What Is Maximal Extractable Value (MEV)?
Maximal extractable value is the profit a party can capture by choosing the order, inclusion, or exclusion of transactions in a block — front-running a trade, sandwiching it, or reordering to arbitrage. It exists because whoever builds a block controls sequence, and sequence has value. For agents transacting on-chain it is a real cost and a real adversary: a naively submitted transaction can be seen and exploited before it settles.
Why ordering is a market
A public mempool shows pending transactions to everyone, and the builder of the next block decides their order. That power is worth money: a profitable trade can be copied and placed ahead of, or wrapped around, the original. The result is an invisible tax on anyone who transacts without protection.
Agents acting at machine speed and volume are especially exposed, which is why private order flow, intent-based designs, and MEV-aware execution matter as much to agent commerce as the price itself.
Related standards
Questions
Is MEV always harmful?
Not all of it — arbitrage that corrects prices is useful; the harmful kinds are those that extract value from a user, like sandwiching.
Can MEV be avoided?
It can be mitigated — private transaction relays, batch auctions, and intent-based systems reduce the exposure of a naively broadcast transaction.
Keep reading
By Michael Gord · published 2026-10-09 · part of the Agentic Encyclopedia. Dates are the day of publication; events are cited at their own dates.