Anthropic’s personnel expense rose 486% to $3,152 million in the six months to 30 June 2026, and stock-based compensation within it was $2.2 billion, according to the Form S-1 the company filed with the SEC on 26 October. By our arithmetic, stock pay was about 70% of the personnel bill, up from about 53% a year earlier.
Strip out stock pay and the picture changes. By our arithmetic, personnel expense excluding stock-based compensation grew about 3.8 times, from $252 million to about $952 million, the same multiple as compute and infrastructure expense, which rose from $2,334 million to $8,945 million.
Business Pill · OPERATING LEVERAGE
A short Business Engineer explainer on operating leverage: why profit can grow faster than sales when costs grow slower. It teaches the general idea only and does not discuss Anthropic.
The key insight: Anthropic’s Form S-1 shows personnel expense of $3,152 million in the first half of 2026, of which stock-based compensation was $2.2 billion; by our arithmetic stock pay was about 70% of the bill, and personnel expense excluding stock pay grew about 3.8 times, the same multiple as compute and infrastructure expense.
The filing says personnel expense for the six months ended 30 June 2026 increased by $2.6 billion, or 486%. “The increase was driven by a $1.9 billion increase in stock-based compensation expense and a $510 million increase in cash compensation, both as a result of headcount growth”, it says.
Personnel fell as a share of revenue, from 46% to 19%, according to the same table. Revenue in the period was $16,286 million, against $1,163 million a year earlier.
The S-1 defines personnel expense as stock-based compensation, cash compensation including base salaries and bonuses, employee benefits and employer payroll taxes. A footnote to the summary table gives stock-based compensation of $286 million and $2.2 billion for the two six-month periods.
Anthropic, six months to 30 June, 2025 vs 2026, $ million, log scale: compute and infrastructure expense rose from $2,334 million to $8,945 million and personnel expense excluding stock-based compensation from $252 million to about $952 million, both about 3.8 times; stock-based compensation rose from $286 million to $2.2 billion. Source: Anthropic Form S-1. Personnel excluding stock pay and the multiples are our arithmetic.
Anthropicโs personnel bill rose 486% to $3.152B, far outpacing a 283% jump in compute, year on year.
Lifted staff spending from $0.23 to $0.35 per compute dollar.
Stock-based compensation drove most of that shift, climbing from $286M to $2.2B and reaching about 70% of personnel expense.
Excluding stock pay, personnel costs grew roughly 3.8X, close to computeโs pace, so the case for labor-heavier research rests mainly on equity accounting.
Anthropic spent $9.741B on research in the first half, but only about $6.6B of its $8.945B compute bill was left for research after it paid to serve customers. That leaves roughly $3.2B of research spending that isnโt compute, which is close to the $3.152B it spent on staff, so most of its staff cost appears to go into research. The filing never says this directly, so treat it as an estimate.
Revenue rose 14 times to $16.286B over the same period, far faster than either cost line, and Anthropic reports trailing revenue per employee above $6.6M, up from $1.4M.
Anthropic has promised many employees shares that only fully become theirs once the company goes public, so it hasnโt yet counted that pay as a cost.
When the IPO happens, it has to record all of that built-up share pay at once, so its staff costs will jump sharply in that quarter even though no one did any extra work.
Rohan Paul posted on 30 October that Anthropic’s personnel bill rose 486% to $3.152 billion against a 283% rise in compute, that stock-based compensation climbed from $286 million to $2.2 billion, about 70% of personnel expense, and that excluding stock pay personnel costs grew roughly 3.8 times. Those are his figures; this piece checks them against the S-1.
Compute Against Payroll Without Stock Pay
Compute and infrastructure expense rose 283% to $8,945 million in the first half of 2026. The filing says “The increase was driven by the delivery of committed compute throughout the first half of 2026 under our CSP arrangements”.
By our arithmetic, personnel expense was $0.23 per dollar of compute and infrastructure expense in the first half of 2025 and $0.35 in the first half of 2026. By our arithmetic, personnel expense excluding stock-based compensation and compute and infrastructure expense each grew about 3.8 times.
The account Rohan Paul posted the same comparison on X on 30 October, writing that excluding stock pay, personnel costs “grew roughly 3.8X, close to compute’s pace”. We checked each figure against the S-1 tables.
The Stock Pay Still to Come
The first-half figures exclude most of the stock pay tied to the IPO. The S-1 says no expense had been recognised as of 30 June 2026 for RSUs whose performance condition is met when the registration statement becomes effective, and that had the offering been completed on that date it “would have recorded $2.9 billion of cumulative stock-based compensation expense related to the RSUs”, as we reported in Anthropic’s IPO Would Trigger a $2.9B Stock Pay Charge.
The filing adds $23.7 billion of unrecognised RSU expense to be recognised over a weighted-average period of about 2.1 years. It also reports TTM revenue per employee of over $6.6 million as of 30 September 2026, which we covered in Anthropic’s Revenue per Employee Tops $6.6M.
The Structural Read
As we read the S-1 tables, the 486% rise in personnel expense is mostly an equity line: the filing attributes $1.9 billion of the $2.6 billion increase to stock-based compensation and $510 million to cash compensation.
As we read the arithmetic, the cash side of the payroll and the compute bill moved together, each up about 3.8 times, while revenue rose from $1,163 million to $16,286 million over the same six-month periods.
As we read the RSU disclosure, the first-half figures still leave out most of the stock pay tied to the listing: the S-1 gives $2.9 billion of cumulative RSU expense that would have been recorded had the offering been completed on 30 June 2026.
Anthropic, PBC Form S-1, filed 26 Oct 2026
“The increase was driven by a $1.9 billion increase in stock-based compensation expense and a $510 million increase in cash compensation, both as a result of headcount growth”
Three Implications
FOR READERS OF THE S-1 Personnel expense fell from 46% to 19% of revenue between the two six-month periods, according to the filing.
FOR THE IPO QUARTER The S-1 says that in the quarter the offering is completed, it will begin recording RSU expense using the accelerated attribution method.
FOR RIVAL LABS The filing gives TTM revenue per employee of over $6.6 million as of 30 September 2026, up from $1.4 million a year earlier.
The framework puts it this way: “The accounting metric (gross margin) and the strategic metric (harness density) are anti-correlated by design.”
As we read it, the S-1 shows a similar split between an accounting line and an operating one: stock pay makes the payroll look like it outran compute, while the cash side moved with it. The framework does not discuss Anthropic’s personnel expense.
What Is Not Established
The S-1 rounds first-half 2026 stock-based compensation to $2.2 billion, so the 70% share and the roughly $952 million of personnel expense excluding stock pay are approximate. Personnel expense excluding stock-based compensation also includes benefits and payroll taxes, so it is not the same as the $510 million increase in cash compensation the filing names. The documents we read do not split personnel expense by function.
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Anthropic’s S-1 shows personnel expense of $3,152 million in the first half of 2026, of which stock-based compensation was $2.2 billion. By our arithmetic, stock pay was about 70% of the bill, and personnel expense excluding stock pay grew about 3.8 times, the same multiple as compute and infrastructure expense.
A note on sourcing. Figures come from Anthropic’s Form S-1 filed with the SEC on 26 October 2026, read from the EDGAR filing. Figures labelled our arithmetic are our own computations from the filing; the S-1 rounds first-half 2026 stock-based compensation to $2.2 billion.
Gennaro Cuofano is a CRO and tech executive who has worked in AI since late 2015, starting with bringing NLP, natural-language generation, voice and chatbot products to the marketing industry. His background is in law and finance: he holds a Master's degree in Law and an International MBA with an emphasis on corporate finance (LUISS Business School and the University of San Diego, 2012), and worked as a financial analyst at a real-estate investment firm in San Diego and as an assistant controller. His work focuses on business model strategy, business engineering and, more broadly, structural analysis: how companies make money, read from their own filings. He created FourWeekMBA and leads research there and at The Business Engineer, his newsletter on AI and business strategy, with over 95,000 subscribers and more than 1,000 published analyses. His writing has also appeared on Entrepreneur (for example, How to Digitize a Family Business in Europe) and HackerNoon. Find him on LinkedIn and Substack. See how we source.
