Poolside Breaks 18-Month Silence With Open-Source AI Model That Rivals Chinese Competitors At a Fraction of the Size

Poolside emerges from 18 months of silence with its open-source AI model Laguna, which rivals top American and Chinese competitors despite being a fraction of their size, while the startup also holds an unreported stake in Fluidstack now worth roughly $860 million following the neocloud's $830 million raise.

• Poolside, cofounded by former GitHub CTO Jason Warner, is back after 18 months of silence with a new open-source AI model called Laguna, which tops public benchmarks against American and Chinese open-source competitors except for Moonshot's Kimi K3, a model 20 times its size.
• A wave of American open-source AI startups including Thinking Machines, Reflection AI, and Poolside are racing to build Western alternatives to dominant Chinese open-source models like Kimi, DeepSeek, and Qwen, with billions in funding at stake and potential U.S. government backing through possible restrictions on Chinese AI model usage.
• Poolside holds a previously unreported investment in British neocloud Fluidstack, which just raised $830 million at a $7.5 billion valuation, putting Poolside's stake at roughly $860 million and potentially providing a financial cushion as it pursues its costly AI model development ambitions.