Stock Diversification: How Many Stocks Make an Ideal Portfolio

Published: 6 months ago, Last Updated: 6 months ago
Jessica Lee
Writer: Jessica Lee
Jackson Rhodes
Reviewer: Jackson Rhodes
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Diving into the world of stock investing? Great! The first puzzle to solve: How many stocks should I own? It’s a simple question with complex answers. Too few, and you’re risking the damaging effects of market volatility; too many, and you might lose track. If you’re new to stock investing, this guide will help you cut through the complexity.

We’re here to demystify stock diversification. By the end of this journey, you’ll not only grasp the “how many” but also the “why” behind each number. So, buckle up, and let’s begin.

How Many Stocks Should You Own?

To answer the question, “How many stocks should I own?” let us begin by saying that it depends on your investment goals, risk appetite, and market knowledge. Let’s explore the different ranges and what they mean for your investment strategy:

Less Than 20

Owning fewer than 20 stocks is often seen as a concentrated approach. This strategy can lead to high returns if your picks perform well, but it also increases risk. Each stock holds a larger percentage of the total portfolio value. Suppose one or more of these limited stocks underperform. In that case, the negative impact on the portfolio is significantly magnified compared to a portfolio with a larger number of stocks, where the risk is more spread out.

For instance, in a portfolio of eight stocks, each representing 12.5% of your total investment, a significant 40% decline in one stock would lead to a 5% overall reduction in your portfolio’s value. In contrast, if you have a 25-stock portfolio, with each stock comprising 4%, a 40% decrease in one stock would only result in a 1.6% drop in the total portfolio.

More Than 60

At the other end of the spectrum, holding more than 60 stocks might sound like a safer bet. Diversification reduces your exposure to the risk of any single stock. However, a portfolio this large can be difficult to manage effectively. It becomes increasingly difficult to maintain an in-depth knowledge of each company’s performance, financial health, and growth prospects.

Moreover, the concept of diminishing returns in portfolio diversification becomes significant in larger portfolios. Essentially, after a certain threshold, typically around 60, each additional stock added contributes less and less to the overall risk mitigation, making further diversification less impactful.

Here’s how the law of diminishing returns works in practice: Let’s say you have 100 stocks, each representing 1% of your portfolio. If one stock increases by 50%, this would only cause a 0.5% increase in the overall portfolio value.

Between 20 and 60

Twenty to 60 stocks is the range that experts often consider the “sweet spot” for stock investment. For those with moderate risk tolerance, this number of stocks offers a blend of stability and growth potential without overwhelming complexity. It also aligns well with different investment goals, whether you’re aiming for long-term growth, income generation, or a combination of both.

Investor researching how many stocks to buy online

Additionally, managing 20 to 60 stocks is feasible for most investors. It balances the need for diversification with the ability to stay informed about each holding, making it a practical choice for those with varying degrees of market knowledge.

In a diversified portfolio of 40 stocks, where each stock represents 2.5% of your total investment, the impact of any single stock’s performance is more balanced. If one stock drops by 30%, it results only in a 0.75% decrease in your overall portfolio value. Conversely, a 30% gain in another stock would contribute the same positive effect.

Is 50 Stocks Too Many?

Is there such a thing as over-diversification? Yes, and 50 stocks might be approaching that limit for some investors. While diversification is key, too many stocks can dilute your returns and can complicate portfolio management. If your goal is aggressive growth and you have a high-risk tolerance, managing 50 stocks might align well with your strategy. 

But if you’re just starting in this field, aiming for 50 stocks immediately could prove challenging. This is because of the complexity of managing a diverse range of companies, sectors, and market trends.

How to Start Investing in Stocks

Entering the stock market is an exciting step toward financial growth. As a beginner, you should understand the various avenues available and choose the ones that align best with your financial goals and risk tolerance. Here’s a breakdown of some common methods to start investing in stocks:

Direct Investing

Direct investing involves buying shares of individual companies through a broker. When you engage in direct investing, a broker acts as your intermediary, executing buy and sell orders on your behalf.

Close up on investor buying stocks on cellphone

The benefits of direct investing include:

  • Full Control: You decide what stocks to buy and sell.
  • Potential for Higher Returns: Picking the best-performing stocks can yield significant returns.
  • Transparency: Direct insight into where your money is invested.

On the other hand, the potential drawbacks include:

  • Requires Time and Knowledge: Successful stock picking demands market research and ongoing monitoring.
  • Brokerage Fees: You need a broker to perform the transaction, which requires you to pay fees that can vary depending on the broker.
  • Higher Risk: Investing in a few stocks can expose you to significant volatility.

Direct investing suits those who have the time and interest in researching and actively managing their stock selections, offering a hands-on approach to stock investing.


For many, a 401(k) plan offered by their employer is a primary entry point into the world of stock investing. Typically, these retirement plans include investment options in stocks, often in the form of mutual funds. While the selection of these stock investments is generally predetermined by the employer, this limited choice isn’t always a downside, as 401(k) plans are strategically diversified across various asset classes, industries, and sectors.

The benefits include:

  • Employer Matching: Many employers offer matching contributions, boosting your investment.
  • Tax Advantages: Contributions are tax-deferred, meaning the money you invest is taken from your income before taxes are applied, reducing your total tax liability.
  • Automatic Investing: Contributions are typically automated through payroll.

The potential challenges include:

  • Limited Investment Options: Choices are often restricted to a select group of funds.
  • Penalties for Early Withdrawal: Accessing funds before retirement age can incur penalties.
  • Lack of Control: Limited ability to influence investment decisions within the fund.

For beginners, a 401(k) offers a straightforward, tax-efficient way to start investing in stocks, especially with the added benefit of employer-matching contributions.

Individual Retirement Account (IRA)

An IRA is another way to invest in stocks with potential tax advantages. Unlike 401(k) plans, these are self-directed accounts and are not sponsored by the employer, giving investors more control. There are two main types: Traditional IRAs, which offer tax-deferred growth, and Roth IRAs, where withdrawals in retirement are tax-free.

The benefits of investing in stocks through an IRA are:

  • Investment Flexibility: Since IRAs are self-directed retirement plans, they allow you to control your budget and choose which stocks or assets to invest in. 
  • Tax Benefits: Traditional IRAs offer tax-deferred growth, while Roth IRAs provide tax-free withdrawals in retirement.
  • Flexibility: You can open an IRA regardless of your employment status and choose how much to contribute each year.

Potential drawbacks can include:

  • Contribution Limits: IRAs come with maximum contribution limits, which may restrict how much you can invest each year.
  • No Employer Matching: Unlike 401(k) plans, employers cannot make matching contributions.
  • Early Withdrawal Penalties: Tax penalties may be applied for accessing funds before retirement age.
  • Requires More Active Management: More involvement is needed in selecting and managing investments.

IRAs are a good choice for those seeking a flexible, tax-advantaged way to invest in stocks, especially for those without access to an employer-sponsored 401(k).

Stock Mutual Funds

Stock mutual funds are a type of investment vehicle that pools money from many investors to purchase a diversified portfolio of stocks. Managed by professionals, these funds aim to provide growth or income by investing in a range of stocks from different companies and sectors.

Investment broker meeting with individual

Benefits of investing in stock mutual funds:

  • Diversification: By investing in a fund, you’re buying a small piece of many stocks, spreading out risk.
  • Professional Management: Fund managers make the investment decisions, which is great if you’re not confident in picking stocks yourself.
  • Affordability: With minimal investment amounts, mutual funds are accessible to most investors.
  • Simplicity: Buying a mutual fund is straightforward, making it less intimidating for beginners.

Drawbacks to consider:

  • Fees: Mutual funds charge management and operational fees, which can eat into your returns.
  • Less Control: You rely on the fund manager’s decisions; you can’t pick individual stocks within the fund.
  • Potential for Lower Returns: Due to diversification, while risk is spread out, high returns on individual stocks may be diluted.

For beginners, mutual funds offer a balance of simplicity, professional management, and diversification, making them a less daunting entry point into the stock market.

You might also be interested in What Happens to the Stock Market During a Recession.

How to Pick the Stocks for a Portfolio

Choosing the right stocks for your portfolio requires a blend of research, strategy, and ongoing assessment. Below are some of the steps to guide you through this process:

Step 1: Define Your Investment Goals and Risk Tolerance

When deciding on your investment strategy, consider your risk tolerance and investment timeframe:

  • High-Risk Tolerance: If you’re open to higher risk for potential long-term growth, you might lean toward sectors with higher growth prospects, acknowledging that these can experience significant price swings.
  • Moderate Risk Tolerance: Investors with a moderate risk tolerance may prefer a balanced approach, combining growth-oriented stocks with stable, dividend-paying ones.
  • Low-Risk Tolerance: Those with a lower risk appetite might focus on stocks with a history of stability and consistent dividends, which generally fluctuate less in price.

Step 2: Conduct Thorough Research

Start with companies you’re familiar with and expand from there. Research the company’s financial health by examining its balance sheet, income, and cash flow statements. These can typically be found in the investor relations section of the company’s website or through financial data platforms like Yahoo Finance, Google Finance, or Bloomberg.

Also, pay attention to key financial metrics like 

  • Price-to-Earnings (P/E) Ratio: Indicates how much investors are willing to pay per dollar of earnings. A higher P/E might suggest expectations of future growth.
  • Earnings Per Share (EPS): Shows the company’s profitability on a per-share basis and is useful for comparing performance between companies.
  • Return on Equity (ROE): Measures how effectively the company uses shareholders’ earnings to generate profits.
  • Debt-to-Equity Ratio: Highlights the company’s financial leverage and stability by comparing its total liabilities to equity.

Step 3: Diversify Your Portfolio

We’ve mentioned it before, and it’s worth emphasizing again: diversification is key to managing risk. Spread your investments across various sectors and industries, such as technology, healthcare, consumer goods, and energy, each responding differently to economic cycles.

Consider varying industries within these sectors, from emerging tech startups to established utility companies, aligning with your risk tolerance and investment goals. This approach not only mitigates risk but also positions your portfolio to benefit from growth opportunities in diverse market areas.

Step 4: Stay Informed and Be Patient

Investing in stocks requires patience and a long-term perspective. Stay informed about market trends and economic factors that could affect your investments by following reputable sources like Bloomberg and The Wall Street Journal. Be prepared for market fluctuations and avoid making hasty decisions based on short-term market movements.

For additional guidance, consider consulting with a financial professional who can provide personalized advice and help navigate complexities. You can find qualified advisors through referrals or by using resources like the Certified Financial Planner Board’s website or the Financial Planning Association.

Step 5: Regularly Review and Rebalance Your Portfolio

Finally, regularly review your personal stock portfolio to ensure it aligns with your investment goals. Rebalance as needed, especially if certain stocks have significantly changed in value, to maintain your desired level of diversification. For instance, if a tech stock becomes overly dominant in your portfolio, consider selling part of it and reinvesting in other sectors to maintain balanced diversification.

How to Diversify Your Stock Portfolio

Portfolio diversity is a fundamental strategy for managing risk in your investment portfolio. It’s about finding the perfect balance between all stocks included in your portfolio.

Diversified investment portfolio

Here, we will explore steps to diversify effectively and the benefits each step offers:

Spread Across Different Sectors and Industries

This reduces the risk of your portfolio being adversely affected by downturns in a single sector. By having a mix of sectors, you can balance out the underperformance in one area with the growth in another, stabilizing your portfolio’s overall performance.

Include a Mix of Stock Types

Incorporate different types of stocks – such as growth stocks, value stocks, and dividend-paying stocks. Growth stocks are expected to grow at an above-average rate, while value stocks are usually undervalued in the market. Value stocks offer potential for appreciation and tend to be more resilient during market downturns. Dividend-paying stocks are generally issued by established companies. This variety caters to different aspects of market performance and investor goals. A blend of stock types can optimize your returns across various market conditions, offering both growth potential and income stability.

Why Would It Be A Good Idea To Mix Stocks And Bonds In Your Investment Portfolio?

Mixing stocks and bonds in an investment portfolio is a prudent strategy because it offers a balance between potential returns and risk mitigation. Stocks generally provide the potential for higher returns but come with higher volatility and risk. On the other hand, bonds are considered more conservative, offering lower returns but greater stability and income through interest payments. By combining the two asset classes, investors create a diversified portfolio that aims to optimize risk-adjusted returns.

Consider Market Capitalization

Diversify by market capitalization, including large-cap, mid-cap, and small-cap stocks. The caps represent the total market value of companies and react differently to market changes. This diversification provides a balance between the stability of large-cap stocks and the growth potential of small and mid-cap stocks.

Geographical Diversification

Expand your portfolio to include international stocks or global mutual funds. Different markets often move independently of each other. International exposure can reduce the impact of domestic market volatility and tap into growth opportunities in emerging markets.

Regular Rebalancing 

This might involve selling some stocks that have grown in value and buying more in underrepresented areas. Rebalancing helps keep your portfolio aligned with your original risk profile and investment goals.

How Often Should You Revise Your Stock Portfolio

Experts recommend reviewing your stock portfolio at least annually. However, more frequent reviews, such as quarterly or bi-annually, can be beneficial, especially in volatile markets. During each review, assess if your investments still align with your goals and risk tolerance. Make adjustments as necessary, considering any changes in the market or your financial situation.

Use market dips as opportunities to buy undervalued stocks and trim holdings in overhauled areas during market highs, keeping your diversification strategy in mind. Remember, regular revisions are key to maintaining a portfolio that reflects your current investment objectives and market conditions.

Sum Up

The ideal number of stocks in a portfolio is a balance tailored to your personal financial goals and risk tolerance. Whether you’re navigating between a concentrated portfolio of less than 20 stocks or managing 50 or more, the essence lies in aligning your strategy with your investment objectives. 

Remember, successful investing is not just about selecting stocks; it’s about continuous learning, adapting to market changes, and making informed decisions.

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