iShares Core U.S. Aggregate Bond ETF (AGG) Exchange: NYSE ARCA

The Fund seeks to track the investment results of the Bloomberg Barclays U.S. Aggregate Bond Index (the “Underlying Index”), which measures the performance of the total U.S. investment-grade (as determined by Bloomberg Index Services Limited (the “Index Provider” or “Bloomberg”)) bond market. As of February 29, 2020, there were 11,152 issues in the Underlying Index.The Underlying Index includes investment-grade U.S. Treasury bonds, government-related bonds, corporate bonds, mortgage-backed pass-through securities (“MBS”), commercial mortgage-backed securities (“CMBS”) and asset-backed securities (“ABS”) that are publicly offered for sale in the U.S. As of February 29, 2020, a significant portion of the Underlying Index is represented by MBS and treasury securities. The components of the Underlying Index are likely to change over time.The securities in the Underlying Index must have $300 million or more of outstanding face value and must have at least one year remaining to maturity, with the exception of amortizing securities such as ABS and MBS, which have lower thresholds as defined by Bloomberg. In addition, the securities in the Underlying Index must be denominated in U.S. dollars and must be fixed-rate and non-convertible. Certain types of securities, such as state and local government series bonds, structured notes with embedded swaps or other special features, private placements, floating-rate securities and bonds that have been issued in one country's currency but are traded outside of that country in a different monetary and regulatory system (Eurobonds), are excluded from the Underlying Index. The Underlying Index is market capitalization-weighted, and the securities in the Underlying Index are updated on the last business day of each month.As of February 29, 2020, approximately 26% of the bonds represented in the Underlying Index were U.S. fixed-rate agency MBS. U.S. fixed-rate agency MBS are securities issued by entities such as the Government National Mortgage Association (“Ginnie Mae”), the Federal National Mortgage Association (“Fannie Mae”), and the Federal Home Loan Mortgage Corporation (“Freddie Mac”) and are backed by pools of mortgages. Most transactions in fixed-rate MBS occur through standardized contracts for future delivery in which the exact mortgage pools to be delivered are not specified until a few days prior to settlement (to-be-announced (“TBA”) transactions). The Fund may enter into such contracts on a regular basis. The Fund, pending settlement of such contracts, will invest its assets in high-quality, liquid short-term instruments, including shares of money market funds advised by BFA or its affiliates. The Fund will assume its pro rata share of the fees and expenses of any money market fund that it may invest in, in addition to the Fund's own fees and expenses. The Fund may also acquire interests in mortgage pools through means other than such standardized contracts for future delivery.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 seeks to track the performance of the Underlying Index by investing at least 90% of its net assets in component securities of its Underlying Index and in investments that have economic characteristics that are substantially identical to the economic characteristics of the component securities of its Underlying Index (i.e., TBAs). The Fund may invest up to 10% of its portfolio in bonds not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index, as well as in certain futures, options and swap contracts, cash and high-quality, liquid short-term instruments, including shares of money market funds advised by BFA or its affiliates. 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.