Frank Thelen opens up: The one decision that cost me £85 million

We know him as the savvy investor from Dragons' Den, the tech visionary always ahead of the curve. But now, Frank Thelen is revealing a completely different side of himself. In an exclusive interview, the 48-year-old gets down to brass tacks and admits to a mistake that proved incredibly costly – eye-wateringly so. We're not talking about a few thousand pounds here, but a sum most people can't even fathom: a staggering £85 million.

The Decision That Still Haunts Thelen

It wasn't a panic move, no fire sale. It was a rational call, made in a moment when Thelen felt the risk was simply too great. We're talking about an investment he decided against. A young company, a promising piece of tech – but Thelen hesitated, pulled his capital, and left the founders high and dry. Today, he knows it was the biggest blunder of his career. "That company later became one of the most successful players in the market. My stake today would be worth around £85 million," he explains, with a mix of self-deprecation and reflection. It's the kind of story that makes any investor break out in a cold sweat – the one that got away, the big fish that slipped through the net.

Thelen isn't naming names, but insiders whisper it might have been a European tech start-up that landed Series A funding from a US giant shortly after he passed. What's clear is that it still stings. "It's not just the money. It's knowing that, at that moment, I simply wasn't bold enough. And that's the very thing I'm always preaching: courage and vision."

From Rags to Riches... and Back Again?

Frank Thelen's story is, for the most part, a roaring success. From school dropout to self-made millionaire, from tech obsessive to one of the most sought-after investors on German TV. Through his investment firm, Freigeist Capital, he's backed dozens of start-ups, some of which have become bona fide unicorns. He was one of the first to back e-mobility and clean energy while everyone else was still debating combustion engines. His keynotes are legendary, his books bestsellers. And yet, his £85 million mistake proves that even the greats have their blind spots.

But Thelen wouldn't be Thelen if he didn't learn from his losses. He's meticulously analysed the error: Why did he hesitate back then? What were the specific red flags that made him baulk? His conclusion is as simple as it is striking: "I was too focused on the short-term risks and underestimated the long-term potential. With disruptive technologies, you can't look at them through a conservative lens."

His Top Stock Picks Right Now

Even though that fateful decision still rankles, Thelen is looking forward. He remains a passionate advocate for future-facing technologies. When asked where he'd park his money today, he doesn't hesitate for a second. He identifies three areas he believes have the power to change the world – and deliver handsome returns for investors:

• Artificial Intelligence & Semiconductors: Thelen is convinced the AI boom is only just getting started. He sees firms like Nvidia and ASML as solid bedrock, but also advises keeping an eye on European AI developers. "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 signals the next industrial revolution. "Quantum computers will handle calculations that would take today's supercomputers millennia. Getting in early could yield profits similar to those of early Microsoft shareholders."
• Green Hydrogen Technologies: Thelen has always championed clean energy. His current focus is on companies making hydrogen usable not just as fuel, but as storable energy for industry and homes. "This will be a game-changer for the climate – and for smart investors."

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

The Dragon Still Has an Appetite

Despite the multi-million-pound misstep, Frank Thelen isn't bitter. He sees the loss as part of the game, an initiation into an exclusive club of investors who all carry their own scars. He'll continue to be a fixture on Dragons' Den, with start-ups still queuing up for his advice. And the £85 million? "I'll get it back," he says with a wry smile. "Maybe with the next quantum start-up. Who knows."

One thing's for sure: spend any time with Frank Thelen and you know he's not a quitter. He remains the hunter, the dragon, always on the scent. And that's precisely what makes him so compelling for us, the audience, and for the start-up scene – in spite of, or perhaps because of, the millions he missed out on.