A bet exchange or p2p (player to player) exchange is a fairly recent Internet phenomenon, and is used to describe a web site acting as a broker between parties for the placement of bets (gambling, in other words). The concept is similar to that of a stock exchange or a currency exchange, where in this case the commodity being traded is a bet, rather than a stock or currency. The UK bet exchanges Betfair and iBetX are some of many successful implementations of the idea. The sites usually make money by charging a commission which is calculated as a percentage of net winnings.

Big betting successful gamblers whose betting activities have traditionally been restricted by bookmakers have found these sites a boon since they are now able to place bets of unrestricted size, providing always of course that there is someone available to match them. Prices offered often tend to be better than bookmakers despite the commission charged.

See also Gambling, Bookmaker, Parimutuel gambling and Spread betting.