Geldanlage: „Auch eine Rentnerin kann 100 Prozent Aktien vertragen“

Many people find investing in stocks and bonds so complicated that they never even start. According to the Deutsche Aktieninstitut, only about one in six German citizens own stocks either directly or through funds. However, financial expert Martin Weber believes this fear is unfounded and can actually backfire. Weber, who has studied investor behavior for decades, offers tips on building investment portfolios for both beginners and experienced investors.

Weber asks: Can anyone create their own investment portfolio? It depends on what one wants and how much background knowledge they have. The most important thing is to invest at all. Many people feel a certain threshold anxiety about putting their money on the capital market. A good bank advisor who doesn't just push their bank's products is a challenge, but financial advisors who charge a fee may be a better choice because they advise more independently.

Furthermore, research shows that talking to friends and acquaintances can be very helpful in understanding the basics of investing and possibly getting some tips. If you want a simple investment, a portfolio with two-thirds stocks and one-third bonds could be a good starting point. More than that is unnecessary. Such a combination may be sufficient at first.

If someone wants to add commodities or real estate, it becomes more complicated, requiring more specialized knowledge and time, which many people don't have or don't want to invest. The two-thirds stocks and one-third bonds combination can seem quite aggressive to some. This brings us to a central question we haven't answered yet: how to determine investment goals.

A 30-year-old who wants to buy a sports car in 10 years will invest differently than a retiree saving for grandchildren. The time one has for investing determines how much risk they can take. So rules like "assets minus age" are useless? Not necessarily. If the goal is to save for oneself and spend the money until death, this rule can be useful.

So-called life cycle funds, which are very popular in the US, do exactly that. Ultimately, the assets percentage should depend on one's risk tolerance, which depends on how long one plans to invest and whether they feel comfortable with the portfolio. If the thought of fluctuating prices causes anxiety, one should have fewer stocks than someone who can handle market volatility.

There are many professional investors with very few different assets in their portfolios. Charlie Munger, Warren Buffett's deceased investment partner, reportedly only had three positions in his portfolio. On the other hand, professionals like Weber recommend maximum diversification. Who is right? Both. If you are absolutely convinced of a single stock and have an informational advantage about the company, you can buy it and make it a central part of your portfolio.

Ultimately, it's about having better information than the rest of the market participants. But most of us, including most fund managers, don't have this information. Therefore, it is wiser to spread the invested money as broadly as possible. Is a US-focused stock index fund enough? No, because while you invest in US stocks, the MSCI World index also includes emerging markets, which have underperformed for the past ten years.

This might be true, but did you bet in 2015 that things would turn out this way? Not really. The problem is we have two perspectives: ex post, after the fact, we all seem clever and know which stocks and markets performed well and which didn't. But ex ante, before the fact, we were all equally foolish and didn't know who would end up winning.

This means it's pointless to look for the best funds or stocks? I would say the opposite: it's enough to invest in the market. This way, you can build wealth over the long term without much stress. Stress is a good word to describe the situation. There was a significant market crash at the beginning of April 2025 that frightened many investors.

What should they do in such a situation? It depends on their investment goal. If they need the money in 20 or 30 years, they can accept such price fluctuations without getting too stressed. To feel more at ease, it helps if they keep their strategy in mind and stick to it. This means not getting worked up and selling stocks just because others are selling.

What about diversification? Is there a limit to how broad one should go? Unless you're the Norwegian state fund, diversifying into stocks, bonds, or term deposits is enough. For stocks, it's important to include both established markets and emerging markets through ETFs. Adding more ETFs is not necessary.