[Circle: cirBTC is now live on Ethereum, providing 1:1 Bitcoin-backed collateral for institutional DeFi] According to official news, Circle has announced that cirBTC is now live on Ethereum, offering 1:1 Bitcoin-backed collateral for the institutional DeFi market. cirBTC is backed 1:1 by native BTC custodied by Circle and provides on-chain reserve transparency through Chainlink's proof of reserves. cirBTC can be integrated with Circle Mint for minting and redemption, forming a unified operational model of dollar liquidity with USDC and Bitcoin collateral. In the future, cirBTC will also expand to multiple chains via Arc.