MEV (Maximal Extractable Value)
Profit that validators or searchers can extract by reordering, inserting, or censoring transactions within a block, often at the expense of ordinary users.
Also known as: miner extractable value, MEV bot
Last reviewed: 10 June 2026
MEV (formerly 'Miner Extractable Value') refers to the additional profit that block producers can generate by controlling which transactions are included in a block and in what order. Specialised bots called 'searchers' scan the mempool for profitable opportunities and submit competing transactions, paying higher gas to get priority placement.
From a consumer-harm perspective, MEV manifests most visibly through sandwich attacks (placing transactions around a victim's trade to profit from the price movement) and front-running. Users who submit large swaps on decentralised exchanges with high slippage tolerance are particularly vulnerable to value extraction they may not even notice.
Privacy-preserving mempools and transaction routing services (such as MEV-protected RPC endpoints) can shield ordinary users from some MEV extraction by submitting transactions directly to block builders without broadcasting them publicly first.