cirBTC Goes Live on Arc as Circle Expands Bitcoin Collateral for Onchain Finance

• Backing and verification: cirBTC maintains a 1:1 parity with native Bitcoin held in segregated custody at a federally chartered trust bank, with real-time reserve auditing powered by Chainlink Proof of Reserve.
• Initial supply and metrics: As of September 20, 2026, the total supply stood at approximately 949 tokens (with around 397 on Arc and the remainder on Ethereum), backed by 951 $BTC worth roughly $77 million.
• Immediate integrations: Protocols such as Morpho recorded more than $150 million in deposits across their $USDC and EURC vaults during the first day, leveraging cirBTC as a collateral layer.

cirBTC is now live on the Arc network, as confirmed this Monday, September 21, by Circle. This launch aims to channel institutional Bitcoin liquidity into lending dApps and decentralized capital markets.

Bitcoin liquidity is now live on Arc.

cirBTC brings 1:1 $BTC-backed collateral into Arc’s stablecoin-native ecosystem, helping $BTC become productive across lending, trading, collateral, settlement, and treasury workflows.

$BTC as collateral. $USDC as borrow and settlement asset.…

— Arc (@arc) September 21, 2026

The issuance of cirBTC operates under a structure where each unit represents one Bitcoin held in segregated custody, separate from the issuer’s corporate balance sheet. Technical documentation from Arc details that the asset was designed without native yield mechanisms or embedded derivatives, preserving strict parity to prevent operational dislocations. Market participants can acquire the token via direct swap features on the Arc Portal or through official bridge transfers from the Ethereum network.