A pretty well known mutual fund manager said, and I paraphrase, "it is very hard to short a bear market, much harder than riding a bull market".  Do you know why?  Because it is much harder to predict how much and how high a bear market will have a temporary rebound versus buy & hold in a bull market (or even market that is in recovery).  

Basically it's like trying to catch a falling knife.  If you time it wrong, you will lose a lot more than you gain.  When a bull market stops being a bull, there is a period of plateau (flat or seesaw pattern) and gradual falling off.  A bear market, during free fall, you will not know when it will stop falling until it starts the slow recovery.  

You make it sound so easy, I would like to see you sell low and buy lower, unless you got a time machine to the future.  By the way, how is that 60 to 300 rebound, well on its way i see.