The Nuremberg native brings over three decades of capital markets experience, backed by a career shaped by deep market insight and a genuine passion for investing. His journey began in 1994 through an investment club among colleagues – a formative experience that sparked a lifelong dedication to identifying compelling investment opportunities.
Following senior editorial roles at Nürnberger Nachrichten, €uro am Sonntag, and €uro, he went on to serve as Editor-in-Chief of the renowned investor magazine Börse Online from 2014, where he played a key role in shaping high-quality financial journalism for a broad investor audience.
Since April 2026, he has been operating independently, fully focused on his core strength: uncovering mispriced equities with significant upside potential – particularly within the small- and mid-cap segment, where inefficiencies create attractive opportunities for discerning investors.
Throughout his career, he has engaged with some of the most influential minds in global finance, including Warren Buffett, Charlie Munger, Jim Rogers, and George Soros. The unique insights gained from these conversations continue to inform his analytical perspective today. As a dedicated value investor, he is committed to translating complex market dynamics into clear, actionable ideas – empowering investors to make better-informed decisions.
Commented by Jens Castner
Commented by Jens Castner on July 31st, 2026 | 07:05 CEST
New to the Index, Then Hit Hard: Hochtief, Almonty Industries, AT&S, and Marvell Technology Put to the Test
Inclusion in a major stock index is often considered a mark of distinction. But at the end of June, it turned into a trap for four stock market stars. Anyone who bet on DAX newcomer Hochtief, the promising tungsten stock Almonty Industries, or the AI-linked high-flyers AT&S and Marvell Technology suffered double-digit share price losses within just a few weeks. This is no coincidence, but rather the result of a market mechanism that investors should be aware of—and one that may now be creating attractive buying opportunities. We take a closer look at all four stocks and compare their current share prices with analysts' price targets.
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Commented by Jens Castner on July 30th, 2026 | 10:05 CEST
DRONESHIELD IN TURBULENCE – CLEAR RUNWAY FOR VOLATUS AEROSPACE AND RED CAT HOLDINGS
A crash landing is dragging down the entire drone industry. When DroneShield's stock slipped on Tuesday despite what were actually strong numbers, other stocks in this young, forward-looking sector also came under pressure—even though their businesses have little to do with the Australian company's problems. This is precisely where a massive opportunity could lie for investors—at least if analysts are to be believed. The experts' price targets signal more than 100% upside potential for Volatus Aerospace and Red Cat Holdings.
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Commented by Jens Castner on July 29th, 2026 | 07:15 CEST
Oversold? Kostolany Buy Signals Emerge for Rheinmetall, Lahontan Gold and Coinbase
Hopes for a lasting ceasefire between the US and Iran are driving stock prices higher. Oil prices are falling, and inflation concerns are easing. Even in such a supportive environment, however, investors should avoid buying indiscriminately. Legendary investor André Kostolany coined the rule: when prices ignore bad news, panic selling has ended. In other words, those who wanted to sell have already done so. This pattern now appears to be emerging in three very different stocks. The German defence contractor Rheinmetall, the Canadian exploration company Lahontan Gold, and the US crypto platform Coinbase have all retreated significantly from their respective highs. Yet, each has recently absorbed negative news without suffering further meaningful declines—potentially signalling that sentiment has begun to stabilize.
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Commented by Jens Castner on July 27th, 2026 | 07:05 CEST
The Week of Truth: Jitters at Amazon, Cool Heads at Vertiv, Bright Prospects at American Atomics
This week is crunch time. Two tech stocks, two earnings dates, one question: How much should artificial intelligence cost? Nervousness is spreading, especially at Amazon, ahead of its quarterly earnings report this coming Thursday. Following Alphabet's results from last week, one thing seems clear: those who invest heavily in AI infrastructure and data centers will be penalized. What appears as a billion-dollar line item on Amazon's expense sheet ends up as an order in the books of cooling specialist Vertiv. Consequently, Vertiv is taking a calm view of the numbers expected on Wednesday. Lurking in the background is a third stock that hardly anyone has on their radar yet: American Atomics. For now, the Canadian uranium explorer is worth little more on the stock market than a medium-sized trade business—yet it could tip the scales for the reactors that tech giants use to power their data centers.
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Commented by Jens Castner on July 24th, 2026 | 08:50 CEST
IMPRESSIVE NUMBERS AT EQUINOR, NERVOUSNESS AT MUNICH RE, A SENSE OF OPTIMISM AT ZEFIRO METHANE
Hardly any other greenhouse gas warms the atmosphere as quickly as methane. That is why a new, still-emerging market for climate credits is developing around the elimination of methane leaks. Investors can profit even in this early phase. Shares of three companies in particular are well-suited for this. Canadian remediation specialist Zefiro Methane provides the service, the long-established German conglomerate Munich Re insures the associated risks, and the Norwegian oil and gas producer Equinor represents the buyer side. While Equinor is benefiting from high oil and gas prices and reporting stellar quarterly results, nervousness is spreading at Munich Re because the executive board intends to review the annual forecast once again. At Zefiro Methane, on the other hand, there is a genuine sense of optimism, driven by a fully loaded order book.
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Commented by Jens Castner on July 23rd, 2026 | 11:55 CEST
The New China: Power Metallic Mines, GE Aerospace, and DHL Group See Investment Opportunities in Saudi Arabia
The FIFA World Cup has just come to an end, and the roadmap for future tournaments is already in place. The most forward-looking executives are now turning their attention to the host nation of the 2034 FIFA World Cup: Saudi Arabia. The Kingdom is not only awash in cash—it is also opening up more and more and strategically channeling its vast oil wealth into new industries. Three companies that stand to benefit particularly from this transformation are Canadian resource explorer Power Metallic Mines, the US jet engine manufacturer GE Aerospace, and the logistics giant DHL Group, still affectionately known to many investors as the former Deutsche Post. At the same time, all three companies are positioned at the center of major long-term trends, including rising military spending, secure supply chains, electric mobility, and the continued growth of e-commerce.
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Commented by Jens Castner on July 22nd, 2026 | 08:10 CEST
100% Upside Potential and More: What Analysts Predict for Desert Gold Ventures, Oracle, and Hypoport
Securities analysts are usually deliberately cautious so as not to raise false expectations. With Oracle and Hypoport, however, they are coming out of the woodwork with price targets that promise the potential for a doubling of the share price—and for the Canadian mining stock Desert Gold Ventures, even significantly more. What is behind these estimates, how realistic are they, and what facts should investors keep in mind?
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Commented by Jens Castner on July 21st, 2026 | 07:20 CEST
GameStop, dynaCERT, Infineon: Three Paths from Penny Stock to High Flyer
GameStop, once on the brink of bankruptcy, now plans to acquire eBay. Infineon, after a near-death experience during the 2009 financial crisis, is now one of the heavyweights on the DAX. The price surges of both stocks serve as a model for a third, significantly smaller case: dynaCERT. The Canadian company improves the fuel economy and emissions of existing diesel engines with a retrofit system. Analysts at GBC Research estimate the share's upside potential at over 500%. A look at the facts reveals whether this is realistic and what the future holds for GameStop and Infineon.
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Commented by Jens Castner on July 17th, 2026 | 07:20 CEST
Chips, Gold, and Dividends: ASML, Lahontan, and Allianz as a Safe Haven Amid Market Turmoil
There are times on the stock market when the hottest stock with the most spectacular story is not the best choice. When market uncertainty rises, investors are well advised to bet on stocks that remain unfazed by geopolitical news. At first glance, ASML, Lahontan Gold, and Allianz have nothing in common: a Dutch manufacturer of highly complex specialty machinery for the chip industry, a Canadian gold explorer, and a Munich-based insurance group. And yet, the three have something in common: they provide solid reasons why their share prices can remain largely immune to the general ups and downs of the markets—whether thanks to genuine underlying demand, robust operational progress, or shareholder-friendly dividend policies.
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Commented by Jens Castner on July 15th, 2026 | 08:35 CEST
Between the Oil Price Rally and Climate Billions: How Shell, Eni, and Zefiro Methane Are Profiting
The escalating conflict between the US and Iran is driving oil prices sharply higher—and with them, the share prices of energy companies like Shell and Eni. For their shareholders, that is the good news. The bad news: ironically, the very oil multinationals currently profiting from the crisis are viewed by the public as greedy climate offenders. To polish up their image, they are among the largest buyers of voluntary CO₂ credits. Many of these, however, are of dubious quality. Anyone looking for a solution to this problem almost inevitably ends up at Zefiro Methane, a largely undiscovered small-cap stock from Canada. The company addresses precisely the issues where Shell and Eni are struggling the most.
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