BeaverBuild's $476K Profit in 45 Days: Backrunning BananaGun via Jaredfromsubway

A Fatter Beaver's Impact on Decentralization.

Sep 17, 2024

As a builder, you have the privilege to see some of the transactions sent to you. For some builders, you can do much more than that.

Yesterday, the famous MEV exposed, MevRefund revealed that Builder Beaverbuild’s new bot shares the same calldata as Jaredfromsubway.eth. He gave these 2 transactions.

Transaction 1 done by Beaverbuild’s new bot:

Transaction 2 done by Jaredfromsubway.eth’s relatively new bot:

Here is the calldata of Beaverbuild’s new bot.

Jaredfromsubway.eth’s relatively new bot’s calldata:

Open the contract profile page of Beaverbuild’s new bot on EigenPhi, we can see:

The bot has earned $6.7K profit over the last 30 days. Seems not that much, right? However, the cost is $412.7K, and it’s well-known that a bot can tip the builder with priority fees to get its transaction on-chain. The tips are also part of the cost.

Take this transaction, for example, in which the bot sends 0.157 ETH as priority fees to Beaverbuild.

It’s an arbitrage backing a trade done by BananaGun, which tips Beaverbuild 0.0002 ETH to get its transaction put on the first position of the block.

The image of the block position can be found here.

So, it’s a win-win scenario for Beaverbuild: the first win comes from the tips by BananaGun, and the second win is the result of its bot’s backrun arbitrage.

You might wonder how you know the bot belongs to Beaverbuild. The contract profile also provides another clue. In the “Builder MEV Acceptance” chart, Beaverbuild takes 98.7% of the 6.7K MEV from this bot.

Using the “transactions involving to” feature, it’s easy to see that most transactions are done in the top section of blocks.

According to Etherscan, the bot was created on August 4th. Since then, it has sent over 200 ETH to Beaverbuild, worth $476K, based on our Builder Rewards Analysis by Bot Dune dashboard, with a majority from private transactions.

To put it into perspective, we computed all the builder payments received by all builders since the bot's birth. It would rank 5th overall in terms of priority fee contribution.

However, it’s not that much compared to Jaredfromsubway.eth’s new bot. Using the dashboard, we can see that Jared’s bot paid 2,291 ETH as priority fees during the same period, while Beaverbuild took 1695 ETH, accounting for 74%.

With all these data in mind, questions still linger:

Does Beaverbuild themselves do the bot or they just outsource the backrun job to Jaredfromsubway.eth?
Is BananaGun aware that their trades are being backrun? If they know, are they and their users getting MEV refunds from Beaverbuild or Jaredfromsubway.eth?
Is Beaverbuild the only major builder backrunning transactions shared with them?

In any case, the income from these backrun arbitrages feeds the beaver fatter and fatter—definitely not a good sign of builder decentralization.

Please leave your comments and any other questions you have.

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