Ineffable Intelligence, a British AI lab founded by former DeepMind researcher David Silver, raised $1.1 billion in April 2026 at a valuation of $5.1 billion. The funding round was led by Sequoia Capital and Lightspeed Venture Partners, with participation from Index Ventures, Google, Nvidia, the British Business Bank, and Sovereign AI — the U.K.’s recently launched sovereign venture fund for AI.
Silver, also a professor at University College London, spent more than a decade at Google-owned DeepMind leading its reinforcement learning team before leaving to found the company. Ineffable Intelligence aims to build what it calls a “superlearner” — an AI capable of discovering knowledge and skills without relying on human-generated data, using reinforcement learning, a technique in which AI systems learn through trial and error.
The approach mirrors Silver’s prior work at DeepMind, where he was involved in developing AlphaZero and other programs that beat professional players at chess and Go by learning purely from experience, without being fed human strategies or game records. Ineffable’s stated goal is for its superlearner to discover all knowledge from its own experience. The company’s website compares the potential significance of its work to Darwin’s theory of natural life — a claim made by the company itself, not independently verified.
Silver has said that any personal proceeds from Ineffable will go to high-impact charities. Several former DeepMind staffers are reportedly set to join the company’s executive team.
Ineffable’s raise places it among a growing cluster of well-funded AI startups founded by prominent researchers. Last month, AMI Labs — co-founded by Turing Award winner Yann LeCun — raised $1.03 billion at a $3.5 billion pre-money valuation. Recursive Superintelligence, co-founded by former DeepMind principal scientist Tim Rocktäschel, reportedly raised $500 million. Together, these companies suggest London may be consolidating its position as an AI hub, a trend partly linked to DeepMind’s continued presence in the city following its 2014 acquisition by Google.
Source: TechCrunch