Gabelli Commercial Aerospace & Defense ETF

This ETF is different from traditional ETFs. Unlike traditional ETFs, this ETF will not tell the public what assets they hold each day. This may create additional risks for your investment. For example:

• You may have to pay more money to trade the ETF's shares. This ETF will provide less information to traders, who tend to charge more for trades when they have less information.
• The price you pay to buy ETF shares on an exchange may not match the value of the ETF's portfolio. The same is true when you sell shares. These price differences may be greater for this ETF compared to other ETFs because it provides less information to traders.
• These additional risks may be even greater in bad or uncertain market conditions.

The differences between this ETF and other ETFs may also have advantages. By keeping certain information about the ETF secret, this ETF may face less risk that other traders can predict or copy its investment strategy. This may improve the ETF's performance. If other traders are able to copy or predict an ETF's investment strategy, however, this may hurt the ETF's performance. For additional information regarding the unique attributes and risks of this ETF, see the "Non-Transparent Exchange-Traded Fund ("ETF") Structure Risk," "Early Close/Trading Halt Risk" and "Authorized Participant and AP Representative Concentration Risk" in the "Principal Risks" section of the Prospectus.

Exchange traded Funds (ETFs) are bought and sold through exchanges trading at market price (not NAV) and are not individually redeemed from the fund. Shares may trade at a premium or a discount to their NAV in the secondary market. There is no guarantee the investment strategy will be successful. Investing involves risk including the possible loss of principal.

Premiums or discounts are the differences (expressed as a percentage) between the NAV and market price of an ETF on a given day, generally at the time the NAV is calculated. A premium is the amount an ETF is trading above the reported NAV, expressed as a percentage of the NAV. A discount is the amount an ETF is trading below the reported NAV, expressed as a percentage of the NAV. The prospectus/registration statement shows the frequency of distributions of premiums and discounts for these ETFs for the most recently completed fiscal calendar year and all completed quarters of the current fiscal year.

Investors should carefully consider the investment objectives, risks, charges and expenses of the Fund before investing. The prospectus, which contains more complete information about this and other matters, should be read carefully before investing. To obtain a prospectus, please call 800-GABELLI or visit www.gabelli.com.

Distributed by G.distributors, LLC, a registered broker dealer and member of FINRA.