which causes bitcoin prices to fall is a issue of negative issues in the news. and lack of supply and demand. this is what causes bitcoin prices to fall. but you do not need to panic because it will be back to stable again.
You have mixed up something there. You said lack of supply and demand, but actually drops are caused by lack of demand and more of supply and in that case a lot of people just want to get out than those who want to get in.
We had a huge hype last year, and I guess this is the post effect of such that we apparently would not have been able to run away from. It will get to the point where a lot of people will start looking for ways to get back into position when there is a glaring move of an uptrend, but for now, we just stay with what we are seeing.