As long as bitcoin functions, I don't think it will ever go to zero. Too many believers out there will try to see if lightning strikes twice. I think if it drops back down to $600 there will be a swarm of buyers to catch the falling knife from going any lower than that. Might pop up again a little bit, but it will slowly trickle to worthlessness given enough time.
A just as dumb prediction as those who say it will become $1.000.000+. The reality will be somewhere in-between. 1) People who missed the boat or the ones who sold too early (even those who sold at $2500), all predict extreme dumps. 2) People who still Hodl or are buying right now, all see moon rides. As I see the exponential rising number of hedge-funds entering this space, my cards are on (2).
My target is $5,000 but could go lower ($4,000) if the good ol' mark manipulators (politicians, corporate executives, media etc) come out to play during the correction. Good luck with $600.
Just as booze in the twenties, gold in the thirties and drugs right now..... Be aware that about 17% of the whole worlds GDP is in the black underground markets and assets: that's more than $10 trillion. Imagine that if only 10% of this market is fled to, if Bitcoin gets a world wide ban, it will lead to a $60.000 price for 1 Bitcoin. No where near your $0 hope.
I agree that it will drop in value someday, but $600 and below is not realistic. There are very big players out there and many of them love bitcoin because it provides them anonymity. So, there will be the big players who are to give all they've got to see that bitcoin remains at a very high level. It isn't going to drop below $1000 in my opinion.
There is no bubble in history that takes longer than 3 years. In 2020 we will be at 12 years. A duration which proves it to be an S-curve technology (instead of a Bell-curve, bubble).