0xd2a79f26…5a0csent to0x309a862b…c8c0·#25,726,296·view on Etherscan
# Update Comet version on Linea and Scroll
## Proposal summary
This proposal upgrades the Compound III USDC and WETH markets on Linea and the USDC market on Scroll to a new Comet version that changes how the base supply index is capped in markets that have lenders but no borrowers.
Previously, `accruedInterestIndices()` applied a post-accrual clamp: whenever `totalBorrowBase == 0`, if `presentValueSupply(totalSupplyBase)` exceeded the Comet's base token balance, `baseSupplyIndex` was forced down to `(balance * BASE_INDEX_SCALE) / totalSupplyBase`. This protected lender withdrawals in reserve-funded markets with no borrowers, but only corrected the index after it had already been pushed too far.
The new version enforces the same cap earlier, in `getSupplyRate()`: when utilization is `0` and `presentValueSupply(totalSupplyBase) >= balanceOf(this)`, the supply rate returns `0`, so accrual stops before the index overshoots rather than being corrected after the fact. Because a single accrual step still applies one rate over the full `timeElapsed`, a long gap between accruals can still overshoot the cap by a few wei; after that, `getSupplyRate()` returns `0` and the supply index no longer increases.
Further detailed information can be found in the corresponding [pull request](https://github.com/compound-finance/comet/pull/1139).
## Audit
The new Comet version has been audited by [Certora](https://certora.cdn.prismic.io/certora/o_tSg8jfh3YhErQ7_Woof-CometPRs-FinalReport.pdf) and no issues were found.
## Proposal Actions
The first action updates the Comet implementation version in V2 Factory on Linea and deploys and upgrades the USDC and WETH Comets to the new implementation.
The second action updates the Comet implementation version in V2 Factory on Scroll and deploys and upgrades the USDC Comet to the new implementation.