Circle launches cirBTC on Ethereum with 1:1 Bitcoin backing

Circle has launched cirBTC on Ethereum, introducing a wrapped Bitcoin token backed 1:1 by BTC and supported by onchain reserve verification through Chainlink Proof of Reserve.

According to Circle, cirBTC is now live on Ethereum and is designed to bring Bitcoin-backed collateral into institutional decentralized finance markets. 

In its June 8 announcement, the company said each cirBTC token is backed by an equivalent amount of native Bitcoin held in custody by a regulated Circle entity, with the assets kept separate from Circle’s corporate holdings.

Built for institutions active in lending, market making, treasury management, over-the-counter trading, and settlement, cirBTC allows firms to use Bitcoin as collateral within Ethereum-based smart contract ecosystems without selling the underlying BTC, according to Circle. The company said native Bitcoin can remain in custody while cirBTC moves through onchain financial applications.

Circle added that reserve transparency is provided through Chainlink Proof of Reserve, allowing counterparties to verify backing through multiple wallet addresses visible on the Bitcoin blockchain. According to the company, the system is intended to give trading firms, protocols, and risk teams continuous visibility into reserve holdings.

Circle enters a competitive wrapped Bitcoin market

Following the Ethereum launch, Circle has formally entered a market already populated by several wrapped Bitcoin providers.

When the company first announced cirBTC in April, Circle described the token as a secure and neutral wrapped Bitcoin product for institutional participants. At that time, it said the asset would launch on Ethereum and later become available through Arc, Circle’s layer-1 blockchain infrastructure.

Existing wrapped Bitcoin products already serve a large portion of the market. BitGo-issued Wrapped Bitcoin remains the largest product in the category with an approximately $8 billion market capitalization, while Coinbase Wrapped Bitcoin reached about $5.9 billion after its September 2024 launch, according to Circle’s earlier announcement. Other exchange-backed offerings include Kraken Wrapped BTC, Binance Wrapped BTC, Bitget Wrapped BTC, and OKX Wrapped BTC.

Circle said its business model differs from some competitors because it does not operate a centralized exchange, decentralized exchange, or lending protocol. The company stated that this structure allows institutions to use cirBTC across different trading venues, client relationships, and liquidity networks without concerns about competing with the issuer.

Integration with Circle Mint and Arc

Alongside the launch, Circle said cirBTC can be minted and redeemed through Circle Mint, its institutional platform for managing digital asset liquidity, adding that combining cirBTC with USDC creates a framework where Bitcoin collateral and dollar-denominated liquidity can operate within the same workflow.

Ethereum was selected as the first network because many institutional DeFi, tokenization, and liquidity activities already take place there, according to Circle. Looking ahead, the company said cirBTC is being designed to expand beyond Ethereum through Arc as part of a multichain strategy focused on interoperable financial infrastructure.

Future Arc integration will extend access to wrapped Bitcoin collateral across additional blockchain environments while maintaining the same custody and verification standards.