Historical stock prices for Blackrock Preferred Oopportunity Trust (BPP). BlackRock Credit Allocation Income Trust III (the Fund), formerly BlackRock Preferred Opportunity Trust, is a non-diversified, closed-end management investment company. The Funds investment objective is to provide high current income consistent with capital preservation. The Fund seeks to achieve its investment objective by investing at least 80% of its assets in credit-related securities, including investment grade corporate bonds, high yield bonds, bank loans, preferred securities or convertible bonds or derivatives with economic characteristics similar to these credit-related securities. It invests in preferred stocks of companies. The Fund's investment advisor is BlackRock Advisors, LLC.