Bitcoin's market is full of fluctuations and if we can see its dump as a better option to make perfect Investment then surely we can make lots of profit , but most of the newbies like you are not able to understand well about such fluctuations .
It may be possible that you are thinking that if dump can happen then still after your Investment may be result into loss for you but you should see it in another way , like if dump happened then after few time later there is increase in the market , so if you can make Investment during big dump then you have much better chances of Investment into big profit .
So don't get panic and make Investment at perfect timing only .