Flaherty & Crumrine Preferred Income Opportunity Fund Incorporated is a close-ended equity mutual fund launched and managed by Flaherty & Crumrine Incorporated. The fund invests in the public equity markets of the United States. It invests in stocks of companies operating in the finance and utility sector. The fund primarily invests in preferred stocks. It typically invests in securities with an average credit rating of BBB- by Standard & Poor's Corporation and Baa3 by Moody's Investors Services, Inc. The fund benchmarks the performance of its portfolio against S&P 500 Index and Barclays Capital U.S. Aggregate Index. Flaherty & Crumrine Preferred Income Opportunity Fund Incorporated was formed on December 10, 1991 and is domiciled in the United States.