DislikedTrue, but retail traders are speculators (for the most part some are gamblers) and that is where it becomes a zero sum game.Ignored
Even futures are not initially meant for speculation (they are tools to protect businesses against the risk of price fluctuation).
The speculator may be at one end of the trade, but often there is someone else at the other end.
If I buy EUR at 1.5 and it goes up and I sell at 1.52, you may say I'm a winner and the seller is a loser, but the seller may have bought at 1.48 (so he is also a winner) and the buyer may have no intention to sell afterwards (for instance if he just happens to get paid in USD but needs to convert them into EUR, his local currency...). Where is the zero sum game in this?