BTC is cooling off after a 300% advance.
Looking for no more than a 40% retrace which would be inline with Bitcoin's history.
A 30% retrace is also the Golden Ratio on Fibonacci Retracement and between 30%-40% retrace would be the top of the multi year Parallel Channel.
Further around 30% we find the 50 Day MA and the 10k psychological support.
There is a lot of support below, the recent 20k Finex shorts claim notwithstanding.
Rough History of Retraces
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02-Nov-15 -> 40%
13-Jun-16 -> 29%
02-Jan-17 -> 38%
06-Mar-17 -> 33%
05-Jun-17 -> 39%
28-Aug-17 -> 40%
06-Nov-17 -> 33%
18-Dec-17 -> 46% (Bear Market Begins)
01-Jan-18 -> 65%
Lastly you can see a faint fractal overlayed. This is from the exit of the parallel channel in April 2017. This is not perfect and does not fit too well, however, let's see how plays out.