AIP - 61: Relaunch Borrowing Module


This is a proposal to re-launch the Borrowing Module on Ethereum, Polygon, Optimism and Arbitrum and add protocol owned liquidity on Uniswap V3 on Arbitrum and Optimism.


On the day of the Euler hack, the guardian multisig set all debt ceilings on the Borrowing module across all the chains where it is deployed to 0. Rationale for this was to prevent people from further shorting agEUR, and reducing the potential surface of exploit for the protocol.

On top of that, before the hack, the protocol invested its surplus in pair with some minted agEUR in liquidity pools on Optimism and Arbitrum. This vote had for instance led the protocol to seed pools on Arbitrum and Optimism with minted agEUR paired with USDC from the surplus.
To limite potential losses for the protocol and the DAO, this liquidity had been pulled on the day of the Euler hack. Now that funds have been fully recovered in the hack (with an excess), and that the protocol has an around $7m surplus, the protocol is again in position to seed pools with USDC.

Having liquidity on chains where the Borrowing module is deployed is essential as it is a guarantee that liquidations can be done efficiently, with no strong concern of accruing bad debt when a position is badly collateralized.
While on Polygon and Ethereum the protocol does have liquidity through incentives, there is no such thing on Arbitrum and Optimism, and it therefore makes sense to seed pools there.


Proposal is to increase the debt ceilings for all the collateral assets of the protocol to the levels they had before the Euler hack on Ethereum, Polygon, Arbitrum and Optimism.

The protocol controls through its Governor and Guardian multisig 224,636 USDC on Optimism, and 204,675 USDC on Arbitrum.
Idea with the proposal is to add these USDC with minted agEUR on Uniswap V3 on both chains. The protocol already controls minted agEUR on Optimism and Arbitrum (the recovered agEUR were not burnt during the wind down process), so it’d just mint in case there’s not enough in the liquidity positions.


As the funds are already on the multisig, this proposal can easily be implemented by the governor multisig for both the liquidity provision and the debt ceilings parts.

Value to the protocol

There are currently no ways to mint new agEUR in the market with the Core module being open just for mints. Reopening the Borrowing Module provides a safe way to bring more agEUR into the market. The state with the Core module open for burns and Borrowing module enabled is a reliable state for the protocol in which it could safely stay until a Core V2 is out.

There would be little to no composability risk whatsoever and agEUR peg’s could easily be sustained while providing ways for the stablecoin to keep scaling.


This proposal implies using a portion the surplus immediately available of the protocol (surplus already present on Arbitrum and Optimism).
There is a risk of bad debt also possible with the agEUR paired with USDC in the liquidity, but given the size of the pool proposed and the surplus, this risk is acceptable as the surplus could easily absorb it at this point.