re: I have a really stupid and dumb (or both) question about shorting a stock...

I'd agree with geauxbears08 for the vast majority of investors. But with respect to shorting, part of the cost of the transaction is going to be the cost to borrow the shares. With respect to a stop, this isn't enough in my opinion, as no guaranty a stock won't open above your stop, and your stop won't adjust, or consequently execute. It could also quickly blow through the stop and not fill. One should be using some type of contingent order. Stops are extremely dangerous. If you can get execution guaranty with a contingent, you've just turned a theoretically unlimited loss into a maximum loss. Most of the time. If a price is blowing through quickly, and you have a contingent trade, if the contingency is hit and the buy is at market after the contingency is hit, the price still could be beyond what would be prudent at that point.

So I wouldn't short as there are other ways to do this. But I do short on rare occasions. But I understand everything I just typed here as well. I won't even get into MM's in a dramatic upward or downward price environment knocking through retail investors stops as a matter of course. I'm assuming the computers are programmed to look for this, and they do as well.

But hell, what do I know anyway?