Everything you need to know ahead of Anthropic's IPO

Anthropic's ( ANTH.PVT ) long-awaited stock market debut may be just weeks away.

The artificial intelligence startup publicly filed its S-1 paperwork for its initial public offering — the prospectus a company must file with the Securities and Exchange Commission (SEC) before selling stock to the public. That started a countdown that could end in one of the largest IPOs in history.

The company hasn't announced a date for its first day of trading, but it's aiming to debut as soon as the week of Nov. 16, according to reports from the Wall Street Journal and Reuters.

Before Anthropic's stock can begin trading, Anthropic's executives and its underwriters have to complete an investor roadshow , set a price, and receive a final green light from regulators.

Earliest date price can be set: Nov. 13, 2026

Exchange : Nasdaq Global Select Market (Class A)

Anthropic reveals amended S-1 outlining huge spending commitments, rising sales

When is the Anthropic IPO? The stock could start trading as soon as Nov. 16.

5 unexpected risk factors Anthropic is worried about

Under SEC rules, the earliest Anthropic could start trading is Monday, Nov. 16, according to Yahoo Finance calculations. Based on the timeline set by SpaceX ( SPCX ) in June that went from public filing to first trade in 23 days, Anthropic would debut on Wednesday, Nov. 18.

Companies that let the SEC review a draft of their IPO paperwork in private are required to wait at least 15 calendar days after making it public before starting their formal roadshow — the meetings where bankers pitch the stock to big investors and take orders. Since Anthropic released its filing to the public on Oct. 26, its roadshow can begin as soon as Nov. 10.

After that, the fastest path runs into a holiday. The SEC is closed for Veterans Day on Nov. 11, and its rules require two business days' notice before the agency declares a filing effective. That makes Friday, Nov. 13, the earliest Anthropic could set its price — a day bankers rarely use, since the stock wouldn't start trading until Monday, leaving buyers to wait out the weekend.

SpaceX started its roadshow the first day it could and priced its stock a week later.

The maker of Claude has yet to disclose how many shares it plans to sell or the price range for its offering.

Those details typically appear in an updated filing before the roadshow begins. The final price is usually set after investors have indicated their demand, the night before the stock starts trading.

Many factors. Market volatility, particularly in comparable stocks already trading, and any outstanding regulatory issues could shift the timetable. The company also hasn't said how long its roadshow will last.