Wikipedia: zero sum game
Zero-sum describes a situation in which a participant's gain or loss is exactly balanced by the losses or gains of the other participant(s).
It is NOT a zero sum game, if not all participants are interested in the same class of gains.
A participant happily paying for entertainment or for "learning" theoretically brings additional, non-tangible gains into the equation.
Likewise a commercial trying to offset non-market risks (e.g. a gold miner hedging against liquidity risks).
A company launching an IPO is (through the mechanics of asymmetrical information) automatically forced to sell at a price under their own perception of value ( if they're not fraudsters).
Anyone remembers the initial offering price of google?
A theoretical player in a hermetic zero sum game should have waited until someone had offered at least 200 or 300$ before selling the first share.
For liquidity and credit risk reasons that did not happen. That's a textbook example of external gains, without any game-internal offset.
To be fair: external gains could be quantified for every single market and weighed against transaction cost. The result should be an expectancy that is skewed slightly to the positive side for the theoretical, unbiased player possessing equal information compared to competitors. A situation, that is very close to the zero-sum game.
It's really, really old stuff in economics...
