Frank Thelen Opens Up: This One Decision Cost Me 100 Million Euros

We know him as the sharp investor from Shark Tank, the tech visionary who always has his finger on the pulse. But now, Frank Thelen is showing a completely new side of himself. In an exclusive conversation, the 48-year-old gets down to brass tacks and admits to a mistake that cost him dearly – and we mean really dearly. We're not talking about a few thousand euros here, but a sum that's beyond the wildest dreams for most people: 100 million euros.

The Decision That Still Haunts Thelen

It wasn't a panic move, no hasty sale. It was a rational decision, made at a moment when Thelen thought the risk was just too high. We're talking about an investment he didn't make. A young company, a promising technology – but Thelen hesitated, pulled his capital back, and left the founders high and dry. Today he knows: that was the single biggest blunder of his career. "That company later became one of the most successful players in the market. My stake would be worth about 100 million today," he explains with a mix of self-deprecation and reflection. It's one of those stories that makes every investor break out in a cold sweat – the missed opportunity, the one that got away.

Thelen doesn't name the company, but insiders whisper it could be a European tech start-up that landed a Series A funding round from a US giant shortly after he passed. One thing's clear: the regret runs deep. "It's not just about the money. It's knowing that I simply wasn't brave enough in that moment. And I always preach the opposite: courage and foresight."

From Rags to Riches and Back Again?

Frank Thelen's story is essentially one long success story. From a school dropout to a self-made millionaire, from a tech geek to the most sought-after investor on German television. With his investment firm Freigeist Capital, he has put money into dozens of start-ups, some of which became genuine unicorns. He was one of the first to bet on electric mobility and clean energy when others were still debating combustion engines. His keynotes are legendary, his books are bestsellers. And yet, the 100-million-euro mistake shows: even the greats have their blind spots.

But Thelen wouldn't be Thelen if he didn't learn from his setbacks. He has meticulously analyzed the error: Why did he hesitate back then? What were the specific signals that spooked him? His conclusion is as simple as it is insightful: "I focused too much on the short-term risks and underestimated the long-term potential. With disruptive technologies, you can't afford to wear the conservative's glasses."

His Current Top Stock Picks

Even though the 100-million-euro decision still stings, Thelen is looking ahead. He remains a passionate advocate of future technologies. When asked where he would invest his money today, he doesn't hesitate for a second. He names three areas that, in his opinion, have the potential to change the world – and deliver solid returns for investors:

• Artificial Intelligence & Semiconductors: Thelen is convinced that the AI boom is just getting started. He considers companies like Nvidia or ASML solid anchors, but he also recommends keeping an eye on European AI hubs. "The next Google and Facebook will come from Europe – I'm sure of it."
• Quantum Computing: An area that still sounds like science fiction to most, but for Thelen, it's already ushering in the next industrial revolution. "Quantum computers will calculate things that would take today's supercomputers thousands of years. Getting in early there could yield profits similar to what early Microsoft shareholders saw."
• Green Hydrogen Technologies: Thelen has always been a fan of clean energy. His focus now is on companies that are making hydrogen usable not just as fuel, but as storable energy for industry and households. "This will be the game-changer for the climate – and for smart investors."

Of course, he also warns against blind stock-picking: "Just because I name a stock doesn't mean you should buy it all tomorrow. You have to understand the business model, know the people behind it. And you need to have patience." It's precisely this patience that he lacked a few years ago – a lesson he now passes on to his children and young founders.

The Shark Remains Hungry

Despite the million-euro faux pas, Frank Thelen isn't bitter. He sees the loss as part of the game, an entry ticket into an exclusive club of investors who all have their scars. He'll continue to be a force on Shark Tank, and start-ups will keep seeking his advice. And the 100 million? "I'll earn it back," he says with a mischievous grin. "Maybe with the next quantum start-up. Who knows."

One thing is certain: anyone who has ever seen Frank Thelen in action knows he doesn't give up. He remains the hunter, the shark, always on the lookout for the next big thing. And that's precisely what makes him so fascinating for us viewers and for the start-up scene – despite, or perhaps because of, his missed millions.