UK-Based AI Startup Ineffable Raises $1.1B Seed Round, Valuing Company at $5.1B

Gate News message, April 28 — Ineffable Intelligence, a London-based AI startup founded in late 2025 by former Google DeepMind researcher David Silver, announced on April 27 that it raised $1.1 billion in seed funding to develop superintelligence using reinforcement learning.

The round values the company at $5.1 billion, marking Europe's largest seed financing. Investors include Sequoia, Nvidia, DST Global, Index, Google, and the UK's Sovereign AI Fund. Unlike large language models that rely on human-produced text, Ineffable's approach trains models through trial and error, drawing from simulations and real-world experience.

The participation of the UK's Sovereign AI Fund, a government-backed investment vehicle, underscores Britain's strategic push in frontier AI development. The fund provides portfolio companies with access to UK supercomputers and expedited visa processing, reinforcing London's position as a hub for advanced AI research.