First Trust Managed Municipal ETF (FMB) is an exchange-traded fund in the Muni National Interm category. It has $2.05B in assets, an expense ratio of 0.39% and a 3.51% dividend yield. Under normal market conditions, the fund seeks to achieve its investment objectives by investing at least 80% of its net assets (including investment borrowings) in municipal debt securities that pay interest that is exempt from regular federal income taxes.