David Silver, one of Britain’s leading AI researchers, is raising $1 billion for a new company, Ineffable Intelligence, in what would become the largest seed funding round ever in Europe. The round, led by Sequoia Capital, is expected to value the start-up at around $4 billion, excluding the new investment, according to sources cited by the Financial Times. The move comes as prominent AI researchers leave major labs to pursue experimental technologies and attract unprecedented private investment.
Silver departed from Google DeepMind late last year to launch his London-based venture. His exit triggered intense competition among investors, with Sequoia managing partner Alfred Lin and partner Sonya Huang traveling to London to meet Silver, who also holds a professorship at University College London. Negotiations are reportedly ongoing with major tech players, including Nvidia, Google, and Microsoft. If finalized at $1 billion, the round would set a new benchmark for first-time fundraising by a European start-up, according to PitchBook.
Ineffable Intelligence plans to advance Silver’s work in reinforcement learning, a method that trains AI systems through human feedback and interaction with their environment, rather than relying solely on massive text datasets. In a paper co-authored last year with Canadian computer scientist Richard Sutton, Silver predicted that AI agents capable of learning from experience could soon achieve superhuman capabilities, marking a potential turning point in AI development. Such agents, capable of completing complex tasks based on human instruction, are increasingly viewed as critical to commercializing AI technologies.
Silver has been a key figure in landmark AI breakthroughs, including DeepMind’s AlphaGo and AlphaStar projects, and contributed to Google’s Gemini family of large language models after the company acquired DeepMind in 2014. He is part of a wave of top AI talent establishing independent start-ups, joining others such as OpenAI executives Ilya Sutskever and Mira Murati, French start-up Mistral founder Arthur Mensch, and Meta’s former chief AI scientist Yann LeCun. Global venture investment in AI is surging, with CB Insights reporting that half of the $469 billion invested by VCs in 2025 went to AI groups.
Ineffable Intelligence, Sequoia, Microsoft, and Nvidia declined to comment on the deal, and Google did not respond immediately. The Financial Times first reported details of the negotiations and the potential $1 billion funding milestone, highlighting the rapid pace and scale of AI commercialization efforts in Europe and globally.
