Diversification risks: 6 practical strategies for risk management

Benefits of diversification

Diversification across assets with lower correlations can provide advantages, helping investors manage risk.

Below are some primary benefits:

Broad risk reduction across asset classes

Diversification can reduce the overall impact of underperforming investments by spreading exposure across multiple asset classes. In this way, a single poor-performing asset may have less impact on the overall portfolio. For instance, a diversified portfolio might offset a loss in equities with gains in less-correlated asset classes, such as real estate or fixed-income securities. By addressing unsystematic risk, this approach may add resilience against market-specific shocks.

Steadier returns over time

Balancing investments across different asset classes and industries may help smooth a portfolio’s return path in some conditions. Assets that perform well in one economic condition may offset the weaker performances of others, although this relationship can change. This consistency can be helpful for long-term goals, such as retirement planning.

Access to diverse market opportunities

Exposure to a variety of markets may provide access to different growth opportunities. For example, developed and emerging markets can have different risk and return drivers. Investing across industries like technology and healthcare also captures a broader range of innovations and advancements.

Mitigation of sector-specific risks

Concentrating investments in a single sector, such as energy or real estate, leaves portfolios vulnerable to industry-specific downturns. Diversification spreads investments across different sectors, which may reduce the impact of sector-specific events, such as regulatory changes or technological disruptions.

Improved risk-adjusted returns

Diversification aims to balance risk and reward by combining assets with different risk levels. High-growth equities may contribute to returns, while fixed-income securities may help reduce volatility under certain conditions. For example, pairing volatile growth stocks with government bonds may help smooth portfolio performance in some periods. This balance aims to improve risk-adjusted outcomes, but there is no guarantee of better returns.

Customisation to individual goals

Diversification enables investors to tailor portfolios to their financial objectives and risk tolerance. A younger investor seeking growth might allocate more to equities, while someone nearing retirement could favour bonds and other stable investments. This flexibility aligns portfolios with unique needs and time horizons.

Improved liquidity

Including a variety of asset types can help balance liquid and illiquid investments. Liquid assets, such as exchange-traded funds (ETFs) or cash equivalents, provide flexibility for immediate needs, while illiquid assets, like real estate, contribute to long-term stability. This balance protects investors against liquidity constraints during unexpected market events.

Types of diversification risks

Diversification can have advantages as a risk management strategy. However, it also has limitations when it is not applied carefully. For example, a diversified portfolio can lag a more concentrated portfolio in strong bull markets, and diversification does not prevent losses during market downturns.

For this reason, it’s helpful for you to know about some of the limitations of diversification. Here is a list of some of the main risks:

Systematic risk

Systematic risk, also known as market risk, affects all investments across the financial market and cannot be mitigated through diversification. Events like recessions, geopolitical crises, or changes in interest rates influence all asset classes. For example, during the 2008 financial crisis, even diversified portfolios experienced losses as nearly all asset types declined in value.

Over-diversification risk

Over-diversification occurs when a portfolio includes too many assets, diluting potential returns. Holding excessive investments may lead to overlapping exposures, where similar assets reduce overall diversification benefits. Additionally, managing an overly diversified portfolio increases costs and complexity without proportionally lowering risks or improving returns.

Liquidity risk

Including illiquid investments, such as real estate or private equity, introduces liquidity risks. These assets may be difficult to sell quickly or at fair value during market downturns. A portfolio overly reliant on illiquid investments might struggle to meet short-term needs or adapt to new opportunities.

Correlation risk

Diversification is effective when assets within a portfolio have low or negative correlations, meaning their performance doesn't move in the same direction. If an investor selects assets that are too correlated, such as equities in the same sector or bonds with similar maturities, diversification will fail to reduce risk effectively. For instance, combining large-cap equities with small-cap equities might seem diversified due to differences in company size, but these assets are often highly correlated as they respond similarly to broader domestic economic factors.

Concentration risk

Concentration risk arises when a portfolio is heavily weighted toward a specific sector, asset type, or geographic region. While diversification is designed to address this, incomplete or imbalanced diversification leaves portfolios vulnerable to industry-specific downturns or localised economic challenges. For example, overexposure to technology stocks during the dot-com bubble led to significant losses for investors.

Misjudging asset behaviour

Diversification relies on the accurate assessment of how different assets behave under various market conditions. Misjudging these behaviours, such as assuming assets are uncorrelated when they are not, can undermine the effectiveness of diversification. This risk often arises from relying solely on historical data, which may not predict future performance accurately.

Diversification risk management: Key strategies

Effective diversification requires more than spreading investments across assets. It demands an approach that allows you to balance risks and returns while ensuring your portfolio adapts to changing conditions. Below are 6 key strategies.

1. Understand correlation

Knowing how assets interact is fundamental to diversification. Assets with low or negative correlations—those that move independently or in opposite directions—may offer diversification benefits. For instance, combining equities with bonds may reduce portfolio volatility, as bonds and equities can behave differently, though correlations can change and bonds can also fall in value. Without understanding these relationships, diversification may provide less risk reduction than expected.

2. Optimise asset allocation

A well-diversified portfolio spreads investments across asset classes, industries, and geographies. This approach reduces exposure to any single market or sector.

For example, a balanced portfolio might include:

• Equities. Divided across domestic and international markets.
• Bonds. Including government and corporate fixed-income securities.
• Real estate. Accessible through REITs or direct investments.
• Commodities. Like gold and metals.

Each allocation depends on individual financial goals and risk tolerance. Adjustments may be necessary over time to align with changing economic conditions.

3. Use diversified investment vehicles

ETFs and index funds simplify diversification by offering exposure to a broad range of assets within a single instrument.

For example:

• Index funds. Track markets like the S&P 500 or FTSE 100, offering exposure to a broad set of securities within the relevant index.
• Sector-specific ETFs. Provide diversification within industries, such as technology or healthcare, without relying on individual stocks.

These investments may be useful for retail investors who look for cost-effective ways to diversify without extensive portfolio management.

4. Balance risk tolerance and goals

Risk tolerance plays a critical role in a diversification strategy. Some younger investors with higher risk tolerance may prioritise equities, while some investors closer to retirement may focus more on bonds or dividend-paying stocks. Customising a portfolio can help align it with personal objectives.

For example:

• A 25-year-old saving for long-term growth might allocate heavily to equities.
• A 55-year-old preparing for retirement might prefer bonds and other conservative assets.

5. Regular portfolio rebalancing

Market conditions can change portfolio allocations over time. Regular rebalancing can help restore the intended balance and reduce overexposure to outperforming or underperforming assets. For example, if equities outperform and grow from 50% to 60% of the portfolio, selling some equity holdings to reinvest in bonds or commodities may help realign the portfolio with the original strategy. This discipline can help keep risk exposure closer to the intended level and reduce emotional decision-making.

6. Managing costs, taxes, and behavioral biases

Costs, taxes, and behavioural tendencies can undermine diversification efforts if not managed properly.

• Costs. Frequent rebalancing or switching funds may incur transaction fees and management expenses, which erode returns.
• Tax implications. Selling assets for rebalancing could trigger capital gains taxes depending on jurisdiction and account type, which should be factored into the overall strategy.
• Behavioural biases. Emotional reactions to market changes often lead to poor decisions, such as over-diversifying or abandoning diversification altogether. Developing a disciplined, long-term approach can help you reduce the risk of this behaviour.

Conclusion: Manage the risks of diversification with discipline

Diversification remains a common strategy for managing portfolio risk. However, its effectiveness depends on understanding and mitigating potential risks, such as over-diversification, liquidity challenges, and misjudged correlations.

You may be able to improve portfolio discipline and risk management by adopting strategies such as regular rebalancing and aligning investments with your financial goals. A disciplined approach can help diversification remain a useful tool for managing risk, but it does not guarantee stronger long-term returns.