Arcee

About Arcee

Arcee AI (Arcee) is a United States AI company building frontier open-weight foundation models and the products that let enterprises, developers and public institutions customize, evaluate and deploy them. Founded in 2023 by Mark McQuade with Brian Benedict and Jacob Solawetz (backgrounds including Hugging Face and Roboflow), Arcee pivoted from specializing small language models toward training its own Trinity open-weight family—scaling from a 4.5B dense model to Trinity Large, a 400B mixture-of-experts model released in early 2026 and developed end-to-end in the United States after Meta stepped back from Llama open releases. The company says its entire 2025 model lineup, including Trinity Large, was built for about $20 million including compute and operations, and it works with the U.S. Department of Energy and national labs (including Genesis-Science-1). In September 2026 Arcee closed a Series B led by Vista Equity Partners, Cambium Capital and Emergence Capital, with AI10 Ventures, Hitachi, IAG, Microsoft’s M12, P7 and Wipro, valuing the company at more than $1 billion; Arcee declined to disclose the raise size, while Fortune reported a source familiar with the matter put it at least at $150 million. Proceeds fund the next Trinity generation, DOE partnerships and open-model product suites. Sources: Arcee blog 16 Sep 2026; Fortune 16 Sep 2026.