[Data: U.S. stock market concentration hits record high, top 10% of stocks account for 78% of total market value] BlockBeats reported on September 27 that trading information platform Kobeissi Letter released data showing that the top 10% of U.S. stocks by market capitalization currently account for 78% of the total market value of the U.S. stock market, setting a new historical high. This figure is 3 percentage points higher than the record peak in the 1930s and also exceeds the peak during the dot-com bubble in 2000, when the proportion was 74%. In contrast, during the 1980s, the total weight of the top 10% of companies by market capitalization was less than 50%. Meanwhile, the percentage of market capitalization held by the top 10 stocks in the S&P 500 Index has reached a record 41%, marking an unprecedented level of market concentration.