Blackstone warns Anthropic may land a junk credit rating after its IPO, reversing its investment-grade call

Anthropic’s path to the public markets hit a financing question on October 30. Blackstone, an anchor investor in the company’s $63 billion chip-financing deal, has told investors that Anthropic is likely to receive a junk credit rating after its initial public offering — the opposite of what it told investors earlier, according to a Financial Times report citing people familiar with the matter.

The warning matters because of scale. Anthropic’s prospectus outlines more than $800 billion in computing infrastructure spending between now and 2045. A credit rating decides, in large part, how cheaply the company can borrow to pay for it — and a rating below investment grade narrows the set of investors allowed to lend.

The warning, and the reversal#

Blackstone has recently indicated that Anthropic is more likely to receive a rating in the double-B range, based on guidance from major credit rating agencies, the people cited in the report said. A double-B rating falls below investment grade. The assessment marks a shift from Blackstone’s earlier guidance that Anthropic could secure an investment-grade rating before the end of the year.

Blackstone is not a distant observer here. The firm is an anchor investor in Project North Star, Anthropic’s $63 billion chip-financing arrangement, and is working with banks involved in distributing the deal’s debt to other investors. Its funds invested $9 billion in the deal’s junior debt at a yield of more than 10%, according to the Financial Times report.

None of this is a rating decision. No agency has issued a rating for Anthropic itself, and Blackstone’s message is an expectation about what the agencies will do — not a verdict they have delivered. The distinction matters: the story is a reversal of expectations from a firm with money in the deal, reported anonymously, not a downgrade.

Project North Star: $63 billion, with Broadcom’s backing#

Project North Star provides funding for Anthropic to lease 1.5 gigawatts of Google semiconductors, banks having completed the $63 billion deal. More than $42 billion of the senior loans is guaranteed by Broadcom, which co-develops the chips and holds an investment-grade credit rating. The remaining $18 billion in junior debt is backed by Anthropic’s lease payments, with senior debt taking priority over junior loans if the borrower defaults.

That structure is why the junior debt already carries ratings while Anthropic itself does not. Kroll Bond Rating Agency (KBRA) gave the $18 billion junior debt a double-B-plus rating with a positive outlook — a modest improvement on the stable outlook assigned to a similar earlier financing, Project Big Sky. Morningstar DBRS also assigned the junior debt a double-B rating, according to people familiar with the matter. Fitch, Moody’s and S&P, the three agencies with the most influence over corporate borrowing costs, have not officially issued credit ratings for Anthropic.

The arrangement also shows how Anthropic has so far solved the borrowing problem: by leaning on a supplier’s stronger credit. Broadcom’s high A-tier rating was an important factor in securing the financing, and a lower rating for Anthropic itself could leave the company continuing to rely on suppliers with stronger ratings to support its borrowing.

What a double-B rating would cost#

A rating below investment grade restricts access to institutional capital. Many insurance companies and pension funds face restrictions on taking large positions in borrowers with junk-rated debt, which reduces the pool of investors available to finance an infrastructure expansion. An investment-grade rating, by contrast, would let Anthropic access debt at relatively lower interest rates.

The context in Anthropic’s filing cuts both ways. The company reported $16.3 billion in revenue for the first half of 2026 alongside an $80.7 billion net loss, and it holds more than $112 billion in cash and equivalents. Investors anticipate it could raise approximately $100 billion through its IPO, which is expected by the end of November on the Nasdaq under the ticker ANT. Cash and a large offering do not remove the borrowing question: the buildout is measured in hundreds of billions, and the rating will help set the price of the debt behind it.

Friday’s market reaction showed how quickly financing worries travel. The Nasdaq 100 fell 3.84% in afternoon trading, in a sell-off that had begun earlier over concerns about the sustainability of AI spending. The credit warning coincided with that weakness; it did not cause it alone, and the broader backdrop included weak results elsewhere in technology. Still, the timing underlines the point Blackstone’s warning makes: for AI companies, the funding story is now part of the valuation story.

What to watch#

The next facts are the agencies’ own. Watch whether Fitch, Moody’s and S&P issue ratings for Anthropic after the IPO, and where they land relative to the double-B range Blackstone now expects. Watch the pricing on Anthropic’s future debt: a junk rating should show up as higher yields and tighter terms. And watch whether the company’s next financings keep leaning on supplier guarantees like Broadcom’s — or whether Anthropic can borrow on its own credit at a price it can live with.

Sources: the Financial Times report as covered by Invezz and TipRanks. Images are AI-generated editorial illustrations.