The IPO Market Is Open For Anthropic. Not For Everyone Else.

It’s a fine time to list shares if you’re Anthropic. If you’re anyone else in the AI world, not so much.

Anthropic is preparing for what could easily be the biggest listing of all time after filing its prospectus with regulators last month. And demand for its shares seems likely to be strong: The company is a leader in AI model development, and it has done much better than its rival OpenAI at translating its technical achievements into a vibrant business.

And yet the listing comes at a jittery time for AI.

Stocks of companies whose fortunes are tightly coupled with the AI boom have been hammered over the past month. AI cloud-computing player CoreWeave’s stock has fallen more than 40% over that period.

Even Big Tech and chip-company stocks are down. Alphabet’s took an unprecedented tumble after reporting weak ad revenue growth last week. AI-related bond yields are up. Fear abounds almost everywhere you look.

Meanwhile, no significant AI-related listing has hit the market since SpaceX’s IPO in June and South Korean computer-memory giant SK Hynix raised money in July via a U.S. listing.

That is not for lack of trying. SB Energy, a SoftBank unit developing data centers and associated energy infrastructure, filed for an IPO in early September. Two months later, it hasn’t pulled the trigger.

SK Hynix, despite the success of its July listing, pulled back a planned U.S. listing of its flash-memory unit Solidigm last month. The U.K.-based cloud-computing company Nscale isn’t likely going public this month as initially planned. Oura, the company behind a line of AI-infused smart rings, also walked back its IPO plans in late September.

Even Nvidia’s backing isn’t sufficient to attract equity investors these days. Nvidia has an equity stake in and credit-support deal with a cloud-computing player called Firmus. Firmus was seeking to raise $5 billion via an Australian IPO that would have been the country’s largest in almost 30 years. The company’s board called it off last month, citing “recent market volatility.”

The hesitation speaks to the fragility of the moment in the AI boom. There have been many periods of jitters and hiccups in recent years as spending on AI ballooned with no sufficient returns in sight. Now, though, a higher interest rate environment and a flood of fresh demand for capital are raising questions about whether investors are comfortable plowing more money into the technology.

Unless you’re Anthropic, they increasingly aren’t.

Earnings last week from Microsoft, Alphabet and Amazon.com told a disjointed story. Microsoft’s results beat expectations, and its cloud-computing revenue soared, painting a picture of stable demand and steady growth ahead. Alphabet and Amazon, though, both had ad-growth trouble. That heightened concerns about the health of core businesses powering AI spending. Alphabet’s shares are down more than 12% since its report. Amazon’s stock initially fell but has since recovered.

Valuation for OpenAI in its latest funding round, falling short of the $1.4 trillion it targeted.

Alphabet’s overall revenue is skyrocketing. The Google parent’s ad business, which has long fueled its growth and funded its AI spending, hasn’t been keeping pace.

That is a real concern for the company’s investors. While Google’s cloud-computing business has taken over as the primary growth engine, ads still account for most of the company’s revenue. Any trouble with that part is trouble for the whole.

But there is also an argument that the current lull will be temporary. Yes, Google is facing search-ad competition from AI agents and chatbots. But it has AI tools of its own that it hasn’t yet fully deployed or monetized.

The company only recently turned on ads internationally for its popular AI Mode, for example, which lets search users ask follow-up questions. And it is planning to release a consumer AI agent later this year, chief executive Sundar Pichai said last week, which could give it better competitive footing against Meta Platforms, OpenAI and Anthropic in the personal-agent world.

Given how chips and AI have been entwined with national security in recent years, it perhaps is no surprise that Nvidia’s chief executive is caught up in a spy caper. Authorities in the U.S., Singapore and Taiwan are concerned that a data-center executive with close ties to Jensen Huang is a Chinese intelligence asset. With the high stakes of the AI race and Huang’s proximity to the Trump administration, it isn’t hard to see how he might be a prime target for foreign intelligence.

WSJ AI & Business is a weekly look at AI’s transformation of the business world. This newsletter was curated and edited by Asa Fitch. Reach him at asa.fitch@wsj.com (if you’re reading this in your inbox, you can just hit reply). Got a tip for us? Here’s how to submit.