Prior to that price has broke above the downtrend and retraced back to the 6k support. Fibonacci applied to the corrective wave down after the breakout could help to determine the upside resistance levels.
If the massive support at 6k will hold, Bitcoin could be starting yet another run right now. But, there is a huge resistance that must be broken first and it is USD 10k physiological level, which corresponds to the 161.8% Fibs retracement.
Break above it should be the confirmation of the further growth, that might result in the strong rise.
The resistance levels to watch:
If Bitcoin breaks above the 10k level, next strong and potential key resistance could be at $17.5k, that is 461.8% Fibs. But... if this level is broken, it could be the long confirmation that the true run has begun. In that case BTC/USD is expected to grow to at least 30-40k range in 2019.