The markets have gotten more efficient and the alpha is gone.  Active funds are having a tougher time making money.  Why?  Increased competition, stricter regulation (insider trading crack-downs), and the internet democratizing information.

Nice quote about mom and pop “main street” investors:


[Main street investors] have decided to take their ball and go home… and by ball, I mean capital, and by home, I mean low-cost index funds.