AI claimed five of the ten largest U.S. funding rounds this week, headlined by a pair of $1 billion deals in cybersecurity and AI infrastructure. Investors also wrote large checks across quantum computing, geothermal energy, crypto, aerospace, and biotech.

The Billion-Dollar Tie

Keyfactor — $1B, Cybersecurity

Keyfactor raised a $1 billion private equity round led by Summit Partners, with participation from Insight Partners and Sixth Street Growth. The Independence, Ohio-based company provides digital identity and machine identity management software, helping enterprises secure certificates, encryption keys, and connected devices. Total funding now stands at $1.21 billion.

SambaNova — $1B, AI Infrastructure

SambaNova officially closed its long-anticipated $1 billion Series F at an $11 billion post-money valuation, led by General Atlantic. The Palo Alto-based company develops AI chips and enterprise infrastructure for training and inference workloads. A broad investor syndicate joined, including Battery Ventures, BlackRock, Intel Capital, Qatar Investment Authority, and Vista Equity Partners. SambaNova has now raised nearly $2.5 billion in total.

The Rest of the Top 10

3. Oratomic — $300M, Quantum Computing

Oratomic closed a $300 million Series A co-led by Arch Venture Partners, Khosla Ventures, and Spark Capital. The South Pasadena startup is building neutral-atom quantum hardware and fault-tolerant architectures aimed at accelerating commercialization. Notable backers include Bezos Expeditions, General Catalyst, and computer scientist Scott Aaronson.

4. Quaise Energy — $134M, Clean Energy

Houston-based Quaise Energy raised a $134 million Series B led by Prelude Ventures to advance its millimeter-wave drilling technology for deep geothermal energy. Total funding reaches $225 million.

5. Prime Intellect — $130M, AI

Prime Intellect secured a $130 million Series A led by Radical Ventures for its open platform enabling AI model training across distributed compute networks. The San Francisco startup counts Box CEO Aaron Levie, OpenAI co-founder John Schulman, and Perplexity CEO Aravind Srinivas among its backers, alongside corporate investors Dell Technologies Capital and Intel Capital. Total raised: $200.4 million.

6. Gauntlet — $125M, Crypto Infrastructure

New York-based Gauntlet reportedly raised a $125 million Series B from sole investor SBI Group. The firm builds simulation, risk management, and optimization tools for decentralized finance protocols.

7. Norm AI — $120M, AI Compliance

Norm AI closed a $120 million Series C led by Khosla Ventures at a $1.2 billion valuation. The New York startup translates complex regulations into software, automating compliance workflows for enterprises. Backers include Bain Capital Ventures, Coatue, New York Life Insurance, and Vanguard. Total funding now exceeds $256 million.

8. Venus Aerospace — $91M, Aerospace & Defense

Houston-based Venus Aerospace raised a $91 million Series B backed by Mercury, Lockheed Martin Ventures, Airbus Ventures, and others. The company is developing hypersonic propulsion technology for both commercial long-distance flight and defense applications. Cumulative funding: $197 million.

9. EDX Markets — $76M, Fintech

Institutional digital asset exchange EDX Markets raised $76 million from sole investor SBI Group — the Japanese firm's second large crypto deal this week alongside Gauntlet.

10. Fore Biotherapeutics — $67.4M, Biotech

Philadelphia-based Fore Biotherapeutics closed a $67.4 million Series D led by SR One to advance precision oncology therapies targeting rare cancer mutations. Total funding now exceeds $274 million.

Notable International Rounds

  • Proxima Fusion (Munich) — €411M (~$468M) Series B to build Europe's first commercial fusion energy plant; backed by Google, RWE, and East X Ventures
  • Skello (Paris) — €200M (~$229M) private equity round led by Bridgepoint Group for its HR and workforce management platform