Michael Burry says Anthropic's IPO filing this week has reinforced his concerns that the entire AI ecosystem is at risk of disaster.

The investor of "The Big Short" fame wrote in a Substack post on Tuesday that the first in-depth look at Claude's parent company, ahead of what could be the biggest IPO in history, threw up a bunch of red flags.

Burry pointed to Anthropic's huge spending commitments, slowing revenue, and tangled ties.

He said that Anthropic has struck deals to buy about $537 billion of compute from the likes of Amazon, Alphabet, and Microsoft, and reached preliminary agreements worth hundreds of billions more with others such as SpaceXAI, putting its total commitments at about 12 times its current annual run-rate revenue.

"This is not stated clearly in the S-1, and in my view it is the most deserved headline from it," Burry wrote in a Tuesday Substack post.

He underscored how hyperscalers like Amazon and Alphabet act as Anthropic's "lenders, vendors, channel providers, and shareholders." He also outlined its deal with Broadcom, which involves Apollo and Blackstone and includes convertible notes and structured credit tranches.

"Just remember, the reason this is so complex is because too much debt is needed, and it must be unloaded from the balance sheets of those involved," Burry wrote.

"While some may see all the circularity and connectedness as security on the way up, and that is not wrong, it does leave the entire organism catastrophically vulnerable either on a pause or on the way down," he added.

He also described financing arrangements in the AI space as "garish and audacious," and said hyperscalers aren't generating enough cash to fund the AI buildout so they're resorting to "Byzantine" deals.

Burry said it was a "very similar" situation with vendor financing during the dot-com bubble, saying "people keep making the same mistakes with every new thing."

Burry's worries

In its filing, Anthropic said its revenue surpassed $16 billion for the first six months of this year, a 14-fold increase from the first half of 2025. Its operating loss narrowed by about two-thirds to below $700 million, and it generated nearly $4 billion in operating cash flow.

Burry initially commented on Anthropic's filing in a Substack chat thread on Monday.

He said that revenue was "slowing," citing Anthropic's claim that third-quarter revenue was 86 times the $197 million it generated in the fourth quarter of 2024, or about $16.9 billion.

That would mean Anthropic's revenue grew by about 46% between the second and third quarters of this year, after soaring 144% between the first and second quarters.

"Overall slowing of growth is not attributed to a decline in tokenmaxxing, but I did not expect that to be mentioned," Burry wrote.

Burry was referring to the trend of maximizing AI token consumption, which has fallen out of favor in recent months given its costs.

In another comment, Burry wrote that large language models (LLMs) like Claude are "improving" and "already being used more efficiently and that trend will continue, to the detriment of their growth rate."

Burry said he's focused on the complexity and fragility of the debt financing many AI deals, hurdles to installing new graphics chips shoring up demand for older chips, a potential crash in memory chip prices once the shortage eases, compression and small language models (SLMs) reducing the need for computing power, and the "fundamentals behind not just companies but the deals they are doing."

Responding to a subscriber who said that Big Tech companies are shifting from Anthropic's AI models to their own, and that tokens are rapidly being commoditized, Burry wrote: "Yes, that is what I hear."

Anthropic did not immediately respond to a request for comment on Burry's posts.

The contrarian investor shot to fame after his massive wager against the mid-2000s housing bubble was chronicled in the book and movie "The Big Short." He pivoted from running a hedge fund to writing about his personal investments on Substack last winter.

A recurring theme of his work since then has been deep skepticism of the AI boom. He's flagged slowing growth, overinvestment in microchips and data centers, aggressive accounting, hidden liabilities, and circular financing deals.