Circle Launches 1:1 BTC-Backed cirBTC on Ethereum Mainnet, Targets WBTC's $9B Market

Circle launched cirBTC, a 1:1 BTC-backed ERC-20 token live on Ethereum mainnet, positioning the new product against Wrapped Bitcoin's roughly $9 billion market and approximately 85% market share. The product went live June 8, 2026, and is built exclusively for institutional participants, OTC desks, market makers, lenders, and DeFi protocols deploying Bitcoin as collateral inside Ethereum-based smart contract ecosystems. The launch marks Circle's entry into tokenized bitcoin, an arena dominated since January 2019 by BitGo's Wrapped Bitcoin and challenged since September 2024 by Coinbase's cbBTC, which has reached approximately $5.9 billion in market value.

The product's central technical differentiator is real-time reserve verification through Chainlink Proof of Reserve, with no reliance on third-party attestations. Each cirBTC token issued as an ERC-20 on Ethereum is backed by native Bitcoin held in segregated regulated custody, and counterparties can verify that backing in real time through multiple wallet addresses visible directly on the Bitcoin blockchain. According to Circle, the design eliminates waiting periods for monthly audits, custodian claims, and off-chain attestation lag. The company framed the launch in a post on X on June 8, 2026, writing that "cirBTC is live on @ethereum," that "Circle helped establish the institutional standard for dollar collateral with USDC," and that "now cirBTC brings that same approach to Bitcoin, bringing 1:1 BTC-backed collateral to institutional DeFi markets with neutrality, transparency, and Circle."

The competitive target is explicit. WBTC, operated by BitGo as sole custodian, publishes wallet addresses for manual verification, but reserve confirmation still depends on BitGo's centralized control and governance multisig. Coinbase's cbBTC, launched in September 2024, has reached approximately $5.9 billion in market value as an institutional alternative. Circle is entering that race with a specific transparency argument and the institutional trust built over years of USDC issuance. As of the report, $BTC was trading at $63,164.52, down 11.01% over 24 hours, though the price data was unrelated to the launch itself.