Index funds are by all evidence the better choice for the average individual, but they present something of a chicken and egg problem.<p>To set the price of the index, you need people buying and selling individual stocks. If everyone owned index funds, there would be no index. What is the percentage of the market owned&#x2F;run by index funds where the premise of following an index starts to break down?<p>The article says we haven&#x27;t reached it, and that at that point active management approaches will regain an upper hand. Still, I wonder if it&#x27;s true and the broader question remains.