Maybe it's upside down. Index funds effectively buy and sell at prices set by non-index fund investors. They are reacting to market price, not trying to predic

Maybe it's upside down. Index funds effectively buy and sell at prices set by non-index fund investors. They are reacting to market price, not trying to predict where the stocks will go in the future. All other investors are betting on the future price moving one way or the other. I'd argue that index funds are an amplifier for demand, but that the actual demand is still generated based on 'analysis' by investors seeing the the current price as an opportunity.