Research finds that Polymarket's over 210,000 suspicious transactions brought in $143 million in profit for "informed" traders.

Gate News reports that on March 28, researchers from Columbia Law School and the University of Haifa analyzed most of the trading data from Polymarket between 2024 and 2026, finding that over 210,000 suspicious trades brought in $143 million in profits for “informed” traders. This study, published this month, is the first to estimate the total profits from suspicious accounts.

The researchers applied five criteria related to timing of trades and bet amounts to filter accounts that made large bullish bets shortly before news releases. The study defines these actions as “informed” trading rather than “insider” trading, as some of the flagged large trades occurred in markets influenced by many factors, such as those related to the 2024 U.S. elections. Among the top 20 most suspicious trades identified, most were related to the outcome of the 2024 election, involving about $16 million in profits, while the rest were related to Federal Reserve decisions and sporting events.

Harry Crane, a statistics professor at Rutgers University, questioned the research methodology, arguing that its ranking of suspiciousness overly relies on profitability. The authors of the study acknowledged that the method may have overly or insufficiently included certain cases, and they characterized the identified volume of suspicious trades as a “conservative lower bound estimate of abnormal profits.”

Polymarket announced earlier this month that it would prohibit trading based on “stolen confidential information” and “illegal tips,” but its offshore exchange does not collect identity information such as users’ names, and the enforcement methods remain unclear.