MARA Sells $1.1 Billion in Bitcoin to Slash Debt as Coinbase Brings Crypto-Backed Mortgages to the Housing Market

MARA Holdings, the largest publicly listed Bitcoin miner in the United States, disclosed in an SEC filing that it sold roughly 15,000 BTC for approximately $1.1 billion between March 4 and March 25 in order to repurchase around $1 billion of its zero-coupon convertible notes at an average discount of 9% to par. The transaction trims MARA’s outstanding convertible debt by approximately 30% to about $2.3 billion and captures an estimated $88 million in savings before transaction costs.

The sale represents 28% of the company’s Bitcoin treasury. According to Bitcointreasuries.net, MARA retains roughly 38,700 BTC on its balance sheet — a stash worth approximately $2.6 billion at Thursday’s trading price near $69,000.

Investors greeted the deleveraging warmly. MARA’s share price rose as much as 12.6% in pre-market trading to $9.29, according to Yahoo Finance, before settling around $8.74 during the regular session — still a gain of more than 5% on the day. The stock remains roughly 44% lower over the past six months, reflecting persistent pressure on mining margins since Bitcoin’s retreat from its October 2025 all-time high above $126,000.

Bitcoin was down 3% today on the news, Source: Brave New Coin

MARA chairman and CEO Fred Thiel framed the move as a deliberate rebalancing rather than a distress sale. In a press release, Thiel said the repurchase eliminates future dilution risk for shareholders and enhances the firm’s optionality as it expands into AI and high-performance computing infrastructure. The company recently agreed to acquire a majority stake in Exaion’s AI-focused data centres, part of a broader industry pivot that has seen miners trade hash power for GPU racks in pursuit of more stable revenue.

Thiel is far from alone in that calculus. Earlier this month, CoinShares research head James Butterfill projected that Bitcoin miners could derive as much as 70% of their revenue from AI by year’s end, citing a decline in Bitcoin hash price to roughly $33 per petahash per second per day — barely half the $64 PH/s recorded in July. Bitdeer has already sold its entire Bitcoin treasury to fund a cloud-and-AI pivot, while the firm formerly known as Bitfarms rebranded to Keel in February and Cipher Mining re-emerged as Cipher Digital, each flagging AI as the centrepiece of their next chapter.

The convertible-note playbook itself has become a defining feature of corporate Bitcoin strategy. Pioneered by Michael Saylor’s Strategy (formerly MicroStrategy), which has raised tens of billions through zero-coupon convertible issuance to fund its accumulation of more than 738,000 BTC, the format gives issuers cheap capital and investors an option to convert debt into equity if the stock appreciates. MARA’s twist is to run the mechanism in reverse — buying back those notes at a discount during a period of depressed share prices to lock in value for existing holders.

Listen to Fred Thiel on the Brave New Coin Crypto Conversation podcast.

Crypto enters the mortgage market

Hours after the MARA filing landed, Coinbase and fintech mortgage lender Better Home & Finance announced the first conforming, token-backed mortgage eligible for purchase by Fannie Mae — a product designed to let American homebuyers pledge Bitcoin or USDC as collateral for a down-payment loan without selling their holdings or triggering a taxable event.

The structure works as a two-loan arrangement. The primary mortgage sits inside the standard Fannie Mae conforming box with all the protections that implies. Alongside it, a second, privately financed loan is secured by the borrower’s pledged crypto, which is held in a Coinbase Prime custody account for the life of the loan and returned once repaid. Crucially, if Bitcoin drops in value, the mortgage terms remain unchanged and no additional collateral is required — liquidation of the pledged assets occurs only in the event of a 60-day payment delinquency, mirroring conventional foreclosure mechanics.

Max Branzburg, head of consumer and business products at Coinbase, said in a press release that token-backed mortgages represent a first step toward unlocking homeownership for younger generations that have faced growing barriers to saving for a traditional down payment.

Better CEO Vishal Garg, in an interview with CoinDesk, estimated that Better could have funded an additional $40 billion in consumer mortgage demand over recent years had the product existed earlier. An estimated 52 million American adults — roughly 20% of the adult population — now hold some form of digital asset, according to Coinbase’s 2025 State of Crypto Report, and data from the National Association of Realtors shows the median age of a first-time buyer has climbed to 40, up from 32 at the turn of the century.

There are trade-offs. A Coinbase spokesperson told Reuters that interest rates on the token-backed mortgages will run between half a percentage point and 1.5 percentage points above standard 30-year conforming rates, depending on the borrower’s profile. If pledging Bitcoin specifically, the initial collateral value must be at least 250% of the fiat down-payment loan amount — a significant over-collateralisation requirement that cushions the lender against volatility. And critics will note that the product effectively adds a second layer of leverage to what is already the largest financial commitment most households ever make.

Still, the announcement slots into a broader pattern of institutional integration between crypto and traditional finance that has accelerated sharply under the current administration. The SEC has wound down enforcement actions against major exchanges, the GENIUS Act has given the U.S. its first federal stablecoin framework, and a Strategic Bitcoin Reserve now sits on the government’s balance sheet. Coinbase described the mortgage product as the practical expression of its “Everything Exchange” vision, where assets are not merely traded onchain but deployed in real-world use cases.

Thursday’s headlines paint a picture of an industry in transition. Miners are selling Bitcoin to survive compressed margins and reposition for AI; at the same time, crypto is embedding itself deeper into the architecture of American consumer lending. Whether that integration ultimately expands access to homeownership or introduces new pockets of systemic risk will depend on how the products perform through a full market cycle — and how regulators choose to respond.