When Wide Diversification Makes Sense

One situation requiring wide diversification occurs when an investor who does not understand the economics of specific businesses nevertheless believes it in his interest to be a long-term owner of American industry. That investor should both own a large number of equities and space out his purchases. By periodically investing in an index fund, for example, the know-nothing investor can actually outperform most investment professionals. Paradoxically, when "dumb" money acknowledges its limitations, it ceases to be dumb.