Trading infrastructure provider 0x says it has observed malicious Uniswap v4 hooks that present attractive swap quotes but deliver worse results when trades execute. Its September 14 research post describes the issue as a risk for aggregators, wallets and trading applications.
Hooks let pool developers attach custom behavior to operations such as swaps. According to 0x, abusive implementations can distinguish quotation from execution or apply behavior that makes the displayed output unreliable. The company reports examples delivering up to 50% less than the quoted amount.
What the findings establish
These are 0x's observations and classifications. They should not be read as proof that every Uniswap v4 pool is unsafe, or as an independently verified loss total across the protocol.
The company says it uses detection and pool screening to exclude suspicious routes. Its recommendations include checking that quoted amounts match execution behavior and giving applications a way to remove risky routes quickly.
For a swap user, the distinction is practical: a familiar interface and a competitive displayed quote do not, by themselves, establish that the underlying pool behaves safely.