Following a $42 million exploit of decentralized exchange GMX's V1 liquidity pool on Arbitrum two days ago, the hacker has started returning stolen assets after accepting GMX's $5 million white-hat bounty offer. The breach, caused by a re-entrancy bug in the OrderBook contract, initially triggered a 28% price crash in GMX tokens.
Blockchain analytics firms confirm the attacker has returned $10.49 million in FRAX tokens as of July 11, 2025. The remaining $32 million—converted to 11,700 ETH during the hack—is now worth $35 million due to market gains, creating uncertainty about whether the hacker will return the initial stolen amount or the current ETH value. GMX's public bounty offer, representing 10% of stolen funds, remains available from its treasury.
The protocol has frozen all V1 trading/minting on Arbitrum and Avalanche, with a post-mortem confirming V2 operations were unaffected. A DAO vote will determine additional user compensation measures. Market response has been positive, with GMX rebounding 15.1% to $13.24 following the fund returns.