If after creating this topic you buy BTC for $ 10.000, then after the peak up to $ 18000, the BTC has exceeded $ 17.000, predicted that this year's BTC will exceed $ 20.000 , is an extraordinary exchange rate increase. It is predicted that by the end of 2018, the BTC price of $ 1 million will be fully based on the current growth rate. So you should invest BTC before it's too late. If the current investment time, next year you will have a large amount of money from this investment. Or you might consider investing in Altcoin because of the strong growth of Ethereum, which promises to grow as strongly as Bitcoin in the next 5 years. 
That is correct, the mathematics and statistics are all favoring bitcoin for next year but i doubt if it will get to 1 million dollars because that is too much an amount of money to price just a single bitcoin. It might be one day but for 2018, that will be too much within a short time.