Temporal's $550M Round Tops a Week of Smaller Checks

Temporal Technologies raised $550 million in Series E funding at a $12.55 billion valuation, the largest U.S. startup round announced for the week of Sept. 12-18, 2026, according to Crunchbase.

The deal sets the tone for a quieter week. After multiple rounds above $1 billion the prior week, investors scaled back. The biggest checks this round of deals landed in the hundreds of millions, with AI-focused companies dominating the list.

Lightspeed, Wellington Management, Goldman Sachs Alternatives and Tiger Global led the financing for Temporal, a Bellevue, Washington-based developer of an open source platform for building and operating long-running AI agents and other enterprise systems.

Impulse Space took the No. 2 slot. The Redondo Beach, California developer of space vehicles that move payloads across and between orbits secured a $308 million Series D extension, bringing the combined round total to $808 million.

Ridgeline, an AI-enabled investment management platform based in Incline Village, Nevada, raised $250 million in Series E funding at a $1.45 billion valuation. Founder and Chairman Dave Duffield led the round.

Cornelis Networks closed $205 million in new funding backed by IAG Capital Partners. The Wayne, Pennsylvania company builds networking technology for AI and high-performance computing workloads.

San Francisco-based Factory, a provider of AI tools for enterprise software development, announced $200 million at a $5 billion valuation, with a long list of venture firms and individual investors backing the deal.

Profound raised $180 million in Series D funding at a $1.8 billion valuation. Sequoia Capital and Kleiner Perkins led the round for the New York startup, whose marketing software helps users appear more prominently in AI results.

Two companies tied at $150 million. Arcee AI, a San Francisco developer of open-weight AI models, closed $150 million in Series B funding at a valuation above $1 billion, with Vista Equity Partners, Cambium Capital and Emergence Capital leading. Nex, also based in San Francisco, secured $150 million in new equity and debt financing for its family-oriented digital games that use body motion instead of controllers. The round included a Series E led by Baillie Gifford and BAI Capital; the company did not break out the equity portion.

Mazama Energy, a Seattle geothermal developer specializing in superhot rock geothermal power, raised $135 million in a Series B led by Centaurus Capital and Doerr Capital.

Sling Therapeutics rounded out the top 10. The Ann Arbor, Michigan developer of a small-molecule therapy for thyroid eye disease closed $123 million in Series C funding led by Forbion Capital Partners.

Data center developer Crusoe also made official its previously reported raise of more than $3 billion, co-led by Atreides Management, Valor Equity Partners and Mubadala Capital.

Crunchbase tracked the largest announced rounds raised by U.S.-based companies for Sept. 12-18, 2026, and notes some rounds may appear with a lag as they are reported late in the week. The mix — AI infrastructure, space tech, energy and biotech — suggests investors keep writing large checks, just with one fewer zero attached.