Anthropic's IPO Could Come Within Weeks. Amazon Already Owns a Piece of It.

Anthropic, the AI lab behind the Claude models, has applied to list its stock on the Nasdaq under the symbol "ANT," but its amended filing on Nov. 2 still didn't give a price range.

Financial news service IFR reported last month that Anthropic plans to begin its roadshow (its pitch to big investors) on Nov. 9 and price the deal the next week, citing a person familiar with the process.

Amazon (NASDAQ:AMZN) shareholders have a lot riding on how it goes.

Amazon has put $18 billion into Anthropic since 2023, and its balance sheet carried those holdings at about $239 billion on Sept. 30. With Amazon shares at roughly $267 as of this writing, the stake is about 8% of the company's market value.

Still, that $239 billion is Amazon's own estimate. I think what the initial public offering (IPO) gives Amazon investors is a market price to check it against.

Image source: The Motley Fool.

What Amazon owns

The stake has two parts. The first is $8 billion in convertible notes (debt that can become shares) that Amazon bought from 2023 through 2025. Some have already converted, and the others are convertible into around 1.84 billion shares, according to Anthropic's filings.

The second is preferred stock. Amazon put $5 billion in Anthropic's Series G round in the second quarter of 2026. It also agreed to make up to $20 billion more available as it delivers computing capacity, and it spent $5 billion of that on the Series H round.

All told, Amazon owned 164 million preferred shares on Sept. 30, and each converts into 10 shares of nonvoting common stock at an IPO.

But the notes have a cap. Unless Amazon waives it, each note converts only up to the point where Amazon would own 12% of Anthropic's capitalization. Whatever can't convert at the IPO rolls over into future quarters or gets repaid in cash at maturity.

How much is the stake worth?

Amazon carried its preferred stock at $14.8 billion at the end of 2025 and at $92.5 billion on Sept. 30, while the value of its notes climbed to $146.2 billion from $45.8 billion. Together, the two came to around $239 billion, almost four times the year-end figure. But the two parts got there differently. The preferred stock was already at $92.5 billion on June 30, when the notes were at $97.9 billion.

The difference comes down to accounting. Amazon adjusts the preferred stock only when there's an observable change in price, like a new funding round, but it reestimates the notes every quarter. Both valuations include discounts for lack of marketability (an adjustment for shares that aren't easy to sell).

Anthropic's revenue, meanwhile, hit $33.2 billion over the first nine months of 2026, up from $2.5 billion a year before.

When Anthropic trades, investors can check Amazon's estimates. Every $10 of Anthropic's share price would be worth around $16 billion on the 1.64 billion common shares Amazon's preferred stock converts to -- and up to about $35 billion including all the notes.

A listing could make Amazon's profits swing more

Amazon's other income hit $68.4 billion in the first nine months of 2026, up from $14.1 billion a year before. And Amazon said the gain was mainly from Anthropic. Earnings per share almost doubled to $10.42 in the same period.

But in the third quarter, Amazon's preferred stock didn't move. Even though operating income rose, earnings per share dipped around 3% year over year to $1.89, which Amazon attributed mostly to $9.5 billion in pre-tax Anthropic gains in the year-ago quarter.

An IPO could make those swings routine. Amazon carries its stakes in publicly traded companies at fair value, so Anthropic's share price might begin moving Amazon's net income every quarter, in either direction.

The notes may also bring a one-time boost. When some converted in past quarters, Amazon shifted part of their unrealized gain out of accumulated other comprehensive income (part of shareholders' equity that skips the income statement) and into reported earnings. With the notes now carried at $146.2 billion, well above what Amazon spent on them, the conversion in the IPO could add a big gain to Amazon's results.

In the end, I think the stake is a valuable asset that Amazon bought cheaply. But I'd judge Amazon's next few reports by operating income and put the Anthropic line aside.

The listing should show what the stake is worth on the open market. I just wouldn't let that number, whichever way it goes, decide what I think about Amazon's stock.

Daniel Sparks and his clients do not have positions in any of the stocks mentioned. The Motley Fool has positions in and recommends Amazon. The Motley Fool has a disclosure policy.