September 2026 Summaries

Arcee AI announced a Series B funding round led by Vista Equity Partners, Cambium Capital, and Emergence Capital, with additional strategic investors, valuing the company at more than $1 billion. The company plans to use the funding to advance its Trinity family of open-weight AI models, expand collaborations with the U.S. Department of Energy and national laboratories, and develop tools for customizing, evaluating, deploying, and operating models. Arcee says it developed its 2025 model lineup, including the 400-billion-parameter mixture-of-experts Trinity Large model, for about $20 million by emphasizing efficient training, sparse architectures, targeted post-training, and economical inference. Its next-generation strategy includes models ranging from device-scale systems for phones and laptops to frontier models for scientific and software-development workloads, while Genesis-Science-1 is positioned as an early effort to support independent research institutions with open models.

Arcee AI has partnered with Bolt on Forge, a month-long research preview running from September 14 to October 14, 2026, that connects opted-in developers’ real software-building workflows with the training and evaluation of future open-weight AI models. Eligible individual Bolt Pro users can receive 50 times more usage on selected models, including GLM-5.3-Flash, GLM-5.3, Kimi-K3, and DeepSeek-v4-Pro, enabling longer development sessions and more experimentation without daily limits. Arcee plans to use Forge session data to study model weaknesses, responsiveness to feedback, and performance across extended creative projects, then release resulting models with open weights for developers to adapt and deploy.