I don't think Bitcoin will follow a parabolic curve. Based on observation of market movements, Bitcoin's price is being driven by a "pump and dump" cycle with the deviation following largely emotional decisions.

If the coin were to "stabilize" which I believe will require much more widespread adoption, I would expect it to be valued at roughly $8,000 USD today with an overall growth over time. The limited supply and increasing demand suggest that growth will continue for at least the next four years (or until the mineable supply is exhausted).

As alt-coins gain ground, those that distinguish themselves from Bitcoin are the ones that will survive and grow overall. With ADA solving the problem of expensive and resource consuming transactions, it is poised to grow steadily and indefinitely. Steem/SBD being based on a marketable service platform are also positioned well for growth.

Paying attention to "blue chips" and learning about what they are doing could be a much better way to invest than Bitcoin in the long haul.