There are always few minor corrections when bitcoin on the rally like this, we've seen some after bitcoin break resistances at $17k-$18k.
a bigger retraction probably 10-20% after bitcoin break the ath at $20k+ but not the massive one like 35%-50%.
Many predictions said bitcoin still in the early phase of bull-run, not even start to pump rapidly like in 2017, it may on that phase in 2021 to reach $30k-$50k.
Saying like that is true that bitcoin will actually reach a rally in 2021, we will look forward to whether this correction can occur in the future.
$18.5k in nov but it is likely that this will continue with the existing rally with 25% gains which will continue to reach its highs.
My piling was strong in December bitcoin was able to reach 20k after seeing such a big move, I see other altcoins will also follow in bitcoin footsteps today.