Ineffable Intelligence, a British AI lab founded by former Google DeepMind researcher David Silver, has emerged from stealth with a valuation of $5.1 billion.
The startup has raised $1.1 billion in a seed funding round led by U.S. venture capital firms Sequoia Capital and Lightspeed, with additional backing from the British government.
Silver left Google DeepMind in late 2025 after more than a decade of contributing to Gemini and building AlphaGo, AlphaZero, and AlphaStar. Ineffable Intelligence was incorporated in November 2025.
Despite the high valuation, the company currently has no product, no revenue, and no public roadmap. It is instead driven by a thesis and the track record of its founder.