Polymarket resumed trading on Oct. 29, 2026, after a security incident that preliminary reports said may have drained more than $2.6 million from users of its international platform. The company said it had fixed the issue and would fully reimburse affected traders, but it had not fully confirmed reported account losses.
Polymarket said a third-party provider was compromised and referred the breach to law enforcement. The Wall Street Journal, citing a person familiar with the matter, linked the incident to website-performance monitoring service DebugBear. Preliminary information suggested malicious code may have accessed active user sessions and sold open positions.
