Bitcoin is trading within a very large on the log scale, and currently we are sitting in the middle of that channel right above the 0.5 fibo. This means upside potential is still massive...absolutely massive. In fact, one day Bitcoin may even be priceless in fiat terms if it decides to breakout of the channel to the upside. That being said, nothing goes up (or to heck) in a straight line, and so at the moment there is also significant downside risk trading far above the noted on the chart.
Parabolic movement will be accompanied by consolidation, that we can be sure of. For this reason I have mapped out the support levels I'm watching. Perhaps these are the levels where we could see consolidation unfold early in 2018 in preparation for the next bull run.
As for ETH, I am very bullish on that one ;)