MEV is an acronym for "maximal extractable value," which is a method to maximize their profits by including, excluding or changing the order of transactions in a block. MEV bots "front-run" users transactions just before they are confirmed on the network. They do so by copying them but setting a higher gas fee to push transactions through ahead of the original one.
Another way to extract value from incoming trades is to submit a sell/buy order between trades. For example, if the MEV bot places a large sell order just before a large buy order, it could decrease the asset price. The goal is to repurchase the asset at a lower price, which the bot would sell for a higher price. This MEV strategy is called a “sandwich attack”
Essentially, this is a malicious way of manipulating the underlying price of the asset so that the bot can steal the price difference from the user.
In addition to several other tokens, this bot's wallet is worth around $4 million.