River AI Raises $1.1B for Open-Weight AI Full Stack
River AI has raised about $1.1 billion in seed and Series A funding led by General Catalyst and AMP PBC, with strategic investment from NVIDIA and AMD Ventures, and is aiming to create AI that belongs to users rather than labs. Its River API enables LoRA fine-tuning and reinforcement learning on frontier open-weight models, allowing developers to train and deploy personal, continually improving AI while highlighting a multi-billion-dollar valuation in coverage of the round.
Business · 18 sources · Aug 11, 2026Read itThe journal
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About Y Combinator
Y Combinator, LLC (YC) is an American technology startup accelerator and venture capital firm launched in March 2005 which has been used to launch more than 5,000 companies. The accelerator program started in Boston and Mountain View, relocated to San Francisco in 2019, and was entirely online during the COVID-19 pandemic. Companies started via YC include Airbnb, Coinbase, Cruise, DoorDash, Dropbox, GOAT, Instacart, Reddit, Stripe, Scale AI, Deel, Helion Energy, Starcloud, Twitch, and Whatnot. Over 400 companies are worth more than $100M, and 100 are unicorns.
Everything about Y Combinator →- Country
- United States
- Headquarters
- Mountain View
- Inception
- March 2005
- Website
- http://www.ycombinator.com