[thick18cm]

your idea has an interesting parallel in econ/finance: trading on inside information (misnomer: insider trading) has the economic effect of moving the prices of securities in the direction they're supposed to go, which is a public good. Stock markets are meant to "crowd source" a price which accurately predicts the future value, and illegal trades by insiders do that precisely, move the price of the security toward its new equilibrium.

If you hold the market portfolio (i.e. invest in a broadly diversified market index ETF, as you in most cases "should") this impacts you by helping you more accurately assess your current postion and make more knowledgeable trades like "sell some now and buy a house" or "retire". Before you object to that, remember these effects occur on margin (econ, not finance)