Charlie Munger, nor I believe that rule to be sensible. Rather, both of us have
consistently thought that at Berkshire this mark-to-market change would produce what I described as “wild and
capricious swings in our bottom line.”

#WarrenBuffet 2018 Letter Our advice? Focus on operating earnings, paying little attention to gains or losses of any variety. My saying
that in no way diminishes the importance of our investments to Berkshire.
#WarrenBuffet 2018 Letter