Polymarket halted all new trading on Thursday, 20 minutes after a trader said $800,000 was drained from his account and warned that other users were hit. The company has not said whether it was hacked.
Until the freeze lifts, users with open positions can cancel pending orders but cannot buy or sell. The trader said a friend lost another $600,000, bringing reported losses to $1.4 million.
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Is Polymarket Hacked？
At 17:45 UTC, the trader, who posts on X as Car, warned users to lock down their accounts.
“If you are a Polymarket user, lock down your account. I just got drained $800,000. Other accounts are also affected. Friend got drained $600k. Please be careful dont interact with the site,” they said.
In a follow-up post, he said every position in his account had been sold.
At 18:05 UTC, Polymarkets status page flagged a major outage. It said the exchange had moved to cancel-only mode while the company investigates an unnamed incident.
Polymarkets status page shows the exchange in cancel-only mode on Oct. 29. Source: Polymarket
Polymarket also paused its relayer. According to its developer documentation, that system sends token transfers and spending approvals on behalf of users Polymarket wallets.
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However, the company has not tied the outage to the drain claims. It has named no cause, victim count, or loss total. BeInCrypto could not independently verify the $800,000 or $600,000 figures.
How Polymarket Handled Junes $3 Million Website Attack
In June, attackers tampered with code from an outside vendor that ran on Polymarkets website, according to reports.
The altered site asked some users‘ wallets to approve transfers to the attackers. About $3 million in pUSD, the dollar-pegged token that serves as Polymarket’s new trading collateral, left fewer than 15 accounts.
The smart contracts holding user funds were not breached. Polymarket then pledged to cover every affected user.
“We are refunding affected users in whole, there are no user ‘losses’,” said William LeGate, Polymarket head of experience.
So far, Polymarket has made no such pledge for Thursdays incident.
The freeze lands two days after Predict.fun, a rival prediction market, lost $400,000 to attackers. Two drain reports in one week put the security of these platforms, not just their markets, under scrutiny.
Polymarket‘s next status update should show whether June’s refund playbook applies again.