Polymarket trader's $200K bet before NYT/Siena poll triggers insider trading alarm

A Polymarket account dropped nearly $200,000 on a single political bet on Oct. 31, wagering that Nebraska Senator Pete Ricketts would win re-election. Roughly an hour later, a New York Times/Siena poll landed showing Ricketts ahead, according to researchers at Vanderbilt University. The timing is raising eyebrows — and insider-trading questions — in prediction market land.

The New York Times reported Friday that it isn't clear whether the trader had inside information, but the bet paid off: the user walked away with more than $77,000. That wasn't a one-off. The same account placed similar large wagers on other markets, including on rival platform Kalshi, per the report.

Brett Goldstein of the Vanderbilt Institute of National Security didn't mince words. According to the report, he said the string of circumstances is hard to dismiss as a random occurrence and deserves further investigation. Polymarket said it flagged the trades and is looking into them. Kalshi declined to comment.

It's not the first time prediction markets have faced this spotlight. Cointelegraph reported in April that a US Army soldier was charged after allegedly making more than $400,000 betting with nonpublic information tied to a US operation involving then-Venezuelan President Nicolás Maduro. The Department of Justice alleged Master Sergeant Gannon Ken Van Dyke helped plan and execute Operation Absolute Resolve, which ended with Maduro's capture at a residence in Caracas, Venezuela, in January.

Prosecutors say Van Dyke used that knowledge to buy 'yes' shares on Polymarket contracts including 'Maduro out by January 31' and 'Trump invokes War Powers against Venezuela by January 31.' Now the Nebraska trades have investigators asking the same uncomfortable question: who knew what, and when did they bet on it?