Dozens of Polymarket Bets Show Signs of Insider Trading, The Times Finds

On the evening of Thursday, June 12, a small group of internet gamblers made a highly specific prediction on Polymarket, the betting website that offers odds on virtually everything.

Thirteen users wagered a total of $140,000 that Israel would strike Iran by the end of that week, even as the odds suggested that an attack was unlikely. Seven of the accounts had been opened just days earlier. Another had a history of bets related to military action against Iran — and had won money on all of them.

Israel attacked Iran later that day, netting the accounts more than $600,000 in profits.

The explosive growth of prediction markets like Polymarket has rattled the political world over the last year, fueling concerns about a new kind of insider trading by military leaders and government officials with access to confidential plans. A military reservist was recently indicted in Israel for a scheme to bet on the June strike, while a U.S. Army Special Forces soldier was accused last month of wagering on the capture of Nicolás Maduro, the president of Venezuela.

Those bets represent only a slice of the suspicious activity on Polymarket. A New York Times examination found that more than 80 Polymarket users have placed bets with suspicious characteristics, including 38 whose well-timed wagers have drawn little or no public attention. They won money across nearly 30 topics dating back to at least 2024, from Israel’s strike on Iran last year to the regulatory debate over cryptocurrency trading.

The Times’s examination also revealed previously unreported red flags in some of the high-profile bets that have drawn scrutiny. The findings were based on a series of warning signs that hint at insider trading without proving it definitively. Those signals include long-shot bets that pay off, well-timed wagers by recently opened accounts and bets by users who gamble on only a few related topics without ever losing, among other considerations.