Amazon’s Lab Stakes: Anthropic $238.7 Billion, OpenAI $50 Billion

SEATTLE, Oct. 30 — Amazon’sAmazon’s holdings in Anthropic stood on its books at about $238.7 billion on Sept. 30, by our sum of two figures in the quarterly report it filed with the S.E.C. on Thursday evening, up from $60.6 billion at the end of 2025. It has put $18.0 billion of cash into the company since 2023, by the same arithmetic.

The report also shows that Amazon has invested $50.0 billion in OpenAI this year, $21.3 billion of it in the third quarter, and carries that stake at the $50.0 billion it paid.

Amazon is now a large investor in both OpenAI and Anthropic, and a seller of computing power to both.AMZNNasdaq240.35▼3.44−1.4%Amazon · Friday’s session By our arithmetic, the two labs account for about 97 percent of the $298.8 billion at which Amazon records all its investments in other companies’ stock, warrants and convertible debt, and Anthropic alone for 19 percent of Amazon’s total assets. Most of that value rests on Amazon’s own estimates, and Anthropic’s planned listing would test them against a market price.

Each lab is also a long-term customer of Amazon Web Services. In the first quarter, the filing says, AWS and OpenAI expanded an existing $38.0 billion commitment by $100.0 billion over eight years; in the second, AWS and Anthropic expanded theirs by more than $100.0 billion over 10 years.Anthropic’s SideAnthropic’s prospectus, filed publicly on Oct. 26, says it committed in April to spend at least $110.0 billion with Amazon between May 2026 and April 2036, “regardless of actual usage.” Anthropic’s prospectus warns that its reliance on a limited number of cloud providers and suppliers, “some of which have strategic and investment relationships with us and are our customers, creates complex dynamics that could give rise to conflicts of interest.”

The Marks

The Anthropic stake comes in two parts. From the third quarter of 2023 to the fourth of 2025, Amazon bought $8.0 billion of Anthropic’s convertible notes; those still outstanding had an estimated fair value of about $146.2 billion on Sept. 30, up from $45.8 billion at the end of 2025. It also held 164 million shares of Anthropic’s nonvoting preferred stock, some of them from notes converted into shares, on its books at about $92.5 billion, up from $14.8 billion. Together, by our sum, that is $238.7 billion, nearly four times the figure of nine months earlier.

The notes are subject to a 12 percent cap on Amazon’s ownership, which Amazon may waive.The CapAnthropic’s prospectus says no part of a note converts if Amazon would then hold more than 12 percent of Anthropic’s capitalization, counted to include outstanding equity awards and convertible securities. The part that cannot convert is reissued as a non-interest-bearing rollover note. Amazon reports them at fair value, a “Level 3” estimate that draws on, among other things, “estimates of expected time to and type of liquidity events and anticipated securities offerings, and discounts for lack of marketability.”Level 3The third tier of evidence in accounting’s fair-value hierarchy, after quoted prices in active markets and other observable inputs. It rests, in the 10-Q’s words, on “unobservable inputs reflecting our own assumptions,” and such valuations “require significant judgment.” The preferred shares are instead adjusted “to reflect observable changes in price related to Anthropic’s fundings.”

The gains travel by different roads. The notes’ unrealized gain, $140.3 billion on Sept. 30 against $39.5 billion at the end of 2025, sits in accumulated other comprehensive income, a part of shareholders’ equity, and moves into earnings as notes convert: $4.5 billion did so in the first nine months of the year. The upward adjustments to the preferred shares go through the income statement: $62.8 billion in the first nine months, against $7.2 billion a year earlier.

Little of the Anthropic gain reached third-quarter profit: upward adjustments on all of Amazon’s private-company holdings came to $39 million, against $7.2 billion a year earlier. Off the income statement, the quarter’s other comprehensive income included $36.0 billion, net of tax, from the change in unrealized gains on Amazon’s available-for-sale debt securities, the category that holds the notes. Over the nine months, other income of $68.4 billion, which Amazon attributes primarily to Anthropic, was 46 percent of its pre-tax income of $147.6 billion, by our arithmetic, and its tax provision included $15.2 billion of net discrete tax expense “primarily attributable to the upward adjustments to our investments in Anthropic.” Net income for the nine months was $113.6 billion, against $56.5 billion a year earlier.

The Facility

The $10.0 billion of new cash Amazon has put into Anthropic this year bought shares: $5.0 billion of Series G nonvoting preferred stock and $5.0 billion of Series H, both in the second quarter. Amazon also agreed to a financing arrangement “not to exceed $20.0 billion” that expires 30 months after an Anthropic listing or other liquidity event. Anthropic’s prospectus says the facility ends sooner if certain commercial agreements with Amazon terminate. The Series H purchase was made under it, leaving $15.0 billion.

The facility is tied to computing. “At inception, there is no amount available to be drawn against,” the filing says; money becomes available for Anthropic to draw “at its discretion” as Amazon reaches “certain delivery milestones of compute capacity” under the two companies’ amended commercial arrangement. Draws come as new convertible notes or, after a listing, as Anthropic common stock, “issued to us in exchange for cash.” The more computing capacity Amazon delivers to Anthropic, in other words, the more money Anthropic can draw from Amazon, up to $15.0 billion, until 30 months after it lists, unless those agreements terminate earlier.The TermsAnthropic’s prospectus says the money becomes available in $5.0 billion increments as compute milestones are met, and that after the listing each draw would be settled in nonvoting Class N shares priced at the trailing 30-day volume-weighted average price of Class A stock as of the relevant compute milestone, subject to the ownership cap. “We do not expect any notes to be issued under the Amazon 2026 NPA prior to the completion of this offering,” it says.

OpenAI

Amazon’s OpenAI stake came in three payments. In the first quarter, the two companies agreed on a commercial arrangement, mainly for AWS cloud services, and a joint collaboration under which “certain services using OpenAI models will be made available to the Company and on AWS.” Amazon bought $15.0 billion of OpenAI’s Series C preferred stock and agreed to buy $35.0 billion more, of which it paid $13.7 billion in the second quarter and the remaining $21.3 billion in the third.

It records the stake at $50.0 billion, with future adjustments for “observable changes in prices or impairments.” If OpenAI goes public, the preferred would convert to common stock, the filing says.

OpenAI, meanwhile, is now seeking about $20 billion at a valuation of $1.25 trillion, down from $30 billion at $1.4 trillion last month, the Financial Times reported, citing people with knowledge of the matter, according to Bloomberg News’s account of the report. Some investors have reduced their commitments, according to the report, which said OpenAI declined to comment. Amazon’s own commitment, by its filing’s account, has been paid in full.

Amazon’s filing hedges its own numbers. “Valuations of private companies are inherently more complex due to the lack of readily available market data,” it says, and adds: “The current global economic conditions provide additional uncertainty.” Its maximum exposure to loss on investments including Anthropic and OpenAI, it says, is “generally limited to the current carrying values of these investments and any future funding commitments.”

Valuations of private companies are inherently more complex due to the lack of readily available market data.

Anthropic had filed no amended prospectus and no price range with the S.E.C. by Saturday morning. It is preparing to go public next month at a valuation of at least $1.5 trillion, the FT reported, by Bloomberg’s account. At a listing, Amazon’s notes would convert to nonvoting common stock, subject to the cap, and each preferred share to ten shares of nonvoting common; Amazon expects “a customary lock-up period.” The facility’s 30-month clock would start the same day, unless the commercial agreements with Amazon end first.

Daily Cortex is written with AI models, including Anthropic’s Claude, and fact-checked with OpenAI’s GPT models.