Arbitrageurs profited over $40 million from pricing mismatches on Polymarket in a single year.

PANews reported on September 18th that, according to Decrypt, a new academic paper revealed systematic pricing biases on the prediction market platform Polymarket, allowing arbitrageurs to profit from it by over $40 million in a single year. The paper, titled "Unraveling the Probability Forest: Arbitrage Opportunities in Prediction Markets," analyzed data from April 2024 to April 2025 and found pricing errors in over 7,000 markets. The research identified two primary arbitrage patterns: one where the sum of "yes/no" share prices in the same market deviates from the theoretical value of $1; and the other where probability divergences occur in logically related markets (such as "Trump wins" and "Republicans win"). By simultaneously buying and selling related contracts, traders can achieve risk-free returns. While arbitrage activity ultimately leads to market price inequality, research indicates that pricing misalignments can persist for hours. This phenomenon is not limited to Polymarket but also occurs on regulated platforms such as Kalshi.