Patent ID: 7668774

Claim:
A computer-implemented method for trading, between a buyer and a seller at an exchange, a futures exchange, an options exchange, or a futures and options exchange, the method being performed on a computer system, the method comprising: receiving, by the computer system, first inputs from the buyer and seller corresponding to a standardized form of contract for trading at a price on which the buyer and the seller agree, the standardized form of contract having contract terms requiring the buyer and seller to settle based on a single final settlement price; receiving, by the computer system, second inputs from the buyer and the seller at or prior to a first reference time wherein the second inputs include bid prices and offer prices for the standardized form of contract; matching, in the computer system, the first inputs and the bid prices and the offer prices and forming a contract based, at least in part, on the matching; and determining, in the computer system, said final settlement price as follows: receiving, in the computer system, a first level of an underlying, the first level of the underlying being an actual value of the underlying actually observed at said first reference time prior to settlement of the contract, the first reference time determined in accordance with the contract terms, the underlying being a specified observable quantity selected from a group consisting of a stock price, a commodity price, a financial asset price, a basket of financial assets price, a financial index value and a financial contract price; receiving, in the computer system, a second level of said underlying, the second level of the underlying being the actual value of the underlying actually observed at a second reference time prior to settlement of the contract, the second reference time determined in accordance with the contract terms and being later than said first reference time; and determining, in the computer system, in accordance with the contract terms, the single final settlement price at the settlement of the contract by reference to both said first level of the underlying and said second level of the underlying, wherein the contract is available to trade before said first reference time.