1. In a computer-mediated network environment comprising a plurality of computers, a method of conducting a competitive simulation between a plurality of users, each said user having an associated team, the method comprising: enabling a plurality of teams to be built in accordance with the requirements of a pre-selected sport, each said team comprising a plurality of players, and each said player representing an asset tradable on an applicable market; defining games to be played between the teams, each said game having a set start time and being played over a common game duration; for each said game, comparing market-related metrics for the players of each team playing in the game, the market related metrics being provided by a feed application running on a computer system; and determining, via at least said computer, a winner of each said game based on the comparing.