Europe's Youngest Self-Made Billionaires

1. 🇬🇧 James Dacombe, 25

Olix | ~$1.27B net worth | $3.3B valuation | 38.6% ownership

School dropout who built a $3.3B AI chip company by age 25. This one is unusually clean. The Times reports Dacombe owns 38.6% through Bletchley Industries. At the new $3.3B valuation, that's about $1.27B.

2. 🇸🇪 Arvid Lunnemark, 26

Cursor | ~$2.7B net worth | $60B acquisition | ~4.5% implied ownership**

Cofounded Cursor at 22 before leaving to build an AI safety startup. There's an important caveat here. Forbes' live profile still says $1.3B based on Cursor's previous $29.3B valuation. But SpaceX agreed in June to acquire Cursor for $60B, and Forbes estimates Lunnemark will be worth $2.7B when the deal closes. That implies roughly 4.5% economic ownership.

3. 🇸🇪 Fabian Hedin, 27

Lovable | ~$3.1B | $13.3B valuation | ~23.3% ownership

Built one of Europe's fastest-growing software companies before turning 30. Today's Series C is confirmed at $400M and a $13.3B valuation. Forbes previously estimated Hedin owned 24% before the round. Assuming the $13.3B figure is post-money and no secondary sale, the new-money dilution is roughly 3%, leaving Hedin at approximately 23.3%, worth about $3.1B.

4. 🇵🇱 Mati Staniszewski, 31

ElevenLabs | ~$1.8B | $11B valuation | ~14.3% ownership

Left Palantir to build one of the world's biggest AI voice companies. Forbes estimated 15% ownership before ElevenLabs' latest $500M round. The company is now valued at $11B. Straight dilution from that round takes the stake to roughly 14.3%. Forbes' current wealth estimate remains $1.8B, which may include assumptions beyond simple stake × valuation.

5. 🇵🇱 Piotr Dąbkowski, 31

ElevenLabs | ~$1.8B | $11B valuation | ~14.3% ownership

Former Google engineer who built ElevenLabs with his high-school friend. Same economics as Mati. Forbes previously estimated both founders at 15% each, while its current net-worth estimate is $1.8B each.

6. 🇫🇷 Arthur Mensch, 34

Mistral AI | ~$1.8B | $14B valuation | ~12.9% implied ownership

Former DeepMind researcher building Europe's leading challenger to American AI labs. Forbes currently puts Mensch at $1.8B and Mistral at $14B. That implies roughly 12.9% economic ownership, although I would label this implied, rather than reported ownership.

7. 🇬🇧 Ben Francis, 34

Gymshark | ~$1.2B | ~$1.45B valuation† | 70% ownership

Went from delivering pizzas to building one of Britain's biggest fitness brands. Forbes explicitly says 70% ownership and $1.2B current net worth.

8. 🇮🇪 John Collison, 35

Stripe | ~$17.5B | $159B valuation | ~11% implied ownership

Cofounded Stripe with his brother and turned it into a $159B payments giant. Stripe's latest tender valued it at $159B, confirmed by Reuters. Forbes estimates John's net worth at $17.5B. Dividing those gives roughly 11% implied economic ownership. Reuters Again, call the 11% implied, because Stripe's actual current cap table isn't publicly disclosed.

9. 🇸🇪 Anton Osika, 35

Lovable | ~$3.1B | $13.3B valuation | ~23.3% ownership Turned an open-source coding project into a $13.3B AI software company. Same calculation as Hedin. Forbes previously estimated 24% ownership. Today's $400M Series C at $13.3B implies roughly 23.3% post-round, worth approximately $3.1B.

10. 🇩🇪 Niklas Köhler, 35

Helsing | ~$2.3B | $18B valuation | 12.6% ownership

Physicist who cofounded Europe's most valuable defense-tech startup. This is probably the cleanest profile after Dacombe. Forbes explicitly estimates 12.6% ownership, $2.3B net worth, and Helsing's latest valuation at $18B.