Anthropic Set to File Public S-1 as Early as Friday in What Could Be Largest IPO in History

Anthropic is preparing to publicly file its S-1 investor prospectus with the SEC as soon as Friday, October 24, according to three people familiar with the plans, Yahoo Finance reported on October 21. The public filing would be the next major step toward an IPO that analysts and market observers believe could surpass SpaceX's June 2026 debut as the largest initial public offering on record.

The Claude maker confidentially submitted a draft S-1 to the SEC on June 1, 2026. A public prospectus had been expected shortly after Labor Day, with a potential listing in late September or early October, but that timeline slipped. The Wall Street Journal and Bloomberg had previously reported Anthropic was targeting a November IPO. A draft prospectus reported by the Journal on Tuesday disclosed an $80.7 billion net loss for the first six months of 2026, alongside revenue of roughly $16.3 billion for that period, compared with $1.1 billion in the year-ago half.

The listing is being closely watched as a test of investor appetite for large-scale AI companies at current valuations. Renaissance Capital has noted that any further delay would narrow the window for Anthropic, and potentially other companies, to complete a 2026 debut before the end of the year.