[1e-9]

No, it is not true. It is not true for options either. The zero-sum trading game fallacy is a common misperception.

For any kind of asset, the ability to transfer it has value. When someone needs to buy a new car, they often sell their old car to a dealer at a price that is lower than what they could get if they sold it to another individual. They do it because it is more convenient and/or they can't wait around for the right buyer to come along. A dealer has a better idea of the car's value and is willing to put it into inventory until someone buys it at a higher price. He takes a risk he might have to wait longer than expected to sell it again (which incurs more inventory cost), but he trades a lot of cars, so on average, his relative risk is lower than yours would be. He essentially charges you a fair price for this service. Even though technically you might say you lost on the deal, both sides are winners if the price was reasonable.

In a similar way, a stock trade can be a win-win situation. One trader may be willing to do the transaction at a discount because they have a better way to use the money or because they need to reduce their risk. Another trader may know more about the stock and/or have a different risk profile, so he is willing to take the risk of holding the asset until a profitable transaction is possible. This provides a win-win for both sides if the charge for the service is reasonable.

Of course, there are traders who are detrimental to a market and provide no value, just as there are crooked car dealers. That doesn't invalidate the value of good trading just as it doesn't invalidate the value of good car dealing.