Reasons why bitcoin has fallen is a lot, but no one can say exactly why. When there is good news, everyone expects to raise prices and vice versa. The bitcoin price is based on good and bad news from the world /adoption of bitcoin by a country, institution permit, and the like/. As far as i noticed, it is so. I do not know exactly what the price you bought bitcoin because you did not write it, but do not worry about the price of bitcoin growing, it just wants patience and strong nerves. If you need urgent money so sell an part and leave the rest in bitcoin.