Pathfounders Newsletter: The fascinating story behind Ineffable’s fundraising

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Mike Butcher writes:

As we covered at the start of the week, David Silver, the AlphaGo architect and former DeepMind reinforcement learning lead, raised a staggering $1.1B seed round for Ineffable Intelligence — possibly Europe’s largest ever — at a $5.1B valuation. Backed by Sequoia, Lightspeed, NVIDIA, Index, Google, DST, the British Business Bank and others, the company is betting that the road to superintelligence runs not through ever-larger LLMs, but through reinforcement learning systems that can teach themselves. Silver calls the mission “making first contact with superintelligence” (whatever the hell that mean) by building a “superlearner” able to discover science, technology and new forms of knowledge from its own experience. This is a bold wager, made more striking by Silver’s pledge to give away 100% of his Ineffable equity proceeds through Founders Pledge, which surely will at some point become the wealthiest charity in the UK at some point.

Less known is how the heck Flying Fish Partners, a small Seattle VC firm with under $250m AUM, managed to get into the round! According to Geekwire, it turn out it was through years of relationship-building with former DeepMind researchers, especially via its early investment in Phaidra, a Seattle AI startup founded by ex-DeepMind engineers. Ah yes, the old ‘Seattle strategy’…

It really does pay to hang out with the scientifically-minded. Flying Fish became unusually embedded in London’s AI scene, hosting dinners and meetings with researchers. But it was Heather Gorham, then a mere principal in the VC firm, who initially reached out to Silver after he published built a relationship with Silver after his “Era of Experience” paper argued that AI trained on human data was nearing its limits.

The firm’s thesis matches Ineffable’s: that LLMs alone will not deliver AGI or ‘superintelligence’. Instead, Silver is pursuing reinforcement learning and AI agents that learn from experience inside simulations. But to get in on the round, Flying Fish had to write the largest cheque in its 10-year history, using a special purpose vehicle to support the investment.

Gorham has since joined Ineffable’s founding team, according to her LinkedIn profile. That’s a pretty slick way to get in on the ground floor of one of the world’s hottest AI companies. Who’s going to write the Netflix script?

The most interesting ‘big play’ of the week?
Google investing $10 billion in Anthropic now, with another $30 billion potentially to follow if Anthropic hits certain performance targets, at a $350 billion valuation, wrote Bloomberg. Four days earlier, Amazon had made a a further $5 billion (it’s total invetsment is now $33 billion) investment into Anthropic, with up to $20 billion more tied to commercial milestones. In a play we have seen several times before by AI companies, Anthropic committed to spending more than $100 billion on AWS technologies over the next ten years.

While we watch the crazy Succession-style court case between Elon Musk and Sam Altman, Anthropic is just getting on with the work…

In other news:
• Lithuania-based Vinted completed a share sale that valued the online marketplace for second-hand goods at €8bn, which reflect is growth and (now) profitability. Investors led by existing shareholder EQT and new backers Teachers’ Venture Growth and Schroders Capital acquired about €880mn of Vinted shares in a secondary share sale.

• Good news for Londoners who are sick of giving Uber’s Lime bikes all their money. London-based shared e-bike operator Forest raised £27 million to expand even more in London. That brings Forest’s total Series B round to £40 million and includes investment from its e-bike supplier Okai, which now takes a minority stake in the company. The funding round included £17 million in fresh equity from Okai and existing investors such as B8 Venture Partners, Fen Ventures and Güil Mobility Ventures.

• Nebius, which is sometimes referred to as a neocloud, acquired acquired San Francisco-based Eigen AI (which specialises in improving the performance of leading open-source AI models) for approximately $643m in cash and stock.

• Everything seems to be about Stockholm all of a sudden. It’s the Lovable-effect, huh? The city hosted a YC meetup. And then Stockholm’s Legora raised a €42 million ($50 million) extension of its previously announced Series D financing, bringing the total round to €513 million ($600 million) in equity and valuing the company at €4.7 billion ($5.6 billion) post-money. Joining the party was Atlassian and NVentures (NVIDIA’s venture capital arm) as corporate investors, alongside new financial investors, including Airtree, Barclays, Geodesic, Insight, Liberty Global and Nikesh Arora. Plus,  Stockholm-based Redpine’s also raised a €6.8 million Seed round. And who hasn’t seen Stockholm’s Legora new hire in the shape of the dreamy Jude Law for its new global brand campaign?

Pathfounders dropped in on UK Fintech Week to interview founders from some of the world most fascinating emerging markets.

We did interviews with:
Ridwan Olalere, Co-founder and CEO
Lucas Vargas, Founder & CEO, Nomad 
Nikolay Seleznev - Co-Founder & Chief Strategy Officer, Uzum
Coen Jonker, CEO and founder, GoTymeBank
Yoshi Yokokawa, CEO and Co-Founder, Alpaca
Constanza Castro Feijóo, Head of London, Endeavor Global

Pathfounders dropped in on UK Fintech Week to interview founders from some of the world most fascinating emerging markets.
By Mike Butcher

VCs actually listen to A new investment vehicle spun out of the Aurora Tech Award wants to turn credibility into capital for overlooked founders in emerging markets.
By Amelia Isaacs

The Chair of the EuroStack Industry Foundation castigates regulators and implores Europe's private, patient, capital to get into the game. And fast.
by Mike Butcher

With only a tiny fraction of global information available for training, the Swedish startup wants to unlock the data layer powering the next generation of AI agents
By Amelia Isaacs

Its mission is to make "first contact with superintelligence” using Reinforcement Learning, creating a “superlearner” which does not rely on human data
By Mike Butcher

• Pathfounders is partnering with the new Renaissance Summit (tickets here), a ‘Chatham House’ gathering of ~90 family offices, VCs, founders, and policymakers, focused on pan-European capital collaboration and Europe’s role in a shifting global landscape. The Renaissance Summit is offering 10 members of the Pathfounders community the opportunity to get a ticket at early bird pricing. Simply apply to join the event by using the voucher PATHFOUNDERS26.

• We’re running The Pathfounders Stage at World Summit AI. Startups can apply for the pitch competition right now! Get tickets here.
• We’re supporting Podim Conference, May 11–13, 2026 in Maribor, Slovenia. Apply now to their pitch competition.
• We’re also partnering with GITEXT AI Europe, 30 June to 1 July 2026 at Messe Berlin

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Guest Column: As UK VCs increasingly look to pension funds to close the scale-up funding gap, James Codling warns that until venture’s track record improves, it may not yet deserve the cheque.

Guest Column: Ivan Nikkhoo argues that without more creative approaches to funding in that crucial inflexion point from Seed to Series A, the UK risks losing a generation of startups to deeper-pocketed overseas investors.

Here’s our events guide for the rest of April and part of May:

MAY
05-05-2026 — 06-05-2026 — OMR Hamburg
06-05-2026 — 07-05-2026 — Tech Show Frankfurt
07-05-2026 — 08-05-2026 — EU Startup Summit
07-05-2026 — VC World Summit Frankfurt
11-05-2026 — 13-05-2026 — PODIM Maribor
REGISTER NOW: Get 10% off with code “pathfounders”
11-05-2026 — 14-05-2026 — WebSummit Vancouver
11-05-2026 — 12-05-2026 — HTGF Day Berlin
11-05-2026 — 12-05-2026 — Dubai Fintech Summit
11-05-2026 — 13-05-2026 — The MedTech Forum
That’s all, folks

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