Anthropic's $1.5T October IPO: What $47B in Revenue Actually Supports
WSJ points to September or early October, Polymarket prices 68% by Halloween, and the revenue trajectory shows Anthropic sprinting past OpenAI on growth
The Wall Street Journal reportedly states Anthropic is meeting with potential investors to shore up confidence ahead of a planned IPO that could launch in September or early October, with a projected valuation of $1.5 to $1.8 trillion. That follows Anthropic's $65 billion Series H at $965 billion post-money on May 28, led by Altimeter, Dragoneer, Greenoaks and Sequoia, which put Anthropic above OpenAI's $852 billion valuation from its $122 billion round in late March (CNBC, May 28, 2026).
WSJ says October, market says likely
Polymarket prices October as the base case, not September. As of Aug 11, 2026:
Valuation markets for Dec 31 tell the same story. $1.25T is priced at 90% Yes, $1.5T at 74.5% Yes, $1.75T at 50.5% Yes, and $2.0T at 40.5% Yes. In other words, if Anthropic lists, the market expects it to clear $1.25T and leans to $1.5T.
For OpenAI, the market expects later. OpenAI IPO by Dec 31, 2026 is only 14.5% Yes, while OpenAI IPO closing cap above $1T is 72.5% Yes and above $1.2T is 58.5% Yes. The sequencing bet is clear: Anthropic first at 84.5% Yes.
Revenue trajectory: Anthropic's sprint vs OpenAI's scale
Bulls cite a $70B run rate. The latest company-disclosed number is $47B. Anthropic reported a $47 billion revenue run rate on May 28, up from $30 billion earlier this year and $10 billion in annual revenue last year (CNBC, May 28, 2026). OpenAI was at about $24 billion annualized on Mar 31, 2026.
The trajectory matters more than the level:
Anthropic:
OpenAI:
| Period | Anthropic | OpenAI | Source |
|---|---|---|---|
| Dec 31, 2024 | $1.0B | $5.5B | CNBC / CNBC |
| Mar 31, 2025 | $2.0B | — | CNBC |
| May 30, 2025 | $3.0B | — | CNBC |
| Jul 29, 2025 | $5.0B | — | Bloomberg |
| Dec 31, 2025 | $9.0B | $21.4B | Bloomberg / The Information |
| Feb 12, 2026 | $14.0B | — | Anthropic |
| Mar 31, 2026 | — | $24.0B | Company disclosed via FutureSearch |
| May 15, 2026 | $47.0B | — | Anthropic Series H via CNBC |
Anthropic grew about 47x from Dec 2024 to May 2026. OpenAI grew about 4.4x from Dec 2024 to Mar 2026. The gap was 5.5x in Dec 2024 and is now about 2x on disclosed numbers. Anthropic's driver is Claude Code and API demand, which is why the growth looks vertical. OpenAI's mix is more balanced between consumer subscriptions and API, which is why its base is larger but its growth is slower.
The $1.5T math: 32x disclosed, 21x if you believe the bulls
At $1.5T, the multiple depends on which revenue you use:
| Scenario | Revenue base | Multiple |
|---|---|---|
| Anthropic $1.5T / disclosed $47B | $47B | 31.9x |
| Anthropic $1.5T / bull $70B run rate | $70B | 21.4x |
| OpenAI $852B / disclosed $24B | $24B | 35.5x |
Bears are right that 32x disclosed ARR is extreme for any software. Bulls are right that it is not above what OpenAI just raised at. OpenAI's March round at $852B was 35.5x its disclosed $24B. If you credit the bull $70B number, Anthropic at $1.5T is actually cheaper on a multiple basis than OpenAI at $852B.
The S-1 will decide which number bankers can underwrite. A $47B run rate needs flawless execution to grow into $1.5T. A $70B run rate makes $1.5T look like 21x, which is still premium but in line with hyper-growth AI labs.
Capex burn is what the S-1 will have to answer
This is the bear case the S-1 will reveal. Both labs are buying capacity ahead of revenue. Note: specific capex and margin figures below are based on industry reports and have not been independently verified; the S-1 will provide audited numbers.
Anthropic's compute spend is estimated at roughly 60% of revenue, with hosting split between AWS Trainium and GCP TPU. The company has made multi-year commitments to Google Cloud and Azure. Gross margins have improved from deeply negative in 2024 to positive in 2025, with inference margins expected to reach the mid-60s percent by 2026.
OpenAI's inference spend was reported at $8.4B in FY2025, with projections of $14.1B for 2026. The company has made multi-year compute and datacenter commitments across multiple vendors. Gross margins were reported at about 40% in 2024 and 33% in 2025.
The bull defense is margin inflection. The bear flag is absolute commitments.
What to watch in the S-1: revenue recognition and concentration, how much is direct vs cloud marketplace resale, committed cloud liabilities, and whether Claude Code revenue is durable or usage-spiky.
Does Anthropic clear the runway for OpenAI in 2027
Yes, that is how the market prices it. Polymarket has Anthropic IPO by Dec 31, 2026 at 84.5% Yes and OpenAI IPO by Dec 31, 2026 at only 14.5% Yes. The head-to-head is Anthropic first at 84.5% Yes.
WSJ framing matches: OpenAI is preparing to file its confidential prospectus and is looking to go public as soon as September, while Anthropic is also getting its IPO ready with timing fluid (CNBC, May 28, 2026). If Anthropic prints $1.5T at 21x to 32x, it validates the $1T-plus range Polymarket already gives OpenAI when it does list.
If Anthropic stumbles on valuation or disclosure, OpenAI's 2027 window gets harder. If Anthropic clears $1.5T, OpenAI's $1T to $1.2T close becomes the market's next anchor.
More research at bargo.ai/research.