bitcoin increases in number by the process of mining that costs electrcity which dictate the price....
now with increase in miners comes increase in price ...
and so on
till the price reaches a peak when people starts taking profits...
and so the price starts falling down...
eventually miners starts shutting down as well because the number of bitcoins mined slows down due to the increasing difficulty of mining and thus there aren't enough bitcoins to cover the cost of electricity...
and so on the more the price falls the more miners shut down...
but only one thing increases in both ways whether price goes up or down and that is the numbers of bitcoins in circulation...
...no matter what, bitcoins always go up!