The 100-Year Stock: A Thought Experiment in Ultra-Long-Term Investing

Exploring the power of century-long conviction and how to identify companies built to last generations

Dear Reader: It’s been a busy few weeks since my last publication. Nevertheless, I've been really active on Substack Notes. If you haven’t used them yet, I recommend that you give them a try. I also want to thank the more than 800 new subscribers since my last post. I hope this and the upcoming articles meet your expectations. So with that, let's dive in.

Dalrymple, L. (1899, April 26). The fool and his money [Chromolithograph]. In Puck (Vol. 45, No. 1155). Keppler & Schwarzmann. Library of Congress Prints and Photographs Division. https://hdl.loc.gov/loc.pnp/ppmsca.28592

“A man has made at least a start on discovering the meaning of human life when he plants shade trees under which he knows full well he will never sit.” — Trueblood, D. E. (1951). The Life We Prize. Harper & Brothers.

Ok, let’s start with the big question: What if you had to hold a single stock for 100 years? In a world where a five-year forecast feels like remote dream, the idea of a century-long investment seems almost absurd. Yet, I think there’s value in pondering the question. This thought experiment stretches our perspective in many ways. You know, even Buffett famously said his favourite holding period is “forever” (in theory at least).

So let’s take that ultra-long view literally. Imagine buying a stock today that you (and even your children and grandchildren) could never sell until the year 2125. What qualities would that business need to have for you to sleep soundly at night for a century? What insights about investing can we get from thinking beyond our own lifetimes?

This isn’t about predicting the hottest tech of the 2120s or which companies will dominate in the next millennium¹. I want to explore the essence of enduring businesses and which is the mindset of an investor who truly thinks in generations.

By stretching our time horizon to its limit, we can uncover fresh insights into what really matters when investing for the ultra long run. Ok, let’s dive into the world of 100-year investing and see what it teaches us about high-conviction, long-term ownership.

What Makes a Business Last 100 Years?

Looking a full century ahead forces you to focus on business qualities that endure. Very few companies manage to survive, let alone thrive, for decades on end. In fact, the average S&P 500 company’s lifespan has shrunk dramatically – from about 60 years in the 1950s to under 20 years today². And of the Fortune 500 companies in 1955, only 53 were still on that list in 2018³.

The world changes fast, and corporate giants can fall just as fast. So, what traits might a “centennial” company – a business built to last 100 years – possess? Let’s start with some key characteristics an ultra-durable business might need:

• Strong Competitive “Moat”: Let us begin with the obvious. If you’re going to hold a stock for generations, it better have some serious defenses against competition. It could be a globally trusted brand, proprietary technology, network effects, or control of irreplaceable assets. The moat doesn’t just protect today’s profits; it gives the company breathing room to adapt over decades. Johnson & Johnson, founded in 1886, built a reputation (and portfolio of brands) in healthcare that has carried it through many lifetimes. A strong moat is like genetic immunity for a business – it helps fight off the constant threats of competition and disruption that accumulate over a century.

• Timeless Purpose and Products: The company should address fundamental human needs or desires that persist over generations. Think of businesses centered on things like food, health, energy, communication, or basic entertainment. If a company’s core product is as relevant in 2125 as it is today (or if it can continually refresh its offerings), it stands a better chance of enduring. For example, people have enjoyed Coca-Cola for over a century and likely will for the next (or some of their other beverages), because the desire for a refreshing drink transcends eras. I think the main thing here is having a mission that doesn’t become obsolete.

• Adaptability and Innovation: A 100-year stock must be a chameleon in the best sense – able to evolve with the times. Technology, consumer preferences, and market conditions will change in unforeseeable ways over a century. The most enduring companies often reinvent themselves while staying true to their core mission. Consider how IBM (International Business Machines Corporation) started with punch-card tabulators in the early 1900s and later pivoted to computers and consulting. Or look at how Netflix (not a century old yet, but instructive) evolved from mailing DVDs to dominating streaming. The lesson is clear: to survive 100 years, a business must continuously learn, innovate, and sometimes completely redefine itself while leveraging its strengths. Yes, this is probably the hardest thing to asses in a company for our little thought experiment.

• Financial Resilience: Across 100 years, a company will face wars, recessions, booms, busts, pandemics – everything you can think about. Only the financially resilient survive the full cycle of seasons. That means strong fundamentals: a solid balance sheet, prudent use of debt, and management that plans for rainy days (or rainy decades). Companies that hoard cash in good times and avoid excessive risk can endure the bad times. Think of firms like Procter & Gamble (founded 1837!) which have lived through countless economic storms by staying financially prudent and diversified. For a 100-year stock, the ability to survive crisis after crisis isn’t optional, it has to be embedded in the culture of the company. Which takes to the next point.

• Enduring Culture and Leadership: No CEO works for 100 years, so the company’s culture and governance must sustain its vision. Businesses that last centuries often have a deep-rooted culture of integrity, innovation, and long-term thinking that gets passed down through generations of leaders. This includes cultivating new talent, succession planning, and a willingness to think beyond quarterly earnings. An example is Toyota (over 80 years old and counting) which instilled continuous improvement (kaizen) as a core value; that philosophy endures even as management changes. In a truly long-lived company, leadership acts more like stewards than opportunists – making decisions with the next quarter-century in mind, not just the next quarter.

These traits all point to one idea: a 100-year stock would be an exceptional business in every sense. It’s not enough to be great in one decade; it must be able to survive upheavals and seize opportunities through many decades. Businesses that can do this are exceedingly rare – but as a thought exercise, identifying these qualities can guide us in seeking this truly high-quality companies for long-term investing. After all, if a company could plausibly be around in 2125, it’s likely a pretty strong candidate for the next 10 or 20 years as well.

The Ultra-Long-Term Investor’s Mindset

Considering a 100-year holding period isn’t just about the company – it’s also about the investor’s mindset.

What kind of mental framework would you need to actually hold an investment for a lifetime (and then some)? This is where the philosophy of long-term, high-conviction investing really comes in. Let’s explore a few key mental shifts that define the ultra-long-term investor:

• Seeing the Big Picture (Focusing on the Underlying Trajectory of the Business): With a century horizon, day-to-day price swings and even year-to-year market cycles start to look like trivial noise. You become almost indifferent to short-term volatility. Instead, you’d focus on whether the company is strengthening its moat, innovating, and still serving a fundamental need. A 20% price drop during a bad year or a missed quarterly earnings target means little if your thesis is rooted in decades. In practice, adopting this mindset even for shorter horizons helps investors avoid panic selling and over-trading. Remember, “Time is the friend of the wonderful business, the enemy of the mediocre”⁴ – given enough time, a great business will reward its owners, whereas a mediocre one will reveal its flaws. The ultra-long-term investor trains themselves to trust in the power of compound growth and the underlying trajectory of the business, rather than getting distracted by temporary setbacks.

• Patience Over Forecasting: If you hold something for 100 years (assuming you are fortunate to live as much), you accept upfront that you cannot predict every twist and turn. Instead of trying to time the market or anticipate every disruption, the focus shifts to patience and resilience. This doesn’t mean “set it and forget it” blindly – it means you do your homework thoroughly at the start, then give the company the time it needs to realize its potential. Some of the greatest investment success stories come from patiently holding and adding to winning businesses over many years, not from constant shuffling. Adopting a patient stance also means being emotionally prepared for long periods where not much “exciting” happens. It’s the art of deliberate inactivity – as one investing adage goes, “money is made by sitting, not trading.” High-conviction investors often say that the hardest part is staying calm and not second-guessing yourself when the market is manic around you. The 100-year thought experiment is like an extreme training in patience: it encourages us to value stability over excitement.

• Conviction in Quality: To hold through thick and thin, you must have rock-solid conviction in the quality of the business you own. This conviction comes from understanding the company deeply – its business model, its competitive advantages, its leadership ethos, and its long-term opportunities and risks. If you’re going to trust a stock as a “family heirloom” investment, you’ll scrutinize it more closely than ever. When you have conviction, you won’t be easily swayed by market whispers or the latest pessimistic analyst note. Instead, you’ll ask: Has anything fundamentally changed with my company? If the answer is no, you stay the course. I wrote about how I think about about conviction before, you can read the article here:

• Adapting Your Thesis (When Necessary): Now, let’s be clear: long-term investing doesn’t mean blind loyalty in the face of obvious decline. Even a 100-year investor must be willing to confront reality if a once-great business loses its way for good. The difference is the threshold for action is much higher. You wouldn’t dump a stock over a bad year or a new competitor, but if a company’s core thesis breaks – say, a disruptive technology renders its main product obsolete and it fails to adapt – then even the ultra-long investor considers moving on. In our pure thought experiment we assumed you had to hold no matter what, but in the real world, long-term investing still allows for occasional course corrections. The key is that these decisions are rare, weighty, and driven by fundamental changes, not by panic. This aspect of the mindset teaches us to distinguish between temporary challenges and permanent impairment. The ultra-long view helps build the discipline to ride out the former and only act in the face of the latter. More thoughts on when to sell here:

By embracing these mental frameworks, even if we never actually hold a stock for decades, we become better long-term investors. We learn to zoom out, cultivate patience, and develop unshakeable conviction in the few things that matter. It’s a mindset of being a caretaker of your investments, almost as if you’re managing a legacy for future generations or a university endowment.

There are few investors who clearly and unequivocally advocate for this philosophy; one of them is Tony Deden.⁵

Scarcity, Endurance, and Independence: Defining Deden's Ideal Company

Tony Deden is an unconventional investor. He manages capital for families and a small group of shareholders. He is also known for his unique investment philosophy that emphasizes long-term capital preservation, a deep understanding of businesses, and a focus on enduring value.

The interview I share below forged many of my views on identifying long-lasting companies and also served as an inspiration for this article.

According to Deden, companies with the characteristics to endure over the long term have specific traits that go beyond typical financial metrics.

So what is he looking for? Let’s see:

• Endurance and Durability: Deden prioritizes companies with a proven history of surviving various economic conditions, including wars and inflations. He seeks companies with a long track record. He believes that a company's ability to endure is more important than its ability to grow. This is probably the core tenet of his philosophy.

• Scarcity and Uniqueness: He looks for companies that have natural barriers to entry, which makes it difficult for competitors to replicate. These can be due to a unique product, technical expertise, or a strategic position in the production structure.

• Independence: Deden seeks companies that are not dependent on government subsidies, tax abatements, or single customers. He prefers businesses that have a high degree of autonomy and are not overly influenced by external forces.

• Ownership Mindset: He looks for companies run by owners and managers who have a long-term perspective, similar to his own. He wants to invest in companies where the owners are motivated by the long-term health of the business rather than short-term financial gains. He prefers companies where the owners are responsible to their families and communities.

If you wanted to summarize his philosophy, you could say he focuses on a collection of assets, that are scarce, enduring, and independent, run by people who are motivated to build something of lasting value.

Investing Beyond a Lifetime

Pondering the idea of “the 100-year stock” is a humbling exercise. It reminds me that truly great businesses are exceedingly rare and precious. It challenges us to ask: Which companies have the DNA to survive and prosper across centuries? More importantly, it forces us to reflect on our own approach to investing. In a world obsessed with the minute by minute news cycle and the TikTok short videos, the ultra-long-term mindset is really like a breath of fresh air. It focus us on what really builds wealth: time, patience, and quality.

No one can know for certain which specific stock (if any) will thrive a century from now. The goal isn’t to actually lock up our money until 2125 (most of us won’t be around). Rather, the goal is to carry lessons from this thought experiment into our everyday investing. If you identify a business that you genuinely believe could be around in 100 years, that’s a strong sign it’s a business worth owning now and holding for as long as possible.

So, next time you evaluate a stock, ask yourself: Would I be comfortable holding this for the next 100 years? It’s a high standard, but it just might reframe your thinking. You may never hold an investment for a century, but by imagining that you could, you’ll gravitate toward businesses built to last and make more thoughtful, conviction-driven decisions.

And that is a legacy any investor would be proud of – one that truly looks beyond a lifetime.

1. But hey, 1899 wasn’t so different after all. The print shows an oversized man labeled "Promoter" sitting atop a ticker tape machine, holding a large butterfly net into which a throng of investors, some labeled "Broker, Merchant, [and] Banker", are tossing money in exchange for balloons labeled "Sash and Door Combine Stock, American Beet Sugar Co., Distillery and Warehouse Co. Stock, American Caramel Co., Auto-Truck Co. Stock, Print Cloth pool Stock, Chicago Milk Co., Knit Goods Co. Stock, [and] International Silver Co." One balloon labeled "Inflated Industrial" has burst.

2. Wei, W. (2019, June 4). Corporate longevity. Brunswick Review. Brunswick Group. https://www.brunswickgroup.com/brunswick-review/resilience-issue/corporate-longevity/

3. Wei, W. (2019, June 4). Corporate longevity. Brunswick Review. Brunswick Group. https://www.brunswickgroup.com/brunswick-review/resilience-issue/corporate-longevity/

4. Ro, S. (2014, March 4). Warren Buffett's 23 best quotes about investing. The State Journal-Register. Retrieved from https://www.sj-r.com/story/news/2014/03/04/warren-buffett-s-23-best/38573681007/#:~:text=,the%20enemy%20of%20the%20mediocre

5. Another investor you might want to check out is

Trung Nguyen @SWIs

from

Sleep Well Investments

; great publication with a long-term mindset.