This period do not encourage trading or investment but at the same time when price is down is good opportunity to buy cheap and when its explode you will gain it. Nothing is lost in bitcoin, those holding for long now are the great benefactors but if you buy this period is more safer.
That is why bitcoin is considered a very profitable long-term investment and you can choose according to your ability to carry out the investment, basically buying bitcoins can be done at any time, as long as you understand investment patterns, both in cheap conditions and when the price goes up and most importantly the amount the authorized capital will affect the profits we get.
If I have money now, I would buy half of bitcoin because in next three months it will double the current price. This is real because it always occur this way after 5 years remember in 2011 and 2017 from the market charts and caps. And this year will break more even.
Mathematical calculations in bitcoin investment are not like that because no one knows price fluctuations, certain periods people take a short term approach for small profits with a standard amount of capital, but you can run long term to get far more maximum profits.