First, a little history on this question. Assuming you plan to live past 2019, you may find the following demonstration useful.
Should you buy Bitcoin in:
2010 – YES
2011 – YES
2012 – YES
2013 – YES
2014 – YES
2015 – YES
2016 – YES
2017 – YES, although it’s scary right now if you bought in December.
2018 – YES? Yes.
2019 – YES? Yes.
The price of Bitcoin today is roughly $6700US or C$8888.88
UPDATE: As of 10:00pm tonight, the price of Bitcoin is roughly $9999.99
Although it will not continue to increase at this rate, and there will be chances to purchase it still for far less than today’s price, the point remains, if you want to turn some money into more money long term, buy and hold Bitcoin long term.