iShares Core 10+ Year USD Bond ETF (ILTB) Exchange: NYSE ARCA

The Fund seeks to track the investment results of the Bloomberg Barclays U.S. Universal 10+ Year Index (the “Underlying Index”), which measures the performance of U.S. dollar-denominated taxable bonds that are rated either investment-grade or high yield (as determined by Bloomberg Index Services Limited (the “Index Provider” or “Bloomberg”)) with remaining maturities greater than ten years. The Underlying Index includes U.S. Treasury bonds, government-related bonds (i.e., U.S. and non-U.S. agencies, sovereign, quasi-sovereign, supranational and local authority debt), investment-grade and high yield U.S. corporate bonds, Eurodollar bonds (i.e., U.S. dollar-denominated bonds issued by foreign issuers outside the U.S.), bonds registered with the SEC or exempt from registration at the time of issuance, or offered pursuant to Rule 144A under the Securities Act of 1933, as amended (the “1933 Act”) with or without registration rights (“Rule 144A Bonds”) and emerging market bonds. The Underlying Index is a subset of the Bloomberg Barclays U.S. Universal Index.As of February 29, 2020, a significant portion of the Underlying Index is represented by treasury securities. The components of the Underlying Index are likely to change over time. The securities in the Underlying Index must have at least 10 years remaining to maturity, or at least 10 years remaining to the first call date in the case of callable perpetual securities. In addition, the securities in the Underlying Index must be denominated in U.S. dollars and be non-convertible. Excluded from the Underlying Index are tax-exempt municipal securities, coupon issues that have been stripped from bonds, structured notes and private placements (excluding Rule 144A Bonds). The Underlying Index is market capitalization-weighted and is rebalanced on the last day of the month.BFA uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued.Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by aiming to keep portfolio turnover low in comparison to actively managed investment companies.BFA uses a representative sampling indexing strategy to manage the Fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to that of an applicable underlying index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market value and industry weightings), fundamental characteristics (such as return variability, duration, maturity, credit ratings and yield) and liquidity measures similar to those of an applicable underlying index. The Fund may or may not hold all of the securities in the Underlying Index.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, including shares of money market funds advised by BFA or its affiliates (“BlackRock Cash Funds”), as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. From time to time when conditions warrant, however, the Fund may invest at least 80% of its assets in 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, including shares of BlackRock Cash Funds, as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund.The Fund may lend securities representing up to one-third of the value of the Fund's total assets (including the value of any collateral received).The Underlying Index is sponsored by Bloomberg, which is independent of the Fund and BFA. The Index Provider determines the composition and relative weightings of the securities in the Underlying Index and publishes information regarding the market value of the Underlying Index.Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities), repurchase agreements collateralized by U.S. government securities, and securities of state or municipal governments and their political subdivisions are not considered to be issued by members of any industry.