Top Funding Rounds: AI Infrastructure and Space Tech Secure Largest Investments

US startups secured significant funding rounds last week, with total amounts reaching the hundreds of millions of dollars, following a week of billion-dollar deals. Leading the pack were AI infrastructure company Temporal Technologies, which raised $550 million, and space technology developer Impulse Space, which secured $308 million.

The remaining large rounds primarily targeted AI-focused companies in sectors including investment management, networking, coding, and marketing. Energy and biotech firms also attracted substantial investments. Data center developer Crusoe also formalized its previously reported funding of over $3 billion.

Temporal Technologies, developer of an open-source platform for building and operating AI agents and enterprise systems, closed a $550 million Series E funding round. The financing was led by Lightspeed, Wellington Management, Goldman Sachs Alternatives, and Tiger Global. Impulse Space, focused on developing space vehicles for payload transportation, secured $308 million in a Series D extension round.

Other notable recipients included AI-enabled investment management platform Ridgeline ($250 million), networking technology developer Cornelis Networks for AI and high-performance computing workloads ($205 million), and AI tools provider Factory for enterprise software development ($200 million).

The funding rounds were tracked for US-based companies during the period of September 12-18, 2026, based on the largest announced deals in the Crunchbase database.