Anthropic S-1: What the IPO Filing Actually Says
Anthropic's S-1 runs 335 pages, and the financial statements add another 65. The risk factors by themselves fill 94.
On October 26, 2026, Anthropic filed its S-1 publicly with the SEC to list Class A shares on the Nasdaq Global Select Market under the ticker "ANT". First-half 2026 revenue in the filing is $16.3 billion, up 1,300%, against an $80.7 billion net loss that is mostly a non-cash accounting charge. The price and share count remain blank.
I worked from the filing itself rather than the coverage, and every number below was checked against it. Treat this as a summary of a public document, not investment advice.
What does Anthropic's S-1 say?
Anthropic's S-1 is the registration statement behind its initial public offering. Inside are the business description, financial statements from 2023 through mid-2026, 88 separate risk factors, an unusual five-class share structure and a staggered lock-up. Anthropic, PBC filed it on October 26, 2026 under SEC CIK 0002130357, following a confidential draft on June 1 and five amended drafts from July 13 to October 9.
Altogether the package holds 87 documents, all listed on the SEC filing index. The main S-1 is 14.2 MB of HTML, while the complete submission reaches 224 MB, mostly images: 44 graphics, many of them customer case studies.
The confidential draft was announced on June 1. Those drafts stayed private during SEC review, and all six now sit on EDGAR beside the public filing.
Where the words go:
| Section | Starts on page | Words |
|---|---|---|
| Prospectus summary | 4 | 11,313 |
| Risk factors | 26 | 69,918 |
| Use of proceeds | 124 | 609 |
| Management's discussion and analysis | 132 | 25,709 |
| Business | 178 | 27,066 |
| Our governance structure and its goals | 242 | not counted |
| Financial statements | F-1 | 65 pages |
The risk factors outweigh the business and financial discussion put together.
When is the Anthropic IPO, and what is the ticker?
Anthropic has applied to list its Class A common stock on the Nasdaq Global Select Market as "ANT". No date, price range or share count appears in the S-1; those fields are still blank. According to Bloomberg News, formal marketing could begin as soon as the week of November 9, 2026. Trading can't start until the SEC declares the registration effective and the offering prices.
Goldman Sachs and Morgan Stanley head the underwriter list on the cover, with J.P. Morgan, Citigroup, Barclays, Wells Fargo Securities, BofA Securities, Deutsche Bank Securities and others after them.
The S-1 also says where the money goes. Proceeds from the shares Anthropic sells go to Anthropic.
Shares sold by the selling stockholders bring the company nothing, and that table names co-founders including Tom Brown, Jack Clark, Jared Kaplan, Sam McCandlish and Christopher Olah. Every share amount is still blank.
Plenty of IPO dates are floating around. None of them checked out against a source I could open, so you won't find one here.
The timing report comes from Bloomberg via Yahoo Finance. The listing details sit in the S-1 itself.
How much revenue does Anthropic make?
For the six months ended June 30, 2026, Anthropic reported $16.3 billion of revenue, compared with $1.2 billion a year earlier, a 1,300% jump. Full-year revenue came to $41 million in 2023, $386 million in 2024 and $4.6 billion in 2025. In the filing, Anthropic says it doesn't expect revenue to keep growing at comparable rates.
Year by year, from the S-1's statements of operations:
| Period | Revenue | Net loss |
|---|---|---|
| 2023 | $41 million | $1.5 billion |
| 2024 | $386 million | $8.3 billion |
| 2025 | $4.6 billion | $42.0 billion |
| First half 2025 | $1.2 billion | $13.0 billion |
| First half 2026 | $16.3 billion | $80.7 billion |
Organizations drive the growth. Customers paying Anthropic $100,000 or more a year rose from more than 600 in June 2025 to more than 6,000 in June 2026, and together they produced $12.0 billion, or 74%, of first-half revenue.
Usage brings in most of the money. Consumption-based revenue reached $13.1 billion, 80% of the first half, with subscriptions at $3.2 billion, or 20%.
Cloud marketplaces carry a large share. Sales through cloud service providers made up 48% of revenue in the first half of 2026, compared with 11% in 2023.
You may have read that two customers account for about a quarter of revenue. That figure belongs to 2025, when two customers each made up 12% of revenue. In the first half of 2026, just one customer passed 10%, at 11%.
Why did Anthropic report an $80.7 billion loss?
Most of Anthropic's $80.7 billion first-half 2026 net loss is an accounting charge rather than spending. Of that total, $72.4 billion is a change in the fair value of convertible notes, derivative liabilities and SAFEs, which the S-1 attributes to Anthropic's rising enterprise valuation. The operating loss, the actual cost of running the business, came to $693 million.
The bridge, in millions:
| Line | First half 2026 |
|---|---|
| Revenue | $16,286 |
| Total operating expenses | $16,979 |
| Operating loss | ($693) |
| Interest income | $1,111 |
| Change in fair value of convertible notes, derivative liabilities and SAFEs | ($72,388) |
| Other expense, net | ($8,757) |
| Net loss | ($80,748) |
When I asked Perplexity what the S-1 says, it described the loss as reflecting "enormous AI compute, chips, and data-center-related costs." The filing tells a different story.
Compute is a big line, just not the $80 billion one. Compute and infrastructure cost $8.9 billion in the half, roughly 55% of revenue.
The operating loss narrowed, too, from $2.1 billion in the first half of 2025.
The remaining $17.0 billion of operating costs breaks into three parts: $3.2 billion for personnel, $3.2 billion for sales, marketing and partnerships, and $1.7 billion for everything else. As the S-1 notes, sales, marketing and partnerships expenses equaled 19% of revenue.
Interest income added $1.1 billion.
What are the biggest risks in Anthropic's S-1?
Anthropic's S-1 sets out 88 separate risk factors in six categories, spread across pages 26 to 119. More than half, 46, deal with the business and industry: compute supply, competition, customer concentration and model safety. Others address the U.S. Department of War's supply-chain risk designation, the governance structure, and the chance that advanced AI could pose "catastrophic or existential risks to humanity."
The count by category:
| Risk category | Risk factors |
|---|---|
| Business and industry | 46 |
| Privacy, cybersecurity and intellectual property | 12 |
| Governance structure | 9 |
| Ownership of Class A common stock | 8 |
| Tax and accounting | 7 |
| Legal and regulatory | 6 |
No risk is spelled out more precisely than the government one. According to the S-1, the Department of War suggested in early 2026 that it could invoke the Defense Production Act, and the Secretary of War directed the department to designate Anthropic a "supply-chain risk to national security." Two letters went to Anthropic on March 4, 2026.
Compute comes up early and keeps coming up. The second risk factor reads: "If we are unable to secure adequate compute or if we fail to direct our compute effectively across our workloads, we may be unable to train models that remain competitive with those of our competitors or adequately serve our customers."
Even the safety commitment is listed as a risk. One heading says that if Anthropic can't manage "the risks related to our focus on and commitment to AI safety," its brand and results could suffer.
The rest are the risks you'd expect, put plainly. One heading warns that the models "may behave in unintended, misaligned, or autonomous ways."
The 2025 figures also include a $1.5 billion "Bartz settlement" line, which the S-1 calls the charge recorded "to settle the Bartz litigation."
Who controls Anthropic after the IPO?
Public shareholders won't control Anthropic's vote after the IPO. One Class F share, held by a company owned by the seven co-founders, carries a fixed 50.1% of voting power. The Class A shares being sold are capped at 49.9% combined. Meanwhile a separate Long-Term Benefit Trust holds the single Class T share and elects directors who form a majority of the board.
The five classes:
| Class | Who holds it | Votes |
|---|---|---|
| A | Public investors and existing holders | Capped at 49.9% combined |
| F | Founder LLC, the seven co-founders | Fixed 50.1% |
| T | Long-Term Benefit Trust | Elects the board majority; generally no stockholder vote |
| N | Holders such as note investors | Non-voting |
| E | Defined in the S-1 | Votes on specific governance matters; no vote on directors |
In the S-1's words, the trust is made up of "financially disinterested trustees with expertise in AI safety, national security, public policy, and social enterprise." The co-founders' company controls the stockholder vote, then, and the trust elects most of the board.
Under Nasdaq rules, that makes Anthropic a "controlled company". It's also a Delaware public benefit corporation, which means its directors have to weigh shareholder returns against its stated purpose.
The S-1's table of holders above 5% names no outside investor.
There's a new auditor as well. Anthropic hired Ernst & Young on October 30, 2025 and dismissed Grant Thornton, reporting no disagreements. Grant Thornton's agreement letter appears as Exhibit 16.1.
When can Anthropic insiders sell their shares?
Anthropic's insiders won't be able to sell all at once. The S-1 lays out 23 separate release dates for locked-up shares, beginning on the first trading day after the prospectus for some employees and directors. Later releases land on the 27th, 48th, 62nd and 76th days, then track earnings releases through 2027, with an extended 365-day lock-up covering part of the stock.
Two clocks run through the schedule. Some tranches count days from the prospectus date. The rest count from earnings releases: six dates tied to the full-year 2026 results, more after the first and second quarters of 2027.
The schedule's share counts are still blank. Look for them in an amended S-1 once pricing is set.
How do you pull Anthropic's S-1 apart in code?
Anthropic's S-1 is available by CIK from SEC EDGAR or through an API, but parsing it is harder than it looks. The HTML is a page-layout export, with every printed line positioned on its own and every section opening on a full-page image. My first script found 74 risk factors. There are 88.
The bug was a small one. Some lines put the font-size rule ahead of the line-height rule, and my pattern expected the reverse. Fourteen headings disappeared.
Two headings beginning mid-sentence gave it away. I then counted a second way, reading every bold-italic text run in order, and both methods landed on 88.
To list every Anthropic filing, query the SEC's submissions API with the CIK. This printed all seven, from the June 1 draft to the S-1:
import requests
r = requests.get("https://data.sec.gov/submissions/CIK0002130357.json",
headers={"User-Agent": "Your Company you@example.com"}, timeout=30)
recent = r.json()["filings"]["recent"]
for form, filed, acc in zip(recent["form"], recent["filingDate"], recent["accessionNumber"]):
print(filed, form, acc)SEC lookups by ticker won't work yet. "ANT" stays out of the SEC's ticker file until the stock lists, so use the CIK there. Edgrapi already maps "ANT" to that CIK.
On Edgrapi, GET /v1/filings/2130357 returns all seven filings, from the June 1 confidential draft through the October 26 S-1. GET /v1/download with the accession number returned the full 14.2 MB document in 3.1 seconds.
Edgrapi's /v1/sections reads S-1s too. On October 27, GET /v1/sections/ANT?form=S-1&item=risk_factors returned the risk factors as 69,539 words of plain text, for 5 credits. Leave out item to list all 16 sections it found, including use_of_proceeds, mda and shares_eligible.
How do you track Anthropic's S-1 amendments?
Follow Anthropic's EDGAR company feed using a declared User-Agent and the CIK 0002130357. Amended S-1 filings will fill in the prices and share counts that are blank today, and the final prospectus arrives as a 424B4 once the deal prices. EDGAR's form filter matches by prefix, so a feed filtered to S-1 also catches S-1/A amendments.
The feed URL:
https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0002130357&type=S-1&dateb=&owner=include&count=40&output=atomOn October 27 it returned a single entry, the October 26 S-1.
Remove the type filter to catch the 424B4 as well. My guide to the SEC RSS feed covers the details, including the 100-entry cap and duplicate rows.
Once the stock lists, insider sales appear as Form 4 filings. That's when the lock-up schedule starts to matter.
Read the filing, then the headlines
Open Anthropic's S-1 and read the summary on page 4 and the loss bridge in the financial statements before you trust any summary, this one included. If you're building on the filing, get a free Edgrapi key and pull it by CIK 0002130357.
Frequently asked questions
When is the Anthropic IPO?
Anthropic hasn't set a date. The S-1 it filed publicly on October 26, 2026 leaves the price range and share count blank. Bloomberg News reported that formal marketing could begin as soon as the week of November 9, 2026. Trading can start only after the SEC declares the registration effective and the offering is priced.
What is Anthropic's stock ticker?
Anthropic applied to list its Class A common stock on the Nasdaq Global Select Market under the ticker "ANT." Until the listing happens, the symbol won't trade or appear in the SEC's ticker file. In the meantime, look Anthropic up by its SEC CIK, 0002130357.
Can I buy Anthropic stock now?
Not on a public exchange. According to the S-1, there has been no public market for Anthropic's Class A common stock. IPO shares go first to buyers the underwriters allocate, and Nasdaq trading begins only after the offering prices. This article isn't investment advice.
Why is Anthropic's loss so large?
Anthropic's $80.7 billion first-half 2026 net loss contains a $72.4 billion non-cash charge from the rising fair value of its convertible notes, derivative liabilities and SAFEs, which the S-1 links to its higher enterprise valuation. Over the same six months, the operating loss was $693 million on $16.3 billion of revenue.
How many risk factors are in Anthropic's S-1?
Anthropic's S-1 contains 88 risk factors in six categories, from page 26 to page 119. Business and industry risks account for 46. The rest cover privacy and intellectual property, legal and regulatory matters, tax and accounting, the governance structure, and ownership of the Class A stock.
Where can I read Anthropic's S-1?
Anthropic's S-1 is on SEC EDGAR under Anthropic, PBC, CIK 0002130357, filed October 26, 2026 with accession number 0001628280-26-067168. The main document is a 14.2 MB HTML file, and the SEC filing index also lists the confidential draft and its five amendments.