A new piece of research says some DeFi liquidity pools are built to lie to the software that routes a user’s trade.

Enso, an onchain development firm, published research on Thursday describing what it calls “toxic pools,” malicious pools that show an accurate, attractive price when a wallet or trading app simulates a swap, then deliver a materially worse result once the transaction is mined.

How the trick works

Most wallets and aggregators decide which route offers the best price by simulating a trade before sending it. A toxic pool is engineered to game that step: it returns a strong quote during the simulation, so routing systems pick it, then behaves differently on-chain. Unlike ordinary slippage or MEV, the deception targets the quote itself, Enso said.

“The industry has spent years optimizing price discovery,” said Milos Costantini, Enso’s co-founder and chief product officer, in a statement accompanying the report he co-authored. “Our findings suggest the next challenge is verifying execution integrity. If transaction simulations can be manipulated while real execution tells a different story, we need better ways to verify what users actually receive.”

What the data shows

Enso documented two cases. A manipulated Curve pool on Ethereum processed more than 129,000 swaps at worse-than-quoted rates, which Enso estimated overstated quotes by roughly $225,000 and burned close to $30,000 in gas on failed transactions. A separate Uniswap v4 hook on Polygon failed 99.1% of the time, repeatedly luring routers before reverting. Enso put the attacker’s realized profit across both pools at about $34,600.

Both pools have since gone quiet, with the Polygon one disabled in May and the Curve pool active through late June. But Enso said the same operator deployed other contracts, suggesting the technique can be repeated, and it found the Ethereum pool alternated between honest and manipulated behavior, so a single check would not catch it.

A vendor with a fix

The disclosure comes as Enso expands Enso Shield, a product it sells to detect exactly this kind of manipulation. The company, which says it has helped settle more than $15 billion onchain, framed the finding as an industry-wide problem and called for independent validation, noting it worked with contacts at Curve and Oku.

Unchained has previously covered how MEV bots quietly extract value from ordinary DeFi trades.

Related Listen: DEX in the City: Why the Market Structure Bill May Not Be Good for DeFi