The Fund seeks to track the investment results, before fees and expenses, of the BofA Merrill Lynch Enhanced Yield 1-5 Year US Broad Bond Index. The Funds offers the potential for enhanced yield relative to the short-term, taxable investment grade fixed income market with comparable risk. The Fund invests primarily in U.S. government securities, debt securities issued by U.S. corporations, residential and commercial mortgage-backed securities, asset-based securities that are publicly offered for sale in the U.S., with a remaining term to final maturity, or an average life, of less than five years.