Bitcoin is used by some people to get an alternative income or to have more money. People are preparing and using their money for the celebration of Christmas. If Christmas affects bitcoin, I don't think so because Christmas just affects those people who uses bitcoin not bitcoin itself. People might sell their bitcoins so they can have more money for the preparation of Christmas. Once people started to sell bitcoin, bitcoin might decrease its price because as many people are selling bitcoin than buying it, bitcoin's price will decrease. Christmas affect people who use bitcoin which affect bitcoin but Christmas does not affect bitcoin directly. I think it is also the same to other holidays.