If you invest and don't diversify, you're literally throwing out money. People don't realize that diversification is beneficial even if it reduces your return. Why? Because it reduces your risk even more. Therefore, if you diversify and then use margin to increase your leverage to a risk level equivalent to that of a nondiversified position, your return will probably be greater.
Jeff YassThe moral is that in trading it's important to examine the situation from as many angles as possible, because your initial impulses are probably going to be wrong. There is never any money to be made in the obvious conclusions.
Jeff Yass