A computer implemented method for facilitation of deterministic management of a plurality of completely received electronic messages comprising financial messages, each of which is communicated as a plurality of electronic message packets transmitted over a period of time to an application for processing via a network from a plurality of message sources (210, 211, 212, 213) comprising market participants, the application comprising an order entry gateway configured with an exchange operational to match trades using the electronic messages, the method comprising: receiving, by a processor, each electronic message packet of the plurality of electronic message packets of each of the plurality of messages from the network at a common destination to which all of the plurality of electronic message packets are directed, the common destination comprising the application; determining, by the processor, upon receipt of an electronic message packet which comprises a last electronic message packet of the plurality of electronic message packets which together form a completely received electronic message of the plurality of electronic messages, data indicative of an order the complete received electronic message was received relative to previously received electronic messages of the plurality of electronic messages stored in one or more buffer memories coupled with the processor, the data indicative of the order being determined irrespective of which message source of the plurality of message sources (210, 211, 212, 213) each of the received electronic message packets originated; storing, by the processor, in the one or more buffer memories, the received electronic message packet in an arrangement which associates the received electronic message packet according to a same respective message source of the plurality of message sources (210, 211, 212, 213) from which the received electronic message packet and each of the stored previously received electronic message packets respectively originated irrespective of the time of receipt thereof; and communicating, by the processor, the determined data indicative of the order the received electronic messages were received to the application for the application to retrieve and process the received electronic messages from the one or more buffer memories according to the determined data indicative of the order and not prior to another received electronic message received prior thereto. receiving, by a processor, each electronic message packet of the plurality of electronic message packets of each of the plurality of messages from the network at a common destination to which all of the plurality of electronic message packets are directed, the common destination comprising the application; determining, by the processor, upon receipt of an electronic message packet which comprises a last electronic message packet of the plurality of electronic message packets which together form a completely received electronic message of the plurality of electronic messages, data indicative of an order the complete received electronic message was received relative to previously received electronic messages of the plurality of electronic messages stored in one or more buffer memories coupled with the processor, the data indicative of the order being determined irrespective of which message source of the plurality of message sources (210, 211, 212, 213) each of the received electronic message packets originated; storing, by the processor, in the one or more buffer memories, the received electronic message packet in an arrangement which associates the received electronic message packet according to a same respective message source of the plurality of message sources (210, 211, 212, 213) from which the received electronic message packet and each of the stored previously received electronic message packets respectively originated irrespective of the time of receipt thereof; and communicating, by the processor, the determined data indicative of the order the received electronic messages were received to the application for the application to retrieve and process the received electronic messages from the one or more buffer memories according to the determined data indicative of the order and not prior to another received electronic message received prior thereto.