OpenAI has become the world’s most valuable private startup, overtaking SpaceX with a $500 billion valuation after a $6.6 billion secondary share sale backed by Thrive Capital, SoftBank, and others. CNBC highlighted strong employee confidence and investor demand. The milestone follows a $1.5 billion SoftBank deal last November. Outpacing SpaceX ($456B), ByteDance, and Anthropic, OpenAI continues investing in AI infrastructure with Oracle and SoftBank amid fierce talent competition with Meta.