🔥Top 10 US stocks now account for 43% of the S&P 500

The current top 10 largest companies account for 43% of the S&P 500’s market cap, near the all-time high. This figure has stayed above 40% for the past 12 months.
A decade ago, this share was only about 18–20%, meaning it has doubled within just 1 decade. By contrast, the smallest 250 companies in the index now account for only ~7% of market cap, the lowest since at least 2014, down by half versus 10 years ago.
-> The top 10 are valued at more than 6 times the total of the smallest 250 companies combined. At the peak of the dot-com bubble in 2000, the top 10 also accounted for only ~26–27%.
The 43% figure alone doesn’t prove a bubble; the issue lies in the gap between weight and returns. The top 10 make up ~43% of market cap but generate only about one-third of the index’s profits. As the gap widens, the market is paying for expectations, not for real cash flows.