Subject: Profit Margins
Was reading an article this weekend that sourced the following, essentially how investors hurt their performance

https://www.ifa.com/articles/u...

the 30 year return of the S&P 500 looked impressive so decided to check how much of it was Multiple expansion. Turns out, not much
PE was 21.34 in Jan 1994 and 24.3 in dec 2023. That was reassuring but problem then is when I checking profit margins. They exploded upwards from around 5% to 12%. As others have pointed out here, this upward trend for the next 30 years is highly unlikely.

How does Berkshires profit margins compare?