In 2007, Mark Sellers of Sellers Capital told a class of Harvard MBAs that there are at least seven traits shared by great investors that are true sources of competitive advantage, "because they can’t be learned once a person reaches adulthood, or can’t ever be learned at all".
Trait #1 is the ability to buy stocks when others are panicking and sell stocks when others are euphoric. "Everyone thinks they can, but when the market crashes few have the stomach to buy – or the willingness to sell at the top." Trait #2 is an obsession with playing the game and wanting to win. "Unfortunately, you can’t learn to be obsessive about something. You either are, or you aren’t."