iShares iBoxx $ High Yield Corporate Bond ETF (iShares iBoxx USD High Yield Corporate Bond) 

The underlying index is a rules-based index consisting of U.S. dollar-denominated, high yield corporate bonds for sale in the U.S. The fund will invest at least 80% of its assets in the component securities of the underlying index, and the fund will invest at least 90% of its assets in fixed income securities of the types included in the underlying index that the advisor believes will help the fund track the underlying index.