River AI Raises $1.1B Seed Round: xAI Co-Founder Builds Open AI Stack with Temasek Backing
River AI, founded by former xAI co-founder Igor Babuschkin, raised $1.1 billion in seed/Series A funding in August 2026, led by General Catalyst and AMP PBC, with participation from NVIDIA, AMD Ventures, Y Combinator, and Singapore's Temasek. The company aims to enable individuals and enterprises to train, fine-tune, and own their own AI models, challenging the dominance of large closed AI labs.