Circle (
@circle) launched cirBTC on Ethereum on June 8, a 1:1 BTC-backed ERC-20 where each unit sits in segregated, regulated custody at a Circle entity, marking a new product line for Circle beyond the stablecoin categories.
The tokenized Bitcoin market currently exceeds $10 billion in total supply across all wrapped formats, one of the most actively used collateral asset classes in DeFi, yet still represents under 2% of Bitcoin's total market cap.
The vast majority of Bitcoin value sits idle, never deployed as collateral or generating yield. For any issuer that can solve the custody and trust problem convincingly enough to attract that capital, the addressable market is orders of magnitude larger than what exists today.
WBTC and
@coinbase cbBTC are the two dominant wrapped Bitcoin formats on Ethereum, together representing the majority of tokenized Bitcoin supply deployed in DeFi.
The protocol that makes most of that supply productive in DeFi is
@aave, being the primary collateral venue where wrapped BTC is usded as the basis for borrowing, leverage, and liquidity strategies.
Looking at the top 50 Ethereum holders of WBTC ($5B) and cbBTC ($2.5B), Aave V3 absorbs $3.1B (41% of combined supply), more than Morpho Blue, L2 bridges, Compound, SparkLend, and all DEXes combined.
There is already an ARFC to onboard cirBTC on both Aave V3 Core and Aave V4 Core on Aave governance, also bringing DeFi utility to Circle new asset.
Running in parallel on Aave V4, @babylonlabs is integrating Trustless Bitcoin Vaults into Aave V4.
Under this model, users lock native BTC directly on the Bitcoin blockchain in Taproot UTXOs and use that position as collateral to borrow stablecoins on Aave V4 through a dedicated Babylon Core Lending Spoke, without wrapping, bridging, or giving up custody at any point. Babylon has already secured 51k BTC trustlessly. This is the first major native BTC collateral primitive on Aave V4.
Bitcoin's market cap stands at $1.32 trillion. The entire tokenized BTC market represents roughly $10 billion in deployed supply, under 2% of that total. Every incremental unit of Bitcoin that moves into regulated wrappers like cirBTC, or gets deployed trustlessly through primitives like Babylon's native BTC vaults, expands the total productive capacity of DeFi in a way that hardly any new stablecoin or synthetic asset can replicate.