The reason for huge raise in bitcoin price last year is due to many reasons.The important one in bitcoin is legal one in China.In china most of mining farm was their last year.The number of trader in China is 3/10 of world investors.The ban news in China affect the bitcoin market very huge.
Well this is all started in the concept of Chinese new year when everyone is trying to sold their bitcoin for this holiday but I think this is not the only reason why the price dump this year. People are being hype last year, so expected the price will rise high that much and this year even we hype the market there is still no reaction because people learn from the previous mistakes, and maybe we are in a normal market now.