Nuveen Insured Municipal Opportunity Fund, Inc. (the Fund) is a closed-end management investment company. The Fund seeks to provide current income exempt from regular federal income tax by investing primarily in a portfolio of municipal obligations issued by state and local government authorities or certain United States territories. The Fund also focuses on enhancement of portfolio value. The Fund's investment adviser is Nuveen Asset Management, which is a wholly owned subsidiary of Nuveen Investments, Inc. (Nuveen). On October 16, 2009, the Fund acquired Nuveen Florida Premium Income Municipal Fund (NFL).