Why Shouldn’t You Put All Your Money in One Investment?

Imagine investing all your money in one company because its products are popular and its share price has been rising.

Then the company reports weak results, loses a major customer or faces a regulatory investigation. Its share price falls sharply, and your entire portfolio falls with it.

No one can predict every problem a company, industry or market may face. Diversification helps you prepare for that uncertainty by spreading your money across different investments.

It cannot prevent every loss, but it can reduce the damage caused by one investment performing badly.

What is diversification?

Diversification means spreading your money across several investments instead of depending on only one.

The basic idea is simple. If one investment falls, other investments may remain stable or rise, reducing the effect on your overall portfolio.

Suppose you invest $10,000 in one company and its share price falls by 40%.

Your investment would lose $4,000.

Now imagine that the same $10,000 is divided equally across ten companies. If one company falls by 40% while the others remain unchanged, the loss from that company would be $400.

The result would still be a loss, but its effect on the total portfolio would be smaller.

This is the main purpose of diversification. It reduces your dependence on a single outcome.

What is concentration risk?

Concentration risk occurs when too much of your money depends on one investment or one source of risk.

You may have concentration risk if most of your portfolio is invested in:

• One company
• One industry
• One country
• One type of asset
• One currency
• Several funds holding the same investments

Concentration can sometimes happen without an investor noticing.

For example, you may own shares in several technology companies and also invest in a technology ETF. Although you hold several investments, much of your portfolio still depends on the performance of one industry.

You may also own two broad ETFs that contain many of the same large companies. The names of the funds are different, but their largest holdings may be almost identical.

Counting the number of investments is not enough. You need to understand what each one contains and which risks affect it.

Diversify across companies

Owning shares in several companies can reduce company-specific risk.

Company-specific risks include:

• Weak financial results
• Loss of an important customer
• A failed product
• Management problems
• High debt
• Legal or regulatory action
• Operational disruption

If one company faces a serious problem, other companies in the portfolio may not be affected in the same way.

However, simply buying more companies does not always provide meaningful diversification.

Five companies that sell similar products in the same market may respond to the same economic conditions. A regulatory change affecting their industry could push all five stocks lower at the same time.

Look for differences in how the companies earn money, who their customers are and what risks they face.

Diversify across industries

Different industries may perform differently under the same economic conditions.

For example:

• Higher oil prices may benefit some energy companies but increase costs for airlines
• Higher interest rates may affect property companies differently from banks
• Weak consumer spending may hurt retailers more than healthcare providers
• New technology may support one industry while disrupting another

Spreading investments across industries can reduce the risk that one sector-wide problem affects your entire portfolio.

This does not mean every industry must be included. It means avoiding excessive dependence on one area simply because it has recently performed well or feels familiar.

Diversify across countries and currencies

Companies operating in different countries may face different economic, political and regulatory conditions.

International diversification can give investors exposure to several markets rather than relying only on the economy of one country.

It may also provide access to industries that are not strongly represented in the investor’s home market.

However, international investing introduces other risks, including:

• Currency movements
• Political changes
• Different regulations
• Tax rules
• Lower market liquidity
• Different financial reporting standards

International diversification spreads some risks, but it also creates new ones. Investors should understand both sides before investing.

Diversify across asset types

Diversification can also involve holding different types of assets.

A portfolio might contain:

• Stocks for potential long-term growth
• ETFs for broader market exposure
• Sukuk for periodic income
• Gold for additional diversification
• REITs for exposure to income-producing real estate
• Shariah-compliant savings for short-term needs and greater stability

These assets do not always respond to market events in the same way.

For example, stock prices may fall during a period of economic uncertainty, while gold may behave differently. Savings products may remain more stable, although they may offer lower long-term growth potential.

The appropriate mix depends on your goals, time horizon, need for income and ability to accept risk.

Diversification does not require owning every available asset. Each investment should have a clear purpose within the portfolio.

How can ETFs help?

A broad ETF can provide exposure to many companies through one investment.

Instead of researching and buying dozens of individual stocks, an investor may use an ETF that follows a broad market index.

This can make diversification easier, but not every ETF is broadly diversified.

An ETF may focus on:

• One company
• One industry
• One country
• A small group of companies
• A narrow investment theme

A technology ETF containing 30 companies still depends heavily on the technology industry. A single-stock ETF does not provide diversification because it follows only one company.

Before buying an ETF, review:

• Its investment objective
• Its largest holdings
• The number of investments it contains
• Its industry and country exposure
• Its fees
• Its Shariah screening methodology

Do not assume that an ETF is diversified or Shariah-compliant based only on its name.

What is correlation?

Correlation describes how closely two investments move in relation to each other.

Investments with high positive correlation often rise and fall together. Holding several highly correlated investments may provide less diversification than expected.

For example, two funds may have different names but hold many of the same large stocks. Their performance may therefore be very similar.

Investments with lower correlation may respond differently to the same market event. Combining them can help reduce fluctuations across the portfolio.

You do not need to calculate correlation yourself to understand the basic idea. Ask whether your investments depend on the same companies, industries, regions or economic conditions.

If the answer is yes, your portfolio may be more concentrated than it appears.

Diversification does not remove all risk

Diversification has limits.

It can reduce the risk connected to one company, industry or asset, but it cannot protect a portfolio from every market decline.

During a major financial or economic crisis, many investments may fall at the same time. Even a diversified portfolio can lose value.

Diversification also does not:

• Guarantee a profit
• Prevent short-term losses
• Make a risky investment safe
• Replace research
• Remove the need to monitor your portfolio
• Make a non-compliant investment Shariah-compliant

Its purpose is to manage risk, not eliminate it.

Can you diversify too much?

Owning more investments is not always better.

If you hold too many investments, your portfolio may become difficult to understand and monitor. You may also own several funds with overlapping holdings or pay unnecessary fees.

For example, buying four ETFs that follow similar large US companies may add complexity without providing much additional diversification.

The goal is not to collect the largest possible number of investments. It is to spread your money across investments with different sources of return and risk.

A simpler portfolio can still be well diversified if each holding serves a clear purpose.

Keep your portfolio balanced

Your portfolio can become more concentrated over time.

Suppose you originally invest:

• 60% in stocks
• 20% in sukuk
• 10% in gold
• 10% in savings

If stocks perform strongly, they may eventually represent 75% of your portfolio. You would then have more stock exposure than you originally planned.

Rebalancing means adjusting your holdings to move the portfolio closer to your intended mix.

This may involve:

• Directing new contributions to underrepresented assets
• Selling part of an investment that has become too large
• Buying more of another asset
• Reviewing overlapping funds
• Removing investments that no longer match your goals

Rebalancing does not require reacting to every market movement. Many investors review their portfolios at set intervals or when the allocation moves significantly away from their plan.

Before selling, consider any fees, taxes or restrictions that may apply.

Diversification and Shariah compliance

Diversification should take place within a Shariah-compliant investment universe.

Buying a non-compliant stock does not become permissible simply because it represents a small part of a diversified portfolio.

Each stock, ETF, REIT, sukuk or other investment should be reviewed according to the relevant Shariah requirements.

Compliance can also change. A company may change its business activities or financial ratios, while an ETF may update its holdings.

Regular monitoring helps ensure that the portfolio remains both diversified and aligned with your Shariah requirements.

Build diversification around your goals

Imagine two investors.

The first is investing for a goal 20 years away and can accept significant short-term changes in value. Their portfolio may contain a larger allocation to diversified stocks and stock ETFs.

The second expects to use the money within two years. A portfolio dominated by stocks may expose that investor to losses shortly before the money is needed. They may prefer to hold more in suitable short-term savings or lower-volatility assets.

Diversification is not the same for everyone.

Your investment mix should reflect:

• Your financial goal
• Your time horizon
• Your ability to accept losses
• Your need for regular income
• Your need to access the money
• Your knowledge of each investment
• Your Shariah requirements

The purpose is to avoid allowing one company, industry or market event to determine your entire financial outcome.

Quiz

Question 1

An investor owns five technology stocks and a technology ETF. What is the main concern?

• A. The portfolio may still be concentrated in one industry
• B. ETFs cannot hold technology stocks
• C. Owning six investments guarantees diversification

Correct answer: A

Several investments can still depend on the same industry. A problem affecting technology companies could cause many of the holdings to fall together.

Question 2

What is the main purpose of diversification?

• A. To guarantee that a portfolio will never lose money
• B. To reduce dependence on one investment or source of risk
• C. To identify the stock with the highest possible return

Correct answer: B

Diversification spreads risk across different investments. It cannot guarantee a profit or prevent every market loss.

Question 3

A portfolio was originally 60% stocks, but stocks have grown to represent 75%. What may help restore the intended mix?

• A. Concentration
• B. Rebalancing
• C. Buying more of the same stocks

Correct answer: B

Rebalancing involves adjusting the holdings to bring the portfolio closer to its planned allocation.

Sources

• https://www.investor.gov/introduction-investing/investing-basics/save-and-invest/diversify-your-investments
• https://www.investor.gov/additional-resources/general-resources/publications-research/info-sheets/beginners-guide-asset
• https://www.investor.gov/additional-resources/information/youth/teachers-classroom-resources/what-diversification
• https://www.investor.gov/introduction-investing/general-resources/news-alerts/alerts-bulletins/investor-alerts/WorldInvestorWeek2023
• https://www.finra.org/investors/insights/concentration-risk
• https://www.finra.org/investors/insights/active-passive-investing
• https://www.finra.org/investors/insights/love-your-company-stock-what-to-know
• https://www.investor.gov/introduction-investing/investing-basics/investment-products/mutual-funds-and-exchange-traded-2
• https://www.investor.gov/introduction-investing/investing-basics/glossary/single-stock-etfs

Frequently asked questions

What is the main purpose of diversification?

Diversification spreads your money across different investments to reduce dependence on one investment or source of risk. It can reduce the damage caused by one investment performing badly, but it cannot guarantee a profit or prevent every loss.

Can a portfolio with several investments still be concentrated?

Yes. Several investments may depend on the same industry, companies or economic conditions. For example, technology stocks and a technology ETF may leave much of your portfolio dependent on one industry.

Do all ETFs provide broad diversification?

No. An ETF may focus on one company, one industry, one country, a small group of companies or a narrow investment theme. Review its objective, holdings, industry and country exposure, fees and Shariah screening methodology before buying.

How does rebalancing help a portfolio?

Rebalancing adjusts your holdings to move the portfolio closer to its intended mix. It may involve directing new contributions to underrepresented assets, selling part of an investment that has become too large or buying more of another asset.

Does diversification make a non-compliant investment Shariah-compliant?

No. Every investment must meet the relevant Shariah requirements individually. Compliance can also change as companies change their activities or financial ratios and ETFs update their holdings, so regular monitoring is important.

Related terms

• Halal Investing