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A crypto trader lost almost all of a $2.01 million Ether swap after a decentralized exchange router sent the order through a low-liquidity pool.
The trader received about $14,500 worth of Lighter tokens, while an Ethereum block builder captured most of the value through a same-block backrun extraction.
1,126 ETH Swap Returned 5,776 LIT
The trader swapped 1,126.44 ETH and received 5,775.66 LIT tokens. The result was a loss of about 99.3% on the trade. The transaction was not described as a wallet hack or a typical phishing theft. It came from how the order was routed and executed on-chain.
Blockchain security firm GoPlus Security said the incident was a “same-block backrun extraction” rather than a classic sandwich attack.
That distinction matters because the loss did not come from an attacker placing trades before and after the victim in the usual sandwich pattern. Instead, the route created a severe price imbalance inside one pool, and another transaction in the same block captured the resulting arbitrage.
Router Sent 1,117 ETH Into Thin AVAIL Pool
The swap route sent about 1,117 ETH into a low-liquidity AVAIL/WETH pool on Uniswap v3. That pushed the trader into buying AVAIL at a heavily inflated price. GoPlus said the execution price was about 120 times higher than what the AVAIL could later be sold for in the market.
The AVAIL was then swapped into about $14,200 of value before the final LIT tokens reached the trader. The route was handled through 0x infrastructure, showing how a quoted swap output can still carry serious routing risk when the path crosses a shallow liquidity pool.
Titan Builder Received 1,018 ETH Reward
GoPlus said Titan Builder was the largest beneficiary from the incident. A backrunning transaction used a small amount of externally sourced AVAIL, sold it into the distorted pool and extracted about 1,072 WETH.
About 1,018 ETH, worth roughly $1.8 million, was then paid to Titan as a builder reward. That does not mean Titan directly removed ETH from the trader’s wallet.
The value came from block ordering and arbitrage around the poor swap route. Titan has generated more than $112 million in block-building revenue this year, based on DefiLlama data cited in market coverage.
Large DEX Trades Face Routing Risk
The loss adds a warning for DeFi users placing large trades through automated routers. Slippage settings are not the only risk.
Traders also need to check the route, pool depth, token path and expected execution before signing, especially when a trade moves through illiquid pairs.
For DEX users, the risk is that a transaction can be valid, approved and executed exactly as routed, while still producing a near-total loss if the path crosses a distorted pool.
