Up to 1.6B Anthropic Shares Unlock Within 76 Days of IPO

Anthropic’s S-1/A of 10 November fills in its lock-up calendar for the first time. Up to 316 million Class A shares can be sold on the first trading day after the prospectus date, including shares held by the chief financial officer. By the 76th day the stages add up to 1,612 million shares, 1.95 times the 825 million shares in the IPO, by our arithmetic.

The full schedule runs to 23 release dates and about 15.5 billion shares, timed to set days and to Anthropic’s results releases through the quarter ending 30 September 2027. As we read the lock-up sections, none of the stages depends on the share price.

Short explainer · IPO float

A Business Pill Short on the IPO float, made for our earlier piece on the draft terms. It explains the general idea and does not discuss the lock-up calendar.

Business Pill · Financial Conditions Explained

A short explainer on financial conditions. It teaches the general idea only and does not discuss this story.

What the Filing Says

The table on page 319 lists the “Earliest Date Available for Sale in the Public Market” for the restricted shares. Its first line: “The first trading day following the date of this prospectus”, for up to 316 million shares held by Anthropic’s non-founder directors, officers and current and former employees and consultants.

Footnote (1) names who is in that first group: “our non-founder officers, including our Chief Financial Officer and Chief Accounting Officer, are eligible to sell shares on the first trading day following the date of this prospectus”. The 2 November amendment already set out the stages and the percentages but left every share count blank, as our option-values piece noted this morning.

Every Release, With Its Share Count

Each line below is the filing’s trigger and its “up to” count. The running total and the multiple of the 825 million shares offered are ours.

Trigger and “up to” counts: Anthropic S-1/A No. 2, 10 November 2026, pages 319-320. Running totals and multiples are our arithmetic. Excludes the 351,351,348 placement shares, which are not locked up.

The filing’s summary says the lock-up and standoff agreements cover “an aggregate of approximately 15.5 billion shares of our Class A common stock”, counting Class N conversions, equity awards and full conversion of the outstanding convertible notes. The 23 release dates sum to 15,465 million, by our arithmetic, which matches that total.

Who Can Sell, and When

The underwriting section on pages 334-335 gives the percentages behind each count. Non-founder directors, officers, employees and consultants may sell “up to 10% of the aggregate number of lock-up securities” from day one and “up to an additional 35%” after the FY26 results. The rest of their shares unlock at the earlier of the Q1 2027 results or day 180.

A second group of holders can sell 6.0% on days 27 and 48, an additional 7.0% on days 62 and 76, 12.5% after the FY26 results and 9.5% at each of five later dates. Holders of more than 0.5% of the fully diluted shares are on a 365-day lock-up with smaller steps, starting at 1.8% on days 27 and 48.

The seven co-founders stay locked until the earlier of the Q3 2027 results or day 365. From the earlier of the Q1 2027 results or day 180, each founder may sell “up to 29% of the aggregate number of lock-up securities held by them”.

Against the Float

The filing says all 825 million shares sold in the IPO will be “freely tradable”, apart from any bought by affiliates. Add the 316 million day-one shares and up to 1,141 million shares can trade from day one, 1.38 times the offer, by our arithmetic. By day 76 that is 2,437 million, or 2.95 times.

At the $74 midpoint of the $70 to $78 range, the day-one tranche is worth $23.4 billion and the 1,612 million shares unlockable by day 76 are worth $119.3 billion, by our arithmetic. The 1,612 million are 21.7% of the 7,427,991,791 Class A shares the filing says will be outstanding.

The counts are ceilings, not sales. Each line says “up to”, and holders who are affiliates stay under Rule 144 volume limits: the filing puts 1% of the Class A stock at “74,279,918 shares immediately after the completion of this offering”.

No Price Trigger, Two Other Valves

As we read pages 319-322 and 330-335, Anthropic’s stages are tied only to days after the prospectus date and to results releases, not to the share price.

The filing does give the banks discretion: “The representatives, in their joint discretion, may release the lock-up securities described above in whole or in part at any time”. Such a release can “trigger a pro rata release of lock-up securities held by certain other holders”.

The second valve is hedging. From day 195, certain stockholders may hedge “up to 20% of each such stockholder’s lock-up securities”, or “up to approximately 719 million shares in the aggregate”. Separately, the 351,351,348 Class N shares in the $26 billion placement “will not be subject to the lock-up or market standoff agreements”, though they are restricted securities under Rule 144.

The Structural Read

As we read the table, the early supply comes in steps rather than one cliff: four tranches of 299 million to 349 million between days 27 and 76, then 1.7 billion on the second full trading day after the FY26 results, by our arithmetic from the filing’s counts.

As we read the lock-up sections, the timing depends on days and on results releases, not on the share price; the filing’s discretionary release by the representatives is the only route it gives to an earlier, unscheduled release.

Three Implications

FOR IPO BUYERS Up to 1,141 million shares can trade from day one, the 825 million offered plus the 316 million day-one tranche, 1.38 times the offer, by our arithmetic.

FOR EMPLOYEES AND OFFICERS The filing lets non-founder directors, officers, employees and consultants sell up to 10% of their lock-up securities from day one and up to an additional 35% after the FY26 results.

FOR THE FOUNDERS The seven co-founders are locked until the earlier of the Q3 2027 results or day 365, with up to 29% releasable from the earlier of the Q1 2027 results or day 180, the filing says.

The Business Engineer Lens

This story maps onto the Business Engineer framework The AI Supercycle.

The framework argues: “The job of any operator, investor, or builder is to know which layer they are operating inside and which layer the binding constraint is rotating toward next.”

As we read it, for Anthropic’s public shares the near-term constraint is the release calendar: up to 1,612 million shares by day 76 and about 15.5 billion over the full schedule, by our arithmetic. The framework predates the filing and does not discuss it.

What Is Not Established

The filing gives no prospectus date and no dates for the FY26 or 2027 results releases, so the calendar cannot yet be pinned to days on a calendar. It does not say how many holders intend to sell at any stage. The range, share split and placement are covered in our piece on the filed $70 to $78 range; the earlier float estimate is in our draft-terms piece, and the whole IPO is mapped in our Anthropic IPO map.

The Bottom Line

Anthropic’s IPO puts 825 million shares on the market, but its lock-up table lets up to 316 million more be sold on day one and up to 1,612 million by day 76, 1.95 times the offer, by our arithmetic. The rest of the roughly 15.5 billion shares unlock on results days through late 2027.