CoWSwap: Refunds Transaction Fee to User Who Lost Over $50 Million in Slippage When Buying AAVE

On March 13, CoWSwap released an official response to the "User’s $50M+ AAVE Purchase Slippage Loss" incident. Earlier today, a trader attempted to swap 50 million aEthUSDT for aEthAAVE via Aave’s exchange interface—powered by the CoW Protocol. Critically, the user received a clear warning that nearly all their transaction value would be lost, and was required to explicitly confirm proceeding after acknowledging the warning. The user chose to move forward with the swap. It bears noting the CoW Protocol is a decentralized trading aggregator that routes trades through nearly all major public and private liquidity sources. No DEX, DEX aggregator, public/private liquidity pool, or combination thereof could execute this trade at a remotely reasonable price. Blocking users from transacting would deprive them of choice and could lead to severe consequences in some cases (e.g., a market collapse). That said, incidents like this underscore that DeFi’s user experience still hasn’t reached a point where all users are fully protected. As a team, we’re reevaluating how to strike a balance between robust safeguards and preserving user autonomy. We will also refund all fees paid to the CoW DAO for this transaction.