Anthropic Holders Sold at $25.91, Then Investors Paid $58.90

Anthropic’s S-1, filed with the SEC on 26 October 2026, says a syndicate of stockholders bought 179,883,540 Class A shares in a tender offer that closed in April 2026, at $25.9136 a share in cash, for $4,661,437,298. The filing says co-founders Dario Amodei and Daniela Amodei sold shares in it, as did executive Krishna Rao and Holden Karnofsky, Daniela Amodei’s spouse.

From May to June 2026, the S-1 says, Anthropic sold Series H-1 preferred stock at $589.0095 a share. Each preferred share converts into 10 Class A shares, so that is about $58.90 per Class A share by our arithmetic, 2.3 times the April tender price.

Video explainer · Anthropic’s S-1

A 16:9 video explainer on Anthropic’s S-1, narrated from the published text of this piece and one related FourWeekMBA piece.

The Tender Matched the Previous Round

Anthropic’s previous round, Series G-1, ran from January to February 2026 at $259.1364 a share, the S-1 says. Divided by the same 10-to-1 conversion ratio, that is $25.91364 per Class A share, the April tender price to the cent, by our arithmetic. The S-1 does not say how the tender price was set.

The notes say the board approved the tender in February 2026: “an offer by a group of third-party buyers to purchase shares of the Company’s Class A common stock at a price of $25.9136 per share from sellers that included current and former employees, non-employee service providers, and donor advised funds.” The shares “were sold at fair value”, so Anthropic booked no stock-based compensation on the sale.

Why Common and Preferred Prices Differ

Preferred stock and common stock are not the same security. The S-1 describes liquidation preferences on the redeemable convertible preferred stock, which common shares do not carry, so a per-share comparison between the two is not like for like.

The 10-to-1 ratio is the conversion ratio the S-1 gives for all series at 30 June 2026, except Series D. The filing says a 10-for-1 split of the common stock on 17 September 2026 is reflected retroactively in all share and per-share figures.

The Earlier Prices

In June 2025, the S-1 says, Anthropic itself bought back 27,942,000 shares at $5.61 a share in a tender offer, for $156,716,898, at a price the notes describe as “in excess of the then-current fair market value”. Both Amodeis sold shares in that tender. The April 2026 price is 4.6 times the June 2025 price, by our arithmetic.

In between, the compensation footnotes put the fair market value of Class A common stock at $17.66 a share at 31 December 2025, “as determined by our board of directors in good faith”: an accounting value, not a price anyone paid.

Connecting the Coverage

On 26 October we reported that Anthropic raised $65.2B at 10.5x its early-2025 share price, from the preferred rounds in the S-1, and that each of the seven co-founders holds between about 231.8 million and 245.3 million Class A shares and can rank up to 10 secret successors.

Today we reported that Anthropic’s compute leases not yet started reached $321.4 billion at 30 June.

The Structural Read

As we read it, the April tender price lines up with the earlier round, not the later one: $259.1364 for Series G-1, divided by the 10-to-1 conversion ratio the S-1 gives, is the tender price to the cent, by our arithmetic.

As we read it, the comparison has limits the filing itself sets out: the preferred stock carries liquidation preferences that common stock does not, so the two prices are for different securities.

As we read it, the sellers are named but the amounts are not: the S-1 says both Amodei co-founders sold in April, and in the passages we read it does not say how many shares each sold.

Three Implications

FOR IPO BUYERS The S-1 leaves the IPO price range blank, and a tender price is not an IPO price; the filing gives the April tender, Series G-1 and Series H-1 prices but does not compare them with the offering.

FOR EMPLOYEES AND EARLY HOLDERS The notes say the April sellers included current and former employees, non-employee service providers and donor advised funds, at a price the board approved in February 2026.

FOR FOUNDERS’ STAKES The principal stockholders table lists each of the seven co-founders with about 232 million to 245 million Class A shares as of 30 September 2026, after the April tender.

The Business Engineer Lens

This story maps onto the Business Engineer framework The AI Capex Map.

The framework sets out its question: “How the money flows, where it cracks, what it buys, who can absorb it, and what happens when revenue can’t catch up.”

As we read it, the tender and the preferred rounds show the “who can absorb it” part from the equity side: outside buyers took employee and founder shares at one price while new preferred came in at a higher one. The framework was published in May 2026 and does not discuss this filing.

What Is Not Established

In the passages we read, the S-1 does not say how many shares each named seller sold in either tender, who the April buyers were, or how the tender price was set. The IPO price range is left blank. A tender price is not an IPO price, and the S-1 does not compare them.

The Bottom Line

Anthropic’s S-1 shows holders including both Amodei co-founders sold 179.9 million Class A shares at $25.9136 in April 2026, the Series G-1 price per Class A share, weeks before Series H-1 preferred priced at about $58.90 per Class A share, by our arithmetic.