At 25, British entrepreneur James Dacombe has joined a rare group of young founders whose fortunes have crossed the billion-dollar mark before most people have settled into a career. The North Yorkshire-born programmer left school at 17 to focus on CoMind, the brain-technology company he had started as a teenager, choosing a path far removed from the usual university route. Years later, another bet on technology has transformed the scale of his wealth.As reported by Fortune, his AI chip company, Olix, raised $312 million in August 2026 at a valuation of about $3.3 billion, sending the estimated value of Dacombe’s roughly 30% stake close to $1 billion. The rise has made him the youngest self-made billionaire in Europe and the UK but the fortune is only part of the story.
How a decision to leave school at 17 changed James Dacombe’s career
Dacombe grew up in North Yorkshire and attended Ashville College in Harrogate. He had already developed an interest in programming well before adulthood, working on websites and apps from the age of 13.By his mid-teens, the conventional path was becoming less attractive. He studied physics, maths, economics and business for his A levels, but his attention was increasingly fixed on CoMind, the company he had started in 2017. At 17, he decided to leave school and concentrate on the business.That choice removed one of the standard milestones expected of someone his age. There was no university degree to follow, no graduate job and no long period spent working inside an established technology company. Instead, Dacombe was trying to develop a young company while still in his teens.
From brain monitoring to AI chips: Dacombe’s unusual tech journey
CoMind became the first major piece of Dacombe’s business career. The company focuses on technology for monitoring the brain, an area quite different from the semiconductor work that would later make him a billionaire.Dacombe founded the company in 2017 and continues to lead it. He owns about 12% of the business, according to the figures reported in August 2026. CoMind raised $102.5 million in August 2025, as reported by Fortune. That investment did not make Dacombe a billionaire by itself, but it added a substantial private-company valuation to a portfolio that would later include his much larger holding in Olix.The two companies also illustrate the unusual breadth of his interests. CoMind sits at the intersection of neuroscience and technology, while Olix is working on hardware designed for the rapidly expanding AI computing industry. His move from one field to the other was not a gradual progression through a conventional corporate career. It came while he was still in his twenties.
The fellowship that backed his unconventional path
A few years after leaving school, Dacombe joined the Thiel Fellowship, the programme associated with entrepreneur and investor Peter Thiel.The fellowship is aimed at young people who want to work on companies or other ambitious projects rather than follow the traditional university route. Participants receive funding and support while they pursue their ideas. For Dacombe, it provided another early institutional vote of confidence in a path that was already unconventional.The programme has also been associated with several technology founders who later built companies worth billions. Dacombe’s inclusion placed him among a group of young entrepreneurs whose careers began outside the standard university-to-employment pipeline.By that stage, however, he was no longer simply a teenager with an interesting idea. CoMind had developed into a funded technology business, giving him experience that would prove useful when he started his next company.
How Olix pushed his wealth past $1 billion
The business that ultimately pushed Dacombe into billionaire territory was Olix. He launched the London-based AI chip company about two years before the latest funding round. Its focus is closely tied to one of the biggest areas of investment in technology: the hardware needed to run increasingly demanding artificial intelligence systems.In August 2026, Olix raised $312 million from investors. The deal placed the company’s valuation at about $3.3 billion, following a sharp increase in its value since February. Dacombe is estimated to own roughly 30% of Olix.A 30% stake in a company valued at $3.3 billion is worth close to $1 billion before accounting for the usual complications surrounding private-company shares, taxes and other assets or liabilities. Based on the reported figures, Dacombe’s personal net worth therefore moved above the billion-dollar mark.
Where Dacombe stands among billionaire founders under 30
Dacombe’s arrival at the billion-dollar threshold puts him among a very small group of self-made billionaires under 30.The group has changed rapidly as private technology companies have attracted enormous amounts of investment. A founder can see a personal fortune rise dramatically without selling the company or taking it public, simply because investors assign a much higher value to the business during a funding round.That has repeatedly reshaped the record for the world’s youngest self-made billionaire.Mark Zuckerberg became a billionaire at 23 after Facebook’s value rose sharply. Snapchat cofounder Evan Spiegel reached the milestone at 24. More recently, the growth of AI and other technology businesses has produced a succession of much younger billionaires.Scale AI cofounder Alexandr Wang, for instance, reached billionaire status in his twenties after the company’s valuation climbed. Other young founders, including Lucy Guo and the founders of Mercor, have also joined the group.Dacombe’s distinction is more specific. At 25, he is reported to be Europe’s youngest self-made billionaire and the youngest billionaire in the UK.