When you’re an investor in stocks, you get emotionally involved. The problem with this is if you look historically at what happens, even to the greatest names, there are massive corrections on sectoral transitions, and you don't know where in the time cycle you're involved. So the rule to follow is no more than 5% in any one stock, and no more than 20% in any one sector. My returns are based on this concept of diversification, although if you looked at what I was doing 20 years ago, I wasn't applying those rules and I got slaughtered.