Methods and apparatus are provided to administer an actively managed investment company that invests assets in fixed income securities. The investment company issues one or more classes of shares that are listed for trading on a securities exchange and that are bought and sold in a secondary market at negotiated market prices. The investment company selects and holds a portfolio of fixed income securities that relate to a benchmark index. The selection is made in an actively managed manner such that the duration range of the securities holdings is either longer than the duration of the benchmark index, close to the duration of the benchmark index, or shorter than the duration of the benchmark index. The investment company defines a creation unit basket that has a duration that is equal to a midpoint of the duration range of the securities holdings of the investment company. The investment company periodically publishes the creation unit basket to facilitate creation and redemption of the exchange-traded shares.