Patent ID: 8224733

Claim:
A method comprising, in a market for a particular type of instrument, receiving by a processing unit trading orders from a plurality of traders via a plurality of terminals that are associated with the plurality of traders, each trading order having an associated price, and the plurality of terminals being communicatively coupled to the processing unit via a communications network; placing by the processing unit the received trading orders on a trading exchange such that the trading orders may be executed; determining by the processing unit that the price of a particular trading order differs from a previous trade price by more than a threshold value; receiving by the processing unit from a particular trader a subsequent order having an original price that would trade with the price of the particular trading order; and based at least in part on determining that the price of the particular trading order differs from the previous trade price by more than the threshold value: communicating by the processing unit an alert message regarding the subsequent order to the particular trader; and preventing by the processing unit the subsequent order from trading with the particular trading order at least until a response to the alert message is received from the particular trader; wherein placing the received trading orders on the trading exchange comprises placing the received trading orders in one of a plurality of trading order stacks; wherein the method further comprises promoting by the processing unit the particular trading order to a top of its respective trading order stack; and wherein the determination that the price of the particular trading order differs from the previous trade price by more than the threshold value is made in response to the particular trading order being promoted to the top of its respective trading order stack.