1. Big institutional investors (Tesla, Microstrategy) pull out or face crashing their stock as well - they bought Bitcoin directly or indirectly with borrowed money https://www.youtube.com/watch?v=st3KJN_DzCg
2. Crypto community panics and claim their money en masse
3. "Satoshi" and other insiders secretly cash out
Since it is mainly a stakeholder manipulated market, regulation had not much impact so far...
As long as the narrative keeps perpetuating belief & demand, it will live.