In August 2026, US startups secured $18.1 billion across 333 deals. While the total number of transactions fell by 32% compared to July, the volume of capital deployed remained high due to a concentration of megadeals. Year-over-year, total funding increased by 123% compared to August 2025.
The average deal size reached $54.4 million, more than double the $20.5 million average recorded in August 2025. Late-stage rounds accounted for 54% of the total capital, with 57 deals totaling $9.81 billion. The top 10 funding rounds alone attracted $6.9 billion, representing 38% of all capital deployed during the month.
River AI led the market with a $1.1 billion Series A round, one of the largest in venture history. Other significant deals included Base Power with $1.0 billion and Castelion with $800 million. These investments highlight a shift toward capital-intensive sectors, specifically AI infrastructure, clean energy, and defense technology.
Early-stage startups remained the most active by volume, completing 135 deals, yet these accounted for only 5% of the total monthly capital. The median deal size for early-stage companies was $5 million. Meanwhile, New York City startups captured a 4.6% share of the national capital, totaling $837.9 million across 34 transactions.
