Anthropic's impending IPO will test a jittery Wall Street but investors say the timing isn't optional. The reason is simple math: the AI giant has grown too big for private fundraising. Why it matters:

Top AI companies like Anthropic and OpenAI are racking up 12-figure spending commitments, straining the financial system's ability to keep up with a buildout that rivals America's railroads or interstate highways.

• With private borrowing costs spiking, tapping the massive liquidity of the public markets is the best way to fund the next phase of the AI arms race, investors say. State of play:

Anthropic's computing commitments could reach $750 billion in the coming years, according to a draft IPO prospectus seen by The Wall Street Journal • The company already faces more than $600 billion in future infrastructure costs and is negotiating additional deals that could add another $150 billion.

• While Anthropic generated $16.3 billion in revenue in the first half of 2026, up from $1.1 billion a year earlier, the company also disclosed an $80.7 billion net loss over the same period, though most of that is tied to accounting charges related to fundraising, per the WSJ. Zoom in:

That math points to a numbers problem that can only be solved by public markets, investors tell Axios.

• OpenAI's most recent fundraising round — the biggest in history — is a case in point. It took the company months to secure more than $120 billion in financing, a historic feat that is unlikely to be repeated in this market climate.

• While demand for Anthropic shares is absurdly high — just ask the guy who offered up his near $5 million home to get some — the souring market climate significantly raises the stakes for a public listing. If it goes well, it could help reset investor angst about the stability of the AI boom.

• Public markets will provide a deeper pool of financing as Anthropic expands beyond traditional venture capital. Follow the money:

The pool of cash on the private markets side is getting harder to tap.

• Anthropic is offering Blackstone a yield exceeding 10% on $9 billion in junior debt as part of a record $60 billion chip-financing package, according to the Financial Times.

• That's above the 8.5% rate on an earlier financing deal, suggesting private investors are demanding greater compensation for taking on AI-related risks.

Between the lines: Private markets have done the heavy lifting on AI investing long enough, and they're ready for somebody else to carry the load.

• Anthropic was widely expected to go public in September before one of its researchers quit and a raft of safety incidents brought new public awareness to AI safety concerns.

• Now, Anthropic is expected to IPO before Thanksgiving. The IPO follows anxiety on Wall Street regarding the AI trade, especially as companies specializing in renting computing capacity and building data centers confront market skepticism.

• Nvidia-backed Australian data center company Firmus scrapped its planned IPO amid market volatility.

• South Korean AI cloud provider Elice saw its shares plunge 32% in their trading debut despite rapid revenue growth.

• Meanwhile, concerns about AI infrastructure debt have pushed borrowing costs for CoreWeave sharply higher, with yields on some of its bonds approaching 15%.

Reality check: Anthropic isn't just any AI startup.

• One Anthropic investor told Axios the company is simply ready to go public given its size and maturity.

• The investor also described Anthropic's latest financial results as "spectacular," pushing back on concerns about slowing revenue growth.

The bottom line: Anthropic may have to go public in less than perfect conditions, but investors see an IPO as the best way to put the AI boom to the market's ultimate test.