Coinbase gets hacked?
It's difficult to imagine how. But, there is always that possibility. That's 1.
Satoshi decides to "take profit"?
We will know if this happens. I think there is always that one guy who checks his balance.
With that event, the whole crypto community will be alarmed and after checking, I guess they will panic and sell their bitcoins.
Yeah, it could also happen.
I think one bad event could flip it but the question is what.
What you mentioned has a lower chance but I can't think of something else yet.
It could be one of the top exchanges falling that could create a bear market.