The fund invests primarily in a portfolio of debt securities including corporate bonds and debentures (including high yield bonds commonly known as "junk bonds"), bank loans, convertible and preferred securities, credit default swaps and other debt instruments and derivatives that the fund's investment adviser believes have debt-like characteristics. It invests in both U.S. and foreign debt securities. The principal types of derivatives in which the fund may invest are credit default swaps, interest rate swaps, total return swaps, futures and options.