Spain bans short-selling of shares as markets fall

[Lars77]

5. Because you are creating an incentive for people to make the market drop,

Which is partly what got us into this mess in the first place. Bad behavior should not be rewarded. When the market drops, real people and real money suffers and so it should not be encouraged.

Also, i am generally against profit making practices which create wealth out of nothing. Wealth should ideally be created from the production of goods and services, or at least be somehow related to those activities.

Short selling produces nothing of value except cash for the people doing it, it has no positive effects for society what so ever. And when you're encouraging that kind of wealth generation you are far, far away from the kind of capitalism that Adam Smith envisioned.