Series b funding surges, yet fewer deals are closing

In 2026, U.S. Series B startup funding has seen a surge in total capital raised, with over $48 billion invested so far this year, the highest in years. However, the number of deals has declined compared to the same period in 2025, indicating a trend toward capital concentration. Smaller Series B rounds have become increasingly rare, with less than a third of deals under $30 million, down from about half in 2021-2025. Rounds under $10 million have also dwindished, with only 26 such deals recorded this year. Conversely, large Series B rounds have gained traction, with at least 110 companies securing $100 million or more in funding. The largest deal was a $12 billion round for Prometheus, a physical AI startup led by Jeff Bezos. Other notable deals include World Labs, led by Fei-Fei Li, and Valar Atomics, both securing $1 billion in Series B funding. AI-focused startups have dominated Series B investments, accounting for about two-thirds of all funding so far this year, up from half in 2025.