Slippage Attacks
Web3 / defi
Slippage attacks manipulate the execution price of trades on automated market makers (AMMs) by exploiting the price impact of large transactions or by front-running and sandwiching trades. When users submit trades on AMMs, the actual execution price may differ significantly from the quoted price due to the trade's size relative to the liquidity pool. Attackers can observe pending transactions in the mempool, submit their own transactions before the victim's trade to move the price unfavorably, and then profit as the victim receives fewer tokens than expected. This practice, known as sandwich attacks, extracts value directly from traders through manipulated slippage. Example: During high network congestion in 2021-2022, sophisticated bot operators systematically sandwich attacked Uniswap users, front-running large swaps to increase slippage and then selling their position at the higher price after the victim's transaction, extracting millions in profits. Why it matters for DeFi: Slippage attacks represent a significant hidden cost for retail traders and undermine trust in decentralized exchanges. Users must set tight slippage tolerances and understand MEV implications, while protocols are developing solutions like MEV-resistant mechanisms and intent-based architectures.
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