Methods and apparatus for performing risk checking

Methods and apparatus for implementing an electronic trading system which supports risk checking as part of standard message order processing is described. In accordance with the invention risk checking is moved into the exchange system, e.g., electronic communications network, responsible for servicing transaction/order messages and implementing trades. Thus, at least some level of risk checking is performed on transactions even if a broker allows a trader to submit orders directly to the ECN without first passing through a broker order/risk checking system. Brokers, clients and/or individual traders provide parameters used to perform various checks which are performed within the exchange on submitted orders. Various checks are broker level checks which test that orders placed by individual clients do not exceed constraints which are based on the aggregate of the holdings of the individual clients of a broker. Additional client level and trader specified risk checking may also be performed.