AI company Anthropic has launched its initial public offering, and the debate over its valuation and competitive barriers is heating up. Prominent AI critic Gary Marcus went public with a bearish call on Nov 10, 2026, saying flatly "Just Say No to Anthropic's IPO," while the investment community argued over whether the stock is worth buying and holding.
The facts: Marcus's core challenge
In a post on his Substack, Gary Marcus said the entire premise of Anthropic's IPO is that the company has an enormous moat — a premise he rejects. "I continue to believe that there is no moat in AI models. None. But the entire premise of Anthropic's IPO is that they have an enormous gulf of a moat," he wrote.
"When a business needs exponentially increasing amounts of capital to make modest increases in quality in an intensely competitive market and still owes far more money than it has ever made, there is a serious problem." — Gary Marcus
Marcus went further, voicing pessimism about the company's survival prospects. He said he would not be surprised if Anthropic collapsed, nor if the IPO failed, drawing a parallel to WeWork's three failed attempts to go public. "If Anthropic doesn't collapse, I'll be surprised," he said.
On spending, Marcus noted that Anthropic has committed $900 billion over the coming years. Most "cults" implode, he said, and Anthropic does not even hide that it is one, questioning whether its financial logic can hold up.
Analysis: the investment community splits on valuation
On the V2EX forum, a user posted about Anthropic's investment value after listing, saying "this valuation feels like something the market will analyze" and asking other users whether they would buy in — whether this is "a rare investment opportunity, or a big trap." How one views Anthropic, the user argued, is essentially a judgment about the future direction of AI, and proposed revisiting the question "in five years."
The discussion reflects two typical attitudes toward Anthropic's IPO: one side accepts its long-term value as a leading AI company, the other worries about an excessive valuation and doubts the sustainability of its business model. Marcus's bearish view echoes the caution in the community, though the source material offers no specific analysis or institutional views from the buy side.
What's next: IPO pricing and the capex match
Anthropic has not yet responded publicly to Marcus's remarks or the valuation controversy. The market is watching whether the IPO pricing draws enough subscriptions, how investors rate the moat of AI model companies, and whether Anthropic's capital spending over the coming years can match its valuation expectations with a credible path to profit. How this debate plays out will also serve as a reference for the capitalization of other leading AI companies.