OpenAI confirmed on 8 June that it has "recently submitted a confidential S-1," the SEC paperwork that begins the process of going public, roughly a week after rival Anthropic filed its own.
A confidential S-1 is a starting gun, not a date. The filing lets a company work through SEC review out of public view; the readable prospectus and any actual offering come months later, and OpenAI was careful to add that it "has not decided on timing yet" and "it may be a while." Reporting pegs a possible debut around September at a valuation north of US$1 trillion.
The symbolism is that the two labs defining the frontier are now reaching for the same public capital within days of each other, a tacit admission that private rounds no longer cover the compute bill. The substance to watch is what the eventual prospectus discloses: OpenAI's real revenue, its losses, and the terms of its restructuring into a public-benefit corporation.