Miner extractable value (MEV) is a measure of the profit a miner can make through their ability to arbitrarily include, exclude, or re-order transactions within the blocks they produce.
Miner extractable value (MEV) is a measure of the profit a miner (or validator, sequencer, etc.) can make through their ability to arbitrarily include, exclude, or re-order transactions within the blocks they produce.
Alongside front running, the most common MEV attacks also include back running, which refers to miners making a profit by taking advantage of how the execution of the users transactions will change the market conditions and placing their specific transaction right after the users.
A sandwich attack is the combination of the above two to specifically make a profit and take advantage of the users’ submitted transaction.
All of these forms of MEV can only be executed by miners, as they are the only ones who have the power to organize transactions within a block. This type of value extraction can occur because of the Ethereum mempool design, since the only motivation for miners to include transactions into a block is the amount of rewards they will obtain.