On June 23 2022, Harmony (ONE) announced that its bridge to Ethereum and Binance Chain was hacked for roughly $100M in assets. The hacker made 11 transactions over an 18 minute period, sending assets from the Horizon bridge to Uniswap to swap for ETH.
Harmony is a Proof of Stake Layer-1 blockchain with low fees and good Ethereum and Binance Chain integrations. During the last bull run, Harmony was known for its P2E games and meme coins. In January 2022, ONE's market cap reached a high of over $4.1B, but today it's just $302M.
The Horizon bridge is operated by the Harmony team. It connects the Harmony network to Ethereum, Binance Chain, and Bitcoin. Harmony says the Bitcoin bridge and its funds are still safe. In the wake of the Wormhole and Ronin bridge problems, investors speculated that Harmony's Horizon bridge could be next.
In April 2022, a Twitter user representing venture fund Ape Dev brought attention to the Horizon bridge's weak security. The Horizon bridge uses a multi-sig wallet with four owners, and it only takes two owners to sign off on transfers of up to $330M. With security like this, it was just a matter of time until someone hacked Harmony's bridge.
So far, only Harmony's ONE token has taken a hit following the hacker's selloff–down ~10% in the last 24 hours. The hacker stole a wide variety of tokens, including Wrapped BTC (wBTC), Wrapped ETH (wETH), Aave (AAVE), SushiSwap (SUSHI), Frax (FRAX), Frax Share (FXS), AAG (AAG), Binance USD (BUSD), Dai (DAI), Tether (USDT), and USD Coin (USDC). So perhaps the sell pressure wasn't too great on any one stolen asset.