According to reports from Fortune magazine, blockchain companies Chaos Labs and Inca Digital analysts have discovered rampant wash trading on Polymarket. They found evidence of false trading activity on Polymarket, where buying and selling is often done simultaneously and repeatedly to create the illusion of trading volume and activity. Chaos Labs found that false trading accounted for about one-third of the trading volume on Polymarket's US presidential election market, while Inca Digital found that a significant portion of the market's trading volume may be due to potential false trading.

Chaos Labs and Inca Digital found that the total presidential election prediction trading volume reported on the Polymarket website does not match the on-chain data. Inca said the actual trading volume for the presidential election prediction market is about $1.75 billion, while Polymarket reported a figure of $2.7 billion. Chaos Labs attributed this to Polymarket mixing trading stocks with US dollars.