An apparatus and method of automatically and anonymously buying and selling positions in fungible properties between subscribers. The specific embodiment described in the disclosure relates to the buying and selling of securities or contracts where the offer to purchase or sell the property may be conditioned...http://www.google.com.hk/patents/US7024387?utm_source=gb-gplus-share專利 US7024387 - Automated system for conditional order transactions in securities or other items in commerce
