Mid-October at the Earliest: Anthropic's Record IPO Slips Past the Prospectus Deadline

The most anticipated initial public offering in artificial intelligence history just got a few weeks longer to wait. Reuters reported on Friday, September 4, that Anthropic is now expected to begin marketing its IPO in mid-October at the earliest, with the listing completing just days before the U.S. midterm elections in early November — a slip from a timeline that had the company’s public prospectus arriving as early as next week.

According to people familiar with the matter, Anthropic had been expected to make its IPO prospectus public as early as the week of September 7 — the crucial step that would formally kick off the final stages of the offering. That release has now drifted to late September, the sources said, with the usual caution that the plans, including all timing, remain subject to change.

What actually moved

Two dates anchor the revised schedule. The first is the analyst education process: Anthropic is looking to finalize its $15 billion revolving credit facility — the massive pre-IPO war chest that Bloomberg reported the company was expanding from its original $10 billion target — after which analysts from the banks involved in the financing are expected to meet with the company. The second is the prospectus itself, which under the new timeline follows several weeks later than previously planned.

The mechanics matter here. Companies typically leave a few weeks between analyst meetings and making the IPO prospectus public, giving underwriters time to digest the financials and build their models. Anthropic is expected to compress that window, one source told Reuters, because analysts already know the company unusually well — its financials have been reported relentlessly for a year, its revenue run-rate is the stuff of daily headlines, and its banker roster reads like a who’s-who of Wall Street.

But compression has limits. Push the analyst meetings to accommodate the credit facility finalization, and the prospectus slides with them — from “as early as next week” to late September, and marketing from late September to mid-October. The finish line, completing the listing before the November midterms, remains fixed.

A $2 trillion listing, now with more runway

The delay pushes back what some investors have said could be a $2 trillion listing — which would make it one of the largest IPOs ever attempted, a debut that would instantly rank the Claude maker among the most valuable corporations on Earth and serve as the single biggest test yet of public-market appetite for the AI industry.

Context for that number: SpaceX went public in June at a record $1.77 trillion valuation. An Anthropic debut at $2 trillion would eclipse it. Earlier reporting through the summer had investors targeting anywhere from $1.5 trillion to $2 trillion, with the company’s annualized revenue projected by backers to reach $100–120 billion by the end of 2026 — a growth curve that makes even the fastest-scaling software companies in history look linear by comparison.

The timing shift is not automatically a warning sign. Companies routinely adjust IPO schedules as they work through market conditions, regulatory reviews, and internal preparations, and Reuters’s sources framed the change as procedural rather than a response to deteriorating demand. If anything, a mid-October marketing start with a pre-midterms finish gives Anthropic a tighter, more deliberate runway — and keeps the listing clear of the late-summer news lull while its credit facility and bank syndicate finalize.

The bank roster and what comes with it

Morgan Stanley, Goldman Sachs, JPMorgan, and Citi are among the banks working with Anthropic on the IPO, according to people familiar with the matter — a four-bank anchor group at the top of the league tables. All of the banks declined to comment, as did Anthropic itself.

The syndicate structure echoes the credit facility: Morgan Stanley is leading the $15 billion revolving facility that precedes the offering, and separate reporting indicates the bank is also positioned for a lead role on the equity deal itself, with Goldman Sachs alongside. For the banks, the fees on a listing of this scale — potentially the largest ever — would be generational.

The OpenAI shadow

Anthropic will not debut alone. The offering is expected to arrive alongside potential listings from other AI companies, including OpenAI — its larger, faster-burning rival, which has faced its own turbulent year of agent incidents, regulatory probes across a dozen-plus states, and safety controversies around GPT-6 Astra. Whichever company prices first will set the reference point for everything after it, which is one reason the midterms deadline carries weight: a listing completed days before the election lands in the last calm window before volatility season.

There is also a competitive-signal dimension. Reuters notes Anthropic’s recent momentum in enterprise adoption — by one measure it has pulled ahead of OpenAI in the share of businesses paying for its models. A successful $2 trillion debut would convert that commercial lead into a capital-markets one, funding the compute buildout (including its $45 billion Nscale deal signed August 26) that the next generation of Claude models will require.

What to watch

The near-term markers are now clear. Watch for the $15 billion credit facility to be formally finalized — that is the gating item, and its completion triggers the analyst meetings. Watch for the public prospectus in late September, which will finally put audited numbers behind the run-rate headlines and reveal the float structure, the governance arrangements (Anthropic’s unusual public-benefit corporation setup and its cap-table history with Google and Amazon will get intense scrutiny), and the use of proceeds. And watch the calendar: if marketing truly begins mid-October, a pricing before November 4 leaves roughly three weeks of roadshow — fast, but workable for a deal of this profile.

Until then, the market’s most consequential unanswered question — what is the public price of the AI trade? — stays open a few weeks longer. Reuters’s framing is worth repeating: this remains one of the most closely anticipated IPOs ever, and one of the largest ever attempted. A three-week slip changes the schedule, not the stakes.

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Sources for this report are listed in the article frontmatter. The timeline details, bank roster, and valuation figures are drawn from Reuters’s September 4 exclusive (Echo Wang, additional reporting by Milana Vinn), with credit-facility context from Bloomberg’s September 3 report.