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Ineffable Intelligence

AI · London, United Kingdom · Founded 2025

Ineffable Intelligence is a London-based artificial intelligence research lab founded in late 2025 by David Silver, the former DeepMind reinforcement-learning lead behind AlphaGo and AlphaZero. Rather than building large language models trained on human-generated text, the company is pursuing reinforcement learning as its core approach, aiming to develop "superlearners" capable of discovering knowledge and skills from their own experience. The lab emerged from stealth in April 2026 with a $1.1 billion seed round, one of the largest in European history, backed by Sequoia Capital, Lightspeed Venture Partners, Nvidia, Google, Index Ventures and the UK's Sovereign AI Fund, valuing the company at $5.1 billion. Ineffable positions itself within the broader race toward artificial general intelligence, distinguishing its research bet on experience-based learning from the data-centric approaches used by most leading AI labs. Artificial intelligence, reinforcement learning, superintelligence, AI research lab, machine learning, AGI, deep learning