The more you wait for opportunity, the higher the possibility that you loss some. If you will keep on waiting for "the right time", you might end up wasting your time since no one can guarantee in Bitcoin will crash dramatically, lower than the current price, in the future. So it is best to buy now then hold, if the price crashed then buy again. As simple as that. At least you did not waste any of your time waiting for something that might not even come in the first place.