The Week’s 10 Biggest Funding Rounds: Almost All About AI

U.S. venture funding this week was dominated by artificial intelligence, with the 10 largest announced rounds including a $1 billion Series C for Instinct and multiple nine- and eight-figure financings for AI infrastructure, cybersecurity and application startups. The tracked period covered Sept. 26–Oct. 2, 2026, and the largest rounds set valuations ranging from roughly $1 billion to $10 billion.

"This week’s list of the largest U.S. startup funding rounds was pretty much all about AI," industry reporting noted, underscoring how the sector continues to attract outsized capital.

Top financings highlight how venture dollars are concentrating on companies that either build foundational AI models and infrastructure or apply AI to vertical markets such as housing, cybersecurity and real estate. The biggest raise was Instinct’s $1 billion Series C, which set a $10 billion valuation for the San Francisco-based developer of a personal AI assistant. Sequoia Capital, Benchmark and Coatue backed the round for the year-old company.

Week’s largest announced U.S. rounds

• Instinct — $1 billion Series C; AI personal assistant; valuation $10 billion; backers included Sequoia Capital, Benchmark and Coatue.
• EliseAI — $350 million; AI for the home rental industry at a $4 billion valuation; led by Andreessen Horowitz and Bessemer Venture Partners; also expanding into healthcare.
• Armadin — $255.5 million Series B; AI-native cybersecurity focused on autonomous security; led by Andreessen Horowitz and Accel; valuation above $2.5 billion.
• Kahua — $250 million growth funding from Bain Capital Tech Opportunities; enterprise project-management platform; valuation over $1 billion.
• GMI Cloud — $223 million Series B plus $445 million in debt financing; GPU cloud infrastructure for AI teams; Archiv led the equity round with participation from Nvidia.
• General Intuition — $220 million; developer of AI models trained on videos and virtual worlds for physical environments; Valor Equity Partners and Atreides Management led the round; valuation $6.2 billion.
• SiMa.ai — $150 million Series C; software platform for scaling physical AI applications; Fidelity and Amplify led; valuation $1.45 billion.
• Supabase — $150 million; AI-enabled open source Postgres platform for developers; led by GIC; San Francisco-based startup also announced acquisition of Turso.
• CScale — $145 million Series C; optical interconnect technology for AI data centers; led by Atreides Management, Valor Equity Partners and Premji Invest; emerged from stealth.
• Homeward — $120 million Series D led by Saluda Grade plus $330 million in debt financing; Austin-based proptech that helps homeowners buy before selling or obtain cash offers.

Investors ranged from traditional venture firms such as Andreessen Horowitz, Accel and Benchmark to strategic backers including Nvidia and large growth investors like Bain Capital Tech Opportunities and Valor Equity Partners. Several rounds also included sizable debt facilities, notably GMI Cloud’s $445 million and Homeward’s $330 million, pointing to a mix of equity and leverage for growth-stage companies.

Outlook: The concentration of funding in AI and adjacent infrastructure signals continued market confidence in both foundational model builders and verticalized AI applications. Startups that combine domain-specific use cases with scalable AI infrastructure—whether for housing, cybersecurity or physical-world robotics—appear most likely to attract large, multiparty financings in the near term. Observers will be watching follow-on rounds, debt/equity mixes and whether high post-money valuations translate into durable revenue growth and eventual exits.