Point of order: Shorting is a bit more complicated than just a "anti-buy". If you short a stock, and it goes up, then you owe your broker money. This is called a "margin call", and if you will recall, it was what bankrupted the Duke brothers in Trading Places.

If you shorted a stock at $50, covered your margins up to $100, and waited another three years to close out your position at $35, either you have testicular elephantiasis, or a goddamn crystal ball.