TL;DRRiver AI raised $1.1bn led by General Catalyst and AMP PBC. NVIDIA and AMD Ventures took strategic stakes, Y Combinator and Temasek joined. Founded by xAI co-founder Igor Babuschkin, incorporated in Nevada in April. Sells fine-tuning and reinforcement learning on open weight models. No valuation disclosed.
River AI has raised $1.1bn, roughly four months after the company was incorporated. General Catalyst and AMP PBC led the round, with strategic investment from NVIDIA and AMD Ventures, and further money from Y Combinator and Temasek. The Palo Alto company was founded by Igor Babuschkin, a co-founder of xAI.
The pitch is that companies should train and own models rather than rent general-purpose ones. River sells an API for LoRA fine-tuning and reinforcement learning on frontier open weight models, taking on the infrastructure underneath, including weight transfers, sampling-training consistency and elastic compute.
Its performance claims are its own and have not been independently tested. River says a complex reinforcement learning run takes 15 to 20 minutes through its API with no infrastructure team required, at two to four times the cost saving of closed-source alternatives. Billing is metered on tokens used for training and inference, which the company says removes the expense of idle GPU capacity.
