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 have also observed it last year when I thought bitcoin went down on January after a good pump on December (2016) and then it started to rise in the mid-February up to how it was on December (2017). Nothing new. Just another opportunity to fill our bags.
Excellent observation guys and the primary reason behind this is most likely the Chinese New Year since many Chinese would want to sell their coins to buy gifts and celebrate the festivities. I feel that bitcoin and all other altcoins will start rallying again sometime in the middle of february just like the previous years and there might be an even bigger rally which will help bitcoin reach a new ATH by April 2018. This is simply my gut feeling speaking and am hoping that these rallies truly happen in the near future. HODLING my bitcoins and altcoins for now!