IMO most serious investors knew that bubble is going to burst but they still saw the opportunity to capitalize, those guys have probably bought millions worth of BTC each and once they saw that 20k peak they knew it's time to sell and once they did, mass followed
and it will continue to decline, this coin literally almost has no use, no business is going to accept bitcoin at its current state, even when it was climbing in price, business would be exposed to potential loss in a day time that's why steam stopped accepting BTC once it started to go up rapidly
now the only way for it to stabilize is when only long time investors are left, then maybe more businesses will accept it as a payment