Polymarket suspends trading after third-party provider compromise, users report drained funds
Polymarket halts trading amid security incident
Polymarket, a prediction markets platform where users trade on the outcome of real-world events, suspended trading on October 29, 2026, after one of its third-party providers was compromised.
The platform reported its Predictions Trading API experienced a "major outage," leading to a temporary pause in all trading activity. Polymarket first put the platform in "cancel-only" mode, meaning users could only cancel existing positions, not open new ones.
As of 7:05 pm UTC, Polymarket said all of its systems were operational again.
Key details of the incident
- A third-party service provider working with Polymarket was compromised
- The platform's Predictions Trading API suffered a "major outage"
- Trading was temporarily halted, and the platform entered "cancel-only" mode
- All systems were reported back online as of 7:05 pm UTC
- Polymarket has referred the incident to relevant law enforcement
- The platform says anyone impacted by the breach will be "made whole"
User reports of drained accounts
Several users claimed online that their Polymarket accounts had been drained of thousands of dollars. These users said their positions were sold without their permission.
These are user reports and have not been independently confirmed by Polymarket or other sources.
Similar breach in June 2026
This is not the first time Polymarket has faced a security issue involving a third-party vendor. In June 2026, the platform reported that hackers drained more than $2.9 million in user funds by compromising a third-party vendor.
What remains unclear
The exact total amount of user funds affected by the October 29 incident has not been confirmed. Polymarket has also not named the specific third-party provider that was compromised, or shared details about how the breach happened.
It is also unclear how many users may have been impacted by the incident.
Sources
Newisty Editorial Team covers technology, cryptocurrency, digital products, online platforms, developer tools and the wider digital economy. Our content is researched from official sources, company announcements, public documentation, market data and other primary or reputable sources. Articles are reviewed and edited before publication for clarity, accuracy and useful context.