The investment seeks to track changes, whether positive or negative, in the level of the DBIQ Diversified Agriculture Index Excess Return? (the ?index?) over time, plus the excess, if any, of the sum of the fund?s Treasury Income, Money Market Income and T-Bill ETF Income, over the expenses of the fund. The index, which is comprised of one or more underlying commodities (?index commodities?), is intended to reflect the agricultural sector. The fund pursues its investment objective by investing in a portfolio of exchange-traded futures.