A method for processing, by an electronic trading system, a data message received via a network from a source (102a, 102b, 102c), the data message comprising data that is generated by the source dependent upon the source receiving an event data message of a plurality of event data messages transmitted by a feed engine of the electronic trading system responsive to the occurrence of an event, the method comprising: monitoring, at message processing logic of the electronic trading system, a time of transmission of the event data message of the plurality of event data messages to the source by the feed engine; monitoring, at a message analyzer, a message latency between a message receiver of the electronic trading system and the source (102a, 102b, 102c); receiving at least a portion of the data message generated by the source (102a, 102b, 102c) at the message receiver coupled with the network; characterized in that the method further comprises: upon receiving at least the portion of the data message generated by the source (102a, 102b, 102c), determining at the message analyzer, a time of commencement of transmission of at least the portion of the data message by the source (102a, 102b, 102c) based on the measured message latency between the message receiver and the source (102a, 102b, 102c), analyzing automatically at least the portion of the data message at the message analyzer to determine if the source (102a, 102b, 102c) commenced transmission of at least the portion of the data message prior to the transmission of the event data message by evaluating a difference between the time when at least a portion of the data message is first received by the message receiver and the time of the transmission of the event data message and comparing the difference to a baseline value; determining, by the message analyzer, that the source (102a, 102b, 102c) commenced transmission of the at least the portion of the data message prior to the transmission of the event data message when the difference deviates from the baseline value; and processing the data message at a message processor and taking an action with respect to the data message when it is determined that the source (102a, 102b, 102c) commenced transmission of the at least the portion of the data message prior to the transmission of the event data message. monitoring, at message processing logic of the electronic trading system, a time of transmission of the event data message of the plurality of event data messages to the source by the feed engine; monitoring, at a message analyzer, a message latency between a message receiver of the electronic trading system and the source (102a, 102b, 102c); receiving at least a portion of the data message generated by the source (102a, 102b, 102c) at the message receiver coupled with the network; characterized in that the method further comprises: upon receiving at least the portion of the data message generated by the source (102a, 102b, 102c), determining at the message analyzer, a time of commencement of transmission of at least the portion of the data message by the source (102a, 102b, 102c) based on the measured message latency between the message receiver and the source (102a, 102b, 102c), analyzing automatically at least the portion of the data message at the message analyzer to determine if the source (102a, 102b, 102c) commenced transmission of at least the portion of the data message prior to the transmission of the event data message by evaluating a difference between the time when at least a portion of the data message is first received by the message receiver and the time of the transmission of the event data message and comparing the difference to a baseline value; determining, by the message analyzer, that the source (102a, 102b, 102c) commenced transmission of the at least the portion of the data message prior to the transmission of the event data message when the difference deviates from the baseline value; and processing the data message at a message processor and taking an action with respect to the data message when it is determined that the source (102a, 102b, 102c) commenced transmission of the at least the portion of the data message prior to the transmission of the event data message. upon receiving at least the portion of the data message generated by the source (102a, 102b, 102c), determining at the message analyzer, a time of commencement of transmission of at least the portion of the data message by the source (102a, 102b, 102c) based on the measured message latency between the message receiver and the source (102a, 102b, 102c), analyzing automatically at least the portion of the data message at the message analyzer to determine if the source (102a, 102b, 102c) commenced transmission of at least the portion of the data message prior to the transmission of the event data message by evaluating a difference between the time when at least a portion of the data message is first received by the message receiver and the time of the transmission of the event data message and comparing the difference to a baseline value; determining, by the message analyzer, that the source (102a, 102b, 102c) commenced transmission of the at least the portion of the data message prior to the transmission of the event data message when the difference deviates from the baseline value; and processing the data message at a message processor and taking an action with respect to the data message when it is determined that the source (102a, 102b, 102c) commenced transmission of the at least the portion of the data message prior to the transmission of the event data message.