International vs Domestic Equity Split
International vs Domestic Equity Split
Most investors hold too few international stocks, a bias known as "home bias." International equities represent 40–50% of global market capitalization. Holding 30–50% of your stock allocation in international funds captures global growth and diversifies away from domestic economic concentration.
Key takeaways
- Home bias: investors hold excess domestic stocks and too few international stocks relative to market weights
- Global market cap is roughly 55% U.S., 45% international; most U.S. investors hold 80–90% domestic, 10–20% international
- A market-weight allocation (57/43 U.S./international) is objective; some prefer 60/40 or 70/30 for simplicity
- International diversification reduces dependence on U.S. economic performance and captures growth in Europe, Asia, and emerging markets
- Currency risk is real but diversifies away over decades; choosing a currency-hedged vs. unhedged fund is a secondary decision
The Home Bias Problem
A remarkable phenomenon in investing: most investors hold far more stocks from their home country than global market weights suggest is optimal. An American investor holds 80–90% U.S. stocks, despite the U.S. representing only 55–60% of global market value. A German investor holds 60–70% European stocks, despite Europe being 20–25% of global value.
This home bias is irrational. It concentrates risk in a single economy. It also causes investors to systematically underweight the world's fastest-growing economies (historically Asia and emerging markets).
Why does home bias persist? Several reasons:
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Familiarity: Investors know U.S. companies (Apple, Microsoft, Tesla) and feel comfortable with them. International companies are less familiar.
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Currency risk perception: Foreign stocks are priced in foreign currencies, which fluctuate. This adds complexity and perceived risk.
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Convenience: Until the 1990s, accessing foreign stocks was difficult and expensive. The habit persists.
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Valuation cycles: Sometimes U.S. stocks are genuinely cheaper than international stocks, justifying overweight. But investors extrapolate, holding U.S. overweight indefinitely.
Global Market Capitalization Weights
As of 2024, the global stock market is roughly:
| Region | Percentage |
|---|---|
| United States | 57% |
| Europe (developed) | 15% |
| Japan | 7% |
| China | 5% |
| Other developed (Canada, Australia, etc.) | 8% |
| Emerging markets (India, Brazil, Mexico, etc.) | 8% |
A "market-weight" global portfolio would hold 57% U.S. and 43% international.
Most U.S. investors hold roughly 80% U.S. and 20% international, which is a 23-percentage-point overweight to the U.S.
Over 30 years, this overweight has hurt U.S. investors. From 1995 to 2015, international stocks beat U.S. stocks by roughly 1% annually. From 2010 to 2024, U.S. stocks beat international stocks by roughly 2% annually. Whichever you overweight will underperform periodically, and home bias ensures you're overweighted in the wrong region sometimes.
The Case for 50/50 Global Allocation
A reasonable starting point: within your stock allocation, split 50/50 between U.S. and international stocks. This is close to market weight and requires no proprietary judgment about which region will outperform.
Example: A 60/40 portfolio (60% stocks, 40% bonds) becomes:
- 30% U.S. stocks (VTI)
- 30% international stocks (VXUS)
- 40% bonds (BND)
This is simple and diversified. You capture U.S. growth and international growth equally. Currency fluctuations in one region are offset by another.
The Case for 60/40 or 70/30 (Tilting Domestic)
Some practitioners argue for a 60/40 or 70/30 split, favoring domestic stocks. Rationales vary:
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Familiarity discount: You know U.S. companies better; this familiarity is a form of risk reduction (knowing what you own).
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Simplicity: A 60/40 split is easier to explain and justify than 50/50.
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Valuation: At various times, U.S. stocks have been cheaper than international stocks, justifying overweight. While this changes, a 60/40 tilt is a reasonable compromise.
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Tax efficiency: Some international funds have higher tax drag; a 60/40 split reduces exposure to them.
Example: A 60/40 portfolio becomes:
- 36% U.S. stocks (VTI)
- 24% international stocks (VXUS)
- 40% bonds (BND)
The Case for 40/60 or 30/70 (Tilting International)
Emerging markets proponents and those skeptical of U.S. valuation prefer 40/60 or 30/70 tilts toward international. This requires conviction that international markets will outperform, which is a forecast. Most academics and practitioners avoid making such forecasts, preferring market-weight splits.
Currency Risk: A Key Consideration
When you buy a Japanese stock priced in yen, you face currency risk. If the yen weakens 20% against the dollar, your U.S. dollar return falls 20% even if the stock's yen-denominated return is flat.
Over short periods (1–5 years), currency fluctuations are significant and unpredictable. Over long periods (20+ years), currency risk diversifies somewhat: the dollar strengthens sometimes, weakens others. A long-horizon investor can largely ignore currency risk because volatility cancels out.
However, currency risk is real. Since 1980:
| Period | USD Index Return | International Stock Return |
|---|---|---|
| 1980–1990 | +40% (strong) | +50% (beat) |
| 1990–2000 | +30% (strong) | -10% (lost) |
| 2000–2010 | -10% (weak) | +100% (huge win) |
| 2010–2020 | +10% (moderate) | +20% (lag) |
When the dollar strengthened (1990–2000, 2010–2020), international stocks underperformed U.S. stocks. When it weakened (2000–2010), international outperformed.
Most long-term investors accept currency risk as part of international diversification, not something to hedge. A few investors buy "currency-hedged" international funds (which eliminate currency risk), but this adds expense (roughly 0.20% annually) and reduces diversification benefits.
Recommendation: For most investors, unhedged international funds (like VXUS, IEFA, IEMG) are preferable. The small extra cost of hedging (0.20%) is not worth giving up currency diversification.
Emerging Markets: A Special Case
Emerging markets (China, India, Brazil, Mexico, Vietnam) are a subset of international stocks. They are faster-growing but more volatile and riskier than developed international markets (Europe, Japan, Australia).
A basic international allocation (via VXUS or IEFA) includes about 20–25% emerging markets automatically. If you want more emerging markets exposure, you can overweight them (via VWO or IEMG), but this requires conviction about their future outperformance.
For most investors, the default weighting in a broad international fund is appropriate. Explicit emerging markets overweights should be a conscious decision, not default.
Practical Implementation
The simplest implementation of a 50/50 U.S./International split:
| Allocation | U.S. Stocks | International | Bonds |
|---|---|---|---|
| 60/40 portfolio (total) | 30% | 30% | 40% |
| Fund choice | VTI | VXUS | BND |
| Or alternatives | SCHB | SCHF | AGG |
Vanguard, Schwab, and Fidelity all offer this split efficiently via low-cost funds.
A more granular approach divides international into developed and emerging:
| Asset | % | Fund |
|---|---|---|
| U.S. stocks | 30% | VTI |
| Developed international | 18% | IEFA or VTIAX (ex-US developed) |
| Emerging markets | 12% | VWO or IEMG |
| Bonds | 40% | BND |
This gives more control but adds complexity.
Rebalancing and Currency
When you rebalance, track your stock allocation in dollar terms, not currency terms. If you target 50/50 U.S./International and currency movements cause the split to drift to 52/48, rebalance back to 50/50 by selling the appreciating currency and buying the depreciating one.
This forces you to buy low (when a currency is weak) and sell high (when it's strong), which is desirable. Rebalancing across currencies effectively hedges currency risk over time.
Tax Considerations (U.S. Investors)
International stock dividends are taxed differently than U.S. dividends in some cases, and foreign tax credits complicate things. However, these considerations are minor compared to the benefit of international diversification.
Within tax-advantaged accounts (401k, IRA), put international stocks. Within taxable accounts, the tax efficiency difference between U.S. and international stocks is small.
How it flows
Next
Within your international stock allocation, you must decide: what percentage in developed markets (Europe, Japan) vs. emerging markets (China, India, Brazil)? The next article explores this split and the case for or against carving out emerging markets specifically.