Anthropic's share price sits blank. Markets moved anyway, the day after the company filed its S-1 with the Securities and Exchange Commission1. Dario Amodei, Anthropic's co-founder and chief executive, named only a possible value near $2 trillion. By Tuesday morning in Asia, that blank number had already moved real stocks.
"Anthropic has filed an S-1 registration statement with the SEC related to its proposed IPO," the company posted on X that morning5. The post is a filing notice. Markets read it as a buy signal for chips.
Markets Moved Before the Ticker Existed
South Korea's KOSPI rose more than 3 percent on Tuesday, after paring an even bigger early gain2. Samsung Electronics climbed 4 percent, and SK hynix, which builds the memory chips AI servers need, climbed 6 percent. Investors read the filing as fresh evidence of AI demand across the whole sector.
Japan's Nikkei 225 added 1.6 percent, SoftBank rose 5 percent, and chipmaking equipment firm Advantest jumped 9.8 percent2. The Philadelphia Semiconductor Index, a U.S. gauge of chip stocks, rose 3 percent, its largest one-day gain in more than a month. Chip supply carried the day's excitement more than any chat software did.
Advantest gained 9.8 percent the day Anthropic filed to go public
Share and market moves on Oct. 27, 2026, the trading day after Anthropic's S-1 filing
Each bar is one stock or index that moved on the filing; chip stocks carry one color, broad indexes a second, and every bar belongs to a company other than Anthropic.
Anthropic's own shares remain unpriced and untraded, so every bar here belongs to a different company.
Sources: U.S. Securities and Exchange Commission [1]; Investing.com [2]. Chart by Ryan Elliott Dennis.
The numbers behind this chart
| Item | Value |
|---|---|
| Advantest (Japan) | 9.8% |
| SK hynix (S. Korea) | 6.0% |
| SoftBank (Japan) | 5.0% |
| Samsung (S. Korea) | 4.0% |
| KOSPI index (S. Korea) | 3.0% |
| Philadelphia Semi Index (U.S.) | 3.0% |
| Nikkei 225 (Japan) | 1.6% |
Monday's filing came from Anthropic alone. Traders read Anthropic's revenue growth as proof that AI spending still pays somebody beyond Anthropic itself2. South Korea's economy also grew faster than forecast in the third quarter, which gave the rally a second reason to run.
The Crowd Outran the Filing
Anthropic's own post pulled 17,671 likes and 1,256 replies within a day5. The news-aggregator account Watcher.Guru spread the same filing to its own, separate crowd within minutes. Both accounts turned a legal filing into a feed moment.
Watcher.Guru@WatcherGuruJUST IN: Claude AI developer Anthropic officially files for IPO under ticker $ANT. pic.twitter.com/p6DwZbjAZv
Wikipedia traffic backs up the rush to read about Anthropic ahead of reading Anthropic. The site's English-language page on the company logged 19,378 views on Monday, up from 5,285 the day before7. That is close to four times the normal traffic, on a page that only describes the company.
Anthropic shared the news cycle with two rivals. OpenAI shipped a cheaper, faster model called GPT-6.1 Terra the same day, priced at one dollar per million input tokens6. Google DeepMind posted its own world-building model, Genie 4, hours later. Each lab picked the same week to remind investors it belonged in the conversation.
The Case for the Rally
Dan Ives is a partner at the merchant bank Yorkville Ives. Ives has covered technology stocks for 25 years and has stayed bullish through several downturns. He told ABC News the filing marks a turning point for the whole trade, beyond one company alone.
"It's a watershed event, not just for tech, but the AI revolution in terms of the role Anthropic plays," Ives said3. He added a specific read on demand for the stock itself.
"I think Anthropic, being that they're the centrepiece of the AI revolution, you're going to see probably a strong appetite for this offering," Ives said3.
Ives stays bullish, putting initial investor appetite near $1.5 trillion to $1.7 trillion, below the $2 trillion figure in circulation3. A higher price would lose him as what he calls "an assertive buyer". He still sees room for Anthropic to grow into that higher range over time, once revenue catches up to the story. His framing treats Tuesday's reaction as early sentiment, ahead of any final verdict.
The Case Against the Price
Guske stays skeptical. He is a senior investment analyst at the research firm New Constructs. A discounted cash flow model he built prices Anthropic from the numbers in its own filing. That model's low scenario prices the company at $144 billion, a tenth of the $2 trillion figure in circulation.
"As more investors realize that Anthropic's business model has no pricing power, they will understand that no amount of revenue growth will make it profitable enough to deserve an IPO valuation anywhere close to $2 trillion," Kyle Guske II wrote4.
That gap runs to 93 percent between his bear case and the number the market cheered on Tuesday4. Guske's model leans on a measure called Net Revenue Retention. That measure tracks how much more the same customers spend a year later. He argues a business that loses money on every dollar of usage needs more than growth to turn a profit.
New Constructs prices Anthropic 93 percent below the IPO's $2 trillion talk
Two estimates of Anthropic's worth, in billions of dollars, as of the Oct. 27, 2026 filing
The first column is the valuation figure attached to the IPO filing; the second is New Constructs analyst Kyle Guske II's low-case model, built from the same filing's numbers.
The $2 trillion figure is market talk reported around the filing, separate from a price Anthropic's own S-1 states; the filing leaves its offering price blank.
Sources: U.S. Securities and Exchange Commission [1]; New Constructs [4]. Chart by Ryan Elliott Dennis.
The numbers behind this chart
| Item | Value |
|---|---|
| IPO talk figure | $2,000B |
| Guske's low case | $144B |
Anthropic's own filing gives Guske's case an opening. The company's risk factors describe its AI as capable of "catastrophic" harm in the wrong hands1. That warning is written for regulators, but a buyer reads it as a warning about the product itself.
Both men read the same filing and the same $16.3 billion of first-half revenue. One sees a company still early in pricing its own value. The other sees a filing that asks public shareholders to fund growth before it becomes profit.
What to do
Treat Tuesday's rally in Samsung, SK hynix and Advantest as a bet on AI demand broadly. Anthropic's own price stays blank, so that rally sits one step removed from a verified price for Anthropic stock12. If your budget tracks AI-exposed equities, separate what the trade did today from what the company is actually worth. This week delivered only the first measure.
Wait for Anthropic's amended S-1, due before any roadshow, to see where bankers actually set the range1. That number will settle which analyst read the filing correctly, ahead of Tuesday's headline reaction.
By the numbers
- South Korea's KOSPI: up more than 3 percent on Oct. 27, the day after Anthropic's filing2.
- SK hynix: shares up 6 percent the same day2.
- Advantest: shares up 9.8 percent, the largest move among the named stocks2.
- $2 trillion: the valuation figure attached to Anthropic's filing, which still waits on a set price1.
- $144 billion: New Constructs' low-case model of Anthropic's actual worth4.
- 93 percent: the gap between that low case and the $2 trillion figure4.
- 19,378: Wikipedia page views for Anthropic's English entry on Monday, up from 5,285 a day earlier7.
- $16.3 billion: Anthropic's reported revenue for the first half of 20261.
What to watch
Watch Anthropic's amended S-1 for the price range bankers actually set, due ahead of a roadshow. A number near Ives' $1.5 trillion to $1.7 trillion band would say the market priced in growth. One closer to $2 trillion would say it priced in the filing-day rally itself.
See whether Samsung, SK hynix and Advantest hold their Tuesday gains past this week, or give them back once the news cycle moves on. A rally that outlives the headline says more about chip demand than one filing can. Price will tell.
Sources
- Anthropic, PBC, "Form S-1 Registration Statement," U.S. Securities and Exchange Commission, Oct. 26, 2026, https://www.sec.gov/Archives/edgar/data/2130357/000162828026067168/anthropicpbc-sx1.htm
- Investing.com, "Asia stocks jump as Anthropic IPO filing revives AI trade," Investing.com, Oct. 27, 2026, https://www.investing.com/news/stock-market-news/asia-stocks-jump-as-anthropic-ipo-filing-revives-ai-trade-4974091
- David Taylor, "Anthropic eyes biggest ever IPO as AI funding starts drying up," ABC News (Australia), Oct. 27, 2026, https://www.abc.net.au/news/2026-10-27/anthropic-eyes-biggest-ever-ipo-as-ai-funding-dries-up/107312804
- Kyle Guske II, "Anthropic Is The Most Ridiculous IPO of 2026," New Constructs, Oct. 6, 2026, https://www.newconstructs.com/anthropic-is-the-most-ridiculous-ipo-of-2026/
- Anthropic (@AnthropicAI), "Anthropic has filed an S-1 registration statement with the SEC related to its proposed IPO.," X, Oct. 26, 2026, https://x.com/AnthropicAI/status/2114705042817110293
- BleepingComputer, "OpenAI launches GPT-6.1 Terra with 3x faster AI agents, 50% lower pricing," BleepingComputer, Oct. 26, 2026, https://www.bleepingcomputer.com/news/artificial-intelligence/openai-launches-gpt-61-terra-with-3x-faster-ai-agents-50-percent-lower-pricing/
- Wikimedia Foundation, "Pageviews per article, Anthropic, English Wikipedia," Wikimedia Foundation, Oct. 27, 2026, https://wikimedia.org/api/rest_v1/metrics/pageviews/per-article/en.wikipedia/all-access/user/Anthropic/daily/20261025/20261026