Since the market is going down and down are you worried about your Bitcoin? I saw someone asking what to do with his/her bitcoin? S/he has 12 bitcoin. What are you doing with your bitcoin?
Hold! don't fret and be firm its normal to have red market trends this time of the year and I would only worry if nothing happens and this continues by the end of 2018 but for now it is still to early to decide to cut your loss for your investments specially if you have a huge amount invested to bitcoin.