"Berkshire Hathaway (-12.2%) has underperformed the S&P 500 (+10.7%) by 22.9 percentage points since May 3 when Warren Buffett announced he would be stepping down as CEO on December 31. Since Berkshire's market value on May 3 was $1.2 trillion, the "Buffett premium" can be estimated as 22.9% x $1.2 trillion = $275 billion.

(Note: This is only an approximate estimation. There are other factors that may have contributed to Berkshire's substantial underperformance since May 3, including a decline in first quarter operating earnings that was also reported on that day. However, prior to May 3, Berkshire had been outperforming the S&P 500 in 2025 by 22 percentage points. The fact that May 3 served as an inflection point, resulting in an abrupt and substantial reversal of relative performance, seems to lead to a reasonable conclusion that the bulk (if not all) of this decline can be attributed to Warren Buffett's surprise announcement.)"

Hard to objectively refute this...

X (Twitter): David Kass on X: "Berkshire Hathaway (-12.2%) has underperformed the S&P 500 (+10.7%) by 22.9 percentage points since May 3 when Warren Buffett announced he