Not for Berkshire. They hold onto shares for a long time and have less than 50 companies (the ones they really like just get acquired). The new AAPL stake is .83% of the portfolio.

If they only make 50 bets, isn't each one substantial by some definition? It's certainly not a scattershot approach.

It depends on the size of the bet, .83% of the portfolio isn't substantial in any way (if AAPL went to 0 tomorrow it would barely budge Berkshire's portfolio). In comparison their Wells Fargo stake is 23x the size of Apple's.

http://whalewisdom.com/filer/berkshire-hathaway-inc#/tabhold...