Anthropic Files S-1 After Raising $65B, Joins OpenAI and SpaceX in $4 Trillion IPO Wave

According to reports, Anthropic submitted a draft Form S-1 registration statement to the SEC at the end of May 2026, becoming one of the first major AI developers to formally initiate an initial public offering. The filing followed the company's completion of a $65 billion Series H funding round at a post-money valuation of $965 billion, backed by Altimeter Capital, Dragoneer, Greenoaks, and Sequoia Capital.

Anthropic's move appears to have outpaced OpenAI, which is reportedly targeting a public market debut later in 2026 at an estimated $1 trillion valuation. SpaceX filed its own S-1 in May 2026 and plans to list on Nasdaq under the ticker SPCX. Combined, the three companies could reach a total valuation of $3.7 trillion to $4 trillion upon entering public markets.