Polymarket Halts Trading After Third-Party Breach Drains User Wallets
Polymarket suspended its international platform on October 29 after a breach of a third-party vendor led to unauthorized withdrawals from user accounts. The company pledged to reimburse affected traders and referred the incident to UK authorities. Trading resumed after nearly an hour, though the U.S. platform remained unaffected.
Key points
- Polymarket halted trading on its international exchange on October 29 following a security incident involving a third-party provider.
- Users reported unauthorized withdrawals from their wallets on social media and Discord channels, prompting the platform to suspend operations.
- The breach is attributed to a compromise of DebugBear, a website performance monitoring service based in the United Kingdom.
- Polymarket stated it has fixed the issue and pledged to fully reimburse any impacted traders, referring the matter to UK law enforcement.
- The incident occurred just days before the U.S. midterm elections, a period expected to see heightened trading volumes on prediction markets.
Background
This incident follows a similar third-party vendor compromise in June 2026, where Polymarket also pledged to refund affected users. The platform, valued at $21 billion after a September investment led by Donald Trump Jr., operates its international exchange on the Polygon blockchain and is not regulated in the U.S. The archive note regarding Google Pixel updates is unrelated to this financial security breach.
How outlets are covering it
CNBC identified the compromised third-party provider as DebugBear, a UK-based performance monitoring platform, and noted that Polymarket referred the matter to UK authorities. NBC News highlighted that while Polymarket did not initially confirm specific losses, crypto news outlet The Block reported approximately $2.65 million in cryptocurrencies were siphoned, citing blockchain analysis group Arkham. Both outlets agreed that the U.S. platform was not affected and that trading resumed at 3:00 p.m. ET. CNBC emphasized the timing relative to the November 3 midterms, while NBC News contextualized the breach within broader regulatory battles between U.S. states and the Trump administration over prediction market oversight.
Why it matters
The breach highlights the vulnerabilities inherent in decentralized finance platforms relying on third-party vendors, especially ahead of high-stakes political events. It underscores the risks of unauthorized fund withdrawals in unregulated international exchanges and the potential financial impact on users during periods of heightened market activity.
What to watch
Polymarket is expected to continue reimbursing affected traders and cooperating with UK law enforcement. The platform will monitor for further security issues as trading volumes rise ahead of the U.S. midterm elections on November 3. Regulators may scrutinize the incident as part of ongoing debates over the oversight of prediction markets.
- Some Polymarket user funds stolen by hackers, exchange referring matter to U.K. authorities CNBC
- Polymarket trading halted after vendor compromise; impacted users will be ‘made whole’ NBC News
- Polymarket halts trading on international platform after third-party provider compromised Reuters
- Polymarket Trading Halted After Reports of Stolen Funds Bloomberg.com
- Polymarket Pauses Trading After Some Users Report Funds Drained WSJ
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