The Fund seeks to track the investment results of the Bloomberg US Floating Rate Note 5 Years Index (the Underlying Index), which measures the performance of U.S. dollar-denominated, investment-grade (as determined by Bloomberg Index Services Limited (the Index Provider or Bloomberg)) floating rate note. The fund generally will invest at least 90% of its assets in the component securities of the underlying 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 underlying index, but which BFA believes will help the fund track the underlying index.