One world. Hundreds of markets. One decision.
A quick story
Imagine two investors.
One decides to invest every euro in America.
The other buys the global market.
Twenty years later, neither remembers which country was leading when they started.
They only remember one thing:
They stayed invested.
That raises an important question.
Should you concentrate on the world's largest economy — or own businesses wherever tomorrow's winners emerge?
Why this matters
This decision isn't really America vs. the world. It's a decision about how much concentration risk you're comfortable accepting.
Concentrating in one country has produced remarkable returns in some decades — and painful losses in others. Owning the world smooths that ride, at the cost of never being fully invested in whichever country happens to be leading.
Understanding the trade-off is what allows you to build a portfolio you can confidently hold — through booms, corrections, and the long stretches in between.
Why do so many investors choose the S&P 500?
The S&P 500 tracks roughly 500 of the largest companies listed in the United States.
Although these companies are based in America, many of them earn a significant share of their revenue globally — which is part of why the index has become a default choice for so many investors.
- 1United States
- 2500 largest companies
- 3Global customers
Where the world's equity actually lives.
A single 100% bar — divided by how the world's investable stock market is weighted today. The United States dominates, but it isn't the whole picture.
Approximate weights, MSCI ACWI Index. Last reviewed: June 2025. Index weights change continuously as markets move; check the latest MSCI factsheet for current figures. Global ETFs generally follow market capitalisation rather than investing equally across countries.
Owning the world doesn't mean avoiding America.
Most global ETFs already invest more than half of their assets in U.S. companies because they follow global market capitalisation.
Why it matters: Choosing a global ETF is often about adding diversification — not reducing America's importance.
Has America always been the best investment?
No.
Different countries have led global markets during different decades.
Japanese equities dominated the world stage — until the bubble burst and a lost decade followed.
European markets surged on the run-up to the euro, before ceding leadership in the 2000s.
China, Brazil and other emerging markets led global returns as commodities boomed.
American technology giants have driven a long stretch of U.S. outperformance — the longest in modern memory.
Every generation believes today's leader will remain on top. History repeatedly suggests otherwise.
Three reasonable approaches
There is no single correct answer here — just different investing philosophies, each reflecting a different view of concentration, humility, and long-term returns.
100% S&P 500
Conviction in America
- Simple, one-line portfolio
- Concentrated in a single country
- Historically strong long-term returns
100% Global ETF
Own the world as it is
- Broad market exposure by default
- Already includes a majority U.S. weight
- No need to predict future leaders
Combination
Global core + U.S. tilt
- Extra emphasis on the U.S.
- Keeps global ownership as a base
- Adjustable to your conviction
For many European investors, a global ETF is a practical starting point.
A global ETF already includes substantial exposure to the United States while reducing reliance on any single country.
The goal isn't to predict which country will outperform. It's to build a portfolio that can benefit regardless of which country leads next.
Home bias is one of the world's most common investing mistakes.
Investors everywhere tend to invest disproportionately in their own country — even when that country represents only a small share of the global market.
Why it matters: Diversification often means investing beyond what feels familiar.
Myth: You must choose between America and the world.
Reality: A global ETF already owns America. It simply owns much more alongside it.
You don't have to predict tomorrow's winning country — you can simply own the world.
Key takeaways
- The S&P 500 invests only in U.S.-listed companies.
- Global ETFs invest across many developed and emerging markets.
- As of mid-2025, the United States represents roughly 63% of global equity indices such as MSCI ACWI — a figure that changes as markets move.
- No country outperforms forever — leadership rotates across generations.
- Broad market exposure reduces reliance on any single country's future.
Which portfolio feels most comfortable to you?
There's no wrong answer — the goal is to understand the trade-offs behind each choice.
Test what you've learned
Three quick questions. Answers and explanations appear instantly.
Q1. What does a global ETF typically invest in?
Q2. As of mid-2025, approximately what share of the global stock market is U.S. companies?
Q3. True or false: A global ETF completely avoids investing in the United States.
Answered 0 of 3.
Grounded in landmark research.
This lesson draws on landmark academic research and evidence that has shaped modern investing.
The future's best-performing country is almost impossible to predict — so build a portfolio that doesn't depend on the prediction.
Broad global ownership is not a bet against America. It's an acknowledgement that markets rotate, and that European investors are best served by portfolios designed to endure across generations — not to time a single decade.
Last reviewed: July 2026
Explore the primary sources behind this lesson.
Lesson-specific sources: original research, regulatory texts, or index methodology — chosen to let you verify the claims in this lesson.
Dimson, Marsh & Staunton — UBS Global Investment Returns Yearbook
Long-run (120+ years) country return data used throughout this lesson.
UBS / London Business School
MSCI ACWI Index Methodology
Rules that determine country and stock weights in the global equity index.
MSCI
S&P Dow Jones — SPIVA Europe Scorecard
Regional evidence on active vs. index performance for European investors.
S&P Dow Jones Indices
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The next great investment opportunity may come from a country nobody expects today.
A global portfolio gives you the chance to own it before anyone knows its name.
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