BlackRock MuniHoldings Investment Quality Fund (the Fund), formerly BlackRock MuniHoldings Insured Investment Fund, is a non-diversified, closed-end management investment company. The Fund seeks to provide current income exempt from federal income tax. It also seeks to offer shareholders the opportunity to own shares, the value of which is exempt from Florida intangible personal property tax. The Fund invests primarily in a portfolio of long-term, investment-grade municipal obligations, the interest on which is exempt from federal income taxes and which enables shares of the Fund to be exempt from Florida intangible personal property tax. It may invest in municipal obligations issued by or on behalf of any state or its political subdivisions, agencies and instrumentalities regardless of geographical location. The Fund's investment advisor is BlackRock Advisors, LLC.