0x Says Uniswap v4 Hooks Were A Mistake, Hayden Adams Says "Skill Issue"

DEX aggregator 0x published a report on Sept. 14 saying a majority of Uniswap v4 hooks it examined behaved maliciously, claiming many hooks quote one price and settle another. Uniswap founder Hayden Adams and Paradigm researcher Dan Robinson pushed back, saying the problem lies with aggregators' routing choices rather than the v4 hook design.

By AI NewsroomPublished about 8 hours agoUpdated about 8 hours ago0 views

Why It Matters

The dispute centers on who bears risk in permissionless DeFi markets: hook authors or the routers and wallets that send orders. With Uniswap v4 gaining liquidity and volume, the answer affects developer practices, aggregator safeguards, and user safety across major chains.

Key Facts

Date of 0x report: Sept. 14, 2026
Date of Hayden Adams reply: Sept. 15, 2026
Hooks analyzed by 0x: 84,163 across six chains
Classification by 0x: 19.4% safe, 54.2% malicious, 26.4% likely malicious (as of Sept. 11)
Example hook on Base (ETH/NVDAc): 3,946 of 6,516 fills charged fees (60.6%), median fee 18% when charged, $143,037 collected

0x published research arguing that a majority of Uniswap v4 hooks it examined are designed to present tight quotes to aggregators and then execute at worse rates, shifting costs onto routers, wallets and end users. Using a combination of static analysis, dynamic tests and observation of settled trades, 0x said it classified 84,163 hooks across six chains and found 54.2% to be malicious, 26.4% likely malicious and only 19.4% safe as of Sept. 11.

The report named live examples to illustrate the behavior. On Base, a hook pairing ETH with NVDAc reportedly charged fees on 3,946 of 6,516 fills (60.6%), with a median fee of 18% when charged and $143,037 collected in total. Another hook on BNB Chain pairing USDT with WBNB charged 1,619 of 4,879 fills at rates up to 12.8%, collecting $18,592. 0x said routed trades sometimes delivered as much as 50% less at execution than the amount quoted to users.

Uniswap founder Hayden Adams and others from the Uniswap ecosystem rejected the framing that v4 itself is the problem. Adams acknowledged 0x’s figures but argued that aggregators should avoid routing to malicious hooks, pointing to Uniswap’s API which he said vets hooks and routes to Uniswap liquidity without added fees. Paradigm researcher Dan Robinson similarly said 0x’s headline misattributes fault to the protocol, asserting that aggregators must choose which hooks to route and linking to Uniswap’s allowlist and routing guidance.

Engineers and industry voices debated technical mitigations. 0x’s Duncan Townsend said his team invested heavily to support hooks in 0x API but that the hook design creates poor expectations between authors and aggregators, and warned simulation is often ineffective because hooks can detect simulated calls. Monad co-founder Keone Hon argued the issue echoes earlier proprietary AMM behavior and recommended fully onchain routing so route choice happens at execution time, removing a spoofing window. Meanwhile, Uniswap v4 continues to see growing uptake: DefiLlama data cited $1.06 billion in TVL (up 39.9% over 30 days) and $38.12 billion in DEX volume over the same period, underscoring the practical stakes for routers and users.