Its hard to say how strong it really is but the fact is that it can be very strong if it stays so stable, its all matters in the stability these days so..
We can see the strength of bitcoin this Christmas season and no doubt about it that the price of it is getting higher and higher. This means that bitcoin is now becoming stronger and a lot of people are now using it. But we may not remove the fact that when there is strength, there is weakness. Let's not just hope that bitcoin will be weaken by some other projects or by the pump and dumps of whales.
Believe me i can't understand about the price of bitcoin increased on Christmas Day?
Because it is not a business day, Christmas Day is a day of enjoyment, so why people buy the bitcoins a lot?
Also you should remember the day of Halving, when many people said that bitcoin price but bitcoin never pick up the rock.
During in this time, bitcoin has better position instead of time of halving. So i think nothing is happened on Christmas Day.