The Fund seeks to track the investment results of the Bloomberg U.S. Agency Bond Index (the Underlying Index), which measures the performance of the agency sector of the U.S. government bond market and is composed of investment-grade (as determined by Bloomberg Index Services Limited (the Index Provider or Bloomberg)) U.S. dollar-denominated publicly-issued government agency bonds or debentures. As of February 28, 2023, there were 447 issues in the Underlying Index. The Underlying Index includes callable and non-callable securities issued by U.S. government agencies, quasi-federal corporations (as described below), and corporate and non-U.S. debt guaranteed by the U.S. government. A minimum 50% ownership rule is used to classify issuers as government agencies.