Christmas is not the same as the thanksgiving day, you should know that christmas is something that is being celebrated all over the world.. While thanksgiving is only celebrated on the united states.
This will give you all the answers that you need about how it will "affect" the price.
From earlier i said that christmas and new year will give bad effect bitcoin and other.
Most of altcoin getting lower in value since they move the money or just stop trading for a while. Most of them sell their coins.