iShares Barclays 20+ Year Treasury Bond Fund (the Fund) seeks investment results that correspond generally to the price and yield performance of the Barclays Capital U.S. 20+ Year Treasury Bond Index (the Index). The Index measures the performance of public obligations of the United States Treasury that have a remaining maturity of 20 or more years. The Fund invests in a representative sample of securities included in the Index that collectively has an investment profile similar to the Index. Due to the use of representative sampling, the Fund may or may not hold all of the securities that are included in the Index. The Fund�s investment advisor is BlackRock Fund Advisors.