The fund generally invests in securities that are included in the ICE BofA US Cash Pay High Yield Constrained Index. ICE BofA US Cash Pay High Yield Constrained Index tracks the performance of U.S. dollar denominated below investment grade corporate debt (junk bonds), currently in a coupon paying period, that is publicly issued in the U.S. domestic market. Qualifying securities must have a below investment grade rating (based on an average of Moodys, S&P and Fitch), at least 18 months to final maturity at the time of issuance, at least one year remaining term to final maturity as of the rebalancing date, a fixed coupon schedule and a minimum amount outstanding of $250 million.