Bean

Bean carries one of DeFi's more infamous scars. In April 2022 an attacker used a flash loan to seize majority governance of Beanstalk, the credit-based algorithmic protocol behind the token, and voted to drain roughly 76 million dollars from its reserves, sending Bean crashing off its dollar peg. The protocol went dark and relaunched that August. Unlike collateral-backed coins, Bean holds no cash or crypto in reserve; it defends its one-dollar target through an algorithmic system of debt and incentives that expands or contracts supply and rewards. There is no issuer to redeem against, so the peg rests entirely on the open market and the protocol's credit mechanics. Bean lives on Ethereum. It is a working example of a purely algorithmic stablecoin still standing after a near-death event, and also a standing reminder of how fragile that design can be.