The quote was just to give an advice to investors. There are many ways to be rich. Investment is not necessarily the only way but people do believe that it helps to become rich. Indeed, most millionaires are investors. The thing is that they invest long before the product becomes famous. In that case, it is easy to be greedy and jump on the opportunity. On the other hand, many people became famous thanks to their intelligence. Here, I am talking about Gates or Mr. Facebook. Inventing something can also help people to be rich. Finally, I think that writing is also a way to become rich. If you are successful, you can make. So again, Be greedy when others are fearful depends on the occasion.