Intrade

Intrade was an online trading platform where people could buy and sell contracts based on the outcomes of various events, like elections or sporting events. These contracts functioned similarly to bets, reflecting the probability of a specific event occurring. For example, you could buy a contract predicting a candidate’s victory, and its price indicated the market's consensus on the likelihood. If the candidate won, the contract paid out accordingly; if not, it didn’t. This system allowed users to gauge public opinion and implied probabilities through market prices, making it a form of prediction market.