The application’s OpenAI CEO, Fidzi Simo, revealed the termination in an internal message to employees earlier this year. The employee “used confidential OpenAI information in connection with external prediction markets (such as PolyMarkets),” he said.
“Our policies prohibit employees from using confidential OpenAI information for personal gain, including in prediction markets,” says spokeswoman Kayla Wood. OpenAI has not disclosed the employee’s name or the specifics of his business.
Evidence suggests that this was not an isolated incident. Polymarket runs on the Polygon blockchain network, so its trading ledger is pseudonymous but traceable. According to an analysis by financial data platform Unusual Whales, there have been clusters of activity around OpenAI-themed events since March 2023, which the service has flagged as suspicious.
Unusual Whales flagged 77 positions across 60 wallet addresses as suspected insider trading, looking at other factors including account age, trading history and investment importance. The questionable trades depended on the release dates of products such as Sora, GPT-5 and the ChatGPT browser, as well as the employment status of CEO Sam Altman. In November 2023, two days after Altman was dramatically ousted from the company, a new wallet placed a significant bet that he would return after making more than $16,000 in profits. The account never placed another bet.
This behavior fits the typical pattern of insider trades. “Clustering is telling. 40 hours before OpenAI launched its browser, 13 brand-new wallets with zero trading history first appeared on the site to collectively wager $309,486 on the correct outcome,” says Matt Sencum, CEO of Unusual Whales. “When you see multiple new wallets placing the same stakes at the same time, it raises a real question about whether secrets are being exposed.”
Prediction markets have exploded in popularity in recent years. These platforms allow clients to buy “event contracts” on the outcomes of future events ranging from the winner of the Super Bowl to the daily price of Bitcoin and whether the United States will go to war with Iran. There is a wide range of markets associated with developments in the technology sector; You can trade on what Nvidia’s quarterly earnings will be, or when Tesla will launch a new car, or which AI companies will IPO in 2026.
As platforms have grown, so have concerns that they allow traders to profit from insider knowledge. “This prediction market world makes the Wild West look pale in comparison,” says Jeff Edelstein, a senior analyst at betting news site InGame. “If a market exists where the answer is known, someone will trade on it.”
Earlier this week, Kalshi announced that it had reported several suspected insider trading cases to the Commodity Futures Trading Commission, the government agency that oversees these markets. In one example, an employee of popular YouTuber Mister Beast was suspended for two years and fined $20,000 for conducting business related to the streamer’s activities; In another, far-right political candidate Kyle Langford was banned from the stage for conducting business in his own campaign. The company also announced several initiatives to prevent insider trading and market manipulation.
While Kalshi has heavily promoted its crackdown on insider trading, Polymarket has remained silent on the matter. The company did not respond to requests for comments.
In the past, major trades in technology-themed markets have fueled speculation that Big Tech employees are profiting by using their insider knowledge to gain an edge. A notorious example is the so-called “Google Whale”, a pseudonymous account on Polymarket, which traded over $1 million on Google-related events, including the market on who will be the most searched person of the year in 2025. (This was singer D4vd, who is best known for being linked to an ongoing murder investigation after the remains of a young fan were found in his registered vehicle.)
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