Circle has launched cirBTC on Ethereum, adding a wrapped Bitcoin token backed 1:1 by BTC held in custody by a regulated Circle entity. The company said those assets are kept separate from Circle’s corporate holdings, and reserve visibility is supported through Chainlink Proof of Reserve.
According to Circle, cirBTC is built for institutional decentralized finance use cases and is meant to bring Bitcoin-backed collateral into Ethereum-based smart contract markets. Firms active in lending, market making, treasury management, over-the-counter trading, and settlement can use Bitcoin as collateral without selling the underlying BTC. Native Bitcoin remains in custody, while cirBTC moves across onchain financial applications.
Reserve checks are tied to Chainlink infrastructure
Circle said counterparties can verify cirBTC backing through Chainlink Proof of Reserve, using multiple wallet addresses visible on the Bitcoin blockchain. The setup is intended to give trading firms, protocols, and risk teams continuous visibility into reserve balances and custody holdings. For institutional users, that verification layer is a central part of the product design.
The company has framed cirBTC as an institutional product since its first announcement in April, when it described the token as a secure and neutral wrapped Bitcoin offering. At that time, Circle said the asset would launch first on Ethereum and later expand through Arc, its layer-1 blockchain infrastructure.
Circle enters an already crowded wrapped BTC segment
The launch places Circle in a market that already includes several established wrapped Bitcoin issuers. BitGo-issued Wrapped Bitcoin remains the largest product in the category, with an estimated market capitalization of about $8 billion. In an earlier announcement cited by Circle, Coinbase Wrapped Bitcoin had reached roughly $5.9 billion after its September 2024 launch. Other exchange-linked products include Kraken Wrapped BTC, Binance Wrapped BTC, Bitget Wrapped BTC, and OKX Wrapped BTC.
Circle said its structure differs from some rivals because it does not run a centralized exchange, decentralized exchange, or lending protocol. In the company’s view, that allows institutions to use cirBTC across trading venues, client relationships, and liquidity networks without dealing with direct competition from the issuer itself.
Circle Mint access and future Arc expansion
Circle said cirBTC can be minted and redeemed through Circle Mint, its institutional platform for digital asset liquidity management. The company also said pairing cirBTC with USDC creates a framework in which Bitcoin collateral and dollar liquidity can operate in the same workflow.
Ethereum was chosen as the first network because a large share of institutional DeFi, tokenization, and liquidity activity already takes place there, according to Circle. The company added that cirBTC is being designed to expand beyond Ethereum through Arc, extending wrapped Bitcoin collateral into more blockchain environments while keeping the same custody and reserve verification standards.