Diversification is often called the only free lunch in investing, but still many investors don’t do it right. They’re either too concentrated, over-diversified, or make it much more complicated than it needs to be.
Diversification is about reducing avoidable risk while keeping our portfolio focused enough to outperform. It’s not about owning more stocks.
Naturally, perfect diversification doesn’t exist. But that doesn’t mean that a simple solution can’t be found. And I’m all for simple solutions.
That’s why I’m breaking down my simple stock diversification strategy for you. Not to copy blindly, but to show you that it can be done.
Let’s get into it.
⚡Key Takeaways
- Traditional diversification advice often leads to over‑diversification, low conviction, and mediocre returns.
- A good stock diversification strategy is about owning the right mix of businesses.
- The real question is how many high‑quality businesses we can understand and monitor well.
- Diversification works best when we spread risk across geographies, economic drivers, and investment categories.
- A simple strategy beats unnecessary complexity every time.
The Problem With Traditional Diversification Advice
Traditional diversification advice sounds reasonable and feels safe. It goes something like this:
- “More diversification means less risk.”
- “Buy a bit of everything.”
- “Spread across every sector and geography.”
- “Index funds offer the best diversification”.
Sounds good in theory but doesn’t work well in practice.
It leads to over‑diversification
Most investors don’t realize this, but after 20–25 stocks, the diversification benefit drops dramatically. Academic studies show that beyond that point there’s barely any benefit in adding more stocks.
On top of that, owning too many stocks adds unnecessary complexity to our portfolio and dilutes our best investment ideas.
The problem with index investing
Index funds are a great invention and make investing accessible to everyone. But they’re not as diversified as most people think they are.
Take the S&P 500 as an example. The top 8 stocks represent over 35% of all money invested. All in the technology sector. And they are responsible for +70% of the S&P 500 total gains over the past 3 years.
The MSCI World index is not that better. It’s top 8 stocks are the exact same as above, and they weigh 26% of the total investment. Plus, U.S. stocks take 68% of all the index.
Not that much diversification if you ask me.
How Many Stocks I Own
The right number of stocks to own is as much as we can understand, monitor, and hold with conviction. No more and no less.
For me that’s around 10-20 stocks at any given time. It’s enough diversification to protect me but not so much that it dilutes my best ideas.
And that’s what data suggests as well.
Fewer than 10 stocks and we’re exposed to too much company specific risk. Even if we choose great businesses, unexpected things may happen.
Much more than 20 stocks and we lose conviction and can’t keep up. Plus, there’s no clear risk reduction by having more stocks.
So, 10-20 stocks range seems to be the sweet spot.
Position Sizing Matters Too
Another thing to consider alongside the number of stocks is position sizing. Aiming at a 10-20 stocks portfolio means having 5-10% position sizes on average.
Here’s where we can also act on our conviction level. Our best ideas can have a higher stake versus our second-best ideas. My high‑quality, predictable compounders might get 8–10% while riskier, more volatile businesses might get just 3–5%.
Why I Focus On Quality Over Quantity
Diversification is not a numbers game.
We can own 50 low‑quality companies and still be dangerously exposed. Or we can own 12 high‑quality companies and be far safer than the average investor.
That’s why my entire diversification strategy starts with one core principle: focus on business quality first. Everything else is secondary.
What “business quality” really means
When I talk about quality, I’m talking about the underlying fundamentals of the business. It’s based on facts and not wishful thinking.
A high‑quality business has:
- Strong and consistent profitability
- Durable competitive advantage
- Predictable cash flows
- Clean balance sheet and low debt
- Clear runway for future growth
When we start with these criteria, our investable universe shrinks dramatically. And that’s a good thing. Quality filters out noise, hype, and mediocrity.
And quality businesses are the ones worth holding for the long term.
Quality reduces the need for excessive diversification
A great thing about quality businesses is that they are less risky than the others. They fail less often, are more resilient in downturns, recover faster, and compound more reliably.
We don’t need 40 stocks or exposure to every sector to feel safe. And we don’t need to hedge against every tiny risk. Quality does the heavy lifting.
Quality gives us conviction
Increased diversification is often used as a substitute for conviction. When investors don’t truly understand what they own, they compensate by owning more.
But conviction is much more intentional. It comes from:
- Understanding the business
- Trusting the long‑term economics
- Believing the company will still be strong in 10 years
When we diversify by quality we worry less and hold through our positions longer. Conviction is the antidote to emotional mistakes. And emotional mistakes are our biggest risk in investing.
My Key Diversification Levels
Real diversification is about understanding what actually drives risk and returns in our portfolio.
That means spreading exposure within different economic forces, not just different stocks. And that’s why I diversify across three key levels:
- Geographic exposure
- Sectors, industries and economic drivers
- Investment categories
These levels influence how a portfolio behaves in different environments and responds to different events.
1. Geographic exposure
So many investors and most global indices are heavily weighted toward the U.S. stock market. Some think that is proper diversification, but not me.
I believe European investors should bet on Europe and that’s what I do. We find there an information edge, reduce currency risk, and often better risk‑adjusted opportunities.
For that reason, I lean more over European stocks while restricting over-exposure to U.S. stocks and leaving some room for opportunities in other regions too.
2. Sector, industry and economic drivers
Sector and industry diversification is another one on my radar. That’s because companies tend to highly correlate with their peers but less much with others.
Plus, I like to consider different economic drivers. Think interest rates for banks, real estate, and insurances. Or consumer confidence for retail, luxury, and travel.
That’s why I don’t let one single sector, industry, or economic driver to dominate my portfolio. But at the same time, I don’t try to get a bit of everything. A few balanced bets are good enough for me.
3. Investment categories
Lastly, I seek to spread my investment between three of Peter Lynch’s stock categories: fast growers, stalwarts, and slow growers (I usually keep away from cyclicals, turnarounds, and asset plays).
These differ in upside potential, stability, volatility, and income.
Fast Growers
Small, aggressive new companies that grow at 20-25% per year. The upside potential is high but so is the risk that they run out of gas and fade away. Plus, volatility is an issue.
Stalwarts
Big companies with predictable financials and strong moats. They still have some room for decent growth and upside potential while being safer than fast growers.
Slow Growers
Usually, big and aging companies that offer little upside potential but pay generous and regular dividends. And they’re less volatile too.
Conclusion
A good stock diversification strategy is simple. It’s not about owning more or buying a bit of everything.
My simple stock diversification strategy is based on:
- Owning high‑quality businesses
- Intentionally spreading risk across key levels
- Staying flexible enough to seize opportunities
This keeps my portfolio focused, resilient, and aligned with my long-term goals. All without adding unnecessary complexity.
👉 Actionable Step: Review your portfolio diversification and write down a few simple guidelines that you can easily follow.
And if you haven’t subscribed yet, now’s the time. Your future self will thank you.
Great content! Keep up the good work!