Will the largest stocks underperform the average S&P 500 stock ahead?
Core argument: Since 1957, the 10 largest S&P 500 stocks have underperformed an equal-weighted index of the remaining 490 stocks by 2.4% per year on average, though the largest stocks do not trail in every period.
The largest stocks certainly don’t underperform all of the time, but on average, they have substantially trailed the average S&P 500 stock, as we can see in Exhibit 2. Since 1957, the 10 largest stocks in the S&P 500 have underperformed an equal-weighted index of the remaining 490 stocks by 2.4% per year. But the last decade has been a very notable departure from that trend, with the largest 10 outperforming by a massive 4.9% per year on average. History suggests that the next decade is likely to see a reversal of the recent pattern with the capitalization-weighted version of the S&P 500 underperforming the equal-weighted version. In such an environment, active managers will suddenly look much better versus the S&P 500 and other capitalization-weighted benchmarks.

