The index includes government-related bonds, corporate bonds, MBS, CMBS and ABS that are publicly offered for sale in the U.S. The fund invests at least 90% of its assets in the index and in investments that have economic characteristics that are substantially identical to the component securities of the index and may invest up to 10% of its assets in certain futures, options and swap contracts, cash and cash equivalents, as well as in securities not included in the index.