Abstract: One aspect of the present invention is a method of event-based investing in which a portfolio of securities having a value that is expected to vary in accordance with possible outcomes of a specific event is established. Buy orders and sell orders for units of the portfolio are received. The buy and sell orders of the portfolio are pooled to determine a net number of portfolio units to be bought or sold, and then purchase or sale of a set of securities corresponding to the net number of portfolio units is initiated. Another aspect of the present invention is a server system for managing and executing event based investments. The server system includes first, second and third sets of servers, with communications to the second set of servers being guarded by a first firewall and communications to the third set of servers being guarded by a second firewall.