CIEI tracks an index that measures the performance of the US Treasury with a remaining maturity of 3 to 7 years. The fund invests in publicly issued, fixed-rate US Treasury bills, notes, and bonds denominated in USD, excluding corporate, agency, and inflation-protected securities. The fund holds bonds rated investment grade with at least 3 years and less than 7 years remaining to maturity. The number of securities depends on factors such as net asset size relative to the number of index constituents, liquidity, price, and transaction costs. The fund uses a sampling method, which means it can invest in a sample of securities that collectively have an investment profile similar to that of the underlying index. In addition, the fund may invest in cash and cash equivalents, money market instruments, and other ETFs for cash management, cost reduction, risk mitigation, or when favorably priced. The index is market value-weighted and rebalanced monthly.