I dont want to pat myself on the back too soon. look at a chart of MBI in the last 8 months, one would think it would be impossible to lose money shorting it, yet somehow I found a way to drop cash there but I learned from it.
I think you are right, chasing a short can be so deadly, I started shorting fnm at $25, when was a $7 you get this urges to short more because you are 'sure' they are toast, then it bounces huge. now I only short rallies or do the plan b, which is to short a little everyday, these simple rules saved me this time