The fund offers broad, vanilla exposure to the investment grade segment of the US fixed income space by tracking a well-known index. The index is a market value-weighted index of US dollar-denominated, investment grade, taxable, fixed-income securities. It has one of the broadest baskets of bonds, with over 10,000 securities. Eligible securities must have at least $300 million outstanding face value and at least one year to maturity. The index includes Treasuries, agencies, CMBS, ABS, and investment grade corporates. The fund may use a sampling method in tracking the index, which means it will invest in a sample of securities that collectively have an investment profile similar to that of the underlying index.