The invention discloses a method and a system for trading in securities at a primary site, the trading being carried out according to information received from market makers and traders, said information comprising quotes and orders for one or more instrument. The method comprises the reception and storing of said information at the primary site, and using said information to create deals in said securities, said deals also being stored at the primary site. The method additionally comprises the use of a secondary site, where replicas of the orders and deals are stored, with the deals stored at the secondary site being used to update the orders stored at the secondary site. The information regarding the replicas stored at the secondary site can be forwarded from the primary site, at which primary site the information on which the replicas are based is first received from the market makers and traders, or it can be received at the secondary site directly from the market makers and traders. |