Most people with an S&P 500 index fund have never put a dollar into Anthropic, yet many own a piece of it anyway. The Vanguard S&P 500 ETF (VOO) holds Amazon.com Inc. (AMZN) and Alphabet Inc. (GOOGL), and both own big stakes in the Claude maker.
That link got louder this week. Anthropic filed its registration statement with the SEC on Monday, Oct. 26, 2026, to list on Nasdaq under the ticker ANT.
Michael Burry, “The Big Short” investor, read the filing and followed the money. His Substack post on Tuesday, Oct. 27, 2026, kept landing on Amazon, Alphabet’s Google, and Microsoft Corp. (MSFT).
Burry argued that this web leaves the system “catastrophically vulnerable” if growth stalls. He tallied about $537 billion in computing and equipment commitments tied to the filing, according to Seeking Alpha.
“There is a lot here but nothing that changes my view,” Burry said.
The dollar figure is striking, but the names explain his worry. Each plays several roles in Anthropic’s business at once.
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The same names show up at every stop
Start with where Anthropic’s money goes. Amazon, Google, and Microsoft supply much of the computing power that trains and runs Claude. Those deals require Anthropic to pay “regardless of usage,” Reuters reported from a draft of the filing.
The list reaches beyond cloud companies. Anthropic expects to pay Elon Musk’s SpaceX (SPCX) about $3.1 billion a month at full capacity, CNBC reported. Bills that size leave little room for a slow quarter.
Now follow it the other way. Amazon and Google are also major Anthropic investors. Amazon even holds convertible notes, a type of loan, and some will convert into Anthropic shares at the listing, according to the S-1.
The same companies help Anthropic sell. About 47% of its 2025 revenue came through Amazon’s and Google’s cloud marketplaces, Reuters reported from a draft filing. The cloud provider keeps a fee on each of those sales.
Anthropic does not hide the tension. Its S-1 warns that these overlapping roles create “complex dynamics that could give rise to conflicts of interest.” It also says some partners build rival models and have not supplied all the computing power it sought.
Amazon’s second-quarter profit included $53.4 billion in non-operating gains, mostly from its Anthropic stake, nearly double its operating income.VCG / Getty Images
The loop already runs through Big Tech profits
This is where Burry’s warning stops being only about Anthropic. Amazon’s second-quarter net income included $53.4 billion in non-operating gains, mostly from its Anthropic investments, according to a press release.
Amazon’s operating income, the profit from its stores, ads, and cloud, was $27.5 billion, as the same release shows. A paper markup outweighed the whole operating business nearly two to one.
Alphabet has felt the same lift. Anthropic stakes were the biggest first-quarter profit driver at both giants, Fortune reported. When they invest more or pledge more cloud capacity, Fortune noted, Anthropic’s valuation tends to climb, and so do their stakes.
That works well while the numbers rise. A stumble at Anthropic, however, would hit their cloud revenue and their investment gains at once.
Growth is what keeps the circle turning
So far, the growth has been real. Anthropic’s second-quarter revenue rose 1,368% from a year earlier, according to the S-1. Compute and infrastructure costs rose 300%, the filing shows, supporting the company’s case that it is getting more efficient.
Then the pace cooled. Anthropic told prospective investors that third-quarter revenue grew about 45% from the second quarter, Reuters reported. Revenue had more than doubled the quarter before.
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Most companies would celebrate that, and Anthropic said it was profitable on an adjusted basis, Bloomberg reported. Its commitments, however, were signed for a steeper curve.
The gap matters because Anthropic typically buys computing capacity 12 to 18 months ahead, according to the S-1, so those costs stay largely fixed. Revenue can slow in any quarter, but the bills arrive on schedule.
Burry is not a neutral reader. Last month, he posted that markets should “tank hard” to keep OpenAI and Anthropic from going public, TechSpot reported. Still, the filing’s own risk section backs his point.
Amazon has felt a paper gain flip before
Amazon shareholders have seen a stake like this reverse. Its holding in Rivian Automotive Inc. (RIVN) produced an $11.8 billion pretax gain in 2021, according to its earnings release.
A year later, Rivian’s sliding shares turned that stake into a $12.7 billion loss, the same release shows. The markdown pushed Amazon to a net loss for 2022.
The lesson is about timing. Rivian traded publicly, so Amazon’s stake reset with its stock price every quarter. The Anthropic stakes mostly reprice when Anthropic raises money, and the listing will change that.
Amazon reports third-quarter results on Thursday, Oct. 29, 2026, its first report since the filing. Next comes the price range in Anthropic’s amended S-1, which will ripple into earnings most index-fund owners already hold.
The biggest players in the AI buildout are increasingly tied together through one another’s stock. Anthropic’s listing is the moment that paper starts trading in public, where it can fall as easily as it rose.
Related: What Jim Cramer is watching as Anthropic heads to Nasdaq