To pursue its goal, the fund normally invests substantially all of its assets in bonds comprising the Bloomberg US Aggregate Total Return Index (index), and TBA transactions (as defined below) representing bonds included in the index. Under normal circumstances, the fund will invest at least 80% of its net assets, plus any borrowings for investment purposes, in bonds, TBA transactions representing bonds and ETFs providing exposure to such securities. The Bloomberg US Aggregate Total Return Index is designed to measure the investment grade, U.S. dollar-denominated, fixed-rate taxable bond market. The index includes Treasuries, government-related and corporate securities, mortgage-backed pass-through securities (agency fixed-rate), commercial mortgage-backed securities (agency and non-agency) and other asset-backed securities having at least one year until final maturity. Treasury, government-related and corporate securities must have $300 million or more par amount outstanding. For mortgage-backed pass-through securities, pool aggregates must have $1 billion or more par amount outstanding. Asset-backed securities must have a minimum deal size of $500 million and a minimum tranche size of $25 million.