In San Francisco, the signs that Tech Week had arrived were hard to miss. Planes towed banners advertising startups above the city. Inflatable company mascots greeted commuters outside transit stations. And hundreds of people lined up outside Anthropic's Claude Founder House for the chance to get inside.

But a few blocks away, the mood was more measured. On Wednesday night, a crowd gathered in the Dogpatch for the Tech Insider: Growth Mode event, sponsored by Fidelity.

Minutes after interviewing Anthropic investor Matt Murphy onstage, Business Insider chief correspondent Ben Bergman put a question to the room: When Anthropic goes public, would you buy shares at a $3 trillion valuation?

Three hands went up.

How about $1.5 trillion? A few more hands rose.

It was a surprisingly muted response for the company that has become one of the clearest symbols of the artificial-intelligence gold rush. Its long-awaited public offering is expected to test how much of that hype can survive the scrutiny of the public markets.

The IPO market is having a strange year. By dollars raised, it has been one of the biggest on record, propelled by SpaceX's blockbuster debut. The prospect of Anthropic following before year-end could push that figure into the stratosphere. But the headline numbers obscure a far thinner market underneath.

There have been relatively few offerings, and some of the most closely watched candidates have stumbled. Just last week, smart-ring maker Oura pulled its planned IPO at the eleventh hour, pointing to choppy market conditions.

For Heidi Mayon, a partner at the law firm Simpson Thacher, who worked on Oura's planned offering, the delay reflected a wait-and-see attitude she's seeing across the market. She told the room that companies have been reluctant to go public before Anthropic and OpenAI do.

"There's sort of an overarching feeling that there isn't enough public investor capital available until those deals get done," Mayon said. SpaceX showed that may not be true, she added, but few companies want to compete with the model providers for investor attention.

The bigger challenge, she said, is that artificial intelligence has pushed valuations sky-high in the private markets.

Rather than squeeze every possible dollar out of an offering, Mayon said, some companies may be better off pricing their shares more conservatively. That could leave room for a first-day "pop" and the momentum that comes with it.

Jack Cassel, Nasdaq's senior vice president and head of new listings, had a different message for the room: There is still plenty of capital to take companies public, but the bar has changed.

After years of growth at all costs, investors are now looking for "growth with cash efficiencies and discipline," Cassel told the room. They are asking tougher questions about the business models, a company's product plans, and what comes after the stock launch.

That scrutiny may keep consumer and software companies on the sidelines until one or both of the frontier labs go public, he said.

Other corners of the market are still moving. Biotech has produced 22 IPOs this year, he noted, with more expected before the end of the year.

When Anthropic finally goes public, it will be the biggest test yet of whether the artificial-intelligence hype train has the financial horsepower to back it up.