Polymarket Halted International Trading After Hackers Drained Accounts

Polymarket, a cryptocurrency-based prediction market, temporarily halted international trading after hackers successfully drained user accounts of approximately $2.7 million. The incident was traced back to a third-party vendor based in the United Kingdom, and UK law enforcement has been notified of the breach. Trading was paused while the company investigated the incident, which took several hours to resolve.

Prominent traders on X expressed concern over their financial losses, while blockchain analytics firm Bubblemaps reported that around 700 users, including traders from the US, were affected by the hack.

The company declined to disclose the exact number of traders impacted or the amount of money lost, but confirmed that it will refund affected users. Polymarket operates two separate prediction markets; one, Polymarket US, is a federally regulated financial exchange within the United States, while the flagship Polymarket platform is a cryptocurrency-based exchange banned in the US and several other countries.

This is not the first security incident for Polymarket; in June 2026, another breach resulted in over $2 million in losses for affected traders.

Since its launch in 2020, Polymarket has been the subject of controversy, with several high-profile alleged insider trading incidents leading to arrests. One case involved a special forces soldier accused of betting on the capture of Venezuela’s former leader, while another involved a Google employee who allegedly used confidential information to make millions.

Both suspects have pleaded not guilty. In August 2026, Polymarket raised $1 billion in a fundraising round led by 1789 Capital, a venture capital firm where Donald Trump Jr. is a partner. The company is now valued at $21 billion.