Sandwich Trading

Sandwich trading is a form of front-running where an attacker monitors the mempool for pending large buy orders and inserts their own transactions before and after the victim's trade. The attacker buys the asset just before the victim, causing the price to rise, and then sells immediately after the victim's purchase to capture the profit from the price movement.

This technique relies on the transparency of the mempool, where transactions wait to be included in a block. By paying higher gas fees, the attacker ensures their transactions are prioritized by validators.

This practice increases slippage for the victim and effectively extracts value from regular market participants. It is a classic example of exploiting market microstructure and the technical mechanics of blockchain transaction ordering.