Study Reveals Only a Small Percentage of Traders Contribute to Prediction Market Accuracy

A recent study has shed light on the inner workings of prediction markets, suggesting that the accuracy of these markets can be attributed to a small group of informed traders, rather than the collective knowledge of the crowd. This discovery challenges the long-held notion that the diversity of market participants is the primary driver of prediction market accuracy. The study, which analyzed trades from 2023 to 2025, found that just 3% of traders are responsible for the majority of price discovery, meaning they are the ones who drive prices towards the correct outcome. These traders consistently demonstrate an ability to predict outcomes and move prices in the right direction, while the remaining 97% of traders tend to lose money, providing liquidity and generating volume, but ultimately being on the wrong side of trades. To differentiate between skill and luck, the researchers simulated each trader's bets 10,000 times, using the same markets, moments, and dollar amounts, but with the direction of the trade determined by a coin flip. The results showed that only 12% of the biggest winners by raw profit consistently outperformed the coin flip, indicating that their success was due to skill rather than luck. Furthermore, the study found that when skilled traders account for a larger share of trading, prices move closer to the correct outcome, especially in the final stretch before resolution. However, the study also raises concerns about the potential for insider trading, highlighting the risk that informed traders may be using non-public information to make trades. While both Polymarket and Kalshi have stated that trading on non-public information is against their rules, the study grounds this risk in a concrete case, where three newly created accounts placed unusually large bets on a contract related to the removal of Nicolás Maduro from power in Venezuela, before the price moved. The findings of this study have significant implications for our understanding of prediction markets and highlight the importance of informed traders in driving market accuracy.