bitcoin slowly went down this year, from almost 20k USD last December and went down at a significant price
what might be the reason why bitcoin's price is going down?
what are the major things that can greatly influence bitcoin?
answers would be fully appreciated

I believe that fake news can actually affect the market price either to pump or to dump even more and that is the reason why you should always watch news that is related to cryptocurrenc, in order to determine if you will be earning profit or not.