Circle Deploys cirBTC on Ethereum, Letting BTC Holders Tap DeFi Without Selling

Circle has launched cirBTC on Ethereum, allowing institutions and BTC holders to deploy bitcoin as collateral in decentralized finance ( DeFi) markets without selling their underlying position.

• Key Takeaways:
• • Circle launched cirBTC on Ethereum with 1:1 BTC backing and segregated custody at a regulated entity.
• • Chainlink Proof of Reserve gives institutions independent, onchain visibility into cirBTC’s BTC holdings.
• • Circle plans to integrate cirBTC with its Arc infrastructure and expand to additional chains beyond Ethereum.

What cirBTC Is

Every cirBTC token is backed 1:1 by native bitcoin. The underlying BTC is held at a regulated Circle entity and kept separate from the company’s corporate balance sheet. Minting and redemption flow through Circle Mint, the firm’s institutional on-ramp.

The launch is early-stage. At press time, the circulating supply stands at approximately 0.0097205 cirBTC across roughly seven holders, according to Etherscan stats.

Why Ethereum

Native bitcoin cannot interact directly with Ethereum smart contracts. Wrapped versions solve for this by issuing a token that mirrors BTC’s value and can move through DeFi protocols.

In the press release published this week, Circle noted that it chose Ethereum as the initial deployment target because institutional DeFi infrastructure is already concentrated there. Lending markets, DEX liquidity pools, tokenized asset platforms, and stablecoin settlement layers operate continuously on the network, giving cirBTC immediate access to established workflows.

Reserve Verification

cirBTC is built with Chainlink Proof of Reserve, which provides ongoing onchain visibility into the BTC holdings backing each token. Counterparties, trading firms, and risk desks can independently verify the reserves directly on the Bitcoin blockchain, without relying on off-chain attestations.

The Neutrality Argument

Circle does not operate a competing exchange, DEX, or lending protocol. The firm frames this as a structural advantage for institutions that need a wrapped BTC issuer with no conflicting venue interest. The stated goal is for cirBTC to work across a client’s own trading venues, liquidity relationships, and risk policies.

What It Means for BTC Holders

For institutions running treasury operations, over-the-counter (OTC) desks, or market-making books, cirBTC creates a path to use bitcoin as active collateral across Ethereum-based protocols without requiring a sale. Native BTC stays in custody; cirBTC does the work in the smart contract layer.

Circle also positions cirBTC within its broader product stack. USDC, the company’s dollar-backed stablecoin, already operates in many of the same DeFi markets where cirBTC will be used, creating a combined collateral and liquidity model for institutions already using Circle’s infrastructure.

What Comes Next

Ethereum is the starting point. Circle has flagged Arc, its stablecoin finance infrastructure, as the next integration target for cirBTC, with a broader multichain rollout planned over time.

The launch puts Circle in direct competition with existing wrapped BTC products, including WBTC and Coinbase’s cBTC.