11.   Brokers said futures-related trading pushed the index up, as the underlying stocks were bought to push spot prices up.

12.   But so too are derivatives -- financial instruments whose value goes up and down with the value of underlying stocks, bonds, currencies, or other assets.

13.   Derivatives are contracts whose value is based on an underlying stock, bond, commodity, currency or index.

14.   For a small fee, they can also turn in HOLDRs at any time and get their portion of the underlying stocks.

15.   Futures traders were selling the July contract and buying the August contract, as well as buying and selling the underlying stocks to hedge their new futures positions.

16.   If prices fall, the bank will hedge by shorting the underlying stocks.

17.   If the price of the underlying stock goes up, owners of the warrants capture virtually all of the increase -- and the percentage gains can be remarkable.

18.   In each, the value of the insurance is related to the underlying stock or interest rate or farm product.

19.   In others, guarantees expired worthless because the underlying stock performed as promised.

20.   Investors buy options to hedge their positions in an underlying stock.