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Polymarket resumed trading after an exploit led to more than $2.6 million in losses within minutes. The platform had put its exchange in cancel-only mode and paused relayer actions while it investigated. Arkham data showed a wallet identified as belonging to a suspected attacker holding about $2.65 million in POL after multiple USDC.e-to-POL swaps through Relay; funds were then moved to other addresses.
Polymarket said it had found and fixed the cause, attributing the incident to a compromised third-party provider. It referred the matter to law enforcement and said affected traders would be fully reimbursed. During the pause, users could cancel orders, but new orders and trades could not be processed.
Why it matters
The incident highlights the security exposure that can sit beyond a platform’s own exchange infrastructure. Polymarket attributed the compromise to an outside provider, making vendor security and the systems that support trading central to the investigation.
This is not the platform’s first security-related incident. Last year, a bet on whether Ukraine would agree to President Trump’s mineral deal faced an alleged governance attack. Earlier this year, suspicious outflows tied to Polymarket’s UMA CTF Adapter infrastructure on Polygon prompted an internal investigation.
Market impact
The trading pause temporarily restricted activity on Polymarket, while the reimbursement pledge shifts the immediate focus to affected users and the platform’s response. The platform said it was back online after fixing the cause, but the incident adds another security event for users to weigh when relying on prediction-market infrastructure.
Frequently asked questions
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How much was lost in the Polymarket exploit?
More than $2.6 million was lost within minutes. Arkham data showed a wallet identified as belonging to a suspected attacker holding about $2.65 million in POL.
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What did Polymarket say caused the incident?
Polymarket said one of its third-party providers was compromised. The platform said it found and fixed the cause.
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What happened to trading during the investigation?
Polymarket placed the exchange in cancel-only mode and paused relayer actions. Users could cancel orders, but new orders and trades could not be processed.
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Will affected Polymarket traders be reimbursed?
Polymarket said it planned to fully reimburse traders affected by the incident.
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Has Polymarket faced other security-related incidents?
The seed also describes an alleged governance attack on a bet last year and suspicious outflows tied to the UMA CTF Adapter infrastructure on Polygon earlier this year.
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