This is total conjecture; please correct me in the comments, because I don’t understand finance at all. This is from a physics standpoint.
In markets, money flows against an information gradient. Traders with perfect knowledge of a stock’s value in the future can make trades with no risk, yielding the highest expectation values of returns E[R]. Traders with zero knowledge of the stock’s value have the worst expectation value. If the market is conservative–that is to say, there is no money added or lost inside the market itself; a stock sells for x dollars and is purchased for x dollars in each transaction, the sum of all expectation values over traders
S = Σ0n E[R(tradern)]