Wall Street's AI rout threatens Anthropic's November IPO. The bigger casualty is its valuation.

Investors doubt the roadshow can start next week, and valuation talk has slid from $2tn to about $1.2tn in five weeks. Prediction markets read a delay rather than a cancellation, and see no sign that the wider economy is cracking.

Five weeks ago, investors were talking about valuing Anthropic at as much as $2tn. Now some are discussing $1.2tn to $1.3tn, and the question is no longer only what the company is worth, but whether it can list this month at all.

The trigger was the worst day for American stocks in more than a year. On Thursday 5 November the Dow fell 1,833 points, the S&P 500 lost 4.4% and the Nasdaq Composite dropped 5.5%, leaving it in correction territory about 12% below its October record. The Philadelphia Semiconductor Index fell about 12%. Prospective investors in Anthropic's flotation are now doubting that its roadshow can start next week in time for a November listing, Reuters reported, citing people familiar with the discussions. Anthropic declined to comment and has announced no change to its timetable.

The stakes go well beyond one company. The offering, which some expect to raise as much as $100bn, would be the first big public listing by a developer of frontier AI models. Its price will set a public benchmark for an industry valued until now only in private rounds. Prediction markets suggest the deal is being postponed and repriced rather than abandoned.

A rally that lasted a day

Investors bought stocks on Wednesday 4 November after the Democrats won both chambers of Congress, helped by falling oil prices and lower Treasury yields. By Thursday's close the rally had gone. Every one of the S&P 500's 11 sectors fell. AMD and Micron each lost more than 17%, and Nvidia fell 9.3%. The Cboe Volatility Index, Wall Street's fear gauge, reached 28.09, its biggest intraday jump in more than 18 months.

Politics turned a slow leak into a rout. Democratic victories revived worries that data-centre construction will face tougher scrutiny of permits, electricity demand and environmental effects. Texas, which flipped to the Democrats in the race for governor, elected Gina Hinojosa, who campaigned for a moratorium on new data centres until the legislature sets statewide rules. Senator Bernie Sanders has proposed a national moratorium, though it has not become policy. And the slide had begun well before the vote: Mark Fuchs of Fuchs Capital Partners said AI shares had been repricing lower for more than a month on worries about valuations, free cash flow and borrowing costs.

From $2tn to $1.2tn in five weeks

Anthropic's valuation has now been marked down twice. In early October investors discussed figures as high as $2tn. After a briefing on the company's financial performance, they told bankers $1.4tn to $1.5tn. On Friday 6 November Bloomberg reported that some prospective investors were discussing $1.2tn to $1.3tn, and that no final decisions had been made.

The timetable is under the same pressure. The roadshow had been expected to start in the week of 9 November, with pricing the week after. Investors also want to see Anthropic's October revenue, left blank in its updated registration statement, to judge whether growth has recovered. Given its record of quarterly losses and its large commitments to partners in the AI buildout, Anthropic may have to offer a bigger discount to win investors over.

A delay, not a death sentence

Prediction markets have moved sharply, but not to the point of writing the deal off. Polymarket traders put the chance of a listing by 30 November at 60% (as of 6 November), down 23 points in a week.

Every other date has fallen by a similar amount. The chance of a listing by 25 November is 55.5%, by 15 December 67.5% and by 31 December 72.5%. Only 17 points separate 25 November from the end of the year, so traders expect the deal either to price roughly on schedule or to slip into 2027, with little in between. And the chance that Anthropic does not list this year at all has risen to 27.5%, from about 8.5% a week ago. That is the real news in the prices.

Traders see a cheaper deal

Markets on Anthropic's value at the close of its first trading day show where the discount is being taken. Traders put a 20.7% chance on a value below $1.25tn, up 17 points in a week, and 22.3% on $1.25tn to $1.5tn, up 12. The chance of $1.75tn to $2tn has dropped 12.5 points to 17.5%. In all, traders now put about 43% on a first-day value below $1.5tn, the top of the range investors were discussing a month ago.

The message is plain: a listing this year is still likely, at a lower price than anyone discussed in October.

The race for the year's biggest listing has turned too. Traders give SpaceX a 91% chance of being the largest IPO of 2026, up 36.5 points in a week, and Anthropic 8.6%, down nearly 38.

Markets panic, the economy does not

The most striking signal is what traders do not expect. The chance of a US recession by the end of 2026 stands at 4.5%, down 2 points on the week, even as the Nasdaq suffered one of its worst days in years.

That gap matters for the deal. Traders are pricing a shock to one sector's valuations, not a downturn, which suggests that funding markets should stay open once the shock fades. The same logic shows up in the race to be the world's most valuable company at the end of December: Apple is at 61.5% and Nvidia at 38.5%, down 12 points in a week as chipmakers took the heaviest losses.

Why the market could be wrong

There are two ways this could break in Anthropic's favour. The first is a quick rebound. AMD's chief executive, Lisa Su, said the market was being "a little bit short-sighted" and that she does not see demand for AI chips slowing any time soon. If chip stocks recover quickly, bankers could hold the November timetable, and the lower valuations would look overdone.

The second is that a Democratic Congress may do little to slow AI. Most data-centre rules are set by states rather than Washington, and President Donald Trump is the buildout's loudest champion: in August he said communities that reject data centres risk ending up "backwards and poor". Against that, Anthropic's losses and spending commitments mean that even a calm market may demand a discount.

What it means for markets, business and politics

• Markets: Volatility is the variable to watch. A deal of this size cannot easily price into a market whose fear gauge has just jumped, so a November listing depends on calm returning within days.
• Stocks and sectors: Chipmakers and data-centre suppliers are most exposed to any political drag on construction, and Thursday showed how fast that fear gets priced. Private AI valuations are now tied to listed chip stocks: when Nvidia and AMD fall, the price of the next AI listing falls with them.
• Business: Other AI companies lining up to raise capital have a new reference point. A lower Anthropic valuation resets the price private investors will pay across the sector, and a delay would push the next listings back too.
• Politics and policy: The fight over the AI buildout is moving to state capitals. Texas, now led by a governor who campaigned for a moratorium, is the first test of whether election results turn into rules that slow data-centre construction.

What to watch

Whether Anthropic starts its roadshow in the week of 9 November. Its October revenue figure, which investors have asked to see. Whether the Volatility Index and chip stocks recover next week. And the 25 November market: a fall below 50% would mean traders have stopped expecting a November listing at all.

Traders have already priced a delay. The open question is how much of Anthropic's valuation the wait will cost.