Where do you invest your money? For most people, the answer is: mostly in their own country’s stock market. This is called home bias — and it is one of the most persistent and costly mistakes in individual investing. The global stock market offers far more than any single country, and accessing it has never been easier or cheaper.
The Home Bias Problem
Despite the fact that the US represents about 60% of global market capitalization and Germany roughly 3%, many German investors hold portfolios that are 50-70% German stocks. Similar patterns exist in every country — UK investors are overweight UK equities, French investors in French equities, and so on.
This is irrational from a risk-management perspective. Your employment, housing value, and career are already highly correlated with your home country’s economy. Concentrating your investment portfolio in the same country doubles down on that existing exposure rather than hedging it.
The Case for Global Diversification
Different Countries Outperform in Different Periods
No single country dominates stock returns over all periods. The US was the best-performing major market of the 2010s; Japan led the 1980s; Europe outperformed the US in the 2000s; emerging markets had periods of spectacular returns. A globally diversified portfolio always holds the leader — whoever it turns out to be.
Reduced Country-Specific Risk
Every country faces unique risks: political instability, natural disasters, regulatory changes, currency crises, or sector-specific downturns (imagine having your entire portfolio in UK equities in 2016 when Brexit uncertainty hit, or in German manufacturing stocks during the 2020s energy crisis). Global diversification insulates you from any single country’s problems.
Access to More Sectors and Companies
Some industries are poorly represented in any single country’s market. Tech giants are concentrated in the US. Luxury brands are concentrated in France and Italy. Mining companies in Australia. Pharmaceuticals span multiple continents. Only global investing gives you proportional exposure to the full range of human economic activity.
The Growth of Emerging Markets
Over 80% of the world’s population lives outside developed markets. China, India, Brazil, Indonesia, and other emerging economies are growing faster than developed world economies. Their stock markets — while more volatile — offer exposure to long-term structural economic growth that developed markets cannot replicate.
What Does the Data Show?
Academic research consistently shows that globally diversified portfolios achieve equivalent or better returns with lower volatility than concentrated home-country portfolios. The correlation between different countries’ stock markets, while not zero, is low enough that diversification provides genuine risk reduction.
The MSCI World Index (23 developed countries) and MSCI ACWI (developed + emerging markets) have delivered compelling long-term returns while diversifying single-country risk substantially.
Currency Risk: The Main Concern
International investing introduces currency risk — the value of your investments changes based on exchange rate movements as well as local market returns. A US stock that rises 10% in USD terms might deliver only 5% if the USD weakens against the EUR.
However, over long periods, currency risk is a double-edged sword that can work in your favor as well as against you. Research suggests that for equity investments held over 10+ years, currency effects wash out significantly. For most equity investors, currency hedging is not necessary or even beneficial over long periods.
For bond investments, currency hedging is more important since bond returns are smaller and currency fluctuations can overwhelm them entirely. Many European-focused bond ETFs offer EUR-hedged share classes.
How to Implement Global Diversification
The simplest approach: a single global ETF.
- MSCI World ETF — 1,500+ companies in 23 developed markets. Simple and sufficient for most investors.
- MSCI ACWI ETF — adds emerging markets (~10-15% of weight) to the developed market coverage above.
- FTSE All-World ETF (Vanguard) — developed + emerging markets in a single fund, one of the most popular choices for passive investors.
A more detailed approach might combine:
- MSCI World (70%) — developed market core
- MSCI Emerging Markets (15%) — developing world exposure
- MSCI Europe (10%) — modest home-region tilt without dramatic home bias
- MSCI Small Cap World (5%) — size diversification
How Much Home Bias Is Acceptable?
A modest home country tilt (5-15%) can make sense for tax and currency reasons — if your spending is in euros, holding some euro-denominated assets reduces currency uncertainty. But dramatic home bias (50%+ in your home market when it represents 2-5% of global market cap) is hard to justify on financial grounds and introduces unnecessary risk.
Think globally. The world’s economy is your opportunity. A simple, low-cost, globally diversified portfolio captures its growth — wherever it comes from.