ETF World vs S&P 500: Which to Choose?

The eternal debate

The choice between a World (MSCI World) ETF and an S&P 500 ETF is perhaps the most common dilemma facing passive investors. Both are excellent core portfolio holdings, but they serve different purposes and carry different risk profiles.

What each index covers

The MSCI World Index tracks approximately 1,500 large and mid-cap stocks across 23 developed markets. The US represents about 70% of the index, with Japan (~6%), UK (~4%), and other developed markets making up the rest.

The S&P 500 Index tracks the 500 largest US companies by market capitalization. It represents approximately 80% of the total US stock market value.

Historical performance comparison

Over the past 10 years (2016-2026), the S&P 500 has outperformed the MSCI World by approximately 2-3% annually. This outperformance is largely driven by the dominance of US tech giants (Apple, Microsoft, Nvidia, Amazon, Google, Meta, Tesla).

However, this hasn't always been the case. During 2000-2010, international stocks outperformed US stocks, and the MSCI World's diversification provided better risk-adjusted returns.

Diversification analysis

The S&P 500 concentrates 100% in the US market. While the US is the world's largest and most innovative economy, geographic concentration creates specific risks: regulatory changes, dollar depreciation, or sector-specific downturns can disproportionately affect returns.

The MSCI World spreads risk across 23 countries. When US markets underperform, other regions can partially offset losses. This is the fundamental value of diversification.

Cost comparison

Both index categories offer very low-cost ETFs:

• S&P 500: TER as low as 0.03% (Vanguard VOO) to 0.15% (European UCITS ETFs)
• MSCI World: TER typically 0.12% to 0.38% depending on provider and PEA eligibility

The S&P 500 generally wins on cost, but the difference is minimal.

Our verdict

For investors building a single-ETF portfolio, MSCI World provides better diversification with still-strong exposure to the US (70%). For those willing to manage a 2-3 ETF portfolio, combining S&P 500 with European and emerging market ETFs can achieve similar diversification at a lower overall TER. Neither choice is wrong — the key is consistency and long-term commitment.