OpenAI sells shares at $500 billion and converts to a PBC

Current and former employees sold about $6.6 billion in OpenAI shares at a $500 billion valuation, Bloomberg reported on 2 October 2025. OpenAI announced its conversion to OpenAI Group PBC on 28 October, after talks with California and Delaware attorneys general.

Why it mattered The nonprofit retained control of the business while holding equity in it. Microsoft held roughly 27 percent and the OpenAI Foundation 26 percent at recapitalization.

Corrections

  • 2026-09-01 - This entry originally said the October 2025 secondary share sale was worth $6.6 billion. That figure belongs to OpenAI’s October 2024 funding round; the cited Wikipedia source states the October 2025 sale was “up to $10 billion,” corrected accordingly.

  • 2026-09-13: This supersedes the amount claim in the 2026-09-01 correction. About $6.6 billion was also reported for the completed October 2025 share sale; that amount did not belong only to the 2024 funding round. Contemporary reporting distinguishes the completed sale from the larger amount authorized. The summary now identifies 2 October as the reporting date, not an established completion date. Replaced the Wikipedia overview with OpenAI’s primary announcement published on 2025-10-28. It describes talks with the attorneys general, not formal approval. The consequence is narrowed to retained nonprofit control and ownership at recapitalization, as documented in the company’s structure account.