iShares Core 1-5 Year USD Bond ETF (ISTB) is an exchange-traded fund that seeks to track the investment results of an index composed of U.S. dollar-denominated, investment-grade bonds issued by U.S. Treasuries, government-related entities, corporations, securitized issuers, and asset-backed securities with remaining maturities between one and five years. The fund's portfolio is heavily weighted toward U.S. Treasury securities at approximately 52%, followed by holdings in issuers such as Federal National Mortgage Association, Federal Home Loan Mortgage Corporation, JPMorgan Chase & Co., International Bank for Reconstruction and Development, Bank of America Corp., European Investment Bank, Morgan Stanley, Asian Development Bank, and Wells Fargo & Company. Launched on October 18, 2012, and managed by BlackRock Fund Advisors with portfolio managers James Mauro, Jonathan Graves, and Marcus Tom, ISTB lists on the Nasdaq with an expense ratio of 0.06% and total net assets exceeding $4.5 billion. The ETF targets investors seeking short-term bond market exposure across fixed income segments including Treasuries, mortgage-backed securities, corporate bonds, and supranational debt, primarily serving institutional and retail investors in the United States. In recent developments, the fund welcomed new portfolio managers Jonathan Graves and Marcus Tom effective August 1, 2025, alongside ongoing performance tracking against the Bloomberg U.S. Universal 1-5 Year Index amid elevated yields, with no major structural changes, acquisitions, or product launches reported in 2024-2025.