OpenAI’s $40B round concentrates US mega-round capital in late-stage AI

OpenAI’s $40 billion financing, reportedly backed by SoftBank, comprised roughly a quarter of all $100 million-plus U.S. mega rounds in 2025, signaling intense capital concentration around late-stage AI. Crunchbase data shows artificial intelligence drew the largest share of dollars as investors prioritized compute, model development, and enterprise deployment. The raise, valuing OpenAI near $300 billion, set a new benchmark for private tech funding. Analysts say mega checks favor firms with predictable revenue, scale economics, and defensible data advantages, while earlier-stage startups face tougher diligence and longer fundraising cycles. Significantly so.