I am not seeing any stability of bitcoin rather a bearish market of it. This I think is normal, last year this was also felt. Plus, we had been hearing news about the government's action against bitcoin so this factor would be affecting.
I think the main reason for this so called "stability" is as a result of investors being afraid of losing their investments as government keeps changing its stance over how cryptocurrencies will be used so people are not so active for now...which explains its stability
Too early to say that Bitcoin price is stable in 2018. It's the first month of the year, and we actually saw strong variations in the past few weeks.
I agree with you but the last days of January has been pretty stable