Bitcoin miners face uneven borrowing costs for AI expansion

Bitcoin miners have secured AI financing at sharply different rates, with IREN’s 6% and 9% agreements showing how project terms have shaped borrowing costs, according to BlocksBridge Consulting.

BlocksBridge Consulting, in its Oct. 8 Miner Weekly newsletter, said lenders have become more selective about data center financing as Bitcoin miners seek capital to deliver large artificial intelligence and high-performance computing contracts.

According to the consultancy, securing an AI customer addresses only part of the funding challenge. Operators still need money to purchase computing equipment, construct facilities and install the power infrastructure required to provide contracted services.

“[B]ig lenders have become more selective about data center loans and decisions increasingly depend on the customer, the contract and the path to completion,” BlocksBridge said.

Bitcoin miners’ AI borrowing costs depend on project terms

For IREN, the newsletter cited a $3.65 billion GPU financing package announced on June 1 to support its Microsoft cloud contract. BlocksBridge put the blended debt cost at 6%.

In its August results, IREN disclosed a separate $2.4 billion financing arrangement carrying a fixed rate of 9%, according to the report. The second package supported the company’s air-cooled expansion at Mackenzie.

Although the rates differ by three percentage points, BlocksBridge cautioned against treating the transactions as a direct increase in IREN’s borrowing costs. The agreements fund different projects and carry different exposures.

The consultancy also distinguished equipment financing from funding an entire development. According to its report, a facility that covers most GPU purchases does not automatically pay for buildings, electrical infrastructure, construction contingencies, and working capital.

Alongside its borrowing arrangements, IREN continued adding customer commitments during the summer. As crypto.news reported on July 20, the company added $2.8 billion in multi-year AI cloud contracts and increased its year-end annualized revenue target from $3.7 billion to more than $4 billion.

In that announcement, IREN said about 85% of the revised target was under contract. The company also disclosed advance payments equal to approximately 45% of the GPU capital spending associated with recent agreements.

According to IREN, the customer payments reduced the amount it needed to finance directly for those deployments. Its July update put cash and cash equivalents at approximately $7.6 billion as of June 30, including restricted cash.

Cipher’s Google backing includes shareholder costs

Beyond interest expenses, BlocksBridge pointed to Google’s support for Cipher Digital’s Barber Lake project as an example of financing that includes an equity component.

Under the September 2025 transaction described in the newsletter, Google agreed to backstop $1.4 billion of Fluidstack’s lease obligations to support project financing. In exchange, Google received warrants representing approximately 5.4% of Cipher’s equity on a pro forma basis, subject to adjustments.

The report noted that the agreement also allowed potential cash settlement under certain circumstances. If exercised for shares, the warrants could dilute existing shareholders, while Google’s credit support helped make the project financeable, according to BlocksBridge.

For investors assessing expansion costs, the consultancy included warrants, required equity contributions, parent guarantees and restrictions on project cash alongside interest payments.

Cipher has separately secured corporate borrowing capacity. In its May 5 business update, the Nasdaq-listed company disclosed a $200 million credit facility supported by a group of financial institutions.

According to the company disclosures covered in that report, the revolving facility matures in March 2030 and includes an option to increase capacity by up to $50 million.

Cipher said the facility carries an interest rate equal to the Secured Overnight Financing Rate plus 1.25 to 1.75 percentage points. The agreement allows rate reductions based on the company’s total debt-to-market-capitalization ratio.

At closing, Cipher reported that the facility remained undrawn. The company designated the borrowing capacity for liquidity, working capital, and growth, including construction and equipment installation across its AI and high-performance computing campuses.

In the same update, Cipher disclosed a 15-year lease for its third large AI campus with an investment-grade customer. The company also reported first-quarter revenue of $35 million and an adjusted EBITDA loss of $48 million.

IREN’s convertible debt carries separate equity terms

U.S. institutional investors have also supplied capital through convertible debt. In May, IREN raised $3 billion through senior notes carrying a 1% coupon and maturing in 2033, according to its financing announcement.

IREN said the transaction included a $2.6 billion base offering and a fully exercised $400 million additional purchase option. The company sold the securities privately to qualified institutional buyers under Rule 144A.

After fees and expenses, IREN reported net proceeds of approximately $2.96 billion. The company allocated $201.3 million to capped call transactions and designated the remaining funds for working capital and general corporate purposes.

According to IREN, the capped calls were intended to reduce potential shareholder dilution if the notes converted into shares. The initial cap price was $110.30 per share, twice the company’s $55.15 share price on May 11.

IREN also disclosed a 32.5% conversion premium. Its announcement said investors had no put option except in certain standard change-of-control circumstances.

Capital spending has exceeded reported AI revenue

Across nine public miners, BlocksBridge’s Aug. 20 analysis found that capital spending reached $5.11B during the first half of 2026, compared with $341.2 million in directly reported AI and high-performance computing revenue.

The consultancy counted companywide purchases of hardware, property, equipment and other productive assets. Some expenditure continued supporting Bitcoin mining, meaning the total did not represent investment in AI alone.

For the second quarter, BlocksBridge recorded $205.8 million in combined AI and high-performance computing revenue, an increase of 52% from the preceding quarter.

The investment changes also reached a U.S. exchange-traded fund. According to the Aug. 21 report, CoinShares renamed WGMI as the CoinShares Bitcoin Mining and Digital Power ETF and expanded its eligible investments to include data center operators, AI semiconductor companies, power producers and advanced computing businesses.

CoinShares reported 29 holdings and approximately $225.6 million in assets as of Aug. 18. According to the fund’s stated investment policy, WGMI must invest at least 80% of its net assets in qualifying companies and does not hold Bitcoin directly or through derivatives.

Earlier, BlocksBridge’s June analysis, using VanEck data, estimated that publicly traded Bitcoin miners needed approximately $50 billion to complete their planned AI infrastructure projects.

The June estimates assigned IREN a $21.1 billion funding gap, followed by Riot Platforms at $7.2 billion and HIVE Digital at $4.6 billion.