Monad co-founder Keone Hon said on X that an article published by 0x earlier in the day examined what he called an interesting and critical phenomenon, one that first appeared in PropAMM, or proprietary AMMs, and has now spread to Uniswap v4 Hooks.
In Hon’s description, malicious market makers toggle between extremely tight quotes and extremely wide ones. They use the tight quote to get selected by aggregators. Once a user’s trade is actually routed to that venue, the quote shifts to a much wider spread.
He said slippage settings, meaning limit-price protection, can shield some users by causing the trade to fail outright. But users who allow higher slippage tolerance can still be exposed to severe losses. According to the article cited by Hon, some Hooks have been switching maliciously between 0% and 18% fees.
Hon also said Solana published a strong article several months ago analyzing a similar pattern on Solana aggregators. In that case, the fee cap was around 1% rather than 18%. He added that the article was quietly taken down a few days later.
Hon wrote that the vision of open systems is to remove middlemen and hidden charges. Aggregator spoofing, in his view, amounts to a large hidden tax. He said the issue can only truly be solved through fully on-chain order routing.
That approach, he added, depends on ample computing power and flexible account access. It also requires a highly performant, efficient Ethereum Virtual Machine, or EVM, along with a well-designed on-chain routing protocol.
Earlier in the day, 0x said the number of malicious Uniswap v4 Hooks has risen noticeably in recent periods. Some Hooks offer attractive prices during the quoting stage, then change the execution price at settlement, allowing funds to be taken from users through aggregators, wallets, and trading apps.