Personally I just think of it this way. Those who have invested their fiat value on btc is starting to take profit from their earnings.
Lets say I invested 1000 USD in btc at the price of 12,000 USD then then it went to 19,000USD then its about time for me to take profit and enjoy my earnings.
but if you are a real believer of crypto curreny, HODL is the key in this business.