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Anthropic's IPO Clock: Why Trading Can't Start Before Nov 16
Anthropic's public S-1 filing on October 26 started a 15-day clock: the roadshow can begin no earlier than November 10, and the shares could start trading on November 16 at the earliest, Yahoo Finance calculated.
Anthropic made its registration statement public on Monday, October 26, and with it started a timetable set by Securities and Exchange Commission rules rather than by the company. Firms that have the SEC review a draft filing confidentially must make it public at least 15 calendar days before starting the roadshow, the series of meetings with institutional investors at which the offering is marketed. That puts the earliest possible start on November 10, Yahoo Finance calculated on October 27.
The rest of the calendar follows from there. The SEC is closed on November 11 for Veterans Day and requires two business days' notice before declaring a registration effective, so the earliest pricing would be Friday, November 13, and the earliest first trade Monday, November 16. Bankers rarely price on a Friday ahead of a Monday debut, Yahoo Finance noted, and reports have said Anthropic is aiming for the week of November 16. At the pace SpaceX set in June, the debut would be on Wednesday, November 18.
SpaceX is the obvious template. It went from public filing on May 20 to first trade on June 12, 23 days, starting its roadshow on the first day allowed and pricing about a week later. Its shares then fell 15% in their first week in the Nasdaq-100. The final prospectus will fill in what the S-1 leaves blank: the number of shares sold, the price range and how many shares each of the lock-up release dates frees for sale. Media reports have put the target valuation between $1.5 trillion and $2 trillion, a figure the company has not confirmed.
For investors the timetable matters because the market will move before the shares exist. The days around November 10 also carry the October jobs report and consumer prices, and Nvidia reports on November 17, the day after the earliest possible debut.
History is a reason for patience. Of more than 9,000 US IPOs from 1975 to 2021, 60% were flat or lower three years after their first-day close, according to data from University of Florida professor Jay Ritter cited by Yahoo Finance. Large, heavily anticipated listings attract the most buyers on day one, which is usually when the price reflects the most optimism.
Sources: Yahoo Finance — When is the Anthropic IPO? SEC rules and SpaceX's sprint point to Nov. 16-18 (Oct 27, 2026); Fortune — What Anthropic's IPO prospectus reveals (Oct 27, 2026)