Circle deployed cirBTC on Ethereum this week, issuing a wrapped bitcoin token backed 1:1 by native BTC held in segregated custody at a regulated Circle entity. The launch integrates Chainlink Proof of Reserve to provide onchain visibility into the underlying bitcoin holdings, enabling institutions to independently verify reserves on the Bitcoin blockchain. Circle chose Ethereum as the initial deployment target because institutional DeFi infrastructure—including lending markets, DEX liquidity pools, and stablecoin settlement layers—is already concentrated on the network, giving cirBTC immediate access to established workflows. The product allows institutions to use bitcoin as active collateral across Ethereum-based protocols without requiring a sale of the underlying BTC. Wrapped bitcoin products solve the technical barrier that prevents native bitcoin from interacting directly with Ethereum smart contracts, creating a tokenized version that mirrors BTC's value and can move through decentralized finance protocols.
Circle Deploys 1:1 BTC-Backed Token on Ethereum
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. Circle does not operate a competing exchange, DEX, or lending protocol, positioning cirBTC as a neutral infrastructure product for institutions that need a wrapped BTC issuer with no conflicting venue interest.
Etherscan Data Shows Early-Stage Adoption
At press time, the circulating supply stands at approximately 0.0097205 cirBTC across roughly seven holders, according to Etherscan stats. The launch is early-stage.
Ethereum Chosen for Established Institutional DeFi Infrastructure
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.
Chainlink Proof of Reserve Enables Onchain 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.
Institutional Use Cases for Wrapped Bitcoin Collateral
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.
Circle Plans Arc Integration and Multichain Expansion
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.
FAQ
What did Circle deploy on Ethereum this week?
Circle deployed cirBTC on Ethereum this week, a wrapped bitcoin token backed 1:1 by native BTC held in segregated custody at a regulated Circle entity, with Chainlink Proof of Reserve integrated for onchain verification of the underlying bitcoin holdings.
Why did Circle choose Ethereum as the initial deployment target for cirBTC?
Circle chose Ethereum because institutional DeFi infrastructure—including lending markets, DEX liquidity pools, tokenized asset platforms, and stablecoin settlement layers—is already concentrated on the network, giving cirBTC immediate access to established workflows.
How does Chainlink Proof of Reserve work with cirBTC?
Chainlink Proof of Reserve provides ongoing onchain visibility into the BTC holdings backing each cirBTC token, allowing counterparties, trading firms, and risk desks to independently verify the reserves directly on the Bitcoin blockchain without relying on off-chain attestations.
