There is no bottom actually. When enough people decide to sell price will move down to any level.
There is no top either. When enough people decide not to sell the price will move upwards to any level (this has happened repeatedly in bitcoin's past five years).
Fiat failed each and every time through history.
Now a good move and safe move is to buy at lease 10~20 bitcoins and even if BTC fails its not a big deal, but when it reaches a million users, you'll be a very rich dude!