Since 2024, "informed" traders on Polymarket have reportedly made $143 million in unusual

Study: 'Informed' Traders Made $143M on Polymarket

Researchers from Columbia Law School and the University of Haifa just dropped a bombshell report on Polymarket. After analyzing most of the platform's trading data from 2024 to 2026, they found that over 210,000 suspicious trades delivered $143 million in profits to so-called "informed" traders.

How did they spot them? Using five criteria tied to timing and bet size, the researchers flagged accounts that placed large bullish bets right before news broke. They use the term "informed" rather than "insider" trading because some of the flagged bets landed in markets with multiple moving parts—like the ones tied to the 2024 US election. The top 20 most suspicious trades were mostly election-related, pulling in about $16 million. The rest tied to Fed decisions and sports events.

Not everyone is buying the methodology. Rutgers statistics professor Harry Crane raised questions, arguing that the ranking leans too heavily on profitability. The study's authors acknowledged that their approach could over- or under-include certain trades. They called the estimated suspicious volume a "conservative lower bound" of abnormal profits.

Polymarket said earlier this month it would ban trading based on "stolen confidential information" and "illegal tips." But since the offshore exchange doesn't collect user IDs, how that ban gets enforced is still unclear.