The First Trust Flexible Municipal High Income ETF (MFLX), formerly known as the First Trust Municipal CEF Income Opportunity ETF, aims to generate current income. Under typical market conditions, the Fund endeavors to meet this goal by allocating a minimum of 80% of its net assets (plus any borrowed capital) to municipal debt securities. These investments feature interest payments that are exempt from regular federal income taxes. Municipal debt securities are commonly issued by or on behalf of U.S. states, territories, and possessions, along with the District of Columbia, and their associated political entities, agencies, and authorities. The Fund may invest in a broad spectrum of municipal instruments, including, but not limited to, municipal lease obligations (and their certificates of participation), general obligation bonds, revenue bonds, municipal notes, municipal cash equivalents, private activity bonds (including industrial development bonds), and bonds that are pre-refunded or escrowed to maturity.