Whenever the largest stocks have a growth spurt, we hear worries about their dominance in the S & P 500 , fears about how disproportional their impact has become, and predictions of their imminent decline. That means it's wise to examine the true power these names have over their smaller colleagues in the index. For the first data cut in this analysis, I focused on the big four: Apple , Microsoft , Alphabet and Amazon . We combined both of Alphabet's share classes for this exercise.
is a recent arrival but trades at such a price to sales premium to the others – at least 30 times for this calendar year – that it might distort the original analysis. Adding up the market value of the top four yields a total dollar amount of $8 trillion and a weight exceeding 20% of the S & P 500. Let's think about what that means. Dollar units for the charts below are in the millions of dollars.