London-based startup Ineffable Intelligence has secured $1.1 billion in a seed funding round, marking the largest seed financing in European history. The company is currently valued at $5.1 billion. The round was co-led by Sequoia Capital and Lightspeed Venture Partners, with additional participation from Nvidia, Google, Index Ventures, and UK government entities, including the Sovereign AI Fund and British Business Bank.
Founder David Silver, formerly of Google DeepMind, has recruited six new cofounders from DeepMind, InstaDeep, and Flying Fish. The team includes Chris Apps, Wojciech Czarnecki, Junhyuk Oh, Lasse Espeholt, and Alexandre Laterre. Silver incorporated the startup in November 2025, left DeepMind in January 2026, and officially exited stealth mode on April 27, 2026.
The company aims to develop a 'superlearner' AI model. Unlike standard approaches that rely on large datasets, Ineffable Intelligence focuses on large-scale reinforcement learning, where AI learns through trial and error in simulated environments. This methodology mirrors the work Silver previously led on AlphaStar and AlphaGo.
David Silver has committed to donating 100% of his equity proceeds from the company to charitable organizations. The startup remains pre-revenue as it continues to build its core technology.
