PitchBook: AI Megadeals Took 87.5% of U.S. VC Dollars in H1 2026, Series D+ AI Valuations Jump 6.6x

PitchBook's Q2 2026 U.S. VC valuations show that AI megadeals captured 87.5% of venture dollars in H1, driving much larger valuation step-ups (median 2.2x for AI vs 1.6x non-AI and 6.6x at Series D+). Liquidity is limited—IPOs are sparse and acquisitions are mixed—while top AI firms like Anthropic are inflating return expectations and skewing the market.