Anthropic Could Be a $1 Trillion IPO This Fall. These 2 Stocks Already Own a Piece.

The next giant public offering is already in motion. Anthropic, the artificial intelligence (AI) company behind the Claude models, confidentially filed to go public on June 1, on the heels of a funding round that raised $65 billion at a $965 billion valuation. Its reported annualized revenue is approaching $50 billion, and a listing reportedly could come as early as this fall.

The trajectory behind those numbers has few precedents. Anthropic's reported revenue run rate was about $4 billion as recently as last July, and expectations reportedly call for $10.9 billion of revenue in the second quarter alone. Only a handful of companies listed on U.S. exchanges carry a market value above Anthropic's last private mark.

Individual investors, of course, can't buy shares yet. But two of the market's most familiar names bought in years ago, and their stakes have quietly become staggeringly large paper windfalls: Amazon(NASDAQ: AMZN) and Alphabet(NASDAQ: GOOG)(NASDAQ: GOOGL).

Which stock gives investors the better claim on the debut? Run the stakes.

Image source: Getty Images.

1. Amazon: the bigger, quieter stake

Amazon invested $8 billion in Anthropic convertible notes from Q3 2023 to Q4 2025, with portions later converted to nonvoting preferred stock. The company has never disclosed an ownership percentage. But estimates built from its filings put the stake in the mid-to-high teens, worth perhaps $135 billion to $160 billion at Anthropic's current valuation -- and Amazon has committed to invest up to $20 billion more. By April, the position -- $42.2 billion of convertible notes plus $32 billion of nonvoting preferred -- was already carried at more than $74 billion on paper, before the latest round could mark it higher.

The mark-ups are already flowing through Amazon's results. In the first quarter, it recognized $16.8 billion of pre-tax gains included in non-operating income from its Anthropic investments -- more than 40% of its pre-tax income for the period.

Set the stake against Amazon's own size, and the leverage shows. At a market value of about $2.6 trillion, a $150 billion position amounts to nearly 6% of the company. A $1 trillion IPO price would push it higher still.

2. Alphabet: the capped stake with a complication

Alphabet's position is more precisely known. Court documents put it at roughly 14% of Anthropic in straight equity, contractually capped at 15% -- worth about $135 billion at the last private valuation. And in April, the company reportedly committed up to $40 billion more, with $10 billion arriving immediately and the rest tied to milestones.

Alphabet's books already show a similar private-investment effect, too. Its first quarter included about $28.7 billion in net income from equity securities gains -- nearly half of a record $62.6 billion quarterly profit.

But the stake lands differently at Alphabet's scale. Against a market value of about $4.4 trillion, $135 billion works out to about 3% of the company. And there's a strategic issue Amazon doesn't carry to the same degree: Alphabet competes directly with the company it part-owns, selling its Gemini models against Anthropic's Claude.

Which stock gives you the better claim?

A public listing changes two things for these holders. It prints a market price on stakes both companies currently value by accounting estimate, and it opens a path -- eventually -- to converting paper gains into cash.

For Anthropic exposure per dollar invested, Amazon wins the math. Its estimated stake is as large as Alphabet's or larger, inside a company about 40% smaller -- so every move in Anthropic's value means roughly twice as much to Amazon shareholders as it does to Alphabet's.

But there are some caveats. These are paper values, and an IPO would finally test them in a public market that can be far less generous than a private funding round. Much of both positions also sits in instruments -- convertible notes, capped equity -- whose economics differ from common stock, which is exactly why the eventual filing details matter.

Still, the conclusion holds. If the reason to own one of these two stocks is Anthropic, I'd buy Amazon: the exposure is meaningfully larger relative to the company's size, and it comes without the awkwardness of funding a direct competitor. Alphabet shareholders get a fine consolation prize -- a capped-but-enormous stake, already padding reported profits. But if Anthropic prices at $1 trillion or more this fall, Amazon is the stock whose windfall is large enough to move the whole investment case.

Daniel Sparks and his clients have no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Alphabet and Amazon. The Motley Fool has a disclosure policy.