Patent ID: 8346651

Claim:
A method of a security transaction-assisting machine, comprising: a processor at a central computer: receiving from at least a subset of a plurality of system participants, initial orders to buy and sell a security; matching at least a subset of the initial buy orders to at least a subset of the initial sell orders based at least on quantity, wherein an initial buy order of the at least the subset of the initial buy orders and an initial sell order of the at least the subset of the initial sell order are considered matched when there is at least a partial overlap between a quantity identified for sale by the initial sell order and the quantity identified for purchase by the initial buy order; and forming an order block of at least a subset of the matched orders; responsive to a threshold volume of matching orders being reached, the central computer broadcasting a notification of cross (NOX) alert to each of the plurality of participants, the NOX alert indicating a beginning of a time window during which further matching orders to buy and sell quantities of the security, which are considered matched when they include a further sell order and a further buy order identifying respectively a quantity identified for sale and a quantity identified for purchase that at least partially overlap, are presentable for inclusion in the order block; and at an end of the time window, executing the order block.