Frank Thelen opens up: The one decision that cost me $100 million

We know him as the savvy investor from Shark Tank, the tech visionary always ahead of the curve. But now, Frank Thelen is showing a whole new side of himself. In an exclusive chat, the 48-year-old gets real and cops to a mistake that cost him dearly – and we mean seriously dearly. We're not talking a few thousand bucks here, but a sum that's mind-boggling for most people: $100 million.

The decision that still haunts Thelen

It wasn't a panic move, no hasty sell-off. 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 passed on. A young company, promising tech – but Thelen hesitated, pulled his capital, and left the founders high and dry. Now he knows: it was the biggest stuff-up of his career. "That company later became one of the most successful players in the market. My stake today would be worth around 100 million," he explains, with a mix of self-deprecation and reflection. It's one of those stories that makes any investor break out in a cold sweat – the missed opportunity, the one that got away.

Thelen won't name the company, but insiders reckon it could be a European tech startup that scored Series A funding from a US giant shortly after he passed. What's clear: the sting is real. "It's not just the money. It's knowing that I simply wasn't brave enough in that moment. And I'm always preaching the opposite: courage and foresight."

From rags to riches to a reality check?

Frank Thelen's story is basically one long success streak. From a high school dropout to a self-made millionaire, from a tech nerd to the most in-demand investor on German telly. With his investment firm Freigeist Capital, he's poured money into dozens of startups, some of which became genuine unicorns. He was one of the first to back e-mobility and clean energy while others were still arguing about combustion engines. His keynotes are legendary, his books bestsellers. And yet, the $100 million blunder shows that even the big guys have their blind spots.

But Thelen wouldn't be Thelen if he didn't learn from his losses. He's meticulously analysed the mistake: why did he hesitate back then? What were the specific signals that threw him off? His conclusion is as simple as it is spot-on: "I was too focused on the short-term risks and underestimated the long-term potential. With disruptive tech, you can't look at it through a conservative lens."

His top stock picks right now

Even though that $100 million call still stings, Thelen is looking forward. He remains a passionate advocate for future technologies. When asked where he'd put his money today, he doesn't hesitate for a second. He names three areas he believes have the potential to change the world – and deliver solid returns for investors:

• Artificial Intelligence & Semiconductors: Thelen is convinced the AI boom is just getting started. He sees companies like Nvidia or ASML as solid bets, but also recommends keeping an eye on European AI players. "The next Googles and Facebooks are coming from Europe – I'm certain of that."
• Quantum Computing: An area that still sounds like science fiction to most, but for Thelen, it's kickstarting the next industrial revolution. "Quantum computers will calculate things that would take today's supercomputers thousands of years. Getting in early there could mean returns 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 making hydrogen usable not just as fuel, but as storable energy for industry and homes. "That'll be the game-changer for the climate – and for smart investors."

Of course, he also warns against blind rushing: "Just because I name a stock doesn't mean you should buy it all tomorrow. You need to understand the business model, know the people behind it. And you need patience." That's exactly the patience he lacked a few years back – a lesson he now passes on to his kids and young founders.

The Shark stays hungry

Despite the million-dollar faux pas, Frank Thelen isn't bitter. He sees the loss as part of the game, a ticket into an exclusive club of investors who all have their scars. He'll keep rocking the Shark Tank, and startups will keep seeking his advice. And the $100 million? "I'll earn it back," he says with a cheeky grin. "Maybe with the next quantum startup. Who knows."

One thing's for sure: if you've ever seen Frank Thelen in action, you know he doesn't give up. He remains the hunter, the shark, always on the scent. And that's exactly what makes him so fascinating for us viewers and the startup scene – despite, or maybe because of, those missed millions.