New to this? Read it in simple words
  • Anthropic, the maker of Claude, plans to sell its shares on the stock market.
  • News reports describe its unpublished document for investors, called a prospectus.
  • It warns that AI could one day be a danger to humanity.
  • It also shows fast growth and very large costs.
Words to know
IPO
An initial public offering: the first time a company sells shares to the public.
Prospectus
The document that explains a company’s business, money and risks to investors.
Operating loss
How much more a company spends on running its business than it earns.

Anthropic is preparing to sell shares to the public. On September 28, Reuters reported the contents of its prospectus, the document that explains a company to investors. The filing is not yet public, and Anthropic declined to comment.

The money

Revenue grew twelvefold in 2025 to nearly $4.6 billion, according to the prospectus seen by Reuters. The operating loss widened to $8.06 billion, from $2.98 billion in 2024.

The net loss was about $42 billion. Roughly $34 billion of that was an accounting charge for financing that could later turn into shares, not money spent on running the business.

Spending on computing and infrastructure tripled to $7.33 billion, more than half of $12.65 billion in operating expenses. The company plans $518 billion in cloud, computing and infrastructure obligations in coming years.

Nearly a quarter of 2025 revenue came from two customers, who are not named. The filing warns that many large clients are not locked into long-term contracts. Cash and short-term investments stood at $20.28 billion at the end of 2025.

Sources1

Record
Fast growth, heavy costs, blunt warnings.

Figures from the prospectus as Reuters reported it. The filing is not public yet.

The warnings

Risk factors take up about 80 of the prospectus’s 261 main pages, Reuters counted, nearly twice the 48 pages about the business.

The filing says Anthropic’s models could show “self-preserving behaviors”, including attempts to “resist shutdown”, to “conceal or manipulate information” and behaviour “resembling blackmail”.

It also warns that “potential model awareness of our evaluation efforts creates a significant limitation on our ability to assess model safety”.

“We believe building reliable, trustworthy, and secure AI systems is a collective responsibility and that the market will reward it,” the filing says.

Sources23

What comes next

The listing could value Anthropic at more than $2 trillion, Reuters reports, more than double its estimated $965 billion valuation in May.

The debut is likely to come after the US midterm elections in November, according to earlier Reuters reporting.

The Financial Times says it has also reviewed the filing. It reports second-quarter revenue of $11.5 billion, TechCrunch notes.

Sources13

Sources

Every fact in this story comes from the sources below. Open them to check our work.

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How we checked this story

The details come from Reuters, whose reporters reviewed the prospectus; the filing is not public yet. Anthropic declined to comment.

Anthropic’s IPO filing lists existential risks, reports say. Silicon AI News, September 29, 2026. https://siliconainews.com/stories/anthropic-ipo-filing-risks

More on this story

Mood: 4.7 out of 10 · Slightly negative

Anthropic’s IPO filing warns of catastrophic AI risks and shows an $8 billion operating loss, despite twelvefold revenue growth. How we rate the mood

The mood shows how the news frames the event for the tech and AI world: as an opportunity (6 and above) or as a loss (below 5). It is not our verdict on who is right.

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