Top 10 U.S. startup funding rounds highlight AI, space tech, and investment management

In the week of Sept. 12-18, 2026, the U.S. startup funding landscape saw its largest deals concentrated in AI infrastructure, space technology, and investment management. Temporal Technologies led with a $550 million Series E round, valuing the Bellevue-based company at $12.55 billion. Impulse Space, a Redondo Beach-based space vehicle developer, secured $308 million in Series D funding, bringing its total to $808 million. Ridgeline, an AI-enabled investment platform based in Incline Village, Nevada, raised $250 million, setting a $1.45 billion valuation. Other notable rounds included Cornelis Networks’ $205 million in networking tech, Factory’s $200 million for AI software development, and Profound’s $180 million for AI marketing tools. Arcee AI and Nex each raised $150 million, with Arcee focusing on foundational AI models and Nex on motion-based gaming. Additional deals included Mazama Energy’s $135 million in geothermal energy and Sling Therapeutics’ $123 million for thyroid eye disease therapy. The Crunchbase Megadeals Board tracks these deals, highlighting the ongoing momentum in tech innovation and venture capital investment.