End of Feb if the past 3 years have anything to say about it.
2017 - drop Jan 4th, back up Feb 17th
2016 - drop Jan 10th, back up Feb 20th
2015 - drop Jan 12th, back up Mar 3rd
I believe bitcoin will start to uptrend once again so for it's time to invest as much as I can.
Some people will afraid with current situation but personally I recommend on to keep HOLD & HOLD