Silver departed from Google DeepMind at the end of 2025 after more than ten years contributing to projects like AlphaGo, AlphaZero, AlphaStar, and Gemini. Ineffable Intelligence was founded in November 2025 and currently lacks a product, revenue, and public roadmap.
The company has a solid thesis and a founder whose history inspires billion-dollar investor confidence solely based on conviction.
Ineffable Intelligence, an AI startup in London established by David Silver, the British researcher behind AlphaGo, AlphaZero, and AlphaStar at Google DeepMind, has secured backing from Sequoia Capital and Nvidia, reaching a valuation of $5.1 billion.
The funding round, among the largest ever for an early-stage startup, was led by Sequoia, with Alfred Lin and Sonya Huang, both partners at Sequoia, traveling to London to meet Silver and finalize the deal.
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Nvidia’s venture division invested at least $250 million. This investment values a company, launched in November 2025, at over five billion dollars despite having no product, revenue, or public roadmap.
Silver dedicated over a decade at Google DeepMind, where his efforts have been pivotal in shaping modern AI history. In 2016, AlphaGo became the first AI to beat a professional Go player without a handicap and famously defeated Lee Sedol, an 18-time world champion, 4-1 in Seoul, watched by 200 million people in Asia.
This moment is ingrained in AI culture: it led to Marc Andreessen’s “Sputnik moment” statement, spurred successive deep learning investments, and laid the groundwork for Demis Hassabis to win the Nobel Prize in Chemistry for AlphaFold.
Silver also developed AlphaZero, which mastered Go, Chess, and Shogi from scratch through pure self-play without human data, proving that a single reinforcement learning system could attain superhuman performance across various complex games simultaneously.
AlphaStar succeeded it, reaching grandmaster-level performance in StarCraft II against professional human players.
Ineffable Intelligence’s thesis directly challenges the existing AI development paradigm. Silver’s 2025 paper, co-authored with Richard Sutton, a University of Alberta researcher and known as the father of reinforcement learning, argues that large language models are inherently limited as they learn solely from human-generated data.
This means they can only synthesize, extend, or remix existing human knowledge without discovering anything genuinely new. In contrast, reinforcement learning enables AI to learn from environmental interaction, trial and error, and self-play, generating strategies and insights beyond human conception.
AlphaGo’s Move 37 in Game 2 against Lee Sedol, not present in any human game records, was discovered through machine reasoning beyond human intuition. Silver is betting that scaling this approach leads to superintelligence.
The valuation context is pertinent. Ilya Sutskever, former Chief Scientist at OpenAI who left in 2024 to start Safe Superintelligence, raised $3 billion with a valuation reaching $32 billion by April 2025, also without a product. Mira Murati, former Chief Technology Officer at OpenAI, launched Thinking Machines Lab and secured a multibillion-dollar cloud infrastructure contract with Google.
Yann LeCun, ex-Chief AI Scientist at Meta, raised $1.03 billion for AMI Labs. The consistent pattern indicates