get the point, so true. I think the green line is super-exponential and hence it is not only parabolic but hyperbolic. Parabolas grow fast, but never reach infinity (mathematically - at least not in finite time but with t going to infinity as well) hyperbolas or super-exponential functions literally explode and go to infinity in finite time. This is why price bubbles are finite-time-singularities like a black-hole and have to correct, otherwise they would go infinite because the time-period for a price doubling is cutted in half each doubling (like Bitcoin in 2017)