NextFin News - The US initial public offering market, which had staged its strongest recovery since 2021, has all but stopped in its tracks, leaving Anthropic PBC's potential blockbuster listing as one of the few deals investors can still count on. In a two-week stretch this September, three high-profile candidates — smart-ring maker Oura, Bamboo Insurance Services, and nuclear services firm Holtec Nuclear — postponed or withdrew their offerings, while two of the most-watched remaining names, SB Energy and AI infrastructure builder Nscale, have filed publicly but not yet begun formal marketing. Against that backdrop, Anthropic's planned debut, which backers have discussed at a valuation of up to $2 trillion, is no longer just another listing. It has become the single test of whether the window for mega-cap technology offerings is still open at all.
The Window That Opened in 2026 Has Narrowed Fast
The reversal is sharp because the setup was so strong. Through the first six months of 2026, 65 traditional US IPOs raised approximately $114.2 billion, more than seven times the $14.8 billion raised by 34 IPOs over the same period in 2025, according to PwC's US Capital Markets Watch. Through August, IPO issuance stood at $137.6 billion, up 464.1% year over year, with total equity issuance at $355.8 billion, up 128.8%, per SIFMA data. At the start of the year, analysts projected 2026 proceeds could quadruple to a record roughly $160 billion. The recovery was broad enough to earn a guarded endorsement from the advisory firms that steer issuance. "What makes this recovery different from the false starts of recent years is its breadth," Karim Anani, EY's global IPO leader, said in the firm's second-quarter trends report.
Then the window shut. Bamboo Insurance set a price range of $18 to $20 per share, targeting a fully diluted valuation of $3.24 billion and a raise of about $665 million at the midpoint, before postponing on September 22 — hours ahead of a pricing that had been scheduled for that evening. Oura delayed its roughly $2.2 billion listing on September 29, a week after Bamboo, despite its offering having been reported as oversubscribed about four times. Holtec Nuclear postponed on September 16 and then withdrew its $825 million offering entirely in a letter to the SEC on September 25. All three cited market conditions rather than company-specific problems, and all three said they intended to keep their SEC registrations active for a later attempt.
The timing matters. The first half of 2026 was carried by a reopening trade that assumed falling volatility, stable rates, and a clear path for the largest private companies to tap public markets. SpaceX's June 12 listing — the largest IPO in history, pricing 556.6 million shares at $135 for a roughly $75 billion raise at a $1.75 trillion valuation — opened at $150, touched an intraday high of $176.52, and closed at $160.95, lifting its market capitalization above $2.2 trillion. That first-day success made a $2 trillion Anthropic valuation feel plausible rather than delusional. But SpaceX priced into a calm window that no longer exists, and it did so with a structure that limited supply: only about 4% of the company was sold, with staged insider lock-ups, so the debut absorbed demand without flooding the market. A $2 trillion AI operator with a full float faces a different test.
Why the Market Stalled: Three Headwinds Collided at Once
The first headwind is rates. On October 12, the 10-year Treasury yield sat at 5.24%, the 2-year at 4.80%, and the 30-year at 5.60% — levels among the highest in two decades, and well above the 4.49% average for the 10-year through 2026. IPOs are long-duration assets: their value sits in earnings expected years out, and higher discount rates compress those valuations harder than they compress mature cash flows. A company that looked reasonably priced at a 3% risk-free rate can look expensive at 5% without a single change to its business. The mechanism runs through the comparables that underwriters use to set offer prices: when public software and AI multiples contract, new issues must be priced at a wider discount to lure investors away from liquid, already-listed peers. The discount is the price of illiquidity, and it widens exactly when issuers need it to narrow.
The second is geopolitics. The war that began with US and Israeli strikes on Iran in late February has spread across the greater Middle East, pushing WTI crude to $93 a barrel and Brent to $106 as of October 12.
"The recent conflict in the Middle East demonstrated just how quickly the conditions underlying an open market window can shift," EY wrote in its second-quarter global IPO trends report, adding that successful candidates must be "flexible and disciplined enough to wait when markets are tight and nimble enough to pursue accommodating conditions."
The third headwind is the AI sector itself. On September 22, OpenAI cut prices on its newest models by half, launching GPT-6 Sol at $2 per million input tokens and GPT-6 Luna at $0.10 input and $0.50 output. The same day, Anthropic launched Claude Opus 5.5 at $4 input and $20 output, about 20% below the prior Opus 5 tier. A price war is good for customers and bad for the margin story that underpins a $2 trillion valuation. Anthropic's annualized revenue run rate climbed from roughly $9 billion at the end of 2025 to $47 billion in May and more than $65 billion by the end of July, and the company reportedly posted its first operating profit in the second quarter. But revenue growth that depends on falling average selling prices must run faster just to stand still, and every percentage point of price erosion has to be recovered in token volume before it shows up in free cash flow.
Anthropic confidentially filed a draft S-1 with the SEC on June 1, 2026, and advisers have said the company pushed its target window from October to November to present third-quarter results first — results that will show whether the September price cuts accelerated demand enough to offset the lower prices. The roadshow is expected to begin around mid-October, with pricing targeted for the weeks before the November midterm elections.
The Cyclical Read Versus the Structural Read
The central question is whether this stall is cyclical — a mean-reverting pause driven by transient rates, a war premium, and a crowded calendar — or structural, a permanent repricing of what investors will pay for pre-profit, hypergrowth technology. Getting this wrong flips the conclusion, so the two need to be separated rather than blended.
The cyclical case is strong. Windows close and reopen; that is the normal mechanics of equity issuance. In 2025, 347 US IPOs raised $66.8 billion, up 153% year over year, after years of near-closed markets. The pipeline behind today's stall is deep: SB Energy, backed by SoftBank with OpenAI as a strategic investor and customer, filed on September 1 for an estimated $5 billion offering, and Nscale, the Nvidia-backed UK AI infrastructure builder, filed on September 18 for a listing that could value it as high as $35 billion, according to reporting on its filing. Companies that postpone rather than withdraw are signaling timing discipline, not a loss of access. When the 10-year yield falls back toward its 2026 average and the Middle East risk premium fades, the deals that are already registered can move quickly. That is the mean-reversion pattern: issuance clusters in windows, and windows follow the bond market.
But there is a structural layer underneath the cyclical one, and it centers on valuation, not timing. The SpaceX IPO trained the market to accept trillion-dollar private marks in public markets. That is a regime shift in what gets listed, and it will not fully revert. Yet the $2 trillion figure now attached to Anthropic is not a company-confirmed number — it comes from investor discussions reported in August, while the last price anyone actually paid was $965 billion in the May Series H round. Doubling a private mark in a few months, into a window where three deals have just pulled, asks public investors to absorb risk that private investors priced at a discount for illiquidity.
The structural risk is compounded by accounting opacity. Anthropic and OpenAI both report revenue on an annualized run-rate basis, but the two may compute it differently, and a public dispute erupted in April when OpenAI's chief revenue officer argued Anthropic's run rate was overstated by roughly $8 billion because of how it accounts for cloud revenue-sharing deals. Third-party trackers have put Anthropic's run rate as high as $74.1 billion versus OpenAI's $41.3 billion as of July, but neither company has filed audited financials. Public markets price disclosed numbers, not disclosed narratives. The S-1 will force clarity, and clarity can cut both ways.
The Second-Order Problem: What a Failed Mega-IPO Does to the Pipeline
The first-order effect of a slowdown is obvious: deals wait. The second-order effect is what happens to the deals that don't wait. If Anthropic prices at the top of its range and trades up, the window reopens behind it and the postponed names — Oura, Bamboo, Holtec's eventual return, Nscale, SB Energy — get their turn. If Anthropic prices conservatively or trades flat, the damage is not confined to Anthropic. A $2 trillion candidate that cannot hold its IPO price becomes the reference point for every valuation conversation in the pipeline, and underwriters will have to reprice risk across the board.
This is why the delay itself is rational. By pushing from October to November, Anthropic buys two things: third-quarter financials that can show whether the September price war hurt growth, and a calendar slot after the November midterm elections, when political uncertainty clears. Prediction-market traders on Kalshi, as of October 8, priced only a 4% chance that an IPO is confirmed before November 1, a 67% chance before December 1 — implying roughly 63% on November alone — and 75% before January 1, 2027. A month earlier, on September 8, the odds of a confirmation before December stood at 92%. In four weeks, the market moved from expecting a fall listing to betting on a single month.
The Strongest Counter-Thesis
The bullish counter-case is that Anthropic is not like the other deals. Oura, Bamboo, and Holtec are small enough that their withdrawals say more about their own investor bases than about the market. Anthropic is a category leader with a revenue run rate that grew more than sevenfold in under two years, a reported first operating profit, roughly 40% of enterprise LLM API spending against OpenAI's 27%, and about 54% of AI coding usage against Codex's 21%, according to Menlo Ventures survey data. In a flight to quality, capital does not spread evenly — it concentrates in the one asset everyone agrees is real. Anthropic could clear the window precisely because everything else failed.
That argument is coherent, but it depends on one assumption: that public investors will underwrite a valuation that assumes today's growth rate persists through a price war. Dr. Chan Ahn, a former Goldman Sachs and JPMorgan executive, said in an interview that supporting a $2 trillion valuation at a 10% cost of equity, a 25% free-cash-flow margin, and a 25x terminal multiple would require roughly $725 billion in annual revenue by 2036; at a 13% discount rate, the requirement rises to about $950 billion. Those are not hostile assumptions. They are the arithmetic of a terminal-value model. The counter-thesis survives only if Anthropic's S-1 shows margins expanding as prices fall — the rare combination that justifies a structural, not cyclical, premium.
What to Watch
The near-term signal is the roadshow. It is expected to begin around mid-October, with pricing targeted for the weeks before the November midterms. A well-subscribed book at the top of the range would confirm the flight-to-quality thesis. A range that comes in below private-mark expectations, or a deal that slips past November, would confirm that the window is narrower than the bulls assume.
The medium-term signal is the 10-year Treasury yield. A sustained move back toward the 4.49% 2026 average would reopen the window for the whole pipeline, not just Anthropic. A move above 5.5% would likely push more names into 2027.
The long-term signal is the S-1 itself: audited revenue, gross margins, and the treatment of cloud revenue-sharing. That document will separate the structural growth story from the cyclical narrative, and it will set the template for OpenAI's own eventual listing.
Base case: Anthropic prices in November, post-election, at a valuation between its last private mark of $965 billion and the $2 trillion ceiling, with modest first-day gains. The window reopens selectively for the strongest pipeline names in early 2027. Downside case: a weak book forces pricing below private-mark expectations, and the postponements turn into withdrawals across the AI infrastructure complex. Upside case: Q3 results show growth accelerating through the price war, the book is oversubscribed, and the mega-IPO market resets higher.
The US IPO market did not break in September — it priced. Anthropic is now the market's way of asking whether the AI buildout is a decade-long boom or a cycle that peaked in 2026, and the answer will arrive not in a press release but in the silence between the roadshow and the pricing.
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