Why Anthropic and OpenAI’s S-1 Filings Matter

On June 1, 2026 , Anthropic said it had confidentially submitted a draft S-1 to the SEC. On June 8, 2026 , OpenAI said it had recently submitted a confidential S-1 too. For frontier AI , that matters. But this is not really an IPO timing story. The better question is what Anthropic and OpenAI are starting to look like. Last week, I wrote that Anthropic’s Series H and Draft S-1 Point to a Bigger…