In the last days, the market couldn't build up enough volume to push the price down.
Like in ethereum, bitcoin broke out of the bearish diagonal and tried to reach price levels above the last high of wave (a).
Since then bitcoin failed in gaining further momentum and as you can see on the chart, the volume is already declining, the chances are pretty high that bitcoin will "re-enter" the diagonal.
The wave structure of the past weeks gives me reason to believe that we are in a-b-c correction in the yellow wave (ii). After completion of wave (ii) we should see harsh selloff in order to establish bearish wave (iii).
Important: As long as bitcoin stays below the resistance @ 18391.0$ we can't expect any bullish reversal whatsoever.