What Is Maximal Extractable Value?
Maximal Extractable Value (MEV, formerly Miner Extractable Value) is the profit that block producers can extract by strategically ordering, including, or excluding transactions within the blocks they create. MEV arises from the block producer's power to determine transaction ordering — they can front-run profitable trades, back-run liquidations, or sandwich DEX swaps.
How Maximal Extractable Value Works
Common forms of MEV: sandwich attacks (buying before and selling after a victim's DEX swap), arbitrage (correcting price discrepancies across DEXs), liquidation (being first to liquidate undercollateralized DeFi positions), and backrunning (placing a transaction immediately after a large trade to capture the price impact). MEV infrastructure like Flashbots has created a specialized ecosystem of searchers, builders, and validators.
Why It Matters for Traders
MEV directly impacts every DeFi user through: worse execution on DEX swaps (sandwich attacks), higher gas prices during competitive MEV opportunities, and delayed transactions when not prioritized by block producers. Protecting against MEV requires: using private transaction relays (Flashbots Protect), setting tight slippage tolerances, and understanding which transaction types are vulnerable. The MEV landscape is a hidden tax on DeFi activity that most users don't even know they're paying.
