The Arc network's cirBTC market holds $14.3 million in outstanding USDC loans against 287 cirBTC, up from $1.37 million on September 17, according to on-chain data reviewed by The Defiant.

Circle, the issuer of the USDC stablecoin, has opened the Bitcoin-backed borrowing facility to its institutional Mint clients, routing the loan mechanics through Morpho, the on-chain lending protocol. The more than tenfold expansion in roughly two weeks illustrates how stablecoin issuers now layer collateralized debt products onto their core minting and reserve businesses.

How does the loan structure split responsibilities?

The arrangement partitions infrastructure among three parties:

• Circle issues the cirBTC wrapper and operates the custody wallet.
• Morpho sets the loan terms, including collateralization ratios and liquidation thresholds.
• Galaxy and Keyrock supply nearly all of the borrowed USDC into the lending pool.

That division lets Circle offer a Bitcoin-collateralized credit product without building a standalone money-market operation. The wrapper model also lets Circle retain direct custody of the underlying BTC collateral, rather than routing that role to an external custodian.

Who is supplying the USDC?

Galaxy and Keyrock supply almost the entirety of the dollar side of the market. Galaxy operates one of the largest digital-asset trading firms in the U.S., with prime brokerage and execution services. Keyrock is a market maker specializing in liquidity provision across centralized and decentralized venues.

Concentration of supply in two institutional desks raises operational questions for borrowers. The depth of available credit depends on those firms' continued participation. Settlement runs on Arc, Circle's own Layer-1 blockchain, so any upgrade or pause to that network affects loan servicing directly.

What does the growth rate suggest?

The $14.3 million in outstanding credit against $1.37 million on September 17 implies a daily compounding pace inconsistent with retail-led adoption. The shape of the curve points to a single wholesale counterparty, or a small number of large desks, drawing on the facility in stepped tranches.

Circle's Mint-distributed approach anchors the lending relationship to its existing institutional client rail. That setup allows the issuer to monetize USDC reserves and BTC-collateralized credit through one corporate interface, extending the company's reach beyond stablecoin minting into on-chain wholesale credit.

What operational risks remain?

Morpho-determined loan terms mean borrowers face protocol-level liquidation risk, not institutional forbearance, if BTC prices fall below the collateral threshold. The $14.3 million in current borrowing remains small relative to the billions of USDC circulating across Ethereum, Solana and Arc.

Circle has not publicly disclosed whether Mint clients can borrow against other collateral types on Arc, or whether the pool will expand to accept additional USDC suppliers beyond Galaxy and Keyrock. Morpho's loan parameters and Circle's wrapper contract will determine whether the market scales beyond its current institutional base.