A group of researchers from the London Business School and Yale University analyzed transactions on Polymarket from 2023 to 2025. They concluded that the platform's predictive accuracy is driven by an "informed minority" rather than the "wisdom of the crowd."
Only 3.14% of users were identified as "skilled winners." This group, along with market makers, accounts for over 30% of all profits on the platform.
The study covered 1.7 million accounts and transactions totaling $13.76 billion.
However, overall income does not always reflect a trader's skill. The analysis revealed that only 12% of the most profitable accounts actually have a strategy. About 60% of these "lucky users" began to incur losses when market conditions changed. Most participants (67%) remain in the red due to lack of experience or bad luck.
The researchers also found signs of insider trading. They identified 1,950 accounts that executed trades just before significant events and ceased activity afterward.
For instance, they cited bets on the resignation of former Venezuelan President Nicolás Maduro. Trades occurred shortly before the U.S. officially announced military operation "Operation Absolute Resolve" to capture the politician.
The findings contradict the positions of Polymarket and Kalshi's leadership. Company heads often claim that predictive markets outperform experts due to the collective intelligence of participants.
In April, the U.S. Department of Justice charged active-duty serviceman Gannon Ken Van Dyke, who is suspected of using insider information to place bets on Polymarket.