Combinatorial matching techniques for electronic data messages

A computer system comprising:

• a memory configured to store a first and second list of data transaction requests as, respectively, a first plurality of data transaction requests for the first list and a second plurality of data transaction requests for the second list, each of the plurality of data transaction requests being associated with a size value and a counter-size requirement value, wherein the first and second lists are contra to each other;
• a transceiver configured to receive an electronic data message, wherein the electronic data message includes a first data transaction request with at least a first size value and a first counter-size requirement value, and a transaction type identifier that corresponds to the first or second plurality of data transaction requests;
• a processing system that includes at least one processor coupled to the memory and the transceiver, the processing system configured to:
• add the first data transaction request to either the first list or the second list of the plurality of data transaction requests based on the transaction type identifier;
• set the first list or the second list as a working side based on which side the first data transaction request was added to and set the other of the first and second list as a non-working side;
• determine, from among the plurality of data transaction requests on the working side, a working data transaction request;
• for the working data transaction request, perform a match eligibility process that includes:
• a calculation, based on the working data transaction request, of a first sum of the size values of data transaction requests on the working side,
• a calculation of a second sum of the size values of the plurality of data transaction requests on the non-working side that each have a counter-size requirement value that is less than or equal to the calculated first sum, and
• a determination of whether the counter-size requirement value of the working data transaction request is less than or equal to the calculated second sum;
• based on the determination that the counter-size requirement value of the working data transaction request is less than or equal to the second sum, match at least some of the size value of the working data transaction request to at least some of the size value from at least one of the non-working side data transaction requests.