Exchange BigONE Hacked for $27M in Hot Wallet Breach

Another exchange hot wallet, another eight-figure loss, but this time with a full-repayment pledge attached from the very first statement.

Crypto exchange BigONE confirmed a $27 million breach of its hot wallet infrastructure after abnormal asset movements tripped its real-time monitoring on July 16. The attacker reportedly infiltrated production servers to bypass internal risk checks rather than exploiting a wallet-level flaw directly, making off with roughly 120 Bitcoin, 350 Ether, 1,800 Solana, and a mix of stablecoins and smaller tokens including SHIB.

BigONE says all private keys remain secure and the attack path has since been identified and contained, and it has activated internal security reserves to keep liquidity pools stable while it works with blockchain security firm SlowMist to trace the stolen funds. The exchange has committed to covering the full loss itself rather than passing any of it on to users.

A server-level breach that bypasses risk checks, rather than a stolen key or a smart-contract bug, points at infrastructure security rather than the custody model itself, and it’s a reminder that “hot wallet” risk isn’t only about where the keys sit. Whether BigONE’s promised full repayment actually gets delivered in full, and how fast, is the part worth watching next.

Not sure how hot and cold wallets actually differ in what they protect against? Learn the basics in the Bitcoin Academy.