Established in the United States on November 19, 2003, the Nuveen Municipal High Income Opportunity Fund operates as a closed-end fixed income mutual fund. Nuveen Investments Inc. originally launched this fund, which is now jointly managed by Nuveen Fund Advisors LLC and Nuveen Asset Management, LLC. Its investment strategy concentrates on the US fixed income markets, specifically targeting investment-grade, tax-exempt municipal securities as its primary holdings.