Don't take this as a recommendation but there seem to be some indications that the bottom might have been made, contrary to my expectations that bitcoin could go to 2000 (see OP and other posts). I don't think that bitcoin is going to go up seriously during 2019, but perhaps it will start a painful recovery that will take more than one year to go back to 10,000. It was something like this that happened in the past every time we had a major crash.
I still expect a fall to at least 3930 perhaps even 3600, but the risk/reward might worth taking a small position with a long term perspective, at least at those values. In order to increase it as the price breaks 4250 and then 4500.

As usual don't trust me. This isn't a recommendation. Do your homework.