> The only reason they can sell something on is because they created an artificial scarcity of the thing. If widget X has a well-matched supply and demand, and a scalper decides to buy 10% of widget X, then 10% of the demand is now unmet, some of the buyers go out of business, and the maker of widget X now has 90 something % of their previous market.

If that happens, then the price drops, and the "scalper" loses money - demand has some elasticity, and a healthy market has some slack in it. Momentum-trading speculation works sometimes, but anyone who uses it as their sole strategy will go bankrupt sooner or later.