Trader on Ethereum lost $2 million after swapping 1,126 ETH in illiquid pool, GoPlus Security reported

Price impact from pool route deepened losses

Instead of receiving assets close to the original amount, the trader ended up with just 5,776 LIT tokens, valued at around $14,200. GoPlus Security clarified that the loss was not caused by a hack or a standard front-running scenario. Rather, it resulted from a backrunning arbitrage mechanism operating within the same block, exploiting price inconsistencies caused by the trade. GoPlus Security is widely recognized for its work on blockchain and smart contract risk assessment.

GoPlus Security emphasized that this was not a security breach or typical front-running, but rather price manipulation from a backrunning arbitrage opportunity occurring within the same block.

The ill-fated swap was routed through the AVAIL/WETH pool on Uniswap V3. With extremely limited liquidity in this pool, the large ETH order instantly pushed the AVAIL token price far above its actual market value. This forced the trader to purchase the token at a dramatically inflated price, resulting in severe losses.

Backrunning arbitrage within the same block draws attention

The transaction continued across additional trading routes. After the AVAIL tokens were swapped for USDC, the trader then bought LIT on Uniswap V4. However, due to unfavorable price execution along each step, almost the entire value of the original ETH was wiped out.

As explained by GoPlus Security, after the large swap disrupted prices in the AVAIL/WETH pool, a backrunning participant acquired AVAIL at or near the fair market value from another source. That trader then sold the tokens into the artificially inflated pool, extracting more than 1,072 WETH as profit.

Glossary: MEV (Maximal Extractable Value) refers to the extra profit gained from prioritizing and ordering transactions during block production. A “backrunner” is a participant who quickly moves in to profit from temporary price swings caused by a large order.

On-chain data showed that roughly 1,018 ETH was subsequently sent to Titan Builder as a block producer payment.

Low liquidity raises risk for large trades

Blockchain records reveal that about 1,018 ETH was later paid to Titan Builder as a block builder fee. This highlights how MEV participants can seize pricing imbalances during block production to generate significant revenue. Titan Builder stands out as a key transaction organizer within the Ethereum block-building ecosystem.

The incident has reignited debate about the risks associated with processing large orders through pools with limited liquidity. When a sizable transaction passes through such markets, even a single order can cause rapid and extreme price fluctuations. While arbitrageurs often restore price equilibrium after the fact, users may end up paying far above the true market value during these episodes.

Ultimately, this example underscores the need for smarter routing technologies in decentralized trading. Systems that avoid illiquid pools and better estimate transaction costs on a route-by-route basis could help prevent similar costly errors in the future.