US Patent 7831504 System and method for providing workup trading

A trading system matches a passive order to buy or sell an item at a price with an aggressive order to hit or lift the item at that price. A workup is initiated during which other parties can submit additional orders at the passive order price. A further order may be submitted during workup with a better price. If the amount at the better price equals or exceeds a threshold value and it can be traded at the better price, the workup is terminated and a new workup initiated at the better price.