Do you continue to short while the stock is up, or short too...

Do you continue to short while the stock is up, or short too during its down? I am a bit confused. You must have a purchased price, unless it is $2, otherwise it doesn't make sense to me.

If your target price is $2, and you keep shorting while the sp is up, then what if the sp is going all the way down? As long as the price is above $2, then you can short either when sp is up and when sp is down.

So the situation to me is like.
1. you have held the stock for a very long time since it is $2. Then whatever you do, you can gain now.
2. you had purchases somewhere below $10, and it is good opportunity for you to short at the moment. And if the sp starts to decrease all the way to $2. Then you probably can sell out all of your holdings, you gain too.
3. you had purchases somewhere above $10 below $13 before, and you bought others below $10, then you use current uptrend as a hedging to offset your previous loss.

So in either case, I don't understand sp moving down to $2 has anything to do with you. Offcoz you may have different strategies.