Curriculum·G104 MEV Analysis·about 30 min
What MEV is, and where it lives in the block
By the end of this lesson you can
- →Define MEV as the value extractable by controlling the order of transactions in a block
- →Explain how an Ethereum validator reordered MEV bots' own transactions to take about 25 million dollars
- →Compute why ordering, not just inclusion, is where the value sits
- →Locate MEV in the block: who chooses the order, and what that choice is worth
Graduate · enrolled learners
This lesson opens with The MEV sandwich reversal, 3 April 2023.
- What happened
- Sandwich bots on Ethereum make money by controlling order: they place a buy just before a victim's trade and a sell just after, capturing the price move the victim causes. For years this worked because the bots could position their transactions around the victim's. On 3 April 2023 the tables turned. A validator, the party that assembles and orders the transactions in a block, exploited a vulnerability in the software the bots used to submit their bundles, and instead of honoring the bots' intended ordering it unbundled and reordered their transactions against them, seizing about 25 million dollars of the tokens the bots had staged for their own sandwiches. The bots were beaten at their own game by the one participant with final authority over order. Every step of it is legible on-chain, because MEV is a consequence of transaction ordering and ordering is a public, recorded fact.
- The decision point
- Most people picture a block as a bag of transactions that either make it in or do not, and reason only about inclusion. The value that MEV names lives one level deeper, in the order. Within a block, whoever decides the sequence of transactions can insert, front-run, back-run, and sandwich, and that power to arrange is worth money, sometimes a great deal of it. The April 2023 reversal is the sharpest possible illustration: the sandwich bots' entire business was exploiting order against victims, and they lost 25 million dollars to the validator who held ultimate authority over order and turned it on them. This is the foundation of MEV analysis: value is extracted not by getting a transaction included but by controlling where it sits relative to others, so the analyst reads a block as an ordered sequence, asks who chose that order, and asks what the choice was worth.
- Recorded loss
- $25,000,000
What you will be able to answer
- →What is MEV?
- →What happened in the April 2023 MEV reversal?
- →Why does MEV live in ordering, not inclusion?
- →Why is MEV legible on-chain?
Orientation and Year One are open: anyone can read them without an account. From Year Two onward the lessons are for enrolled learners, because progress through the later years only means anything if it is tracked against a record.
It is free. We do not sell the list and there is nothing to buy at the end of it.
Sources and review
- https://www.coinbase.com/en-gb/blog/around-the-block-25m-mev-bot-exploit
- https://ethereum.org/en/developers/docs/mev/
- https://www.paradigm.xyz/2021/02/mev-and-me
Confidence high·Volatility high·Reviewed 2026-09-15·Owner unassigned
Contested
The 3 April 2023 exploit is widely reported at about 25 million dollars; exact figures and the precise vulnerability in the relay software are described across analyses and were the subject of a criminal case. The mechanism, a validator reordering bundles it was trusted to relay faithfully, is the documented core.
MEV is a broad and evolving phenomenon; this lesson defines it via ordering and uses one vivid case, and later lessons cover its specific forms.