A recent study from Columbia University has revealed troubling insights into the operations of Polymarket, a cryptocurrency-based prediction market. Researchers discovered that approximately 25% of the trading volume on the platform is attributed to what they describe as “artificial trading” practices. Over a three-year investigation into the buying and selling activities on Polymarket, the research team identified a significant presence of wash trades, a practice wherein traders simultaneously buy and sell the same contract to inflate trading volume and create a false sense of market interest.
While the researchers did not claim that Polymarket itself engages in such manipulative practices, they suggested that the choice of a cryptocurrency stablecoin as the medium of exchange may facilitate these illegitimate transactions. Utilizing an algorithm, the study pinpointed accounts that primarily interacted with a limited number of other accounts. These patterns of trading, where one account consistently bought what another was selling, indicated the presence of networks engaging in wash trading.
The analysis flagged nearly 15% of user wallets on the platform—equating to approximately 1.26 million accounts—as participants in these artificial trading activities. While overall, 25% of the trading volume has been linked to these questionable practices, the research noted that instances of wash trading surged at certain times. For example, in December 2024, researchers estimated that up to 60% of the volume could be attributed to phony orders.
Polymarket did not respond to inquiries regarding the findings of the study. Nevertheless, the platform appears to actively stimulate trading volume through marketing efforts, particularly around significant events. On November 4, coinciding with the New York mayoral election, the company ramped up its promotional strategies to attract more traders. They circulated claims about candidate Mamdani being listed multiple times on the ballot, which was factual but misrepresented by some right-leaning social media accounts as part of a broader narrative. They also highlighted a supposed influx of “whale” traders betting on Andrew Cuomo, enticing further speculation by asking rhetorically if these traders possessed inside knowledge.
While these strategies may not constitute outright market manipulation, they nonetheless raise ethical questions about the transparency and integrity of trading practices on the platform. This study serves as a critical reminder of the complexities and potential pitfalls within the cryptocurrency trading space, particularly concerning emerging markets like Polymarket.

