The Fund is an actively managed exchange-traded fund (ETF) that seeks high current income and long-term capital appreciation by investing in unaffiliated closed-end funds that the Fund's investment adviser, Calamos Advisors LLC (Calamos Advisors or the Adviser), believes offer both attractive income opportunities as well as arbitrage opportunities resulting from such closed-end funds trading at attractive discounts (market prices that are less than the closed-end funds' net asset value (NAV)). The Fund's strategy seeks to identify closed-end funds trading at attractive discounts and sell such funds when the arbitrage opportunity has either been achieved by capturing the benefit of discount narrowing or when the Adviser determines the discount level no longer represents an unusual divergence from the fund's underlying asset value. Under normal circumstances, the Fund seeks to achieve its investment objectives by investing at least 80% of its net assets (plus borrowings for investment purposes, if any) in U.S. and non-U.S. closed-end funds.