Series B Funding Is Up, But Fewer Deals Are Getting Done

Crunchbase News — more money, fewer rounds. That, in short, is the state of U.S.

Series B startup funding in 2026, as venture capital investment continues to concentrate heavily around a handful of AI hotshots. Crunchbase data shows that so far this year, investors have poured around $48 billion into financings around the Series B stage 1, the highest tally in years. Yet round counts are below year-ago levels and are on track for a multiyear low. Smaller Series B rounds grow scarcer One trend driving capital concentration is a sharp decline in small and mid-sized Series B rounds. So far this year, less than a third of deals in our sample set 2 were for under $30 million. By contrast, between 2021 and 2025, rounds in this range accounted for about half of deals, per Crunchbase data. The smallest Series B deals have gotten particularly scarce. This year there were just 26 rounds under $10 million in our sample set. Big rounds still a big thing On the flip side, really large Series B rounds are quite popular. At least 110 companies have raised rounds of $100 million or more around this stage so far this year. That’s roughly a quarter of all deals. Of these, the largest by far was a $12 billion round 3 for Prometheus, Jeff Bezos’ physical AI startup that launched last year. Model developer World Labs, led by AI pioneer Fei-Fei Li, was tied for next-biggest fundraiser, closing on $1 billion in February. Nuclear energy startup Valar Atomics also secured $1 billion in Series B funding across tranches this year, with Sequoia Capital as lead investor. For  a wider snapshot, below we put together a sample list of more of this year’s biggest U.S.