Polymarket Temporarily Froze Trading After Hackers Reportedly Stole Millions Via Third-Party Service

Some traders reported unauthorized withdrawals from their accounts on Thursday as Polymarket temporarily froze trading on its international exchange.

The disruption stemmed from a breach at DebugBear, a web performance monitoring firm located in the UK and a vendor for Polymarket.

Polymarket stated that all customers will receive reimbursement for any losses incurred during this security event.

This incident impacted the international, crypto-based site; the federally regulated Polymarket US exchange was unaffected, according to Wired.

In a thread, Polymarket disclosed that "one of our third party vendors was compromised," shortly after DebugBear tweeted about an "ongoing security incident" affecting its Real User Monitoring (RUM) service.

Blockchain analytics data indicated a suspected attacker stole roughly $2.65 million in tokens.

The platform halted activity around 2:00 p.m. ET, and later announced the matter was resolved as of 3:00 p.m. ET, after reporting the event to police.

This security hiccup follows previous issues, including a $3.1 million phishing spree and a $520,000 theft exploiting contract infrastructure.

The platform, which recently raised $1 billion led by 1789 Capital, has also faced scrutiny regarding alleged insider trading involving figures like Donald Trump Jr., who advises Kalshi.