Bitcoin is one of the most important collateral assets in digital finance, but native BTC cannot move directly through smart contract markets. cirBTC is designed to connect BTC collateral with USDC liquidity, helping institutions access borrowing, treasury, hedging, and settlement workflows without fully unwinding BTC positions. Now available on Ethereum, with Arc Testnet support coming soon. https://www.circle.com/blog/how-usdc-and-cirbtc-unlock-capital-efficiency(Circle)