I think bitcoin doesn't follow its path in 2017, and I'm not sure whether bitcoin will be high in December, and bitcoin still needs more time for it, my estimate is that bitcoin will rise in 2020 or 2021.
Btc might break 2017 high this year itself and has a long way to go as well considering the future growth and Formans is concerned which means that price will continue to move up the ladder and grow from their onwards .
If you are really believing and you can take the risk, the market can grow to what the last maximum height it went before, the current moment is giving investors and idea where to place thier money, Bitcoin being one of the best investment and individual can have will bring everything high again.
Trust in how you interpret the situation and bring good outcome to your investment.