Anyone else not a believer in broadly diversifying ? Friends have portfolios with 50 or more stocks. Why? Just buy an etf if you are going to do that. If you are going to beat the averages you have to make concentrated bets.

Not saying it is recommended. But if you happen to know more about a particular industry than the general public does then perhaps that's what you focus on. For me it's the government tech and public safety space and that's why I focus on cyber security stocks and companies that focus on public safety agencies. I am 40% in spy and 10 Vxus and 50% in 10 stocks.