Anthropic has publicly submitted its preliminary IPO prospectus, disclosing for the first time its operating performance for the first half of this year, new corporate governance rules, and a risk disclosure section spanning more than 90 pages.
The S-1 filed on Monday paves the way for Anthropic to kick off its investor roadshow in roughly two weeks.
The company aims to complete its listing in the week of November 16, ahead of Thanksgiving, with shares to be listed on the Nasdaq under the ticker ANT.
Overall, the preliminary prospectus reveals the scale of its compute procurement commitments, the company's efforts to boost revenue per unit of input, and the fact that customer concentration remains elevated; many specific figures in the filing are left blank, and it does not include full third-quarter financial results.
The market expects this IPO to value Anthropic at $1.5 trillion or more, though the prospectus does not disclose a price range.
Rapid growth with early signs of profitability
In the six months ended June 30, Anthropic generated $16.3 billion in revenue, of which $11.6 billion came in the second quarter alone.
That means second-quarter revenue reached 2.5 times its full-year revenue last year.
The company's business is highly concentrated among a small number of customers: in the nine months through September, its top five customers contributed about 25% of revenue.
The company says no single customer accounted for more than 10%; however, in the first half, one customer did account for 11%.
Customer concentration risk has eased somewhat compared with prior years: in 2025, two customers each accounted for 12% of revenue.
The company's sales of AI models also rely heavily on partnerships with cloud providers.
In the first half of 2026, revenue generated through cloud provider channels was about $7.8 billion, accounting for 48% of total revenue.
Anthropic recognizes as revenue the income from cloud providers such as Google and Amazon reselling its models, while the revenue-sharing payments made to cloud providers are booked as sales and marketing expenses.
As of June 30, the company posted a net loss of $80.7 billion for the half-year, far wider than its full-year 2025 loss of $42 billion.
But the vast majority of that loss stems from accounting adjustments tied to a specific investment structure: investors such as Amazon contributed through convertible notes, which are recorded as liabilities in the financial statements; when the share price linked to those notes rises along with the company's valuation, this paper loss is generated.
Excluding such accounting adjustments, the half-year net loss was about $8.4 billion, slightly wider than the full-year 2025 loss of $7.7 billion.
Despite the sharp jump in revenue, this also indicates an improvement in the company's gross margin.
In the second quarter, the company posted operating profit of $974 million, compared with an operating loss of $1.7 billion in the first quarter.
Operating cash flow in the first half of 2026 was $3.9 billion; a year earlier it was -$1.5 billion, and for full-year 2025 it was -$2.6 billion.
Compute efficiency continues to improve
Hardware costs for model training and operation, along with researcher compensation, are the biggest expenses.
In the first half of 2026, the company's stock-based compensation expense was $2.2 billion, more than seven times the year-earlier level; compute and infrastructure investment rose to $8.9 billion, up 3.8 times year over year.
Anthropic's compute efficiency continues to improve, with each dollar spent on compute generating more revenue.
By the end of the second quarter, compute spending as a share of revenue fell to 48%; it was 72% in the first quarter, and as high as 251% in the first quarter of last year.
Efficiency gains, combined with large-scale fundraising over the past year, have allowed the company to build up a huge cash reserve.
As of June 30, cash and equivalents stood at $112 billion.
Current liabilities for the same period were $7.2 billion, with $108.6 billion in convertible notes payable.
The company said it can continue to take on debt to meet funding needs, with an existing revolving credit facility of up to $15 billion.
An extremely complex lock-up arrangement
Anthropic is asking shareholders to accept a tiered lock-up, similar in concept to this year's SpaceX and Cerebras IPOs, but far more complex in its rules.
For some insiders other than the co-founders: they may sell up to 10% of their holdings on the first day of listing; after full-year 2026 results are disclosed, they may sell up to another 35%; the lock-up ends at the earlier of the release of first-quarter 2027 results or 180 days after listing.
The prospectus also confirms an earlier report: some shareholders can sell shares at the IPO issue price.
The unlock rules for the seven co-founders: 180 days after listing, or the second full trading day after first-quarter 2027 results are disclosed, whichever comes first; at that point they may sell up to 29% of their locked-up shares.
All shareholders accept a relatively long lock-up: full unlocking of all shares takes as long as 180 or 365 days after listing, but shares can be sold in batches during specified windows.
Different shareholders are subject to different terms, and it is not fully clear who can reduce holdings and when.
Total compute contract commitments exceed $650 billion
Cloud server rental spending in the first half was $8.9 billion.
The S-1 filed on Monday did not specify the total compute budget, but it disclosed cloud computing agreements: over the next 7-10 years, total contracted payables are about $657 billion, of which $417 billion is under irrevocable contracts.
Itemized compute commitments: Google Cloud: $114.5 billion; Amazon Web Services: $110 billion; Microsoft: $44.9 billion (higher than the previously disclosed $31 billion).
The above three contracts cannot be canceled unless the cloud provider breaches.
The scale of compute procurement from SpaceX is also higher than previously disclosed: the plan is to purchase $120.5 billion in compute from Musk's company by 2029; most of the contract can be canceled with 90 days' notice.
Once all compute is delivered, monthly spending would be about $3.1 billion.
Other compute contracts: AMD: $20 billion; Nscale: $44.6 billion; Lambda Labs: $41.3 billion (cancelable only if the counterparty fails to deliver on schedule).
In addition, the company plans to lease Google chips from Broadcom under a five-year contract totaling $161 billion, which is irrevocable.
It is also negotiating alternative channels to procure Google chips, with potential additional investment of $125 billion-$150 billion; that portion depends on supply availability and is not included in locked-in contractual commitments.
Based on all contracts disclosed in the current prospectus, if fully performed, Anthropic's total compute spending could reach as much as $806 billion.
The company said in the filing that to meet compute demand, it is shifting from a purely fixed cloud contract model to a hybrid model: directly leasing chips and deploying them in data centers dedicated to Anthropic.
A unique governance structure: five classes of common stock
As a Public Benefit Corporation, Anthropic has a special governance structure: management can pursue social goals in addition to generating profits for shareholders; substantial power is vested in the Long-Term Benefit Trust, whose members are not company shareholders and provide independent advice on safety and social risk matters.
The prospectus discloses five classes of common stock: Class A: ordinary shareholders, one vote per share. Class N: mainly for strategic partners, with no voting rights; when transferred to an unaffiliated third party, it generally automatically converts to Class A. It is also used in connection with employee donation policies. Class E: issued to non-founder employees after the IPO, with voting rights only on a small number of specified matters and no economic rights. Class F: a single share issued separately on the eve of the IPO, granted to the founder-controlled entity Founder LLC. Class T: held by the Long-Term Benefit Trust, which has the right to appoint and remove a majority of the board; it has no ordinary voting rights and no economic rights.
Under this arrangement, as long as at least three of the seven co-founders retain a minimum stake, the Class F shares held by Founder LLC will give the seven founders a combined 50.1% voting right on major matters.
The filing also sets "sunset clauses (expiration termination clauses)" for the Class F and Class T shares: the Class T trust shares have no automatic expiration date, but can be revoked with the consent of 80%+ of the board and 80% of the trust trustees.
In two scenarios, Class T shares can also be revoked even if the trustees object: within three years after the IPO, with unanimous consent of all founders + majority consent of employees + majority consent of public shareholders; with no time limit, with two-thirds consent of founders + 75% consent of employees + majority consent of public shareholders.
The trust's revocation mechanism may raise concerns among people in the safety field and those worried about concentration of power.
Trust members have no economic interest in Anthropic, with the original intent being to allow the company to make safety decisions that could harm commercial interests.
But the company has also previously said the trust structure still has room for modification in the future.
The Class F voting rights arrangement for the seven founders can be voluntarily terminated with the consent of an overwhelming majority of founders; if more than four founders cease to be "continuing founders" (through departure, death, substantial share sales, etc.), it is automatically triggered for termination.
If there are fewer than three continuing founders for 90 consecutive days, a 450-day transition period will begin, after which the special Class F shares will lapse.
Shareholders and partnerships
Google and Amazon are among Anthropic's largest shareholders, having invested tens of billions of dollars over the years while also signing large compute and chip procurement contracts.
The prospectus does not disclose their current shareholdings, but sets ownership caps: Amazon at no more than 12%, and Google at no more than 14.99%.
Convertible notes held by some investors can be converted into shares after listing; but if conversion would breach the ownership cap, the excess portion must be converted later.
Amazon holds $6.2 billion in outstanding notes.
The initial S-1 does not list the size of notes held by Google or other parties; the notes are only part of the company's debt.
The filing also states Amazon's important coordinating role between Anthropic and the U.S. government: government customers outside the United States and workloads in classified environments access the Claude model through Amazon's Bedrock platform.
Anthropic pays distribution fees to cloud providers that resell its models, and in the first half of 2026 those fees accounted for about 17% of revenue.
The seven co-founders, including CEO Dario Amodei and President Daniela Amodei, each hold roughly 2%.
Dario and Daniela each had a base salary of $654,167 last year; including equity awards and other compensation, Dario's total pay was close to $18 million, and Daniela's about $16.4 million.
Spark Capital keeps increasing its stake
Few venture capital firms are mentioned in the prospectus, and Spark Capital is one of them.
The firm led the Series C round in 2023 and has added to its investment in every round since.
Since 2023, it has invested nearly $800 million across six rounds.
The latest was the June Series H round, in which it invested about $440 million and increased its holdings by about 747,000 shares.
Spark partner Yasmin Razavi led the investment and is the only venture capital representative on the board.
Goldman Sachs serves as lead underwriter
More than 20 investment banks are participating in this IPO, and the filing specifies the underwriting syndicate ranking.
This large deal will bring hefty underwriting fees to Wall Street.
Goldman Sachs serves as lead left bookrunner, once again securing a top role after SpaceX; Morgan Stanley is also a joint lead underwriter and serves as stabilizing underwriter, responsible for stabilizing trading in the early days of listing to ensure a smooth open.
Anthropic is following SpaceX's approach with a global offering covering investors in Australia, Canada, Europe, Japan, Switzerland, the United Kingdom and other regions; however, it did not disclose the allocation of shares to retail investors.
Comments