I expect Bitcoin will be gone by the end of this year, but it might not.
It will definitely be gone in a couple of years.
It might be doing something on the Dark Web at that stage - but even that is probably unlikely.
Normal citizens who have bought Bitcoin will not be able to realise any cash for them legitimately within a few years.
Is that precise enough?
From a practical point of view, I am simply trying to stop people losing money. I am also trying to help those of you who have been lucky enough to make money, to preserve your wealth. If you lose 98% of your money but get some satisfaction by coming back to me at the end of 2020 saying "Ha, ha, Brendan - you were wrong. Bitcoin is still worth 10 cents per unit on the Dark Web" so be it.
Bitcoin is worth nothing. No one should be buying it. Those of you who have should sell it as soon as you can.
Brendan