Anthropic's IPO Could Hand Alphabet and Amazon a Paper Windfall, and Hand Lenders a Giant New Borrower

The hook: a quarter of Anthropic is about to get a price tag

Anthropic lists on Nasdaq next week, and two of the most-watched companies on the planet have a lot riding on it. According to The Daily Upside, Google and Amazon are Anthropic's two largest outside shareholders and together own about a quarter of the company. Until now, nobody had to put a daily price on that stake. Soon the market will do it for them.

The Daily Upside calls the IPO "both boom and bust for Big Tech." The boom is easy to see: a possibly enormous paper gain. But the more consequential story may be on the debt side. Marc Rubinstein at Net Interest argues the listing turns Anthropic into a major new borrower in the markets that pay for AI's data-center buildout. If you own Alphabet, Amazon, Broadcom, or a bond fund, that matters to you.

A $1.4 trillion market cap would be nice, and would give comfort to lenders, but it can't be used to repay debt: you need free cash flow for that.

Why Alphabet's and Amazon's earnings could get noisy

Here's the mechanic. Under standard US accounting (GAAP), a stake in a private company is often held at roughly what you paid. It only gets updated when there's a clear signal of value, like a new funding round. Once the shares trade publicly, the stake can be "marked to market," meaning revalued to the current share price, and the change can run through net income every quarter. That depends on how each company classifies its holding, and our sources don't say.

They don't give the companies' current carrying values either, so nobody outside can size the jump precisely. The rough scale is still eye-opening. Rubinstein mentions a $1.4 trillion market cap. A quarter of that is about $350 billion. Some of that value may already be on their books from earlier private rounds. Even so, the gain could be big enough to swamp a quarter's results.

So what? For the next few quarters, Alphabet's and Amazon's headline earnings per share may tell you more about Anthropic's stock price than about search ads or AWS. Look past the bottom line to operating income, which is profit from the actual business. Treat the Anthropic gain as what it is: non-cash, outside the core business, and capable of turning into a loss if the shares slide.

The 'bust' half: it cuts both ways

The Daily Upside's piece doesn't spell out the bust in the material we have, so here's our read. First, the accounting runs in both directions. A newly public AI stock can be volatile, and any drop lands in the same earnings line that the gain did. A windfall in one quarter can become a write-down in the next.

Second, a public Anthropic is a more independent Anthropic. Rubinstein notes it has so far relied on equity investors and suppliers, who together put in more than $140 billion. Once it's listed, it has a cash pile he puts at $212 billion, tradable shares, and potentially access to the bond market. A company that can fund itself is less dependent on any single backer. That's our inference, not something the sources report about specific deals. But if you hold Alphabet or Amazon for their long-term ties to Anthropic, watch the relationship, not just the mark-to-market gain.

The bigger picture: why Net Interest calls it a credit event

Rubinstein's point is that the IPO money is only the start, because a public company with a big equity cushion can borrow a lot more. As a young startup burning billions a year, Anthropic "would hardly have had a look-in" in the bond market. Now its IPO banks have already given it a $15 billion revolving credit facility, which works like a corporate credit card it can draw and repay. For now the line is secured, meaning backed by collateral. That requirement goes away and the interest rate improves once two of the three major rating agencies call Anthropic investment grade. The template is SpaceX, which sold $25 billion of senior unsecured bonds (plain IOUs with no collateral behind them) shortly after its June IPO.

Investment grade means BBB– or better. It opens the door to the $13 trillion market dominated by insurers and pension funds. Morgan Stanley and Goldman Sachs are lobbying Moody's and S&P. The early verdicts are mixed. AIR Platforms, a startup founded by Moody's and Goldman veterans, rates Anthropic BBB, two steps above OpenAI. It isn't an officially recognized rating agency, though, so its opinion doesn't count. Kroll, which is recognized, says BB+, one step short. Blackstone, which marketed the latest Broadcom-backed deal, expects BB-range.

Broadcom is why this reaches beyond Anthropic. It first agreed to stand behind $30 billion of debt used to buy hardware leased to Anthropic, and a second deal last month took its commitments past $70 billion. CEO Hock Tan told analysts Anthropic's "investment credit will change" after the IPO. An investment-grade rating would let future deals rest on Anthropic's own credit rather than its suppliers'. If the rating falls short, suppliers like Broadcom stay on the hook for more.

The broader AI-spending mood is helping. CoreWeave, a so-called neocloud that rents out AI computing power, just posted record revenue of $3.7 billion, up 168% from a year earlier, which eased fears of an AI spending bust. That says nothing about Anthropic's own books, though. Rubinstein's warning is the one to remember: lenders get repaid from free cash flow, the cash left after running the business and investing in it, not from market cap. Watch for Moody's and S&P's first ratings, whether the credit line's collateral gets released, and how Anthropic's first bond deal is priced.