Glossary
Sandwich Attack
An MEV technique where a searcher buys an asset just before a victim's swap and sells it immediately after — extracting the slippage the victim takes.
A sandwich attack works in three transactions: front-run the victim's swap by buying the same asset, let the victim's swap execute (now at a worse price because of the front-run), then sell immediately back into the pool the victim just moved.
The victim pays for the attacker's profit in the form of extra slippage. Sandwiches are most profitable on large swaps with loose slippage tolerances; users defend by tightening slippage, using private mempools (Flashbots Protect, MEV Blocker), or routing through aggregators that simulate execution privately.