Polymarket Bets on OpenAI, Google Raise Insider Trading Suspicions

Over the past week, a handful of accounts on Polymarket, the predictions site, bet OpenAI would release a new large language model by December 13. On Thursday December 11, OpenAI released GPT-5.2, and four of these accounts together made over $13,000, according to the trades displayed on their accounts.

The payout is adding fuel to suspicions that a handful of accounts on prediction sites such as Polymarket and Kalshi aren’t just lucky—they’ve got access to private information about tech companies including Google and OpenAI, perhaps because the account owners work there. As the popularity of these prediction sites jumps, more companies are making sure policies that have long prohibited employees from trading stocks based on confidential information also include prediction markets, which allow users to place small bets on events from Taylor Swift’s engagement to the chance of a SpaceX public offering.