This recent dip is most likely caused by Asians cashing out for Lunar New Year... the last three years, the Yearly-Lows have been at around the exact same time, three weeks before the Lunar New Year.
Actually, I wrote a more detailed post about that today, you can read it here:
https://steemit.com/crypto/@memekings/the-yearly-crypto-low-in-january-here-is-why