depends on who you trade with.
personally i trade with a world renown bank because of the security involved.
also, they ALWAYS pick up the phone and the customer service reps are excellent.
i had a long talk with a rep yesterday about shorting.
each institution has their own rules.
in this particular case, they will not short anything below $3.00
however,
if you were to purchase a stock, say at a high price (say after a R/S)
and shares were available, there is no reason that you could only hold for a 100% gain on a short.
it would make no sense, seeing that you can hold for 100%+ on a stock that goes up.
just need to choose your stocks wisely AND make sure shares are available to short.