Polymarket Confirms User Funds Safe After Private Key Incident

Polymarket Vice President of Engineering Josh Stevens has officially denied rumors claiming the platform suffered a smart contract hack. According to Stevens, all user funds remain secure, and the recent security incident did not compromise Polymarket’s trading infrastructure or liquidity systems.

The panic began after blockchain analysts detected suspicious transfers exceeding $520,000 connected to Polymarket’s UMA CTF Adapter on the Polygon network. The adapter plays a critical role in linking Polymarket prediction markets with UMA’s oracle system, which handles market outcome settlements and payout verification.

Despite early concerns from the crypto community, Stevens clarified that the issue was not caused by a vulnerability in Polymarket’s smart contracts. Instead, the breach stemmed from the compromise of an outdated private key created nearly six years ago. The old key was tied to an internal “top-up config” system used for automated balance replenishment. Once compromised, the attacker managed to redirect funds to an external wallet address.

Blockchain investigators traced the suspicious activity to wallet address 0x8F98...9B91, which allegedly received the stolen assets. Reports also identified a drained technical wallet associated with the platform’s infrastructure.

Polymarket has since taken immediate action to contain the incident. The compromised key was rotated and fully removed from the production environment, while all related permissions were revoked. To strengthen platform security, the company also announced a migration of all sensitive credentials to cloud-based Key Management Systems (KMS), reducing the risk of future private key leaks.

The security event arrives as prediction markets face increasing regulatory scrutiny in the United States. The U.S. House Oversight Committee recently launched an investigation into possible insider trading activities tied to geopolitical and election-related betting markets. Polymarket is expected to submit details regarding its user verification and suspicious transaction monitoring processes by June 5.

Despite both technical and regulatory challenges, Polymarket insists the platform continues operating normally, with no impact on customer balances or trading activity.