Polymarket Investigates Bets Before Times/Siena Polls

Vanderbilt University researchers said a Polymarket account made large, profitable bets shortly before two Times/Siena polls were released, including a wager of about $191,000 on Nebraska Republican Sen. Pete Ricketts. Polymarket said it detected the trades and opened an investigation, but the account’s controller has not been identified and the reporting does not establish whether the trader had nonpublic information.

The Ricketts bet was placed on October 31, 2026, about an hour before a poll showed him leading by six points, according to the researchers’ findings. The account reportedly earned more than $77,000 on the position. Polymarket odds of a Ricketts reelection rose from about 67 percent before the poll to 79 percent afterward, the findings said.

The researchers also reported that the same trader wagered more than $622,000 on Abdul El-Sayed, the Democratic nominee in Michigan’s Senate race. A subsequent Times/Siena poll showed El-Sayed with a significant lead, and the position reportedly generated more than $180,000 in profit. Together, the two bets produced reported gains exceeding $257,000.

Vanderbilt researcher Brett Goldstein said the timing and circumstances...