...ECDSA were broken and for some crazy reason the opportunity to exit above zero existed.

Beyond that, I seriously can't think of a case.

Indeed! A sudden bubble means, at least for me, that someone is playing the market. Which, in turn, means that this bubble will eventually collapse, leaving me with more fiat for more bitcoins!

Some people here will just hold bitcoin forever in expectation of some unreal price like $10.000. And I think it is not the way to live with bitcoin.
You just want to have some fun with bitcoin, it is just a form of currency after all. You are supposed to be buying stuff with it! So I guess I would sold 70% of my coin if price will be good enough $700+ and then start to grind it again.

I needed the money for a cure of some health related issue. Then I don't have BTC in an amount that would under any circumstances be useful in that situation.

I would spend* all my Bitcoins if Im sure I have only few day/weeks left

* Sorry had to correct it a bit

My price was paid.

i am 100% sure i can rebuy at lower price or i am 100% sure Bitcoin will fail in next months, so in other words most possibly never.

I would sell all of my bitcoins if a quantum computer are cracking one private key per minute on the block chain, but actually I don't believe quantum computer can reach that kind of maturity in any meaningful time

I would sell all my bitcoin if 1BTC = $750 this year

I hope this is really happening