Study Reveals Only a Small Group of Informed Traders Drive Prediction Market Accuracy

A recent scandal involving a Green Beret arrested for betting on a classified U.S. raid may be more than an isolated incident, as a new study suggests that a small group of informed traders, like the accused soldier, are actually responsible for driving prices on prediction markets, while the majority of participants lose money. The study, conducted by researchers from London Business School and Yale, analyzed 1.72 million accounts and $13.76 billion in trading volume on Polymarket, finding that a mere 3% of traders account for most price discovery, consistently predicting outcomes and moving prices in the right direction. The remaining 97% of traders provide liquidity and generate volume but tend to be on the losing side of trades against the informed minority. To distinguish between skill and luck, the researchers simulated each trader's bets 10,000 times, finding that only 12% of the biggest winners by raw profit consistently outperformed the benchmark. The study's findings have significant implications for the industry, challenging the notion that prediction markets work due to the collective knowledge of their participants and instead highlighting the importance of informed traders in driving market accuracy.