Patent attributes
A computer system includes a memory that stores two lists of electronic data transaction requests. Stored and received data transaction requests are associated with a size value and a counter-size requirement value. When data transaction requests are received they are added to one of the two lists and list to which the data transaction request is added is set to a working side. A working order is selected from the working side and a first sum of size values of data transaction requests is calculated from the working side. A second sum of size values is calculated from the non-working side from data transaction requests that have a counter-size requirement value that is less than the first sum. If the counter-size requirement value is less than or equal to the second sum, the electronic data requests from the respective lists are matched.