I think Bitcoin is in a bubble indeed, but in the very beginning of a new bubble. The last bubble took months before it popped, and it shouldn't surprise me if this bubble will go on all the year of 2017 and rise to 8.000 - 10.000. The crash will be huge, but I think it will never come lower than it was before the bubble (1.200), because the fundamentals of bitcoin are very good. I think you can still buy BTC for the short term to ride the bubble or for the very long term till the next bubble (then you have to hold on for years). For medium term I should be careful now.