One of the first investment books I read was the book The Art of Thinking About Money by André Kostolany.
For many investors, the first books they encounter are often about valuation models, technical indicators, or portfolio theory. Kostolany's writing was different. Instead of focusing on formulas, he focused on psychology, speculation, human behavior, and how investors think.
Even today, many of his ideas remain surprisingly relevant.
Who Was André Kostolany?
André Kostolany was a Hungarian-born investor, speculator, and financial journalist who spent more than 70 years participating in financial markets.
He lived through wars, inflation, booms, crashes, and multiple economic cycles.
Unlike many modern investment authors, Kostolany was not a pure academic. He was a practitioner who made and lost fortunes in the market and learned from both success and failure.
His writings often emphasized that investing is not simply about numbers. It is about understanding human behavior, market psychology, and managing uncertainty.
The Quote That Stayed With Me
Among his many famous quotes, one stands out to me the most: "A successful speculator is right in 51 out of 100 cases, and wrong in 49. He lives on the difference."
When I first read it, it completely changed how I thought about investing.
Many new investors believe they must be right most of the time.
They think successful investors win 80%, 90%, or even 100% of their trades.
Reality is very different.
Kostolany reminds us that success does not require perfection.
Success requires an edge.
Even a small edge, applied consistently over a long period, can produce extraordinary results.
The Best Investors Are Not Always Right
This idea became even clearer to me after following participants and champions from the United States Investing Championship (USIC).
Many people are surprised to discover that some highly successful traders only have winning rates of around 30% to 50%.
At first glance, that sounds terrible.
How can someone lose half the time and still achieve exceptional returns?
The answer is simple:
They understand risk and reward.
A trader who wins only 40% of the time can still be highly profitable if the average winner is several times larger than the average loser.
The win rate alone tells only part of the story.
Risk and Reward Matter More Than Accuracy
One of the biggest mistakes investors make is focusing exclusively on being right.
In reality, investing is not an exam.
There are no prizes for achieving a high percentage of correct answers.
The market rewards outcomes, not accuracy.
Suppose an investor risks $1 to potentially make $5.
Even if the investor is only correct 30% of the time, the overall result can still be highly profitable.
This is why professional investors spend so much time thinking about position sizing, downside protection, and expected returns.
The goal is not to maximize the number of winning trades.
The goal is to maximize expected returns over many trades.
What Makes a Good Investment Opportunity?
Over time, I have become less interested in predicting whether a stock will go up tomorrow.
Instead, I focus on whether the opportunity is asymmetric.
For me, a good investment opportunity offers:
Limited downside
Significant upside
Favorable risk-reward characteristics
In other words: The potential reward should be meaningfully larger than the potential risk.
This does not guarantee success.
The stock can still fail.
The thesis can still be wrong.
But if the reward is sufficiently larger than the risk, the odds become favorable over a large number of investments.
This way of thinking aligns closely with Kostolany's philosophy.
You do not need to be right every time.
You simply need to ensure that when you are right, you make significantly more than when you are wrong.
Conslusion
One of the most valuable lessons André Kostolany taught me is that investing is not a game of perfection.
It is a game of probabilities.
Many investors spend their careers trying to improve their win rate.
A better question may be:
"What happens when I am right, and what happens when I am wrong?"
The difference between those two outcomes often matters far more than the percentage of winning trades.
As Kostolany said, a successful speculator does not need to be right all the time.
He only needs an edge.
And for me, that edge comes from finding opportunities where the potential reward is far greater than the potential risk.