Titan Builder Nets $1.8M as Router Sends $2M ETH Swap Through Thin AVAIL Pool

A trader swapping 1,126.44 ETH — worth roughly $2.01 million — walked away with just $14,500 in tokens after a decentralized exchange router sent the order through a thin liquidity pool, letting an Ethereum block builder pocket $1.8 million in the same block. GoPlus Security labeled the incident a “textbook case of same-block backrun extraction,” a distinct pattern from the more familiar sandwich attack.

The swap occurred Monday at 1:59 am UTC. Instead of routing efficiently, roughly 1,117 ETH was pushed into a low-liquidity AVAIL/WETH pool on Uniswap v3, executing at approximately 120 times the price AVAIL could later be sold for on the open market, according to GoPlus Security.

Anatomy of the extraction

The trader initially received nearly 6.67 million AVAIL tokens at the inflated price. The 0x router then sold a small amount of externally sourced AVAIL into that same pool, extracting approximately 1,072 WETH from the imbalance it had just created.

From that extracted value, 1,018 ETH — worth $1.8 million — was paid to Titan Builder as a block reward. The remaining AVAIL was then swapped for just $14,200 worth of Lighter (LIT) tokens, leaving the trader with a 99.3% loss on the original transaction.

“This was a real, highly imbalanced backrunner arbitrage, not a classic sandwich attack,” GoPlus Security said, drawing a distinction traders should track when auditing routing risk on DEX aggregators.

Route inspection, not confirmation speed, was the failure point

Crypto trader Ruslan Khairullin pointed to signature latency as the root cause. “This is what happens when you clicked confirm faster than you read the route. Painful lesson to see in a real time,” he said.

For active traders, the takeaway is procedural: aggregator-quoted routes through unfamiliar or shallow pools carry execution risk that a simple slippage tolerance setting does not capture. A route touching a pool with limited depth can be arbitraged intra-block regardless of the slippage parameter set at signing.

Titan Builder’s MEV revenue keeps climbing

Data from DefiLlama shows Titan Builder has generated $112.6 million in revenue from block-building services so far this year. The builder’s largest single day came in March, when it extracted around $34 million in arbitrage profit tied to a MEV bot incident on CoW Protocol.

The recurrence of large single-block extractions involving the same builder underscores a structural feature of current block-building markets: builders that consistently capture outsized MEV opportunities tend to compound revenue over time, reinforcing incentives to prioritize orderflow that produces backrunnable imbalances.

Cointelegraph reported it reached out to Titan for comment but had not received a response at time of publication.