What’s riding on Anthropic’s market debut? Nearly everything.

SAN FRANCISCO — When Anthropic goes public as soon as next month, its initial offering will be more than just a coming-out party for the artificial intelligence company. It will also be a litmus test for the economy, with trillions of dollars at stake.

Anthropic, which makes the Claude chatbot, is a tent pole of the AI industry. Valued in the private markets at nearly $1 trillion and backed by more than $130 billion in funding, it could raise $100 billion in its offering and promptly become one of the world’s biggest public companies. But the stakes are even higher than that.

Anthropic and OpenAI, its chief rival, sit atop a pyramid of business partners and suppliers — infrastructure providers, chipmakers, energy companies, and AI start-ups — that have all spent heavily over the last four years because they believe demand for AI products will keep growing.

Anthropic’s listing will provide the first in-depth look at the health of a key business underlying the AI boom — and will be a test of its durability. Is there unending appetite for AI services to justify the spending on chips, data centers, and other infrastructure? Or will Anthropic’s performance show that there are limits?

“For the market, it’s a bellwether,” said Umesh Padval, an investor at Seligman Ventures, who has worked in tech for nearly 40 years.

If Anthropic disappoints in its public debut, that could hurt investor confidence and cascade into a wider market sell-off, casting doubts on how much longer the AI boom can go. A successful offering could lift the market and pave the way for more AI companies to go public.

Stock markets are already on edge, with technology stocks broadly falling this month, led by a sell-off in the companies that design and produce the computer chips that power AI. The Philadelphia Semiconductor Index is in a bear market, defined as a decline of 20% or more from a recent high and a sign of significant investor angst, after falling 26% from its June peak.

Over the last couple of weeks, Microsoft canceled a deal with Nscale, a provider of data centers. A report from the research firm Gartner predicted that 80% of “neoclouds,” the companies that provide data and computing power for AI firms, could be forced out of business. And Ken Griffin, the billionaire owner of the hedge fund Citadel, said AI investors were “almost certainly” in a bubble.

Those negative signals have added to fears about the huge piles of money being spent on AI infrastructure. Amazon, Meta, Google, and Microsoft have said they plan to spend at least $740 billion on AI infrastructure, including data centers, this year. Private market investors have poured $1.1 trillion into Anthropic, OpenAI, and other AI companies since 2022, according to PitchBook, which tracks investments.

As spending and investment have risen in private markets, public investments have grown, too, increasing the stock market’s reliance on the performance of the AI industry. The top 10 stocks in the S&P 500 are worth more than $1 trillion together, with eight of them being tech companies. Combined, the top 10 account for over 40% of the index, up from less than 20% a decade ago.

When Anthropic is added to the index, it is likely to displace either Berkshire Hathaway or Eli Lilly, the only non-tech companies with valuations above $1 trillion, from the top 10.

“There is a lot riding on this one,” said Brad Gastwirth, the global head of research and market intelligence at Circular Technology, a supply chain services firm. “If it goes bad, it’s going to bring down the market.”

This month, Anthropic gathered investors at its San Francisco headquarters to present its financial performance and growth plans. By most measures, its numbers were astounding. The company’s revenue hit $16.8 billion in the third quarter, up 45% from the prior quarter. But investors compared that with even faster growth of 141% in the second quarter.

How Anthropic explains that slowdown will be important. If it was because the company lost market share to OpenAI or companies using cheaper open-source AI models — the technology that powers chatbots and other tools that generate videos, text, and computer code — that means the overall demand for AI services remains healthy. If Anthropic’s growth slowed because the entire market saw less demand for AI products, the reaction could be more dramatic.

Anthropic declined to comment. (The New York Times has sued OpenAI and Microsoft, claiming copyright infringement of news content related to AI systems. The two companies have denied those claims.)

For the past year, Anthropic has been Silicon Valley’s hottest company, thanks partly to Claude Code, the service that transformed how software engineers write code. The company’s revenue soared, causing private market investors to drive up its valuation to $965 billion, topping OpenAI.

To meet the demand for its AI products, Anthropic struck deals worth hundreds of billions to lease computing power from Google, Amazon, and Microsoft. It has also spent on chips from Nvidia and data centers from Nscale and others. The companies serving Anthropic are, in turn, shelling out money to their suppliers.

But over the summer, some Anthropic customers concluded they were spending too much on “tokens,” or units of data processed and generated by AI systems. They sought cheaper options. Meta, one of Anthropic’s largest customers, projected this year that it would spend as much as $10 billion a year on the company’s technology, but pulled back as it switched to other AI models.

Stocks of some AI companies that went public this year have wilted. Shares of Cerebras, a Silicon Valley maker of AI chips, have fallen roughly 40% from their offering price in May. Shares of Accelevation, an AI infrastructure company, are trading about a third lower than their $18 offering price in September. Elon Musk’s SpaceX, which went public in June, has also fallen far from its peak, though it remains roughly 9% above its offering price.

Against this backdrop, the market for initial public offerings has slowed. Holtec Nuclear, based in Camden and which provides nuclear energy to the AI sector, withdrew its listing last month. SB Energy, a data center company controlled by SoftBank, one of OpenAI’s biggest backers, and Aggreko, a power company that works with data centers, have delayed their plans to go public.

AI infrastructure is a “dominant theme” of the IPO market this year, said Matthew Kennedy, a senior strategist at Renaissance Capital, which tracks public listings. “It’s also been among the hardest hit by the sell-off these past few weeks.”

Bankers have warned companies that they may not get the valuations they were contemplating just two months ago. In an earnings call this month, David Solomon, the CEO of Goldman Sachs, said that while the market for public offerings was “wide open,” companies seeking valuations close to those discussed this summer might choose to wait.

“Things got a little bit softer in September,” he said.

Anthropic’s revenue numbers have added to the doubts. The company had been expected to go public at a valuation as high as $2 trillion. But after seeing the slowing growth and the market doldrums, some investors have started discussing a valuation of $1.5 trillion to $1.7 trillion, according to one person with knowledge of the matter.

AI executives have been trying to provide reassurance. Taiwan Semiconductor Manufacturing Co., which supplies chips to the AI sector, saw “no ceiling” to its profits, its chief executive, C.C. Wei, said this month.

Late last week, amid growing concerns about AI spending, the markets fell further. The tech-heavy Nasdaq experienced its largest drop since June.

This article originally appeared in the New York Times.