The investment seeks investment results that correspond to the total return (which includes capital appreciation and income) of the Bloomberg U.S. Aggregate Bond Index ("index"). The fund invests at least 80% of its net assets (plus borrowings for investment purposes) in investment-grade debt instruments rated at least A by Moody's Investors Service, Inc., at least A by S&P Global Ratings, or are of comparable quality if unrated, which are at the time of purchase, included in the index; derivatives whose economic returns are, by design, closely equivalent to the returns of the index or its components; and exchange-traded funds that track the index.