🏆 Deal of the Week · CW 18/2026
Ineffable Intelligence raised USD 1.1 billion in a Seed round, with valuation remaining undisclosed. The round was co-led by U.S. venture capitalists Sequoia and Lightspeed. The deal was named Deal of the Week for KW 18/2026 by Venionaire DealMatrix.
Ineffable Intelligence — key deal facts
| Company | Ineffable Intelligence |
| Founded | 2025 |
| Headquarters | London, United Kingdom |
| Amount raised | USD 1.1b |
| Valuation | Valuation Remains Undisclosed |
| Round | Seed |
| Investors | The round was led co-led by U.S. venture capitalists Sequoia and Lightspeed, with participation from Nvidia, DST Global, Index, Google and the U.K.’s Sovereign AI Fund, among others. |
| Sectors | AI, Machine Learning |
Who invested in Ineffable Intelligence?
The Seed round was co-led by Sequoia and Lightspeed, with participation from Nvidia, DST Global, Index, Google, and the U.K.'s Sovereign AI Fund, among others. The investor mix is notable for combining leading U.S. generalist venture firms with strategic technology investors, a sovereign AI fund, and global crossover capital—an unusually broad coalition for a pre-product company at Seed stage.
What does Ineffable Intelligence do?
Ineffable Intelligence is a London-based AI research company founded in 2025 by David Silver, creator of AlphaGo and former research leader at Google DeepMind. The company's stated mission is to develop reinforcement learning systems that improve through interaction and experiential learning, positioning this approach as an alternative to large language model-only architectures. It is currently a pre-product startup with no public roadmap or revenue. Silver serves as founder and CEO and deliberately chose London as the company's base.
Ineffable Intelligence valuation & multiples
Ineffable Intelligence operates in AI and machine learning, with a specific focus on reinforcement learning systems that learn through experience rather than human-labelled data. European benchmarks for AI and machine learning businesses as of Q1 2026 indicate EV/Sales multiples in the range of 3.76x–4.14x and EV/EBITDA multiples in the range of 16.84x–18.96x. Detailed sector valuation multiples for AI and machine learning are available through the DealMatrix Platform.
Explore the benchmarks: Seed Machine Learning.
Frequently asked questions
How much did Ineffable Intelligence raise in its Seed?
Ineffable Intelligence raised USD 1.1 billion in a Seed round, recognised as Deal of the Week for KW 18/2026.
What is Ineffable Intelligence's valuation?
Ineffable Intelligence's valuation was not disclosed as part of this Seed round.
Who invested in Ineffable Intelligence?
The round was co-led by Sequoia and Lightspeed, with participation from Nvidia, DST Global, Index, Google, and the U.K.'s Sovereign AI Fund, among others.
When was Ineffable Intelligence founded and where is it based?
Ineffable Intelligence was founded in 2025 and is headquartered in London, United Kingdom.
Source: original announcement — read the full report.