Wall Street Cheating - Compare Apples to Oranges
09/09/2021
The S&P 500 Index started tracking stocks 64 years ago. The problem is most of those stocks are no longer in the index.
To remain indicative of the largest public companies in the United States, the index is reconstituted quarterly.
The S&P 500's most recent restructuring was on Mar. 12, 2021. NXP Semiconductors, Penn National Gaming, Generac Holdings, and Caesars Entertainment were added, replacing Xerox Holdings, Flowserve, SL Green Realty, and Vontier.
So when you see the chart, it is not giving you the performance of the same 500 companies over time. Rather it is skewed to high-performance companies each and every quarter.