Best time to buy is at the bottom when the shit hits the fan. Nothing beats having your position secured with a 25% profit an hour after you buy.
And how do you know if you just clean your face and the fan turns around at your direction AGAIN?
Aaah it's so easy to talk hindsight :-)
Its been very easy to identify short term bottoms by looking for a certain volume level and aggression of large buy orders / buys on gox and stamp.