The index is designed to track the performance of publicly-listed real estate investment trusts ("REITs") (or their local equivalents) in both developed and emerging markets. The fund generally will invest at least 80% of its assets in the component securities of the underlying index and in investments that have economic characteristics that are substantially identical to the component securities of the underlying index and may invest up to 20% of its assets in certain futures, options and swap contracts, cash and cash equivalents.