Anthropic filed its S-1 on 26 October, the first formal step toward a Nasdaq listing under the ticker ANT. The price range and number of shares have not been set, and the filing is not yet effective. So nothing has been sold, and every gain discussed below is on paper.

The filing shows an unusual ownership picture. Per TechCrunch's reading of the S-1, none of the well-known venture firms, including Menlo Ventures, Sequoia, Sound Ventures and Spark Capital, holds 5% or more, the line for the principal stockholders table. Anthropic's last private round, in May, valued it at $965 billion post-money. At that size, 1% is worth close to $10 billion. Menlo's position, reported at roughly $14 billion, would be about 1.5%.

Amazon's position is built differently. It put $8 billion into Anthropic convertible notes between the third quarter of 2023 and the fourth quarter of 2025, according to Amazon's own quarterly filing. As of 30 June, the S-1 shows $6.2 billion of principal still outstanding, all held by Amazon, as reported by CNBC, Yahoo Finance and TechCrunch. Those notes could turn into roughly 1.84 billion shares when the IPO closes, according to the same reports. The conversion is capped at 12% of Anthropic's partially diluted share count, and Amazon can waive the cap. Notes that cannot convert stay outstanding.

BUSINESS INSIGHT

The notes were a loan that can turn into equity at the IPO. Because Anthropic's value has risen so far, that conversion right is worth far more than the principal. Secondary reports put the accounting value of the notes in the tens of billions of dollars and attribute most of Anthropic's first-half 2026 loss to marking them up, but outlets quote different figures, so we do not repeat one here. Read the exact numbers in the S-1.

Amazon also earns as a supplier. Amazon's quarterly filing describes an expanded commitment of more than $100 billion over ten years for AWS cloud services, and CNBC reports the S-1 puts Anthropic's commitment at at least $110 billion. Google is another big beneficiary. TechCrunch cites court-filing reports of about 14% early last year and a PitchBook estimate of around 5.6% now, after dilution. That is an estimate, not a disclosed figure.

THE FUNDFORGE TAKE

For founders and investors, the lesson is about structure. In a company this large, the biggest winners may be strategic backers whose capital came as debt-like instruments tied to compute and cloud spending, not the venture funds that took early equity. The S-1 itself warns that cloud partners also build rival AI models and may not always want what Anthropic wants.

Treat the numbers with care. They come from a draft filing and secondary reports, the final share count and price are unknown, and gains stay on paper until shares are listed and can be sold. "Billions" describes what stakes could be worth at a given price. It does not describe cash received.

SOURCES

Anthropic, announcement of S-1 filing, 26 Oct 2026. Anthropic, Series H announcement, 28 May 2026. Amazon Form 10-Q for the period ended 30 June 2026 (SEC). TechCrunch, Marina Temkin, 27 Oct 2026. CNBC, Anthropic IPO live updates, 26 Oct 2026. Reuters, 28 May 2026.

Venture Capital

Anthropic's IPO filing: why Amazon may gain more than the VCs