OpenAI announced on its website that it had confidentially filed for an initial public offering with the U.S. Securities and Exchange Commission, saying it recently submitted a confidential S-1 and expected it to leak. OpenAI did not share terms or size and said it has not decided on timing, which may be a while because some things are easier as a private company, though the filing gives it the option to go public sooner. Reuters previously reported OpenAI is eyeing an IPO as early as September at a valuation of $1 trillion. Anthropic announced last week that it filed to go public with the SEC and has not shared share price or timing details; its filing came days after a fundraising round valued it at $965 billion, more than OpenAI’s $852 billion, and it shared revenue numbers surpassing OpenAI’s reported revenue. OpenAI and Anthropic are among the most valuable privately held AI companies, along with xAI, which recently merged with SpaceX. Ziff Davis, Mashable’s parent company, filed a lawsuit against OpenAI in April 2025 alleging copyright infringement.