Polymarket Halts International Trading After Vendor Compromise

Prediction markets platform Polymarket suspended trading on its international platform for nearly an hour on Thursday due to a compromise of third-party software. The company committed to fully reimbursing any affected traders following unconfirmed reports of user wallet drains.

What Happened

Polymarket was compelled to halt trading on its international platform, Polymarket.com, for approximately one hour on Thursday, October 29, 2026, due to what it described as a compromise of third-party software, according to NBC News. The company stated in an X post that it had identified and resolved the issue affecting its international operations.

During the outage, users reported on Polymarket’s Discord channel that their cryptocurrency wallets had been drained, though Polymarket did not confirm these reports, as per NBC News. The company subsequently announced on X that “anyone who has been impacted will be made whole” and that it would be “fully reimbursing all affected traders.” The attack reportedly originated in the United Kingdom, and Polymarket has referred the matter to British law enforcement authorities, NBC News reported.

A person familiar with the details, granted anonymity due to the evolving security situation, indicated that hackers accessed funds through software provided by DebugBear, a web analytics and website performance tool. DebugBear had also announced an “ongoing security incident” via X around 2 p.m. ET on Thursday. Crypto news website The Block, citing data from blockchain analysis group Arkham, reported that approximately $2.65 million in cryptocurrencies had been siphoned from Polymarket users’ wallets, a figure a Polymarket representative declined to comment on, according to NBC News.

Key Details

• Polymarket’s international platform, Polymarket.com, halted trading for nearly an hour on Thursday, October 29, 2026, due to a third-party software compromise (NBC News).
• The company confirmed it would fully reimburse all traders impacted by the incident, as stated in an X post (NBC News).
• The attack reportedly emanated from the United Kingdom, and the matter has been referred to British law enforcement authorities (NBC News).
• The compromise specifically involved software from DebugBear, a web analytics tool (NBC News).
• Reports cited by The Block, referencing Arkham data, suggest approximately $2.65 million in cryptocurrencies were siphoned from user wallets (NBC News).

Why It Matters

This incident underscores the cybersecurity risks inherent in digital trading platforms, particularly those reliant on third-party vendors. The compromise of a web analytics tool highlights a common vector for malicious actors to gain access to larger platforms, as noted by NBC News. For Polymarket, which was valued at $21 billion in September and processes approximately $200 million in daily trading activity, this breach represents a significant security challenge.

The company’s swift commitment to full reimbursement aims to mitigate user financial losses and maintain confidence in its platform. The event also occurs amidst ongoing regulatory scrutiny and legal battles concerning the regulation of prediction markets in the U.S., as well as internal investigations into potential insider trading threats related to political events, including the U.S. midterms and Israeli elections, according to NBC News.

What’s Next

Polymarket has referred the incident to British law enforcement authorities for further investigation, according to NBC News. Trading on the international platform resumed at 3 p.m. ET after the nearly hour-long halt. Polymarket’s U.S.-based platform was reportedly unaffected by the breach.