La diversification comme clé pour minimiser les risques dans le portefeuille

Reading Time: 10 minutes

En tant qu’investisseur, vous êtes constamment confronté au défi d’exploiter les opportunités de rendement tout en réduisant les risques. La diversification du portefeuille, souvent citée, en est un élément crucial. Cela signifie que, au lieu de mettre tous leurs œufs dans le même panier, les investisseurs investissent dans une gamme de produits financiers et de classes d’actifs différents. Cela leur permet de répartir leurs chances de succès sur plusieurs piliers et d’obtenir un résultat stable à long terme.

Maîtriser la diversification est crucial pour optimiser la performance et la résilience d’un portefeuille. Cette stratégie permet de compenser les développements risqués ou temporairement négatifs de certains investissements.

Traduit, la diversification signifie « variété ». Mais comment mettre en œuvre la diversité nécessaire dans l’allocation de capital ? Pour ce faire, il est essentiel de se renseigner sur les différentes formes, telles que les classes d’actifs ou les régions. Cet article vous donnera un aperçu initial.

Les faits essentiels en résumé

• La diversification signifie utiliser la variété pour réduire les risques d’investissement.
• Répartir les risques est essentiel pour les investisseurs institutionnels et privés.
• Diversification des actions : exploiter les opportunités avec un risque acceptable.
• Les exigences personnelles déterminent la stratégie de diversification.
• Les ETF permettent une diversification simple et rentable.

Diversification : définition, explication et exemple

Le proverbe bien connu conseille de ne pas mettre tous ses œufs dans le même panier, soulignant ainsi l’importance de répartir les risques. Ce concept est couramment appelé diversification dans le secteur financier. Les recherches et la littérature soulignent régulièrement l’importance d’une allocation d’actifs diversifiée – répartir les investissements entre différentes classes d’actifs. Cela est crucial pour optimiser la dynamique risque-rendement et atteindre un succès d’investissement durable.

L’objectif principal de la diversification est de réduire le risque en répartissant les investissements sur différents instruments. Cela réduit l’impact des évolutions défavorables dans un seul investissement. Ce principe de base repose sur l’idée que différents actifs présentent souvent des mouvements de prix différents et non corrélés. Cela s’applique également au sein des classes d’actifs individuelles. La diversification dans les actions, par exemple, conduit à un ratio risque/rendement équilibré.

La corrélation est donc au cœur de la diversification. Elle indique la manière dont les rendements de différents actifs ou classes d’actifs sont liés entre eux. Une corrélation positive indique que les rendements évoluent simultanément dans la même direction, tandis qu’une corrélation négative indique des mouvements opposés. Un portefeuille avec des corrélations faibles entre les investissements individuels offre une plus grande diversification et donc un risque plus faible.

Diversification de portefeuille et le prix Nobel

En 1952, l’économiste américain Harry Markowitz a présenté sa théorie du portefeuille, dans laquelle il exposait la justification scientifique et la quantification de la diversification des risques dans les investissements.

Il a déterminé les titres et leur proportion nécessaires pour un portefeuille optimal afin de minimiser le risque sans compromettre le rendement attendu. Le scientifique a pris en compte les préférences des investisseurs en matière de risque, de rendement et de liquidité.

Markowitz a reçu le prix Nobel d’économie en 1990 pour ce travail.

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Risk management is vital for both institutional and private investors

Diversification serves as protection against the unpredictability and volatility of the financial markets. By spreading investments across different asset classes, such as equities, bonds, real estate and commodities, investors can spread risk and minimize the impact of adverse market movements on their overall portfolio.

Diversification is also a powerful tool for optimizing risk-adjusted returns. By diversifying the portfolio, investors can potentially achieve a more favorable balance between risk and return, which optimizes the overall performance of their portfolios. This risk management approach is a cornerstone of a sound long-term investment strategy.

Diversification is not limited to a specific group of investors. The principles of diversification apply from individual investors seeking to build a secure financial future to institutional investors managing large portfolios.

• Retail investors, especially those with long-term financial goals, can benefit significantly from the protective shield of diversification. By diversifying their investments, individuals can navigate the volatility of financial markets with greater confidence. They know that their portfolios are protected against unforeseen market downturns.
• Institutional investors, such as pension funds, foundations and asset management companies, use diversification to protect the financial interests of their stakeholders. Finally, the size of institutional portfolios requires careful risk management and makes diversification an indispensable tool.

Reading tip: Investing in volatile markets: Risk strategies for investors

Portfolio diversification vs. cluster risks: These are the scenarios

To illustrate the differences between a diversified portfolio and a portfolio with bulk risk, two hypothetical investment portfolios are compared below.

Two investors have assets of CHF 500,000 and are invested in the financial market as follows:

• Investor A: The portfolio is focused on technology stocks within one geographical region.
• Investor B: The investments are spread across various asset classes (equities, bonds and commodities) and various sectors and are geographically diversified.

The potential differences in performance and risk exposure between these two portfolios are significant.

While a diversified portfolio may generate more stable and consistent returns due to its exposure to different areas of the market, a pooled portfolio may face increased volatility and potential losses if the concentrated sector or region experiences a downturn.

The following scenarios are hypothetical. However, they illustrate the different impacts.

• Scenario 1 – negative market development: In a scenario where the market plummets by 30 percent, Portfolio B’s diversified holdings can mitigate the impact, resulting in a value decline of only 10 percent. Portfolio A, on the other hand, which is subject to cluster risk, could suffer a 35% decline, highlighting the increased vulnerability of concentrated portfolios in unfavorable market conditions.
• Scenario 2 – normal market development: If the market as a whole rises by 5 percent, the diversified portfolio A can record an increase in value of 3 percent and thus benefit from the general market upswing. In contrast, Portfolio A’s concentrated exposure could lead to a 7% increase in value, boosted by the positive performance of the specific sector in which it is heavily invested.
• Scenario 3 – positive performance: If the market generally rises by 15 percent, Portfolio B’s diversified approach can lead to an 8 percent increase in value as it absorbs the general market growth. In contrast, Portfolio A’s concentration can achieve a substantial 20% increase in value as it benefits from the strong performance of its focus sector.

Understanding the opportunities and risks associated with both portfolio strategies is of paramount importance. A diversified portfolio offers stability and the potential for consistent returns. However, it can limit opportunities in the event of exceptional performance in a particular sector or region.

On the other hand, a concentrated portfolio offers the opportunity for substantial gains if the specific focus area experiences exceptional growth. However, it carries the risk of significant losses if that sector or region faces challenges.

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Types of diversification in the portfolio

There are different types of diversification that investors can implement in their portfolio. These types differ in the way in which the portfolio is diversified.

First of all, diversification can be divided into three areas:

• Horizontal diversification: horizontal diversification refers to spreading the portfolio within an asset class. This means that investors invest their money in different securities within the same asset class. For example, within equity diversification, an investor can invest in shares of companies from different industries to minimize risk.
• Vertical diversification: Vertical diversification refers to spreading the portfolio across different asset classes. Investors can invest their money in different asset classes such as equities, bonds, commodities or real estate. The risk is reduced as the different asset classes usually perform differently.
• Geographical diversification: This refers to the distribution of investments across different countries. Investors invest their money in companies from different countries in order to minimize risk. In this way, they can benefit from economic developments in different countries and offset risks arising from economic problems in certain countries.

Diversification by asset class

Spreading assets across different asset classes is one of the key instruments of risk management.

The main asset classes are

• Equities: With equities, investors invest in companies. They can be divided into different categories, such as growth stocks, dividend stocks or blue chip stocks. Experience has shown that investors achieve higher returns with equities than with fixed-interest securities, although this is associated with higher risks.
• Bonds: These are debt instruments issued by governments, companies or other organizations. Investors receive regular interest payments and the capital is repaid at the end of the term. Bonds are generally less risky than shares, but offer lower returns in the long term.
• Real estate: Real estate is considered to be quite stable in value. As the investments are more difficult to liquidate, investors should already have a certain amount of financial assets before committing to real estate for a longer period of time. In addition to buying your own home, investments in REITs (real estate investment trusts) or real estate funds are a good option.
• Commodities: These include gold, silver, oil and agricultural commodities. Commodities can serve as a hedge against inflation and currency fluctuations, as their value is generally independent of the equity and bond markets.
• Alternative investments: These include hedge funds, private equity funds, works of art, collector’s items and other alternative forms of investment.

Industry and sector diversification

Sector diversification is used to offset negative developments in specific sectors.

Well-known sectors are

• Technology
• Healthcare
• Energy
• Financials
• Consumer goods
• Industry

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Risk diversification depending on investment strategy and investment horizon

In order to determine a suitable investment strategy, the investment horizon and individual risk tolerance are decisive.

• Defensive: The focus here is on preserving value or generating a secure income. This conservative strategy is aimed at investments such as fixed-interest securities or fixed-term deposits. The investment horizon tends to be short.
• Balanced: The strategy includes a balanced mix of fixed-income securities and a small proportion of high-yield investments such as equities. The aim: capital growth with manageable risk.
• Growth: The strategy is usually accompanied by a predominantly equity component. The focus is on high returns, for which higher risks are also taken.

Diversification within the asset class

Within an asset class, differentiated parameters must be taken into account for meaningful diversification. This is explained in the next two sections for the important asset classes equities and bonds.

Equities: volatility and correlation

Volatility is the standard deviation of price movements. Even a portfolio that only contains equities with high volatility can be less risky overall. This is because, with the right mix, some shares can fall sharply on one day while others rise in price. This means that a portfolio with relatively high-risk investments can increase returns and offset the risk taken with low-risk stocks.

The correlation coefficient is decisive for the relationship between securities. It ranges between -1 and 1. A correlation coefficient of -1 means that the shares move in exactly the opposite direction, with one share falling while the second rises to the same extent. A value of 1 shows that the shares behave identically and have an identical return pattern. This high correlation between the shares implies similar behavior in their movements. A value of 0 means that there is no linear correlation at all.

Shares within a sector generally have a very high correlation as they behave similarly due to their dependence on the sector. Diversification can mitigate this dependency and reduce risk by selecting stocks with a lower correlation.

Bonds: issuer risk

In the supposedly safe asset class, the risk is primarily the default of the debtor. Diversification here can mean investing in government bonds from countries with good ratings and, at the same time, increasing returns with higher risk by investing in corporate bonds.

Implement diversification simply and cheaply: ETFs

Investing individually in shares and bonds can be both time-consuming and costly. Fund companies take over this process. An equity fund that combines the largest companies in industrialized countries is a good starting point for many. ETFs that track established share indices, which in turn reflect the economic performance of a country, region or sector, are particularly cost-effective. An ETF portfolio thus enables simple and cost-effective diversification for a wide range of investors.

Reading tip: The most important Swiss equity indices at a glance

Risk minimization: opportunities and limits

Past experience has shown that in times of high market volatility, effective diversification protects portfolios from significant downturns. Asset allocation strategies tailored to clients’ risk tolerance and investment objectives have led to sustainable returns even in a difficult economic environment.

However, the principle that risk and return are fundamentally interdependent also applies here. If you try to compensate for every supposed risk, you will end up with no return. Investors must therefore be aware that systematic risk in particular can never be completely ruled out.

Systematic vs. unsystematic risk

Diversification is a powerful tool for minimizing risk. Nevertheless, there are clear limits, especially in connection with systematic and unsystematic risk. Systematic risk, also known as market risk, relates to the overall market or economy and cannot be « diversified away ». On the other hand, unsystematic risk, also known as specific risk, can be mitigated by diversification in relation to individual assets or sectors. In the case of shares, for example, this risk consists of the factors that influence the management of a company.

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Implementing diversification strategies: Practical implementation

The diversification of a portfolio can only succeed if the investment strategy has been determined. This essentially depends on the investment horizon and personal risk appetite. This results in a sensible equity allocation, which should be in the context of age, assets and income.

When selecting asset classes, the main focus is initially on equities, bonds, commodities and, where appropriate, real estate. When choosing, it is advisable to invest in different sectors and regions. Exchange-traded funds give private investors very simple and cost-effective access to various asset classes and provide diversification at the same time.

Those who invest directly in individual securities take correlation and volatility into account when making their selection. A correlation analysis helps to understand the dependencies between the individual investments. Historical data is used to calculate the correlations. Suitable investments with a low correlation can be selected on the basis of this information.

Conclusion: All investors benefit from the power of diversification

In times of uncertainty and market volatility, diversification is more important than ever, even if it is increasingly challenging.

In these market conditions, it is necessary to expand into additional asset classes such as commodities, currencies, gold and digital assets. Implementing strategies that respond to market trends and market changes are added to this. The good news is that access to these options is no longer limited to large institutional investors. Innovative digital wealth advisory services enable a wide range of investors to act professionally. It is therefore important to focus on diversification, gather comprehensive information and seek expert advice where necessary.