Bitcoin will rise during the Christmas holidays, just like it did during Black Friday/ thanksgiving holiday. So hold your positions.
Not really, all eyes are on segwit2x fork. Christmas will not going to affect the price much but the upcoming segwit2x fork (on 28th Dec) will surely affect it, because people are much suspicious about it and till that the price will remain oscillating around $13-14k.
Don't try to compare it with last year(i.e Dec 2016), that doesn't justify this prediction.