Bitcoin miners looking to convert power capacity into AI and high-performance computing contracts are finding that borrowing costs depend heavily on the details. BlocksBridge Consulting said in its Oct. 8 Miner Weekly that big lenders have become more selective about data center loans. Decisions now hinge on the customer, the contract, and how likely the project is to finish. Securing an AI customer, in other words, does not solve the funding problem by itself.
Lenders get pickier about data center debt
Operators still need capital for GPUs, buildings, electrical infrastructure, construction contingencies, and working capital. That gap explains why financing terms vary so much, even among miners with similar expansion plans. A facility that covers most equipment purchases may leave other costs for the company to fund.
IREN’s two packages tell different stories
IREN offers a clear example. The company announced a $3.65 billion GPU financing package on June 1 to support its Microsoft cloud contract. BlocksBridge estimated the blended debt cost at 6%. In August, IREN disclosed a separate $2.4 billion arrangement with a fixed 9% rate. That second package backed its air-cooled expansion at Mackenzie.
The three percentage point gap might look like a simple rise in IREN’s borrowing costs. BlocksBridge cautioned against that view. The deals fund different projects and carry different exposures, so comparing them directly can mislead.
IREN also kept adding customer commitments. It announced $2.8 billion in multi-year AI cloud contracts in July and raised its year-end annualized revenue target from $3.7 billion to more than $4 billion. About 85% of that target was under contract, the company said. IREN also reported advance payments equal to roughly 45% of the GPU capital spending tied to recent agreements. Those payments reduced the amount IREN needed to finance directly. Its July update put cash and cash equivalents at about $7.6 billion as of June 30, including restricted cash.
Cipher adds equity and credit to the mix
Cipher Digital shows another path. Google agreed to backstop $1.4 billion of Fluidstack’s lease obligations for the Barber Lake project in a September 2025 transaction. In return, Google received warrants for about 5.4% of Cipher’s pro forma equity, subject to adjustments. The deal also allowed possible cash settlement in some cases. If the warrants are exercised for shares, existing holders could face dilution, though Google’s support helped make the project financeable.
Cipher separately disclosed a $200 million credit facility in May. The revolving line matures in March 2030 and includes an option to add up to $50 million. It carries interest at SOFR plus 1.25 to 1.75 percentage points, with possible reductions based on debt-to-market-capitalization. At closing, the facility was undrawn.
Spending outruns reported AI revenue
BlocksBridge’s Aug. 20 analysis of nine public miners found $5.11 billion in capital spending in the first half of 2026, against $341.2 million in directly reported AI and high-performance computing revenue. Some spending still supported Bitcoin mining, so the total was not AI investment alone. Second-quarter AI and HPC revenue reached $205.8 million, up 52% from the prior quarter. A June estimate said public miners may need about $50 billion to finish planned AI infrastructure, with IREN facing a $21.1 billion gap, Riot Platforms $7.2 billion, and HIVE Digital $4.6 billion.
