Polymarket resumes trading after precautionary halt of about an hour following third-party breach
Key Facts
Polymarket resumed trading on its international platform after a precautionary halt lasting about an hour on Thursday, following a security breach involving a third-party provider, according to the company and media reports. The platform said it had identified and fixed the problem, then temporarily halted trading as a precaution. Its status page said the incident was marked resolved at 7:05 p.m. UTC on Oct. 29. The company pledged to fully compensate all affected traders without disclosing their number, the amount of losses or the compensation mechanism. It also said it had referred the incident to a law enforcement agency in the UK, without naming it.
Polymarket has not announced an official financial tally of the damage. Reuters reported that the company said it would return all funds to affected traders, but its report did not give a figure for the losses. The $2.65 million figure therefore does not represent a confirmed theft total; earlier reports indicated that it referred to the value of POL tokens in a wallet linked to a suspected attacker. Media coverage also linked the incident to website monitoring tools provider DebugBear, but Polymarket did not name the provider in its statement. Reuters cited a source familiar with the matter identifying DebugBear as the company linked to the incident, while that information remained separate from an official announcement by the platform.
Polymarket described the incident as a breach of a third-party provider that affected its international platform, saying on its status page: "One of our third-party providers was breached." The company did not disclose how the breach occurred or how it reached the platform. Media reports linked the incident to DebugBear, a UK company that provides website performance monitoring tools, while security coverage described malicious code as a possible mechanism. Polymarket itself has not disclosed the provider's identity or the method of the breach. The company said it fixed the problem before precautionarily suspending trading and restoring service.
The halt affected the international platform, which is built on blockchain technology and used by traders dealing in cryptocurrencies. That service differs from Polymarket's U.S. platform, which operates on a more centralized infrastructure, is regulated by the Commodity Futures Trading Commission and is funded in U.S. dollars, according to the Associated Press. This difference places the third-party provider incident within the international service and does not establish that a similar impact occurred on the U.S. platform. Data cited by the news agency show prediction markets have expanded, with trading volume across Polymarket and rival Kalshi reaching a combined $26.6 billion at the time of its report in July 2026, compared with $9.75 billion in October 2025. The figures were based on data from blockchain analytics platform Dune.
The compensation pledge comes as trust features in Polymarket's efforts to expand its U.S. business. Dan Lee, the company's U.S. chief operating officer, told the Associated Press: "Trust is the product we're building here." He added that the scale of the company's international activity could obscure the progress it is making in the United States to broaden acceptance of its business. Polymarket has not set a date for publishing further details on compensation or the investigation, while its status page recorded the incident as resolved on the evening of Oct. 29. The next stated step is to address affected traders' losses, with no published details on how payments will be made.