Polymarket resumes international trading after third-party security incident

Polymarket temporarily halted trading on its international platform after a security incident involving a third-party provider, then resumed activity about an hour later on Thursday, according to The Guardian UK and ABC News US. The company said it took the platform offline “out of an abundance of caution” after identifying and fixing the issue. Trading resumed on Thursday afternoon.

Polymarket also said it would fully reimburse any traders affected by the incident. “We’ll make this right and are fully reimbursing all affected traders,” the company posted on X after trading had restarted. The company later said that anyone affected “will be made whole”, although neither report established how many users or transactions were involved.

Polymarket referred the incident to a law-enforcement agency in the United Kingdom, the reports said. The action followed the company’s identification of a problem involving a third-party provider rather than a security issue described as originating directly within Polymarket’s own systems. Reports linked the provider to DebugBear, a UK-based company that supplies website performance-monitoring tools.

DebugBear’s website was unavailable on Thursday afternoon, according to The Guardian, and the company said on X that it had been “impacted by an ongoing security incident”. DebugBear also advised clients using one of its products to remove the relevant embed code from their websites. The company did not immediately respond to a request for comment cited by The Guardian.

The reports did not provide a technical explanation of what had been compromised or how the incident affected Polymarket’s international service. The temporary suspension limited the disruption to roughly an hour, based on the company’s account. However, the breadth of the incident remained uncertain after trading resumed.

The Guardian said it was not immediately clear to what extent traders had been affected or how wide the impact had been. Both publishers reported the same sequence: a third-party security incident, a precautionary pause, the restoration of trading and a promise of reimbursement. Neither report identified individual traders, specific markets or the value of any transactions affected.

The incident nevertheless placed attention on the external services used by online platforms. In this case, the available reports identify DebugBear as the provider connected to the disruption, but do not establish whether Polymarket’s customers suffered losses, had account information exposed or experienced any effect beyond the temporary trading suspension. Polymarket’s public statements focused on remediation rather than the technical cause.

The company said it had fixed the issue, resumed the international service and sent the matter to UK law enforcement. Further details about the investigation, the number of affected users and the reimbursement process were not included in the supplied reports.