Patent ID: 8630936

Claim:
A method, comprising: in a market for a particular type of instrument, receiving by a processing unit trading orders, each trading order having an associated price; placing by the processing unit each of 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 at least one comparison price by more than a threshold value; and based at least in part on determining that the price of the particular trading order differs from the at least one comparison price by more than the threshold value, taking, by the processing unit, a restrictive action regarding the particular trading order; wherein: placing each of the received trading orders on the trading exchange comprises placing each of the received trading orders in one of a plurality of trading order stacks; the method further comprises promoting by the processing unit the particular trading order to the top of its respective trading order stack; and the determination that the price of the particular trading order differs from the at least one comparison 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.