVERSIFICATION RISK. The Fund is classified as “non-diversified” under the 1940 Act. As a result, the Fund is only limited as to the percentage of its assets which may be invested in the securities of any one issuer by the diversification requirements imposed

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by the Internal Revenue Code of 1986, as amended. The Fund may invest a relatively high percentage of its assets in a limited number of issuers. As a result, the Fund may be more susceptible to a single adverse economic or regulatory occurrence affecting one or more of these issuers, experience increased volatility and be highly invested in certain issuers.

NON-U.S. SECURITIES RISK. Non-U.S. securities are subject to higher volatility than securities of domestic issuers due to possible adverse political, social or economic developments, restrictions on foreign investment or exchange of securities, capital controls, lack of liquidity, currency exchange rates, excessive taxation, government seizure of assets, the imposition of sanctions by foreign governments, different legal or accounting standards, and less government supervision and regulation of securities exchanges in foreign countries.

PORTFOLIO TURNOVER RISK. High portfolio turnover may result in the Fund paying higher levels of transaction costs and may generate greater tax liabilities for shareholders. Portfolio turnover risk may cause the Fund’s performance to be less than expected.

PREMIUM/DISCOUNT RISK. The market price of the Fund’s shares will generally fluctuate in accordance with changes in the Fund’s net asset value as well as the relative supply of and demand for shares on the Exchange. The Fund’s investment advisor cannot predict whether shares will trade below, at or above their net asset value because the shares trade on the Exchange at market prices and not at net asset value. Price differences may be due, in large part, to the fact that supply and demand forces at work in the secondary trading market for shares will be closely related, but not identical, to the same forces influencing the prices of the holdings of the Fund trading individually or in the aggregate at any point in time. However, given that shares can only be purchased and redeemed in Creation Units, and only to and from broker-dealers and large institutional investors that have entered into participation agreements (unlike shares of closed-end funds, which frequently trade at appreciable discounts from, and sometimes at premiums to, their net asset value), the Fund’s investment advisor believes that large discounts or premiums to the net asset value of shares should not be sustained.

SHORT SALES RISK. In connection with a short sale of a security or other instrument, the Fund is subject to the risk that instead of declining, the price of the security or other instrument sold short will rise. If the price of the security or other instrument sold short increases between the date of the short sale and the date on which the Fund replaces the security or other instrument borrowed to make the short sale, the Fund will experience a loss, which is theoretically unlimited since there is a theoretically unlimited potential for the market price of a security or other instrument sold short to increase. In addition, as a series of an investment company registered under the 1940 Act, the Fund must segregate liquid assets, or engage in other measures to “cover” open positions with respect to short sales. The Fund may nonetheless incur significant losses on short sales even if they are covered.

SIGNIFICANT EXPOSURE RISK. To the extent that the Fund invests a large percentage of its assets in a single asset class or the securities of issuers within the same country, state, region, industry or sector, an adverse economic, business or political development may affect the value of the Fund’s investments more than if the Fund were more broadly diversified. A significant exposure makes the Fund more susceptible to any single occurrence and may subject the Fund to greater market risk than a fund that is more broadly diversified.

SMALLER COMPANIES RISK. Small and/or mid capitalization companies may be more vulnerable to adverse general market or economic developments, and their securities may be less liquid and may experience greater price volatility than larger, more established companies as a result of several factors, including limited trading volumes, fewer products or financial resources, management inexperience and less publicly available information. Accordingly, such companies are generally subject to greater market risk than larger, more established companies.

SWAP AGREEMENTS RISK. Swap agreements may involve greater risks than direct investment in securities as they may be leveraged and are subject to credit risk, counterparty risk and valuation risk. A swap agreement could result in losses if the underlying reference or asset does not perform as anticipated. In addition, many swaps trade over-the-counter and may be considered illiquid. It may not be possible for a Fund to liquidate a swap position at an advantageous time or price, which may result in significant losses.

TRADING ISSUES RISK. Although the shares of the Fund are listed for trading on the Exchange, there can be no assurance that an active trading market for such shares will develop or be maintained. Further, secondary markets may be subject to irregular trading activity and wide bid-ask spreads (which may be especially pronounced for smaller funds). Trading in shares on the Exchange may be halted due to market conditions or for reasons that, in the view of the Exchange, make trading in shares inadvisable. In addition, trading in shares on the Exchange is subject to trading halts caused by extraordinary market volatility pursuant to the Exchange’s “circuit breaker” rules. Market makers are under no obligation to make a market in the Fund’s shares, and authorized participants are not obligated to submit purchase or redemption orders for Creation Units. In the event market makers cease making a market in the Fund's shares or authorized participants stop submitting purchase or redemption orders for Creation Units, Fund shares may trade at a larger premium or discount to their net asset value. There can be no assurance that the requirements of the Exchange necessary to maintain the listing of the Fund will continue to be met or will remain unchanged. The Fund may have difficulty maintaining its listing on the Exchange in the event the Fund’s assets are small or the Fund does not have enough shareholders.

VALUATION RISK. The Fund may hold securities or other assets that may be valued on the basis of factors other than market quotations. This may occur because the asset or security does not trade on a centralized exchange, or in times of market turmoil or reduced liquidity. There are multiple methods that can be used to value a portfolio holding when market quotations are not readily available. The value established for any portfolio holding at a point in time might differ from what would be produced using a different methodology or if it had been priced using market quotations. Portfolio holdings that are valued using techniques other than market quotations, including

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“fair valued” assets or securities, may be subject to greater fluctuation in their valuations from one day to the next than if market quotations were used. In addition, there is no assurance that the Fund could sell or close out a portfolio position for the value established for it at any time, and it is possible that the Fund would incur a loss because a portfolio position is sold or closed out at a discount to the valuation established by the Fund at that time. The Fund’s ability to value investments may be impacted by technological issues or errors by pricing services or other third-party service providers.

VOLATILITY RISK. Volatility is the characteristic of a security, an index or a market to fluctuate significantly in price within a short time period. The Fund may invest in securities or financial instruments that exhibit more volatility than the market as a whole. Such exposures could cause the Fund’s net asset value to experience significant increases or declines in value over short periods of time.

Performance

The Fund does not have performance history. Once available, the Fund’s performance information, and information that gives some indication of the risks of an investment in the Fund by comparing the Fund’s performance with a broad measure of market performance, will be available on the Fund’s website at www.ftportfolios.com. The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Management

Investment Advisor

First Trust Advisors L.P. (“First Trust” or the “Advisor”)

Investment Sub-Advisors

Vivaldi Asset Management, LLC (“Vivaldi” or the “Sub-Advisor”)

Portfolio Managers

The following persons serve as portfolio managers of the Fund.

•	Michael Peck, CFA, President and Co-Chief Investment Officer at Vivaldi
•	Scott Hergott, Co-Chief Investment Officer at Vivaldi
•	Brian Murphy, Portfolio Manager at Vivaldi
•	Jeff O’Brien, Portfolio Manager at Vivaldi
•	Daniel Lancz, Portfolio Manager at Vivaldi
•	Michael Grayson, Portfolio Manager at Vivaldi

The portfolio managers are primarily and jointly responsible for the day to day management of the Fund. Each portfolio manager has served in such capacity for the Fund since 2020.

Purchase and Sale of Fund Shares

The Fund issues and redeems shares on a continuous basis, at net asset value, only in Creation Units consisting of 50,000 shares. The Fund’s Creation Units are generally issued and redeemed in-kind for securities in which the Fund invests and, in certain circumstances, for cash and only to and from broker-dealers and large institutional investors that have entered into participation agreements. Individual shares of the Fund may only be purchased and sold on NYSE Arca and other eligible securities exchanges through a broker-dealer. Shares of the Fund trade on NYSE Arca at market prices rather than net asset value, which may cause the shares to trade at a price greater than net asset value (premium) or less than net asset value (discount).

Tax Information

The Fund’s distributions are taxable and will generally be taxed as ordinary income or capital gains. Distributions on shares held in a tax-deferred account, while not immediately taxable, will be subject to tax when the shares are no longer held in a tax-deferred account.

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), First Trust and First Trust Portfolios L.P., the Fund’s distributor, may pay the intermediary for the sale of Fund shares and related services. 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.

You can find the Fund’s statutory prospectus and other information about the Fund, including the statement of additional information and most recent reports to shareholders, online at www.ftportfolios.com/retail/ETF/ETFfundnews.aspx?Ticker=MARB.

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