Abstract: This invention concerns trading in financial instruments, such as by use of a computer based cash management facility electronically linked to a computer based clearing house, and an automated real time screen trading system operated by the investor using standard personal computers linked by a communications network to a central clearing house computer. In particular, this invention concerns a contract exchange and protocol, and in another aspect it concerns a financial instrument. The contract exchange may provide direct entry to the market, and the opportunity to trade 24 hours a day, to potential investors from every office and home in the world. Trading need never cease on the Contract Exchange even with an external world catastrophe.