I think it is just panik. Many people who got in at 10K and above es that in the last weeks bitcoin know only one direction. Now they try to save as much of their money as they can.
Lets be honest, a bitcoin for 19K like we saw it in December, that is overvaluated. Maybe in a few years that will be a fair price.
It's funny that the price was almost 20000 USD with the network being slow and bottlenecked, fees reaching over 20USD for a single transaction and completely no solutions being implemented.
Now we have segwit, lightning transactions being tested, much less transactions in the mempool, cost of a transaction being down to 4USD if you don't have segwit set up and only 2 USD with segwit. So the network has improved and the price is below 50% of ATH. Crazy!