Anthropic filed its IPO prospectus on Monday without filling in the formal share price, but Protos reported that a footnote in the filing reveals how the board was valuing the stock only weeks earlier: about $71.43 per share.
According to the report, the company recognized a $2 billion expense in the third quarter to match shares that employees donated to charity in August. In October, Anthropic settled that obligation with approximately 28 million non-voting Class N shares. Dividing $2 billion by 28 million shares yields about $71.43 per share.
Because both figures were rounded, Protos said the technical range runs from $69.52 to $73.35, though the midpoint is the more likely figure.
How the donation-matching plan exposed the valuation
Anthropic is a Delaware public benefit corporation and promotes philanthropy. Under its donation-matching plan, when an employee donates vested shares to charity, the company may add a matching corporate gift in non-voting stock.
For employees whose offer letters were issued on or after May 17, 2024, the plan states: 「the company will donate one non-voting share for each donated share equivalent that the participant donates.」
Protos said that ratio provides the first input needed to estimate Anthropic’s share price as of September 30. The second input is the dollar value assigned by the board. In this case, the board said 28 million Class N shares were worth $2 billion.
Anthropic’s donation-matching plan defines that figure as 「the per share fair market value of a share, as determined by the administrator in good faith.」
A brief history of Anthropic’s stock price
The report also laid out a timeline of recent financing rounds and internal pricing marks.
In March 2025, Series E investors paid the equivalent of $5.61 per common share.
By September 2025, Series F investors paid $14.10 per share at a $183 billion valuation.
Series G closed in February 2026 at a $380 billion valuation, or $25.91 per share.
In April 2026, Anthropic facilitated a tender offer at $25.91 per share. Sellers included CEO Dario Amodei, his sister Daniela Amodei, and her husband Holden Karnofsky.
Series H in May 2026 valued the company at $965 billion, or $58.90 per common-share equivalent.
After June 30, the board approved grants of approximately 91 million RSUs with an aggregate grant-date fair value of $5.8 billion, implying a stock price of roughly $64.
That was followed by the September donation-match mark of $71.43, about 21% above the Series H round.
On October 9, Nasdaq Private Market indicated a stock price of $85.10, about 19% above Anthropic’s September 30 price.
Private-market signals and possible IPO pricing
Protos said live estimates of Anthropic’s current stock price are near $90.80 on a split-adjusted basis. It noted that the private data provider Notice had not adjusted its quote for Anthropic’s 10-for-1 split on September 17, 2026.
Notice displayed an estimated price of $908, which is equivalent to $90.80 after adjusting for the split. Protos said that split-adjusted figure is the one used in most press coverage discussing the likely trading price of ANT, Anthropic’s planned Nasdaq listing.
The report added that stock splits are common ahead of major corporate events such as an IPO, and the exact split-adjusted opening price for retail trading later this year remains unknown.
Both Notice’s $908 indication and Nasdaq Private Market’s $85.10 imply a valuation near $1.5 trillion, according to Protos.
At $71.43 per share as of September 30, Anthropic’s 16.9 billion share count implied a valuation of roughly $1.2 trillion, slightly below estimates near $1.5 trillion in late October.
A $1.5 trillion valuation works out to about $88.56 per share.
Protos also wrote that if Anthropic reaches a $2 trillion valuation at IPO, the stock price could hit $118. Additional valuation gains, or split adjustments, could push the eventual price higher.
Why $71.43 may not be the public trading price
The board’s $71.43 mark as of September 30 likely included what the S-1 described as a discount for lack of marketability, because the shares were not yet publicly traded, the report said.
In other words, Protos expects Anthropic to begin trading on public exchanges at a level well above $71.43.
Anthropic is requesting the ticker symbol ANT when its shares begin public trading.
