How can anyone ever be THAT sure? 2020 is a very short time for bitcoin to go that high, and, even if, theoretically, it did, then it would be for a very short while, due to an overbought trend, and will start dropping like hell, that too very rapidly. It would become very unstable as a currency which would result in mass decline, so I think that it better not go anywhere near that value in such less time, for it's own sake. A gradual, slow rise is much more beneficial to itself.