Patent ID: 7412415

Claim:
A computer implemented method for fulfilling a pair trade request, comprising the steps of: receiving a plurality of pair trade requests, comprising one pair trade request and another pair trade request, wherein each pair trade request comprises a request to trade a first security, a request to trade a second security, and a request to trade said first security and said second security with a minimum spread limit, and wherein said first security and said second security each have a bid price and an ask price; determining the bid/bid spread in the market of said first security and said second security; determining the ask/ask spread in the market of said first security and said second security; determining that the minimum spread limit of each pair trade request is met by a range of said bid/bid spread and said ask/ask spread; executing a transaction between a first portion of the trade of said first security in said one pair trade request and at least one non-pair trade request, provided that the minimum spread limit of said one pair trade request is met by said range of said bid/bid spread and said ask/ask spread; and matching, using a computer, a second portion of said trade of said first security in said one pair trade request and at least a first portion of the trade of said second security in said one pair trade request against said another pair trade request, provided that a range of the minimum spread limit of said one pair trade request and said another pair trade request overlaps with said range of said bid/bid spread and said ask/ask spread.