Onboard cirBTC on Aave V3 Core and Aave V4 Core

Simple Summary

This proposal seeks to onboard Circle Wrapped Bitcoin (cirBTC) to the Aave V3 Core Instance and the Aave V4 Core Instance on Ethereum, with collateral functionality enabled.

Motivation

cirBTC is an ERC-20 representation of native BTC issued by Circle, launched on Ethereum mainnet on June 8, 2026. Each unit is backed 1:1 by Bitcoin custodied at a regulated Circle entity and segregated from Circle's corporate assets.

Onboarding cirBTC as a collateral asset is aligned with the DAO's long-term objectives in several ways:

• It broadens the set of BTC denominated collateral available on Aave, complementing existing wrapped Bitcoin exposures already present on the Core instances.
• It enables users to borrow against a regulated, BTC backed wrapped representation, supporting demand from institutional participants and DeFi protocols.
• It strengthens the Core instances' position as a venue for BTC denominated leverage and liquidity strategies.

Specification

cirBTC: 0x72DFB2E44f59C5AD2bAFE84314E5b99a7cd5075E

Aave V3 Specific Parameters

Instance: Ethereum Core

Parameter	Recommendation
Borrowable	Yes
Collateral Enabled	Yes
Supply Cap	250
Borrow Cap	20
LTV	73%
LT	78%
Liquidation Bonus	5%
Liquidation Protocol Fee	20%
Reserve Factor	50%
Base Variable Borrow Rate	0.25%
Variable Slope 1	4%
Variable Slope 2	60%
Uoptimal	80%
Flashloan Enabled	Yes

A seed amount of 0.001 cirBTC is supplied to the Dust Bin on behalf of the protocol.

Aave V4 Specific Parameters

cirBTC is listed on the Core Hub with the Core Hub's interest rate strategy 0xAD88791B0F81D1FA242f637eB05bee0cbc53fe2f and a Core cirBTC Tokenization Spoke (Wrapped Aave Core cirBTC, waCorecirBTC), and is added as a reserve on the existing Main Spoke.

Spoke Parameters

Chain	Hub	Spoke	Reserve	Collateral Factor	Max Liquidation Bonus	Borrowable	Collateral Risk	Liquidation Fee	Risk Premium Threshold	Receive Shares
Ethereum	Core Hub	Main Spoke	cirBTC	78%	5.55%	TRUE	0	10%	0	TRUE

Add and Draw Caps

Chain	Hub	Spoke	Reserve	Add Cap	Draw Cap
Ethereum	Core Hub	Main Spoke	cirBTC	250	25
Ethereum	Core Hub	Core cirBTC Tokenization Spoke	cirBTC	25	0

In line with WBTC, cbBTC and LBTC on the Core Hub, cirBTC also gets a Tokenization Spoke. Tokenization Spokes serve as the standard entry point for integrators, vaults, aggregators, and other strategies routing liquidity into Aave V4 markets. They are supply-only, so the draw cap is set to 0.

Interest Rate Curve

Chain	Hub	Asset	Base	Slope 1	Slope 2	Uoptimal	Liquidity Fee
Ethereum	Core Hub	cirBTC	0.25%	4%	60%	80%	20%

Price feed Recommendation

We recommend using Chainlink’s SVR BTC/USD feed to price cirBTC on Aave V3 and V4. The same feed already prices BTC wrappers on the Aave V3 Core instance and on the Aave V4 Main Spoke.

Price feed: 0xb41E773f507F7a7EA890b1afB7d2b660c30C8B0A

Disclaimer

This proposal was prepared by Aave Labs in its capacity as a contributor to the Aave ecosystem. Aave Labs has no financial relationship with Circle or any of its affiliates and has not received compensation from Circle in connection with this proposal.

References

• Implementation: AaveV3Ethereum, AaveV4Ethereum
• Tests: AaveV3Ethereum, AaveV4Ethereum
• Snapshot
• Discussion

Copyright

Copyright and related rights waived via CC0.