Ex-DeepMind Leader Raises $1.1B in Massive Bet on New AI Startup Ineffable

Ineffable Intelligence, founded in late 2025 by AlphaGo architect David Silver, secured Europe’s largest-ever seed round at a $5.1 billion valuation; the company is building an AI Lab system designed to acquire knowledge without human-generated training data.

David Silver, the University College London professor who led Google DeepMind’s reinforcement learning team and spearheaded the AlphaGo and AlphaZero programs, disclosed Monday a $1.1 billion seed round for Ineffable Intelligence, a London-based AI startup he founded in late 2025. The raise values the company at $5.1 billion and is the largest seed round ever closed by a European startup, according to the company.

Sequoia Capital and Lightspeed Venture Partners co-led the round. NVIDIA, Google, DST Global, Index Ventures, the British Business Bank, and the U.K. government’s Sovereign AI Fund also participated, per statements from Sequoia and the U.K. government published Monday. 

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Ineffable Intelligence is developing what Silver calls a “superlearner”: an AI agent trained exclusively through reinforcement learning, without reliance on pre-existing human data. Reinforcement learning is a technique in which models acquire capabilities through trial and error and interaction with an environment, rather than by processing textual data or human-generated examples. The approach underpinned AlphaGo Zero, which Silver led at DeepMind, achieving superhuman performance in the game of Go without exposure to any human game records. 

Our mission is to make first contact with superintelligence. We are creating a superlearner that discovers all knowledge from its own experience, from elementary motor skills through to profound intellectual breakthroughs.
David Silver, Founder, Ineffable

The company’s website states the goal as building AI capable of transcending what it describes as the greatest inventions in human history, including language, science, mathematics, and technology. Ineffable Intelligence was incorporated in November 2025.

The raise comes amid a broader wave of researcher-founded AI labs attracting outsized early-stage capital. AMI Labs, co-founded by Turing Award winner Yann LeCun after he departed Meta AI, closed a $1.03 billion seed round in March at a $3.5 billion pre-money valuation. Separately, Recursive Superintelligence, co-founded by former DeepMind principal scientist Tim Rocktäschel and also incorporated in the U.K., has reportedly drawn investor demand for up to $1 billion, per prior reporting.

The move is drawing explicit support from the U.K. government, which co-invested through its Sovereign AI Fund alongside the British Business Bank. “This investment in Ineffable will support a company at the very frontier of AI, with the potential to transform entire sectors, underlining our determination to ensure that the UK isn’t just an AI taker but an AI maker,” Science and Technology Secretary Liz Kendall said in a statement published on gov.uk. 

Silver spent more than a decade at DeepMind, where he was one of the company’s earliest employees after its founding in 2010. He retains his professorship at University College London. Ineffable Intelligence has no public product or revenue. The company is actively recruiting AI researchers, according to its website.

Disclaimer: This news is based on publicly available information. NervNow has not independently verified any claims.

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