Indexy a trhy
Global vs. Domestic Stocks: How Large Is the Home Bias?
Key takeaways
- Home bias is the tendency of investors to overweight stocks from their own country.
- The Czech stock exchange represents a fraction of a percent of global market capitalization — excessive concentration there brings unnecessary risk.
- Global diversification reduces portfolio volatility without having to sacrifice returns.
- It is key to distinguish home bias from a deliberate share of the domestic economy.
- The easiest route to global diversification is All-World or MSCI World ETFs.
Home bias is the tendency of investors to assign disproportionately large weight to stocks from their own country — even when it makes no sense from a diversification standpoint.
How large is home bias in practice?
Globally, US stocks make up roughly 65% of global market capitalization, European stocks about 15%. Yet the average German investor holds more than 40% of their portfolio in German stocks — and the average Czech investor tends to assign a large weight to domestic names or the Central European region, which represents less than half a percent in the global index.
Why home bias hurts
The problem is not patriotism — it is risk concentration. The Czech economy is heavily dependent on manufacturing, the automotive sector, and exports to Germany. When these sectors suffer, the entire local market suffers at once. A globally diversified portfolio responds to such local shocks much less sensitively.
When does a domestic overweight make sense?
There are legitimate reasons for a higher share of domestic assets:
- Income in Czech crowns, expenses in Czech crowns — currency risk is reduced.
- Tax advantages of certain domestic products.
- Better knowledge of specific companies.
A deliberate mild overweight (5–10% of the portfolio) is a different matter from an unconscious excessive concentration. The problem of home bias as one of the key investment mistakes is discussed in more detail in the investment mistake of the month article.
How to correct home bias
The simplest remedy is a global ETF — MSCI World covers developed markets in 23 countries, FTSE All-World adds emerging markets as well. A comparison of both approaches is in the All World vs. S&P 500 analysis. The overall portfolio setup for a beginner is described in the guide on how to build your first portfolio.
FAQ
What is home bias?
The tendency of investors to overly concentrate their portfolio in stocks from their own country. It arises from familiarity with domestic companies, comfort with one's own currency, and psychological proximity.
Does home bias hurt returns?
Yes, if it brings excessive concentration. Small economies (including the Czech one) are less diversified and more volatile than the global market. A global ETF reduces this risk without a significant loss of return.
How can you avoid home bias?
The foundation is a global ETF — MSCI World or FTSE All-World. Domestic stocks then make up only a marginal part of the global index, not the dominant component of the portfolio.