Self-Custody Or Nothing: Matej Zak On Why 98% Of Crypto Users Are Still At Risk

In this episode of When Shift Happens, I sit down with Matej Zak to discuss why self-custody matters, how Czech history shaped his worldview, and what it really takes to build Trezor, the world’s most trusted hardware wallet. From a brutal 1953 monetary reform in Czechoslovakia to today’s billion-dollar exchange hacks, Matej explains why most people in crypto still do not truly own their money, and what would need to change for that to become the norm.

A Czech History Lesson 

Matej opens with a brutal story. In 1953, the Czech government launched a surprise monetary reform, forcing people to swap old banknotes for new ones at insane rates that made them lose more than 90% of everything they owned. State bonds and life insurance were wiped out, while elites protected their own wealth. 

His grandparents still talk about savings and family land disappearing overnight. That experience, plus 50 years of communism and capital controls, explains why many Czechs are instinctively sceptical of authority and attracted to money that cannot be debased or confiscated at will. “That’s why Bitcoin makes so much sense,” Matej says.

The Product-Led CEO

When I ask who he is, Matej does not lead with “CEO.” He describes himself as a problem solver. He joined Trezor seven years ago as a product manager and became CEO about three years ago which says a lot about the company. 

“We are product-led,” he says. Trezor does not start with revenue targets or channel strategies. It starts with concrete problems people face in storing their wealth and works backwards to products that solve them. His philosophy is “people, product, profit” in that order. Hire people smarter than you, give them the right environment, and let them build genuinely useful products. 

“If you have an amazing product, the profits will come.” He calls himself “a capitalist”, but one who thinks trust and security are the real long-term edge in crypto.

Self-Custody As Freedom Technology

That historical and personal context leads to his central claim: self-custody is “true ownership.” In Matej’s words, it means there is “no intermediary”, and you can move your funds “anytime, anywhere as you wish” without asking permission. 

To put it in context, we rewind the tape to 1953 and imagine Bitcoin already exists. One version of Matej’s grandfather holds cash and state bonds and gets wiped out overnight. The other senses the danger, converts his savings into BTC and holds it in self-custody on a device the state does not even know exists. 

The point is that owning Bitcoin through a bank, ETF, or government-regulated custodian would not have saved you because those claims can be frozen or voided just like bonds and deposits. Only by holding your own keys are you truly outside that reach. That is why Matej calls Bitcoin plus self-custody “freedom technology. 

Why 98 Percent Of Crypto Users Are Still Exposed

The uncomfortable reality is that almost nobody actually lives the self-custody ideal. Across the entire industry, hardware wallet makers, i.e., Trezor and its competitors combined, have sold around 15 million devices. Meanwhile, roughly 600 million people are estimated to own crypto. 

That means only about 2% use hardware wallets; the remaining 98% are trusting exchanges, hot wallets and custodians that can be hacked, regulated, mismanaged or rug-pulled. Matej thinks that the gap is partly a perception problem and partly a UX problem. Self-custody has been presented as something only an engineer can do, full of warnings about seed phrases and irreversible mistakes. 

Writing 12 or 24 words on a piece of paper and hiding them somewhere does feel “archaic” for something we call digital property. And yet the BIP39 standard invented by Trezor’s founders is still what hundreds of millions rely on today. 

Trezor’s response is to make the secure path feel normal: the new Safe 7 “almost feels like an iPhone in your hand” but is single-purpose, stripping away attack surfaces, and the team is working on NFC-based backups so that, as he puts it, “your mum would not have to write anything down” at all.

Hardware Security And The Open-Source Line 

From the outside, a hardware wallet can look like an expensive USB stick. But it’s far from it. “Hardware is hard,” Matej jokes. Unlike software, you cannot ship patches every week to fix physical design choices. You move through design, engineering, production and mass-production validation phases where one mistake can burn millions. 

That is why Trezor employs around 200 people: embedded engineers, cryptographers, security researchers, product designers, and even specialists. Security is a moving target, and the bigger the honeypot, the more effort attackers invest. Even in 2025, 16 years into Bitcoin’s existence, the industry’s biggest hack ever hit a custodian holding around $1.5 billion which is a reminder, Matej says, that concentrating keys at scale is inherently dangerous.

Where Trezor really differentiates, in his view, is its commitment to open source. He tells the story of a “secure element” chip that Trezor evaluated a few years ago, the same model that a competitor was already using. After signing the usual NDA, Trezor’s researchers quickly found a serious vulnerability that would allow secrets to be extracted. Because of the NDA, they could not warn anyone without risking a lawsuit. Devices using that chip are still on the market, and sophisticated attackers almost certainly know how to exploit it. 

That experience pushed Trezor’s founders to help create Tropic Square, a company building a truly open, auditable, secure element. Its first chip now ships inside the new Safe 7.

The One Takeaway

When asked what people should remember from the conversation, Matej goes back to basics. Self-custody matters. Learn the difference between Bitcoin and the broader “crypto” casino. 

Read books like The Bitcoin Standard or Ray Dalio’s ‘Why Countries Go Broke’, get angry,” he says, and then channel that anger into taking control of your savings. In a world where history keeps repeating itself and 98% of crypto users still hand their keys to someone else, his message is blunt: if you are not in self-custody, you are still trusting the same kind of system that wiped out his grandparents. And history has shown exactly how that story ends.

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