MSCI World vs S&P 500: which index should you choose for your ETF?
The S&P 500 already accounts for 67% of the MSCI World. Choosing between the two is not neutral: you are either betting on global diversification or on the lasting dominance of large US companies. Performance, composition, risk and overlap compared.
Composition: MSCI World vs S&P 500
These two indices are the most widely used by individual investors, but their construction is fundamentally different.
| Criterion | MSCI World | S&P 500 |
|---|---|---|
| Number of companies | ~1,400 | 500 |
| Countries covered | 23 developed countries | United States only |
| US weight | ~67% | 100% |
| Market cap coverage | 85% of developed markets | ~80% of US market |
| Dominant sectors | Tech, Finance, Healthcare | Tech, Finance, Healthcare |
| Rebalancing | Quarterly (MSCI) | Quarterly (S&P) |
The MSCI World covers developed markets as a whole: the United States, but also Japan, the United Kingdom, France, Germany, Canada, Australia, Switzerland and 15 other countries. The S&P 500 focuses exclusively on the 500 largest US companies listed on the NYSE or NASDAQ.
The US weight: 67% vs 100%
This is the central point of the debate. The MSCI World allocates approximately 67% of its market cap to the United States: a proportion that has grown mechanically with the rise of US technology mega-caps (Apple, Microsoft, Nvidia, Alphabet, Amazon, Meta).
The direct consequence: the overlap between an MSCI World ETF and an S&P 500 ETF exceeds 65%. Holding both results in a massive overweight to the United States, and more specifically to the same mega-caps that make up the top 10 of both indices.
Top 5 common holdings (May 2026)
What the MSCI World adds beyond the S&P 500: meaningful exposure to Japan (~6%), the UK (~4%), France (~3%), Germany (~2.5%), Switzerland (~3%) and other developed markets. These countries collectively represent about 33% of the MSCI World,entirely absent from the S&P 500.
Historical performance over 5, 10 and 15 years
The S&P 500 has outperformed the MSCI World over the past decade, driven by the concentration of US technology mega-caps. This outperformance is real, but it results from a survivorship bias that deserves careful interpretation.
| Period | S&P 500 (annualised) | MSCI World (annualised) |
|---|---|---|
| 5 years (2021-2025) | ~14.2% | ~12.8% |
| 10 years (2016-2025) | ~13.1% | ~11.4% |
| 15 years (2011-2025) | ~14.5% | ~12.2% |
| 2000-2010 (lost decade) | –1.0% | +0.4% |
Our reading
The 2000-2010 period illustrates the risk of US concentration: during the American "lost decade", the MSCI World held up better thanks to international diversification. The S&P 500's recent outperformance is not a natural law, it reflects multiple expansion in US mega-cap valuations that could reverse.
Risk and volatility
Concentrated in a single country and a single market, the S&P 500 is structurally more volatile than the MSCI World. The geographic diversification of the MSCI World cushions shocks specific to the US economy.
| Indicator | S&P 500 | MSCI World |
|---|---|---|
| Annualised volatility (15 years) | ~15% | ~13.5% |
| Max drawdown (2008 crisis) | –51% | –54% |
| Max drawdown (March 2020) | –34% | –33% |
| USD/performance correlation | High | Moderate (multi-currency) |
Note: in 2008, the MSCI World recorded a slightly larger drawdown because it included European and Japanese markets, also severely hit by the financial crisis. Geographic diversification does not protect against all crises, but it reduces the risk of concentration on a single economy.
Fees compared: available ETF TERs
S&P 500 ETFs are on average cheaper than MSCI World ETFs, due to intense competition on this index and the simpler management of a 500-stock US-only universe.
| ETF | Index | TER | French PEA |
|---|---|---|---|
| SP5C (Amundi) | S&P 500 | 0.09% | Yes |
| CSPX (iShares) | S&P 500 | 0.07% | No |
| BNP500 (BNP Paribas) | S&P 500 | 0.15% | Yes |
| WPEA (Invesco) | MSCI World | 0.19% | Yes |
| CW8 (Amundi) | MSCI World | 0.38% | Yes |
| IWDA (iShares) | MSCI World | 0.20% | No |
TER as of 25/04/2026. Verify PEA eligibility with your broker before placing any order.
For French PEA investors: S&P 500 access goes through SP5C (0.09%) or BNP500 (0.15%),both synthetic. CSPX (iShares, physical) is cheaper in TER but is not PEA-eligible. For the MSCI World in a PEA, WPEA (0.19%) is now the reference following the March 2026 TER cut.
Which one to choose depending on your profile
There is no universal answer. The choice depends on your conviction about geographic concentration, your tax wrapper, and your investment horizon.
Profile
You are just starting out and want simplicity
Recommended choice
MSCI World (WPEA or IWDA)
Instant diversification across 23 countries. One ETF is enough for a balanced portfolio. The S&P 500's historical outperformance is not guaranteed for the next decades.
Profile
You invest through a French PEA
Recommended choice
WPEA for MSCI World, SP5C for S&P 500
Both are PEA-eligible via synthetic replication. IWDA and CSPX (physical, cheaper) are not accessible in a PEA. Choose WPEA if you want the MSCI World.
Profile
You have a strong conviction on the US
Recommended choice
SP5C (PEA) or CSPX (standard brokerage)
If you believe US mega-caps will keep outperforming, a pure S&P 500 ETF maximises that exposure. This is a deliberate concentration bet.
Profile
You want maximum diversification
Recommended choice
MSCI World + MSCI Emerging Markets
The MSCI World covers developed countries. Adding an Emerging Markets ETF (80/20 or 90/10 allocation) provides full global exposure with less than 5% overlap between the two ETFs.
Frequently asked questions
Can I hold both an MSCI World ETF and an S&P 500 ETF?▾
Technically yes, but it is generally not useful. The overlap between an MSCI World ETF and an S&P 500 ETF exceeds 65%. By combining both, you are overweighting the US and tech mega-caps without meaningful additional diversification. If you want more US exposure, simply increase your allocation to the S&P 500 ETF alone, rather than stacking both.
Will the S&P 500 keep outperforming the MSCI World?▾
Nobody knows. The American outperformance from 2010 to 2025 is linked to multiple expansion in US tech mega-caps (Apple, Microsoft, Nvidia),a phenomenon that could reverse. During the 2000-2010 decade, the S&P 500 returned approximately –1% per year while the MSCI World held up better through geographic diversification. Choosing a global index is a form of neutrality in the face of this uncertainty.
CSPX vs SP5C: which one to choose for the S&P 500?▾
CSPX (iShares, TER 0.07%) is slightly cheaper and uses physical replication,but it is not PEA-eligible. SP5C (Amundi, TER 0.09%) is PEA-eligible via synthetic replication. If you invest in a PEA, the choice is SP5C. In a standard brokerage account, CSPX is marginally cheaper.
MSCI World or MSCI ACWI for full global diversification?▾
MSCI ACWI adds emerging markets (China, India, Brazil, Taiwan…) to the MSCI World. It covers approximately 2,800 companies versus 1,400 for the MSCI World. The downside: ACWI ETFs are slightly more expensive (VWCE: TER 0.22%) and few are PEA-eligible. A popular alternative: MSCI World + MSCI Emerging Markets as two separate ETFs, allowing you to freely adjust the emerging markets weighting.
Summary
The S&P 500 has slightly outperformed the MSCI World over the past 10-15 years, but this outperformance is concentrated in a handful of US tech mega-caps and is not guaranteed for the coming decades. The MSCI World offers diversification across 23 countries, with a US weighting of 67%, already very significant.
For French PEA investors, the practical choice in 2026 is WPEA (MSCI World, TER 0.19%) for global diversification, or SP5C (S&P 500, TER 0.09%) for a US conviction play. Do not combine both: the overlap exceeds 65% and you are simply paying twice for the same companies.
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