‘Fat Fiinger’ Nightmare? Crypto Trader Just Made $50 Million Mistake

There is no customer service hotline to call when you make a mistake. One trader learned this lesson the hard way after executing what appears to be one of the most devastating errors in recent Ethereum history.

According to on-chain data, an unknown user swapped $50.4 million USDT for a mere 35,900 AAVE tokens, a catastrophic transaction that resulted in an instant loss of over $50 million.

Aave CEO Stani Kulechov confirmed the incident on X. “We sympathize with the user and will try to make a contact with the user, and we will return $600K in fees collected from the transaction. The key takeaway is that while DeFi should remain open and permissionless, allowing users to perform transactions freely, there are additional guardrails the industry can build to better protect users,” he said. 

$50 million on a phone 

Most decentralized exchanges operate on an Automated Market Maker (AMM) model, relying on liquidity pools. The price of an asset in a liquidity pool is determined by a mathematical formula based on the ratio of the two tokens in that specific pool.

The user dumped $50.4 million USDT into the pool and drained its AAVE reserves. The mathematical curve aggressively drove the price of AAVE up within that specific pool.

Slippage tolerance acts as a safety net. It automatically makes a transaction if the executed price deviates too far from the quoted market price (usually set to a 0.5% or 1% limit). For this transaction to go through, the user either manually disabled the slippage protection or overrode the DEX’s warning prompts.

“Given the unusually large size of the single order, the Aave interface, like most trading interfaces, warned the user about extraordinary slippage and required confirmation via a checkbox. The user confirmed the warning on their mobile device and proceeded with the swap,” Kulechov explained. 

CoW Protocol is specifically designed to protect users from bad trades, MEV (Maximal Extractable Value) bots, and extreme slippage by using third-party “solvers” to find the most efficient routing for a trade.

“The transaction could not be moved forward without the user explicitly accepting the risk through the confirmation checkbox. The CoW Swap routers functioned as intended, and the integration followed standard industry practices. However, while the user was able to proceed with the swap, the final outcome was clearly far from optimal,” the CEO noted. 

Kulechov has stated that the Aave team will be investigating ways to improve these safeguards going forward.