Patent ID: 8380610

Claim:
A computerised method of trading an item, comprising: receiving from a first trader a first passive order to buy a security at a computerised matching engine; following receipt of the first passive order to buy, receiving from a second trader a passive order to sell the security; providing the first trader that submitted the first passive order to buy with an exclusive opportunity to aggress against the passive order to sell for a predetermined period; while the first trader that submitted the passive order to buy has said exclusive opportunity, receiving at the computerised matching engine from a trader a second passive order to buy the security at a price better than the price of the first passive order to buy the security; storing at the computerised matching engine the second passive order to buy as a non-transactable order which cannot be matched with an order to sell; upon termination of the exclusive opportunity after the predetermined period, converting, at the computerised matching engine, the stored second passive order to buy to a transactable passive order to buy which can be matched with an order to sell or cancelling the second passive order to buy.