How many shares should you own?

One of the most debated questions in the world of investing isn’t just what to buy, but how much of it to hold. If you put all your money into one stock, you’re gambling. If you buy 500 different stocks, you might as well just buy an index fund and save yourself the headache.

Finding the “Goldilocks zone”—the perfect number of stocks that balances risk and reward—is essential for building long-term wealth. In this guide, we’ll explore the math, the psychology, and the expert strategies behind determining exactly how many stocks you should have in your portfolio.

The Magic Number: What Do the Experts Say?

For decades, financial theorists and legendary investors have tried to pin down a specific number. While there is no one-size-fits-all answer, a general consensus has emerged from academic research and historical data.

The 20 to 30 Rule

Most academic studies, including the seminal work by Lawrence Fisher and James Lorie, suggest that a portfolio of 20 to 30 stocks provides the vast majority of the benefits of diversification.

Once you move past 30 stocks, the marginal benefit of adding one more company to reduce risk becomes very small. At that point, you aren’t really “diversifying” as much as you are simply “collecting” stocks, which can lead to average performance.

The Concentrated Approach

On the other end of the spectrum, investors like Charlie Munger and Warren Buffett have famously argued for a more concentrated approach. They believe that if you truly understand a business, holding just 5 to 10 high-quality companies is safer than holding 100 companies you know nothing about.

“Wide diversification is only required when investors do not understand what they are doing.” — Warren Buffett

Understanding Systematic vs. Unsystematic Risk

To understand why the number of stocks matters, we have to look at the two types of risk every investor faces.

1. Unsystematic Risk (Company-Specific Risk)

This is the risk that something bad happens to a specific company. Maybe the CEO resigns, a product fails, or a warehouse burns down.

• The Solution: You can virtually eliminate this risk by owning more stocks. If you own 25 stocks and one goes to zero, you only lose 4% of your portfolio.

2. Systematic Risk (Market Risk)

This is the risk that affects the entire economy. Think of a global recession, a sudden spike in interest rates, or a geopolitical conflict.

• The Reality: No amount of diversification can protect you from systematic risk. When the entire market drops 20%, even a portfolio of 500 stocks will likely drop with it.

The Danger of “Deworsification”

Peter Lynch, the legendary manager of the Magellan Fund, coined the term “Deworsification.” This happens when an investor adds so many stocks to their portfolio that they actually lower their expected returns without significantly lowering their risk.

Why More Isn’t Always Better

• Diluted Winners: If you have 100 stocks and one of them “moons” (grows by 500%), it will have almost no impact on your total wealth because it only represents 1% of your portfolio.

• Lack of Knowledge: It is nearly impossible for an individual investor to stay updated on the quarterly earnings, management changes, and competitive landscapes of 50 different companies.

• High Transaction Costs: Even with zero-commission trading, managing a massive portfolio takes time—and time is money.

Sector Diversification: It’s Not Just About the Number

If you own 30 stocks, but all 30 are in the Artificial Intelligence sector, you are not diversified. If the tech sector takes a hit, your entire portfolio will bleed.

To achieve true diversification, your 20–30 stocks should be spread across different sectors:

• Technology: Growth-oriented companies.

• Healthcare: Traditionally defensive and resilient.

• Consumer Staples: Companies that sell things people need regardless of the economy (soap, food, etc.).

• Financials: Banks and insurance companies that often benefit from interest rate changes.

• Energy and Utilities: Providing a hedge against inflation and offering steady dividends.

Choosing Your Strategy Based on Your Investor Profile

The “right” number of stocks for you depends largely on how much time you want to spend “working” on your investments.

The Hybrid Approach: The “Core and Satellite” Strategy

If you are torn between wanting the safety of diversification and the excitement of picking individual stocks, the Core and Satellite strategy is likely your best bet.

How it Works:

1. The Core (70–80%): Put the majority of your money into a broad market ETF (like VOO or VTI). This ensures you get the market’s average return and total diversification.

2. The Satellites (20–30%): Use the remaining money to buy 5 to 10 individual stocks that you believe will outperform the market.

This allows you to “bet” on your favorite companies without risking your entire retirement fund if you happen to be wrong about one of them.

When Should You Sell or Add a New Stock?

Maintaining a portfolio is like tending a garden. Sometimes you need to plant new seeds, and sometimes you need to pull the weeds.

Signs You Have Too Many Stocks:

• You can’t remember why you bought a specific stock.

• You haven’t read the last two earnings reports for several of your holdings.

• Your portfolio performance is identical to the S&P 500 (in which case, just buy the index!).

Signs You Have Too Few Stocks:

• A 5% drop in a single company causes you physical stress or loss of sleep.

• One company makes up more than 15-20% of your total net worth.

• You are heavily concentrated in only one or two industries.

The Role of Dividends in Portfolio Size

If your goal is income generation, the number of stocks you own might be slightly higher. Dividend investors often hold 30 to 50 stocks to ensure a consistent monthly “paycheck” from various companies that pay dividends at different times of the year.

By spreading out your dividend-paying stocks, you reduce the risk of a “dividend cut.” If one company stops paying its dividend, it only represents a small fraction of your total annual income.

Quality Over Quantity

At the end of the day, the number of stocks you should own is the number that allows you to sleep at night while still giving you a chance to beat the market. For most people, 20 to 25 stocks spread across different industries is the “Sweet Spot.”

Don’t feel pressured to buy more stocks just for the sake of a higher number. Focus on owning great businesses at fair prices. If you find you don’t have the time to research 20 companies, there is absolutely no shame in using low-cost index funds to do the heavy lifting for you.