Maximal Extractable Value
Maximal Extractable Value, or MEV, is the maximum profit that miners or validators can extract from blockchain transactions by manipulating their inclusion, exclusion, or ordering within a block. Because validators are responsible for building blocks, they have the power to decide which transactions are processed and in what sequence.
This capability allows them to insert their own transactions, sandwich user trades, or perform complex liquidations to capture arbitrage profits. MEV represents a systemic phenomenon where the consensus layer interacts with the application layer to create economic incentives for transaction manipulation.
While it can improve market efficiency by closing price gaps, it often harms end users by increasing slippage and transaction costs. It is a critical concern for the fairness and neutrality of decentralized financial systems.