A contract on the future delivery of interest-bearing securities, primarily U.S. Treasury bills (on the Chicago Mercantile Exchange) or Treasury bonds (on the Chicago Board of Trade), although contracts on certificates of deposit, Ginnie Mae certificates, and Treasury notes are also available. As with other futures contracts, interest rate futures permit a buyer and a seller to lock in the price of an asset (in this case, a specified package of securities) for future delivery. The contracts are large in amount ($1 million for bills and $100,000 for bonds) and lend themselves to sophisticated analysis. Amateurs beware!