And there is one problem: "belief". Some people can walk through Xerox PARC and bet their company on 3-4 things they see. Others can own Xerox PARC and bet their company on 3-4 largely different things.

In EMH there is cooked in some notion of overall largely rational beliefs, and yet the shares trade hands from someone selling to someone buying - both of which feel they got a good deal worth making money from.