
Introduction
Some important ideas in investing are born after years of academic research. Others emerge from carefully designed experiments. But one of the most memorable ideas in investment history was born from an unexpected incident in the life of an investment professional.
The idea is known today as Coffee Can Investing.
Its central message is simple: buy carefully selected investments and give them a very long time to grow, instead of constantly buying and selling them.
The phrase "Coffee Can Portfolio" was coined by American investment manager Robert G. Kirby, but the experience that inspired the idea occurred much earlier, in the mid-1950s, when Kirby was working as an investment counsellor. The discovery came from an unexpected comparison between two investment portfolios belonging to a husband and wife.
Kirby had been professionally managing the wife's investments. Her husband, however, had quietly been following the investment firm's recommendations for his own portfolio. There was just one crucial difference: the wife followed both the buy and sell recommendations, while her husband followed the buy recommendations but ignored the sell recommendations.
When the husband suddenly died and Kirby was asked to examine his investment portfolio, he discovered something extraordinary. Some of the investments had performed badly, but several had become extremely valuable. One investment, originally a small commitment in a company called Haloid, had grown into a position worth more than $800,000. That holding eventually became associated with Xerox. Remarkably, that single investment was worth more than the entire professionally managed portfolio of the wife.
This unexpected discovery changed Kirby's thinking about investment management. It made him realise that a few exceptional investments can create enormous wealth if they are allowed to grow for a very long time.
That is the fascinating story behind Coffee Can Investing.
Robert Kirby and the Investment World of the 1950s
To understand the birth of Coffee Can Investing, we need to understand the investment environment in which Robert Kirby was working.
In the mid-1950s, Kirby worked for a large American investment-counselling organisation whose clients were primarily individuals. The firm's approach was relatively conservative. Its principal responsibility was not necessarily to make already wealthy clients extraordinarily richer. Its objective was largely to preserve their capital and protect the standard of living that their wealth provided.
The investment managers therefore followed a conventional approach. They researched companies, recommended stocks to buy, monitored those investments and subsequently recommended when they should be sold.
If a stock had risen significantly, the manager might recommend selling some or all of it and taking profits. If the company's prospects changed, the manager might recommend exiting the position. If another investment appeared more attractive, money could be moved from one investment to another.
From the perspective of conventional portfolio management, this made perfect sense. A professional manager was expected to monitor a portfolio continuously and make decisions whenever circumstances changed.
But Kirby eventually discovered that this approach had an unintended consequence.
A manager could identify an outstanding investment correctly and still fail to capture most of its ultimate wealth-creating potential by selling it too early.
The discovery came from a remarkable incident involving one of Kirby's clients.
The Client and Her Husband
Kirby had been working with a woman as an investment client for approximately ten years. Her financial affairs were largely handled by her husband, who was a lawyer and served as the principal contact between the family and Kirby's investment firm.
During those years, Kirby and his organisation made investment recommendations for the wife's portfolio. They bought stocks, sold stocks and adjusted the portfolio according to their assessment of risk and opportunity.
Everything was being done according to the firm's normal investment process.
Then, unexpectedly, the woman's husband died suddenly.
The widow contacted Kirby and explained that she had inherited her husband's estate. She wanted to add his investments to the portfolio that Kirby's firm was already managing for her.
She therefore provided Kirby with a list of her husband's securities.
What Kirby discovered when he examined that list would remain with him for the rest of his professional life.
Kirby Makes a Strange Discovery
Kirby discovered that the husband had been secretly following the investment recommendations that Kirby's firm had been making for his wife.
Whenever Kirby's firm recommended buying a particular stock for the wife, the husband apparently bought the same stock for himself.
But the husband had introduced one very important modification.
He ignored the sell recommendations.
He followed the firm's advice when it said "buy", but when it later said "sell", he simply did nothing.
According to accounts of Kirby's original story, the husband invested approximately $5,000 in each purchase recommendation. After buying the stock, he placed the stock certificate in a safe-deposit box and essentially forgot about the investment.
This was not a carefully designed investment experiment. The husband was not trying to prove a financial theory. He was simply following the investment recommendations in his own way.
Yet when Kirby examined the portfolio, the results were astonishing.
An Odd-Looking Portfolio
The husband's portfolio looked very different from a professionally managed portfolio.
It contained several investments that had performed terribly. Some holdings were worth less than $2,000, even though approximately $5,000 had originally been invested in each of them.
From the perspective of conventional portfolio management, these were obvious failures. The husband had failed to sell them when the investment professionals recommended doing so.
But then Kirby noticed something else.
The portfolio also contained several investments worth more than $100,000.
And then came the extraordinary discovery.
There was one investment worth more than $800,000.
The astonishing part was that this single holding was worth more than the entire value of the wife's professionally managed portfolio.
Kirby had discovered something that challenged his assumptions about investment management.
The husband's strategy had produced both losers and spectacular winners. But the spectacular winners had become so large that they more than compensated for the disappointing investments.
The $800,000 Investment: Haloid and Xerox
The most remarkable investment in the husband's portfolio came from a relatively small commitment to a company called Haloid.
Haloid was involved in the development and commercialisation of xerography, the technology that eventually transformed the copying industry. Its history became closely connected with the company that the world would later know as Xerox.
This part of the story is particularly fascinating because the husband could not possibly have known how large this investment would eventually become.
When he initially bought the shares, he did not know that the company would become synonymous with photocopying. He could not have known how dramatically the business would expand or how valuable his shares would eventually become.
He simply held them.
And that is precisely what made the story so powerful.
The investor did not need to predict the entire future of the company. He only needed to remain invested while the company created that future.
The Wife Followed the Advice. The Husband Followed Only Half of It.
The comparison between the two portfolios was at the heart of Kirby's discovery.
The wife had followed the professional investment process. When the investment managers recommended buying, she bought. When they recommended selling, she sold. Her portfolio was actively managed.
Her husband's portfolio followed only the first half of the process. He bought the recommended stocks and then stopped listening.
He did not sell.
The result was a strange portfolio containing some substantial losses alongside a handful of spectacular winners.
But those winners had become so large that they transformed the overall result.
This was the crucial insight.
The husband's success did not come from avoiding every bad investment. He did not.
It did not come from correctly predicting every future winner. He could not.
It came partly from allowing the winners to become enormously valuable.
The losses were limited to the amounts originally invested. But there was theoretically no similar upper limit on how large a successful investment could become.
A $5,000 investment could fall to $2,000. But a $5,000 investment could also become $50,000, $100,000, $500,000 or even more.
That asymmetry fascinated Kirby.
The Moment of Realisation
The discovery forced Kirby to reconsider the role of an investment manager.
He had been trained to manage risk, protect capital and make sensible portfolio decisions. Yet here was an example where doing less after the initial investment had produced a remarkable result.
The husband's approach had an important advantage. Once the shares had been purchased, there was almost no further decision-making.
There were no repeated decisions about whether to sell. There was no constant portfolio rearrangement. There was no attempt to predict short-term market movements.
There was simply ownership.
Kirby began to recognise that investment management itself could sometimes become a source of unnecessary interference.
A manager might correctly identify an outstanding company but sell it after a substantial rise. The manager might believe that the stock had become too expensive or that another investment looked more attractive. The decision might be perfectly reasonable at that particular moment.
But it could have one serious consequence:
It could prevent a truly exceptional investment from becoming an enormously valuable investment.
Why Did Kirby Call It "Coffee Can"?
Kirby needed a memorable way to describe this approach.
He used an analogy from the American Old West.
Before modern banking became widespread, people sometimes kept valuables in simple household containers such as coffee cans and hid them safely under mattresses. Once the valuables were placed there, the owner did not repeatedly take them out, trade them and put them back.
They were simply stored.
Kirby applied this image to investing.
Imagine selecting valuable investments carefully, putting them into a "coffee can" and then leaving them there for a long period.
The critical work takes place before the investments go into the can.
Once they are there, unnecessary interference is avoided.
This became the memorable expression "Coffee Can Portfolio."
The name therefore does not mean that investors should literally put their share certificates in a coffee can. It is a metaphor for careful selection followed by extraordinary patience.
The Importance of the Original Selection
One of the most important points in understanding Kirby's idea is that Coffee Can Investing does not mean buying random stocks and forgetting them.
The husband's portfolio worked spectacularly because he was piggybacking on professional investment research.
His initial selections came from Kirby's firm's recommendations.
He did not know which stocks would become extraordinary winners. He simply gave every selected investment the opportunity to become one.
Therefore, Coffee Can Investing has two distinct stages.
The first stage is careful selection. The investor must study the business, understand its prospects, consider its financial strength, examine its competitive position and decide whether it has the potential to grow for many years.
The second stage is patient ownership. Once the investment has been selected, the investor should avoid selling merely because the price has risen, because the market has temporarily fallen or because another stock suddenly appears exciting.
The difficult work happens before the investment goes into the "coffee can."
Why the $800,000 Winner Was So Important
The enormous Haloid/Xerox investment revealed something fundamental about equity investing.
Suppose an investor invests $5,000 each in ten companies.
Several may fail.
Several may produce ordinary returns.
A few may perform very well.
But one exceptional investment could potentially become worth hundreds of thousands of dollars.
The investor therefore does not necessarily need every investment to succeed.
A few extraordinary winners can have a disproportionate effect on the final result.
This is why selling successful investments too early can be so damaging.
Imagine buying a company for $5,000 and selling it when it becomes worth $10,000. You have doubled your money and made a respectable profit.
But what if that same company eventually becomes worth $100,000?
What if it becomes worth $500,000?
The investor who sold at $10,000 has made a profit—but has lost the opportunity to participate in the much greater compounding that could have followed.
Kirby's client's husband unknowingly avoided this problem.
He never took the profits.
He allowed the investment to continue growing.
Coffee Can Investing and the Power of Time
Coffee Can Investing is therefore closely connected with one of the most powerful forces in finance: compounding.
A good company may need many years to reveal its full potential.
A new technology may take years to become commercially successful. A company may need years to build its brand, expand its distribution network, enter new markets or develop new products.
An investor who holds a stock for a few months may never experience the complete story.
An investor who holds for ten or twenty years may witness an extraordinary transformation.
Time gives a successful business the opportunity to reinvest profits, expand operations, increase earnings and potentially increase its value.
The husband's portfolio provided Kirby with a dramatic real-world illustration of this principle.
1984: Kirby Formally Presents the Coffee Can Portfolio
The original experience occurred in the 1950s, but Kirby did not immediately publish a formal investment theory based on it.
The experience remained with him for many years as he continued his career in the American investment industry.
Nearly three decades later, Kirby finally put the concept into writing.
In 1984, he published an article titled "The Coffee Can Portfolio" in The Journal of Portfolio Management. The article appeared in the Fall 1984 issue, Volume 11, Number 1, on pages 76–80.
This publication gave the Coffee Can idea a formal place in investment literature.
Kirby used the story to discuss a broader question: Can investors improve long-term investment outcomes by reducing unnecessary portfolio activity?
His answer was essentially that they could, provided that the investments were selected intelligently in the first place.
The Problem of Excessive Buying and Selling
One of the important themes in Kirby's thinking was the cost of excessive activity.
Every time an investor buys or sells, there can be costs. Brokerage charges, bid-ask spreads, taxes and other expenses can reduce returns.
But the bigger cost may be psychological.
Frequent buying and selling gives investors more opportunities to make emotional decisions.
A stock rises sharply, and the investor becomes afraid of losing the profit.
A stock falls, and the investor becomes frightened.
Another company suddenly becomes fashionable, and the investor wants to switch.
The result is a cycle of constant activity.
Coffee Can Investing offers an alternative.
Instead of asking, "What should I buy today?", the investor asks:
"What businesses are worth owning for many years?"
Once that question has been answered carefully, there may be much less need for constant action.
The Problem of "Taking Profits"
One of the deepest lessons in Kirby's story concerns the common advice to "take profits."
Suppose an investor buys a stock at $50 and it rises to $100.
The investor may think, "I have doubled my money. I should sell."
That decision may indeed be sensible in some circumstances.
But there is another possibility.
The company may continue growing.
The $100 stock could become $150, then $200, then $500 over a sufficiently long period.
The investor who sold at $100 has guaranteed a profit, but has sacrificed the possibility of participating in the company's further growth.
Kirby's client's husband had unknowingly solved this problem.
He did not take profits.
He simply continued owning the shares.
His exceptional investment was therefore allowed to become exceptionally large.
Coffee Can Investing Is Not Blind "Buy and Forget"
The Coffee Can story is sometimes reduced to the phrase "buy and forget."
That interpretation is incomplete.
The husband's portfolio was not based on random stock selection. His purchases were based on the recommendations of professional investment managers.
The crucial lesson was therefore not that investors should stop monitoring everything forever.
It was that good initial decisions should be given sufficient time to work.
If a company's fundamental business deteriorates dramatically, if its management becomes unreliable or if the original reason for owning the company disappears, an investor may have a legitimate reason to sell.
Coffee Can Investing is therefore better understood as:
Think deeply before buying, and interfere very little without a compelling reason after buying.
What Robert Kirby Really Discovered
Did Robert Kirby invent long-term investing?
Not really.
People had been buying and holding investments long before the 1980s.
What Kirby discovered was something more subtle.
He discovered how excessive activity could prevent exceptional investments from becoming exceptional portfolio holdings.
The husband's portfolio provided a natural experiment.
Both husband and wife were exposed to similar investment ideas.
The wife followed the professional managers' complete instructions.
The husband followed only the buying instructions.
The husband therefore accidentally created a portfolio in which successful investments were allowed to become disproportionately large.
The result was astonishing.
That was the insight Kirby carried forward.
The Lasting Significance of the Coffee Can Story
The Coffee Can story remains memorable because it is really a story about human behaviour.
Investors naturally want to act.
When a stock rises, they want to take profits.
When a stock falls, they want to escape.
When the market becomes exciting, they want to participate.
When the market becomes frightening, they want to protect themselves.
And when nothing is happening, they feel that they should do something.
Kirby's client's husband accidentally discovered the opposite approach.
He made relatively few decisions.
He bought the investments.
Then he waited.
Some decisions failed.
Some merely survived.
But a few extraordinary decisions changed the entire portfolio.
That is the remarkable lesson hidden inside the Coffee Can story.
Conclusion: The Investment Lesson Hidden in a Coffee Can
The story of Coffee Can Investing is ultimately the story of an accidental discovery.
Robert Kirby did not set out to invent a new investment philosophy. He was simply doing his job as a professional investment counsellor in America in the 1950s.
He researched investments. He recommended stocks. He recommended when to sell them.
Then a client's husband quietly followed the investment ideas—but ignored the selling.
When the husband died, Kirby discovered the consequences.
There were losers. There were modest winners. There were spectacular winners. And there was one extraordinary investment that had grown from a small commitment in Haloid into a holding worth more than $800,000, eventually associated with Xerox.
Kirby realised that the husband's success was not the result of perfect prediction. He had not known which investment would become the great winner.
His extraordinary advantage was that he did not sell it.
He allowed time to work.
The Coffee Can metaphor captures this beautifully. The investor does the difficult work before putting the investment into the "can": researching the business, judging its quality and deciding whether it deserves long-term ownership.
After that comes the difficult discipline of waiting.
The story therefore gives us a powerful lesson:
Choose carefully. Buy quality. Hold patiently. Give exceptional investments the opportunity to become exceptional.
The coffee can is only a metaphor.
The real investment strategy is patience.
And the deeper lesson Robert Kirby discovered more than seven decades ago remains remarkably relevant:
A good investment may need years to reveal how good it really is.
Sometimes, therefore, the hardest part of investing is not finding something wonderful.
It is having the patience not to get in its way.


