The subset makes up approximately 10% of the market value of the S&P 500. Pension plans hold on average 3% as reported by Bloomberg, but that number excludes exposure via investment managers, which is likely much higher.
Still got bite
The collection of tech, or tech adjacent, stocks has driven index performance in recent years, notably in 2015 when the index finished up only 1.4%, buoyed in large part by these stocks. Netflix and Amazon posted returns of 134% and 118% in 2015, respectively; Apple was the outlier than year as shares were down 4.6%.