I'm doing day trade shorting of stocks. Only if it is available to short. Setup an "One cancels other" bracket and you're greatly protected against reversal where price explodes back up. It's the same trading on the way down as on the way up. Folks just don't use the OCO brackets to protect themselves from a huge price move. That said... I think companies should get to choose whether or not they are shortable. You can drive price down in the same way that guy describes shorting. But it would require you have a large position. That would also mean you have cheese in the game. That would also mean you have more interest in driving price up. Or, it could mean you're an institutional investor hoping to drive price down so you can scoop up the newly freed float because you caused all those other folks' stoplosses to trigger.