A cryptocurrency investor lost most of their assets while trying to swap tokens worth about $50 million. More than 99 percent of the value disappeared in a single transaction, drawing attention as a warning case about DeFi trading structures.

CoinDesk reported on March 12 that the user tried to swap $50.43 million worth of EthUSDT, an interest-bearing token, into aEthAAVE. More than 99 percent slippage occurred during the large token swap, cutting the transaction value to about $36,000. As a result, the wallet was left with about 327 aEthAAVE tokens.

The incident occurred during an attempt to swap a token used in Aave’s DeFi lending protocol into another asset. The trade was reportedly executed via CoW Protocol, a decentralised trade-routing optimisation platform.

The exact cause has not been confirmed, but analysts have pointed to the possibility of extreme slippage. Slippage is the difference between the intended execution price and the actual execution price, referring to losses when an order is not filled as requested. If a large order is executed in a pool with insufficient liquidity, prices can become sharply distorted and the trade may be filled at a far worse price than expected.

Another possibility raised is a misconfigured trade order or a routing error. DeFi trades are often executed through multiple smart contracts, creating the possibility of errors in complex paths.

Stani Kulechov (스타니 쿨레초프), Aave’s founder, said the user attempted a swap worth about $50 million and an abnormal slippage warning was displayed on the interface. He added the user appeared to proceed after checking the warning message on a mobile device. He also said Aave plans to return about $600,000 in fees incurred during the process.

The incident is a large loss in terms of a single transaction, but it is not expected to have a major impact on the overall market. The remaining AAVE tokens amount to about 327, which is very small compared with overall market liquidity or market capitalisation.

Still, the incident is seen as another example showing that traders must fully consider liquidity structures and slippage risk when moving large assets in decentralised finance markets. Analysts say it again confirms that in a DeFi environment combining automated arbitrage bots with complex trade routes, small configuration mistakes or a lack of liquidity can lead to losses of tens of millions of dollars.