A recent scandal involving a Green Beret's alleged use of classified information to place bets on a U.S. raid has highlighted the potential risks of insider trading in prediction markets.
However, a new study suggests that this incident may be part of a larger trend, in which a small group of informed traders consistently drive price discovery, while the majority of participants lose money. The study, which analyzed over 1.7 million accounts and $13.7 billion in trading volume on Polymarket, found that just 3% of traders account for the majority of price movements, with these individuals consistently predicting outcomes and moving prices in the right direction.
The remaining 97% of traders, on the other hand, tend to provide liquidity and generate volume, but ultimately end up 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, using a coin flip to determine the direction of the trade.
The results showed that only 12% of the biggest winners by raw profit were able to consistently beat the benchmark, suggesting that many apparent winners may have simply been lucky. The study's findings have significant implications for our understanding of how prediction markets work, and challenge the idea that these markets are driven by the collective knowledge of the crowd.
Instead, it appears that a small group of informed traders play a crucial role in driving price discovery, and that their activity is essential for market accuracy.