According to @KobeissiLetter, the top 10% largest US stocks now account for a record 78% of total US equity market capitalization. According to @KobeissiLetter, this exceeds the previous record from the 1930s by 3 percentage points and is above the 74% peak seen during the 2000 Dot-Com Bubble. According to @KobeissiLetter, in the 1980s the top 10% share was below 50%, underscoring how unprecedented today’s concentration is. According to @KobeissiLetter, the top 10 stocks now represent a record 41% of the S&P 500’s market cap, indicating that market leadership is extremely concentrated.