Anthropic plans IPO with prospectus unveiling after Labor Day

Anthropic is planning to publicly unveil its initial public offering prospectus after Labor Day in September 2026, targeting a potential listing in late September or early October. The artificial intelligence startup, which has raised at least $130 billion, is racing with rival OpenAI for a market debut. Anthropic is considering unique structures, including allowing secondary share sales for existing holders, requiring employee sales via 10b5-1 plans, and implementing lockup periods longer than 180 days.

Anthropic IPO timeline

• ▪Anthropic confidentially filed for a public listing earlier in 2026, racing with rival OpenAI to make their market debuts amid strong investor appetite for artificial intelligence firms
• ▪Anthropic plans to publicly unveil its initial public offering prospectus after Labor Day in September 2026, with a potential listing in late September or early October 2026

Secondary share sales

• ▪Anthropic is considering allowing existing shareholders to sell shares as part of its initial public offering
• ▪Anthropic has considered requiring rank-and-file employees to sell shares through preset 10b5-1 trading plans rather than typical post-earnings selling windows
• ▪Anthropic is expected to surpass the $86 billion raised by SpaceX in its June 2026 initial public offering
• ▪Allowing secondary stock sales in the initial public offering would distinguish Anthropic from other 2026 tech listings, SpaceX and Cerebras, which did not have existing stockholders sell shares

Extended lockup periods

• ▪Anthropic is weighing initial public offering lockup periods longer than the customary 180 days
• ▪It remains unclear how much of Anthropic's initial public offering would consist of newly issued shares versus sales by existing holders

Fundraising size expectations

• ▪Anthropic has already raised at least $130 billion to support its intensive compute demands
• ▪SpaceX's first lockup expiry in August 2026 more than doubled its publicly traded shares, with another 12.9 billion shares scheduled to be unlocked by mid-2027