TL;DR · 30-second read
The Short Version
CleanSpark, a company best known for mining bitcoin, is borrowing about $2.3 billion to finish a huge building full of computers for artificial intelligence. The tenant is a company owned by Meta, the parent of Facebook and Instagram, and Meta itself guarantees 20 years of rent.
Even with that promise, lenders are charging nearly 8% interest, or about $179 million a year.
Why so expensive? The building is not scheduled to start paying rent until late 2027, and lenders are betting it gets finished. That interest rate shows what it costs a bitcoin company to become a landlord for artificial intelligence.
On September 18, 2026, CleanSpark (Nasdaq: CLSK) said in an 8-K that its wholly owned subsidiary CSDC Finance I, LLC had priced $2.276 billion of 7.875% senior secured notes due 2031 at 98.5% of face value. The deal is expected to close on September 25. It is larger than the $2.227 billion CleanSpark proposed a day earlier. The notes were sold privately to large institutional investors under Rule 144A and to non-U.S. buyers under Regulation S.
The proceeds will finish building CleanSpark’s Sandersville Facility, reimburse the company for equity it has already put into the project, and fund debt service reserves. The investor presentation CleanSpark furnished on September 17 describes Sandersville as a 175 MW AI data center campus. It is leased for 20 years to Anviran, LLC, a wholly owned Meta subsidiary, and Meta guarantees the rent and operating expenses. First-phase rent is targeted for Q4 2027.
Executive Summary
CleanSpark has raised project-level debt for its first large AI hosting campus, and the price is specific: a 7.875% coupon, sold at a 1.5-point discount. The notes are secured by first-priority liens on the Sandersville project and the issuer’s equity, a completion guarantee from CleanSpark backs them, and part of the proceeds funds cash reserves for interest payments. Behind all of that sits a 20-year triple-net lease guaranteed by Meta, a company the presentation values at about $1.7 trillion.
The notable feature is the gap between the tenant and the terms. Meta’s credit is not in question. The coupon and the protective package reflect what is still unfinished: a building that is not scheduled to earn rent until late 2027, owned by a sponsor that is moving from bitcoin mining into data center development. For operators trying to turn mining power into AI capacity, this deal is a concrete, disclosed reference point for what that conversion costs to finance.
Meta Signed the Lease. Lenders Still Priced the Build.
On paper, Sandersville is about as strong a credit story as a data center gets. The investor presentation CleanSpark furnished on September 17 describes these terms:
- a 20-year base lease with Anviran, LLC, a Meta subsidiary, plus two five-year extension options;
- Meta itself as guarantor of rent and operating expenses;
- a triple-net structure, meaning the tenant covers taxes, insurance and upkeep;
- a 3% annual rent escalator;
- about $6.6 billion of base-term contract value.
To underline the tenant’s strength, the presentation cites Meta’s $117 billion of first-half 2026 revenue.
Even so, the notes carry a 7.875% coupon, the fixed annual interest rate. They were also sold at 98.5 cents on the dollar, which by rough estimate lifts investors’ effective yield to a little over 8%. Bondholders also received three protections. They hold first-priority liens on substantially all assets of the issuer and its guarantor subsidiary, plus the issuer’s equity. Reserves funded from the proceeds cover debt service. And CleanSpark gives a completion guarantee, a promise to supply more money if the proceeds cannot finish the facility on time. Each protection guards against the same thing. The question is not whether Meta can pay. It is whether the building gets delivered.
The timeline explains why. First-phase rent is targeted for Q4 2027, so interest accrues for more than a year before rent arrives, and the lease pays only once the capacity exists. For a bitcoin miner moving into AI hosting, a lease with a hyperscaler (one of the giant cloud and internet platforms) turns megawatts into something lenders will finance. It does not, on its own, earn the borrowing costs of the investment-grade tenant. Construction and sponsor risk sit in between. In this deal, CleanSpark carries the construction risk directly through its guarantee.
The Per-Megawatt Math Behind $2.276 Billion
The presentation puts development cost at about $11.9 million per megawatt of critical IT load, which is the power delivered to the servers themselves, not counting cooling and building overhead. For 175 MW, that implies roughly $2.1 billion. At 98.5% of face value, $2.276 billion of notes raises about $2.24 billion before fees, which is more than that implied total cost. That fits the stated uses: finishing the build, reimbursing CleanSpark’s prior equity contributions, and funding reserves. In practice, the debt is sized to fund close to the whole project, and CleanSpark recovers part of what it has already spent.
Annual interest on the notes comes to about $179 million, or roughly $1.0 million per megawatt per year. Net operating income (NOI) is rent minus operating expenses, and under a triple-net lease it is nearly all of the rent. CleanSpark projects average NOI of about $330 million a year, or roughly $1.9 million per megawatt. That covers interest about 1.8 times on average. The early years are thinner. The presentation’s schedule shows NOI of about $220 million in 2028, the first full rent year, which covers interest about 1.2 times, before the escalator widens the margin.
The resizing is worth noticing. CleanSpark proposed $2.227 billion on September 17 and priced $2.276 billion the next day. At the 98.5% price, the larger deal raises slightly more than the original principal target. The extra $49 million of face value more than offsets the discount. CleanSpark has not said why it changed the size. Either way, the issuer now pays 7.875% on the larger amount.
What 7.875% Means for Miners Sitting on Megawatts
CleanSpark says it controls more than 1.8 GW of power, land and data centers. Sandersville’s 175 MW of IT load is less than a tenth of that figure. The comparison is only rough, because IT megawatts and grid megawatts are measured differently. The company’s own forward-looking disclaimers list the risks of converting mining sites into data centers: permitting and utility constraints, construction delays, cost overruns, financing, supply chains and tenant performance. Sandersville is where that list first meets billions of dollars of committed capital.
The 2031 maturity matters as much as the coupon. The notes come due about four years after targeted rent start, while the lease runs 20 years. If the campus is delivered and paying rent by then, the construction risk that shaped this coupon will be gone, which could support cheaper refinancing. That outcome still depends on rates and credit markets in 2031. The refinancing risk moves to a later date; it does not disappear.
For other miners pursuing the same path, this is one data point, not a trend. It shows that an investment-grade lease plus secured, project-level debt can fund a full AI build, at this price and with the parent still responsible for completion. Three groups are affected. CleanSpark shareholders get part of their equity back but take on a contingent obligation. Noteholders hold a claim on a single asset. Other operators now have a public benchmark that their own conversions will be compared against.
Background
CleanSpark, based in Las Vegas and listed on Nasdaq as CLSK, built its business on bitcoin mining. It now describes itself as a data center developer that controls more than 1.8 GW of power, land and data centers across the United States. Its investor materials describe an evolving strategy: expanding into data center development, high-performance computing and AI, including by converting some of its bitcoin mining sites into data centers for other uses.
The move follows a wider pattern. Bitcoin miners hold what AI developers most need: land with large grid connections already in place. Turning a mining site into an AI data center, however, takes a different class of building, with heavier cooling, redundant power and stricter uptime requirements. It also takes financing on a different scale. That is why Sandersville’s financing terms draw attention well beyond CleanSpark itself. Source: Is CleanSpark (CLSK) Undervalued On Its New 7.875% Notes And Expansion Plans? (Yahoo Finance), coverage of CleanSpark’s new senior secured notes and data center expansion. Primary sources: CleanSpark Form 8-K filed September 18, 2026; CleanSpark, Inc. Announces Pricing of $2.276 Billion of Senior Secured Notes (Exhibit 99.1); CleanSpark Form 8-K filed September 17, 2026; Sandersville Investor Presentation, September 2026 (Exhibit 99.1); CleanSpark, Inc. Announces Proposed Offering of $2.227 Billion of Senior Secured Notes (Exhibit 99.2).Sources