Analysis
US investors have poured roughly $48 billion into financings around the Series B stage so far in 2026, the highest tally in years, even as the number of Series B deals falls to a multiyear low, according to Crunchbase News. About two-thirds of that Series B funding has gone to AI-focused startups, up from roughly half in 2025.
Dollars up, deal count down
Crunchbase's analysis found that round counts are "on track for a multiyear low" even as dollar volume hits its highest point in years -- a sign capital is concentrating in fewer, larger checks rather than spreading across more companies.
- Large rounds -- at least 110 companies have raised rounds of $100 million or more around the Series B stage this year, roughly a quarter of all deals Crunchbase tracked.
- Small rounds shrinking -- just 26 rounds came in under $10 million this year.
- Mid-size share falling -- rounds under $30 million made up about half of all Series B deals from 2021-2025; this year they are under a third.
“- Small rounds shrinking -- just 26 rounds came in under $10 million this year.”
How much of Series B funding is going to AI startups
More than half of all reported US Series B deals in 2026 have gone to AI companies, and AI startups have captured about two-thirds of Series B dollars overall. The largest named rounds Crunchbase identified at this stage:
- Prometheus -- Jeff Bezos-backed physical AI startup, reportedly raised $12 billion, by far the largest round, per Crunchbase and Axios reporting; the company has not publicly confirmed the round as a Series B.
- World Labs -- the spatial-intelligence startup led by Fei-Fei Li closed $1 billion in February, tied for the next-largest raise Crunchbase identified.
- Valar Atomics -- the nuclear-energy startup raised $1 billion in Series B funding across tranches this year, with Sequoia Capital as lead investor.
What this means for founders and funds raising outside AI
Pulse's own tracking shows a related pattern in physical AI investment, which hit $72.2 billion in the first half of 2026 alone, already topping all of 2025's full-year total. Together, the two data sets point to the same conclusion: capital at the growth stage is increasingly binary -- either a company is AI-adjacent enough to compete for a nine-figure check, or it is fighting over a shrinking pool of smaller, non-AI rounds. Founders raising a traditional $20-30 million Series B without an AI angle are now competing in a category Crunchbase says is actively shrinking, with fewer comparable deals to point to when setting terms.
What to watch next
Whether 2026's record Series B dollar total holds up once a handful of outlier mega-rounds like Prometheus's reported $12 billion are stripped out is the open question -- remove that single deal and the "record year" framing looks considerably less dramatic. The next data points worth tracking are whether deal counts stabilize in the fourth quarter, and whether any of this year's AI-labeled Series B companies show revenue growth that matches their round sizes rather than just their valuations.