If you buy BTC today at say $1150, you need it go to $2300 per BTC in 2017 to double your money, a bit maybe/maybe not feeling. If you want to risk that money and "maybe" make a huge return, buy Monero(XMR) instead, it is a secure, private, untraceable currency that more likely will earn you a lot more % on your investment. Monero(XMR) is at about $19 today, and has more potential of growth short term then BTC has. Read up on it, you will be glad you did.
BTW, I have both, so I am not just promoting Monero(XMR), just letting you know about it.