PS Looking at the way NFLX marched up all afternoon right through the close yesterday, it's a REALLY dangerous time to short. Sure, it may consolidate. But that move yesterday is a red flag. If I traded the afternoon shift, I might have held some overnight. I probably don't do that 3 times a year.
Agreed - never short on valuation alone. You need a coming compelling event or series technical issues with the high valuation to short a momo stock. Even then you can get burned .. wall street loves a growth story and will pay anything for it (especially in times of very slow growth and easy money).