Authorities are investigating whether former politician George Santos engaged in insider trading by betting on a prediction market about whether he would show up at US president Donald Trump’s State of the Union address in late February.Just before the speech, Santos announced on social media that he planned to attend. Whether he would be there or not was a hot topic on the prediction market Kalshi, with users wagering on the guest list.“I’m gonna be in the gallery,” Santos teased in a video on the social platform X.But Santos missed the speech, and around the time of the event, Kalshi detected that Santos had bet against his own attendance, according to a person familiar with the matter who spoke on condition of anonymity to discuss an ongoing investigation.The company referred the matter to the Justice Department and the Commodity Futures Trading Commission, a financial regulator that oversees prediction markets, the person said.The CFTC is now investigating Santos, according to another person, who also spoke on condition of anonymity. It was not immediately clear whether the Justice Department had opened an investigation.Santos did not immediately respond to a request for comment.The investigation comes as the Trump administration is under pressure to show it can police insider trading and other abuses on the fast-growing, highly lucrative prediction markets. Kalshi is one of several prediction market companies with ties to the president’s business empire. Early last year, the firm appointed Donald Trump Jr, the president’s oldest son, as a “strategic advisor”.A New York Times investigation published last month found that under the Trump administration, the CFTC, a little-known but crucial financial regulator, has repeatedly ruled in favour of prediction markets. Two senior career officials at the agency who raised questions about the handling of prediction market cases were put on investigative leave, barred from the office and placed under investigation late last year, the Times reported.In an interview with The New York Times, Michael S Selig, the chair of the CFTC, promised that regulators would hold wrongdoers to account.A former Republican member of Congress from New York, Santos (37) was charged with fraud in 2023, after The New York Times and other outlets reported that he had lied extensively about his biography. Prosecutors accused him of lying on official forms and stealing from donors, among other schemes. He was expelled from the House and ultimately sentenced to seven years in prison.Santos was released from prison in the autumn after Trump commuted his sentence.The investigation into Santos’ prediction market trading was reported earlier by National Public Radio.The inquiry is the third insider trading case to come to light in recent weeks. Last month, the Justice Department and the CFTC charged a Google employee with using insider information to bet on internet search results.And in April, a member of US Special Forces was charged with illegally using confidential government information to make more than $400,000 betting on the operation to capture Nicolás Maduro, the president of Venezuela.This article originally appeared in The New York Times.