Sandwich pattern evidence
This is a deterministic on-chain pattern: the same address appears before and after one or more other swaps in the same block and reverses direction. It is detection evidence, not proof of intent.
01 · The origin
A meme born in plain sight.
Vitalik noticed something beautifully obvious: one animal is literally named “wild beast.” The internet did what it does best. A herd formed.
I still love how there's a type of wild beast that's literally just called a “wildebeest”.vitalik.ethOriginal post · September 19, 2026View the post ↗
02 · The crossing
Every migration has predators.
A transaction entering the public mempool can be seen before it lands. Searchers may reorder around it—much like predators reading a herd at the river. Try both routes below.
Interactive MEV field guide
Mempool bank
Confirmed bank
HERD = pending transactions
RIVER = public mempool
CROCODILES = searchers
RIVER = public mempool
CROCODILES = searchers
Confirmed0Sandwiched0Block#26,074,628
The herd is moving through the public mempool.Crocodiles can observe the crossing and position around a transaction.
Test transactionSearcher activity
This is a simplified teaching model. Not all MEV is malicious, and not every public transaction is attacked.
Ethereum MEV WatchMonitoring ETH/USDC, WETH/USDT and WBTC/WETH Uniswap V2 pools ↗
Calculating current DEX volume coverage…
Calculating current DEX volume coverage…
—patterns · last 24 hours
—transactions caught · 24h
—ETH/USDC swaps · 24h
Reading persisted on-chain history…
Building the persistent archive…
Scope: the ETH/USDC Uniswap V2 pool only. A result is counted when the same actor brackets one or more swaps in the same block, reverses direction, and leaves a positive gross USDC spread before gas. This is detection, not proof of intent.
Scope: the ETH/USDC Uniswap V2 pool only. A result is counted when the same actor brackets one or more swaps in the same block, reverses direction, and leaves a positive gross USDC spread before gas. This is detection, not proof of intent.
03 · The only contract
Verify. Then run.
Names and tickers can be copied. Contract addresses cannot. Always verify the full address before interacting.
Official Ethereum contract
0x57737ded3870e43fed7d80d31e0ced3d5fb0cccc
View on Etherscan ↗