Comment by efromvt

Hmm yeah it depends on your definition of insider. If you assume all raw information is public-ish, a market can reward those who can synthesize/operate on that knowledge to predict better. (The cars in the lot, etc. there is friction to this discovery; the knowledge can be communicated to others through the market after discovery to profit off the initial cost of discovery). There is symmetric competition to some degree. If you have true non public knowledge (I’m going to say something to tank the stock on this date) then you are purely extracting value from others because you will always win; they will never have that info and the incentive for anyone else to participate in price discovery would go away.