I follow many money managers. Two of my favourites to watch are Warren Buffett of Berkshire Hathaway and David Einhorn of Greenligh Capital.
After comparing their top 10 holdings side by side, I noticed they have only one stock in common: Apple (AAPL).
Their history on Apple ownership is, however, very much different. Einhorn initiated position in Apple as early as in Q2 2010* where as Buffett's position in Apple was disclosed in Q1 2016*.
Einhorn has reduced his position in recent quarters. Apple used to be his top position still in Q4 2016*. Now it's 5th largest*. In Berkshire's portfolio Apple is currently* 3rd largest investment.
Despite following both closely, I don't share any of their top 10 holdings currently. I admit I have considered Apple multiple times and regret for not hopping on board then.
(*) Reference for positions and their history: Dataroma.com.