Circle Launches Bitcoin-Backed USDC Borrowing in Circle Mint

Short answer: On September 21, 2026 Circle launched Digital Asset-Backed Borrowing in Circle Mint, a service that lets eligible institutional customers borrow USDC against bitcoin without selling it. The customer deposits BTC, mints Circle Wrapped Bitcoin (cirBTC), supplies it as collateral to a third-party lending market and receives USDC in the Circle Mint balance. It runs on Arc and Ethereum, with Morpho as the only protocol at launch and Aave announced for later. It is not available to retail users or to customers in New York, and Circle itself does not originate or fund the loans.

What did Circle launch?

Circle Mint is the company's platform for institutions that mint and redeem USDC directly. The new feature adds a borrowing workflow on top of it. Instead of selling bitcoin to raise dollars, a treasury team can keep its BTC exposure and take an overcollateralized USDC loan. Circle presents it as one coordinated process: the steps that previously required several separate services — wrapping BTC, moving it on-chain, opening a position in a DeFi market and bringing the dollars back — are handled inside Mint.

The key design choice is that Circle acts as infrastructure, not as the lender. The loans come from Morpho markets funded by third parties, and Circle states that interest rates, collateral requirements, liquidation thresholds and available liquidity are set by the chosen market and can change over time. Because positions are overcollateralized, access depends on collateral and market parameters rather than a traditional credit check.

The launch landed on the same day bitcoin reached an eight-month high above $87,000, before slipping back toward $85,000 on September 22. It also came days after Circle opened the Arc mainnet, its own layer-1 blockchain, where cirBTC is now available.

Key facts at a glance

Item	Detail
Product	Digital Asset-Backed Borrowing in Circle Mint
Launch date	September 21, 2026
Who can use it	Eligible institutional Circle Mint LLC customers; no retail access; New York excluded
Collateral	BTC, wrapped 1:1 into cirBTC
Loan asset	USDC, credited to the Circle Mint balance
Networks	Arc and Ethereum
Lending protocol	Morpho at launch; Aave planned, no date given
Liquidation LTV	86% on the Morpho cirBTC market, as reported by crypto.news and The Cryptonomist
Early usage	About $18.9 million borrowed against about $158 million available liquidity (reported September 22)
Custody of BTC	cirBTC issued by Circle International Bermuda Limited; underlying BTC safeguarded by Circle National Trust
Rates and fees	Set by the lending market, not by Circle; variable

How does the cirBTC loan actually work?

Deposit and wrap. The institution sends BTC to Circle and mints cirBTC, a token that Circle says is backed one-to-one by native bitcoin held through its trust bank.
Move to a Smart Wallet. cirBTC goes to a customer-controlled Smart Wallet. According to The Cryptonomist, it uses a two-of-two multiparty computation setup, so Circle cannot move funds on its own. At this point the assets leave Mint's custody environment.
Post collateral and borrow. The wallet supplies cirBTC to a Morpho market and borrows USDC, which lands in the Mint balance.
Repay and release. Positions are open-ended: the borrower repays USDC plus interest when it chooses and gets its cirBTC back, which can then be redeemed for BTC.

Why it matters

Borrowing against bitcoin is not new — crypto lenders and DeFi protocols have offered it for years, and several centralized lenders collapsed in 2022 after rehypothecating client collateral. Circle's version tries to split the risks: a regulated entity holds the bitcoin, while the lending itself happens in transparent on-chain markets where anyone can see collateral, debt and utilization. For institutions that already hold USDC at Circle, it removes the need to sell BTC, trigger a tax event or deal with an opaque lender.

It also shows the direction stablecoin issuers are taking. With a federal framework for payment stablecoins in place in the US (see our overview of stablecoin regulation in 2026), issuers are looking for ways to make USDC more useful beyond payments. Circle has been raising its profile on several fronts, from Arc to its Chelsea sponsorship, and credit is a logical next step. The trade-off is that Circle now sits closer to DeFi smart-contract risk, even if it says it does not control the protocols.

Crypto-backed loans: what can go wrong?

Liquidation risk

A loan-to-value (LTV) ratio is debt divided by collateral value. If you post $100,000 of BTC and borrow $50,000, your LTV is 50%. With an 86% liquidation threshold, the position becomes liquidatable once the collateral falls to about $58,100 — roughly a 42% drop in BTC. Interest accrues on the debt, so that line moves closer over time. On-chain liquidations are automatic and do not wait for a phone call; after bitcoin's 8-month high, a sharp reversal is exactly the scenario to plan for.

Custody and counterparty risk

Wrapped bitcoin is only as good as its issuer and the reserves behind it. With cirBTC you rely on Circle's custody and redemption process; with the loan you rely on Morpho's smart contracts, the price oracle and the lenders providing liquidity. Circle's own disclosures mention smart-contract vulnerabilities, network disruptions and the absence of recourse for transaction errors, and note that digital assets are not FDIC-insured.

Rate and liquidity risk

Morpho rates float with utilization. If many borrowers draw liquidity at once, borrowing costs can jump, and lenders may be unable to withdraw until loans are repaid.

Checklist: questions to ask before borrowing against crypto

Who holds my collateral, and can it be lent out? Prefer arrangements where collateral is segregated or visible on-chain, never rehypothecated without your consent.
What is the liquidation LTV, and what price triggers it? Calculate the exact BTC price at which you get liquidated, and keep a wide buffer.
Is the rate fixed or variable? Check today's rate and how it has moved during past volatility.
What happens during liquidation? Ask about penalties, whether the whole position or part of it is sold, and whether any notice is given.
How do I top up or repay fast? Keep spare USDC or BTC ready, and know which network and wallet you need to use.
What if the wrapped token depegs? Understand how redemption works and how long it takes.

For retail users, who cannot use Circle's product, the simplest alternative to borrowing is often not borrowing at all: keep long-term BTC in your own wallet (see our self-custody security guide) and, if you need dollars, swap only the amount you need. Comparing rates across services on the exchangers list helps keep that cost low. This article is for information only and is not financial advice.

FAQ

What is Circle's Digital Asset-Backed Borrowing?

It is a Circle Mint feature launched on September 21, 2026 that lets eligible institutions deposit BTC, mint cirBTC, post it as collateral in a third-party lending market such as Morpho and borrow USDC without selling their bitcoin.

Can retail users borrow USDC against bitcoin with Circle?

No. The service is limited to eligible institutional Circle Mint customers, and customers in New York are excluded. Retail users would need to look at other lenders or DeFi protocols directly.

What interest rate and LTV does Circle offer?

Circle does not set them. Rates, collateral requirements and liquidation thresholds come from the chosen lending market. Reports cite an 86% liquidation LTV for the Morpho cirBTC market at launch, with variable interest.

Who holds the bitcoin behind cirBTC?

cirBTC is issued by Circle International Bermuda Limited and is backed one-to-one by bitcoin safeguarded through Circle National Trust. Once cirBTC is posted as collateral, it sits in Morpho smart contracts via a customer-controlled Smart Wallet.

What is the main risk of a bitcoin-backed loan?

Liquidation. If BTC falls far enough that the loan-to-value ratio reaches the market threshold, the collateral is sold automatically to repay the debt. Smart-contract, custody and variable-rate risks come on top of that.