Presumably, there are multiple sophisticated investors competing with each other, and all of their bets affect the market price. There shouldn't be a replicable

Presumably, there are multiple sophisticated investors competing with each other, and all of their bets affect the market price. There shouldn't be a replicable strategy for beating everyone else if the market is large enough. If there is a distribution of skill in investors, using mutual funds might prevent you from being in the lower percentiles of under-performing investors. However if you really have a strategy that involves taking the market price that manages to consistently under-perform, then you could make money off of that strategy too.