Sandwiches

The most harmful type of MEV is sandwiches. Sandwiches make money by maximizing the slippage of a user's transaction.

For example, let's say you want to swap 1 ETH for 2000 USDC and you set the slippage to 5%. Which means that you'll accept at minimum 1900 USDC for your 1 ETH (2000 - 5%). Sandwiches bot will maximize your slippage to 5% and pocket the $100.

The way sandwich bots maximize slippage is by placing a buy order directly before your transaction and a sell order directly after your transaction:

A sandwich