Proposal: Arb Fast Lane Vault Vortex

Expected on Snapshot May 12, 2024


  • The Arb Fast Lane has since become a very important part of the Bancor Ecosystem.
  • There are two components to this system
    • Arb Fast Lane Smart Contract - where the bots feeds relevant info
    • Arb Fast Lane Bot - Off-chain logic that anyone can run
      • So far there are 78 callers of this decentralized system.
    • Data can be seen at the links below:
  • The Arb Fast Lane is deployed alongside all Carbon deployments
  • A recent proposal has outlined a method for the Carbon Vortex on Ethereum to sell its tokens: Snapshot
  • I propose to deploy such a vortex on every chain where the Arb Fast Lane Bot system is active. This will allow these vaults to consolidate holdings into a single token in preparation for sending it back to the Carbon Vortex on Ethereum mainnet.
  • No changes are proposed to the Ethereum Vortex as this remains valid.

Arb Fast Lane Vaults Not on Ethereum




As Carbon and licensed deployments expand to more chains, so will the Arb Fast Lane.


  1. Deploy a vortex alongside each Carbon and/or Fastlane deployment.

a. Does not matter if the deployment is licensed or not

  1. That vortex will allow the vault to sell its TKN for a final target token.

Final Target Token

The goal of choosing a final target token is to ensure the fees are all in one token thereby reducing the cost of sending to the Carbon Vortex on Ethereum. The process of sending to Ethereum will be outlined in a future proposal.

Careful consideration should be given to choosing the final target token.

First Choice

  • ETH

ETH is chosen as it can be bridged to the mainnet and has deep liquidity.

Second Choice

  • WETH
  • To be used if it is not possible to set ETH as the final target token

Third Choice

  • Gas token of the chain
  • To be used if it is not possible to set ETH or WETH as the final target token
  • The gas token is only an option if it has liquidity on Ethereum mainnet. Otherwise, it can be bridged to the Ethereum Carbon Vortex but not ever sold if there is no liquidity.

Fourth Choice

  • If none of these is possible, a proposal should be made.


The goal here is to define the correct parameters that will work with most chains without the DAO being required to vote on parameters for each.

Define target token: (Gas Token of the Chain)

Define final target token: See section above

Define Caller Incentive: 0.1% (this represents a reduction from current incentives)

Define Half Life: 12 hours


  • Users can call a public function that does the following:
    • Enable a TKN to Target Token trading
    • Withdraws accumulated TKN from the Arb Bot Vault
    • Caller gets 0.1% of TKN transferred amount (caller incentive)
  • TKN is put up for sale at an arbitrarily high price with exponential decay and defined half life.
  • To prevent abuse, calling this function will reset the auction price if over half of the TKN has been sold already
  • Users can call the public function to trade TKN for target token at any time or price point.
  • If the target token is not the final target token, it is put up for sale for the final target token at an arbitrarily high price with exponential decay and half life of 12 hours.
    • Similar to the POL contract, this can be triggered with a bucket system (LINK)


Deploy the Arb Fast Lane and the Fast Lane Vault Vortex on every chain where there is a recognized Carbon deployment.


Do nothing.


looks good to me tbh


I fully support this proposal.