In June 2024, the top 10 stocks in the S&P 500 accounted for 38% of the index's total market capitalization, which is twice as much as during the period from 2010 to 2014. From 2018 to June 2024, these top 10 stocks contributed to about 50% of the overall market capitalization growth of the S&P 500. This trend highlights an increasing concentration of market value among a small group of leading companies.