Overview
- The S&P 500 is market-cap weighted so the largest companies carry the biggest share of the index and today that produces heavy concentration in a few firms.
- About 37% of the Vanguard S&P 500 ETF is invested in its top 10 holdings and roughly 14% of the index comes from Nvidia and Apple with Microsoft and Alphabet pushing the four-name total above 25%.
- Invesco’s S&P 500 Equal Weight ETF holds the same 500 stocks but assigns nearly equal weights at rebalance so megacap names have about 0.2% each and the fund shifts sector exposure toward industrials and financials.
- The equal-weight approach reduces single-name sensitivity but has lagged recently because it underweights the tech giants that have led the market and could continue to trail if those firms keep outperforming.
- Despite concentration and current elevated valuations near 29 times earnings, the S&P 500 has delivered roughly 10% average annual returns since 1957 and has outpaced long-term Treasuries over multi-decade stretches, so investors must weigh diversification choices against the index’s long-term track record.