If bitcoin retains the strength it is showing now after the Segwit 2X fork in Novemeber, I would guess it will end the year 2017 with above 6000 USD in value. It has had a wonderful run in this year and there is no reason it will end the year downtrend. 
There are many reasons for a downtrend, never forget we are in the mess of a civil war.Best to do a worst case TA as a guideline. I tend to start at the 3/25/2017 at $916, ignoring the mid July dip since it was highly artificiall, but taking the $3000 of 9/15/2017 since that has been reassuring the preceeding ATH as a support line. Those $3000 mark the floor from now on.
That line predicts you $4300 for New Year's Eve. So nearing that value would trigger a bullish take on markets. Right now we are kinda high, more in a selling position.
