Anthropic’s $63 Billion Financing Risks a Post-IPO Junk Rating

By Nathan Brooks

Blackstone has warned investors in Anthropic’s $63 billion Project North Star chip financing that the Claude chatbot developer “may not secure an investment-grade credit rating immediately after listing,” the Financial Times reported. The Financial Times said Blackstone now sees a BB-range outcome as more likely, which would place the debt in the highest tier of “junk” status.

The warning reverses Blackstone’s earlier expectations. People familiar with the matter told the Financial Times that Blackstone spent the past few months assuring partners Anthropic could secure an investment-grade rating by the end of this year. The Financial Times reported that Blackstone recently revised its view as major rating agencies issued guidance.

That shift could raise Anthropic’s bond borrowing costs significantly. The Financial Times said higher costs would create a headwind for the company’s compute-infrastructure plan, which exceeds $800 billion.

What does a “junk” rating change for Anthropic?

Under S&P and Fitch frameworks, only BBB- and above qualifies as investment grade; BB+ and below falls into speculative territory. The BB range—BB+, BB and BB-—sits just below that threshold as the highest tier of junk status.

The Financial Times said most insurers and pension funds may hold only investment-grade bonds or impose strict caps on junk-rated debt. If Anthropic lands at BB+ or below, its pool of available institutional capital would shrink sharply.

For Anthropic, the practical change would be narrower demand for its bonds and higher funding costs. Those costs would apply to chips and compute capacity through 2045.

Project North Star shifts risk to Broadcom and lease payments

The Financial Times reported that Wall Street banks completed the $63 billion financing earlier this week. Its proceeds will cover costs related to Anthropic’s lease of 1.5 gigawatts of chips from Google.

Blackstone served as lead investor and worked with lending banks to resell the debt to other investors. More than $42 billion of senior loans carry Broadcom guarantees.

Broadcom co-developed the chips and holds a high single-A investment-grade rating, which was a key condition for Anthropic to obtain the financing. Senior debt ranks ahead of subordinated debt in a default and has long been favored by institutional investors, the Financial Times reported.

The $18 billion subordinated tranche has repayment supported by Anthropic’s lease payments, leaving lenders with more direct credit risk. A Blackstone fund subscribed for $9 billion of that debt at a high yield above 10%.

KBRA rated the subordinated debt BB+ with a positive outlook. The agency called that an improvement over the stable outlook on Project Big Sky, a similar deal four months earlier, while Morningstar DBRS assigned a BB rating.

Fitch, Moody’s and S&P still haven’t issued formal ratings for Anthropic. The Financial Times said the three agencies exert the greatest influence on corporate financing costs. Banking teams for Anthropic and rival OpenAI are lobbying all three for investment-grade assessments immediately after listing.

The IPO could raise roughly $100 billion

Anthropic formally filed earlier this week and could list on Nasdaq as soon as next month under the ticker “ANT.” Market expectations already call it the largest IPO in history, according to the Financial Times.

Its prospectus calls for more than $800 billion in compute-infrastructure investment from now through 2045. Anthropic also holds more than $112 billion in cash and cash equivalents, while the IPO could raise roughly another $100 billion.

The offering would bring in about as much money as the cash Anthropic already holds. That balance could ease near-term financing pressure even if a post-listing rating falls short of investment grade.

Wall Street’s pre-IPO valuation expectations range from $1.5 trillion to $2 trillion. At those levels, Anthropic would surpass the $1.77 trillion valuation record SpaceX set when it listed in June, the Financial Times reported.

The Financial Times said Anthropic chose to go public amid rising concern about an AI bubble and intensifying tech-stock volatility. U.S. tech stocks weakened on Friday, the 30th, and the Nasdaq 100 Index closed down 3.5%.

Amazon and Intel earnings had already sharpened concern over whether AI capital spending can produce real returns. A U.S. tech-focused fund manager told the Financial Times that access to credit is critical for Anthropic and that a failure to secure investment grade would raise financing costs for all parties involved.

Anthropic’s first-half loss reached $80.7 billion

Anthropic reported $16.3 billion in revenue in the first half of this year. It also reported an $80.7 billion net loss over the same period, nearly five times revenue.

Management attributed the loss largely to an increase in the fair value of convertible bonds. As of Sept. 30, Anthropic had more than 1,900 customers, each contributing at least $1 million in annual revenue.

Credit ratings will test the AI funding chain

The Financial Times framed the episode as a test of the funding structure behind AI infrastructure. Whether capital-intensive developers can enter the corporate bond market with investment grade will affect borrowing costs and the pace of capacity expansion.

The structure also links chip suppliers and their customers more tightly. When Broadcom guarantees customer debt with its own high rating, the AI supply chain carries more of the end customer’s credit risk, the Financial Times said.

Anthropic, Blackstone, KBRA, Morningstar DBRS and S&P declined to comment on the report. Fitch and Moody’s did not respond to requests for comment.

The next test comes when Fitch, Moody’s and S&P rule after the listing. Their decisions will determine whether Anthropic can finance its expansion at investment-grade terms or must accept significantly higher bond borrowing costs.