Bitcoin's surge poses no threat to gold's status as the currency of last resort, Goldman Sachs...

Number 1 rule of investing is: diversify. You cannot argue with the fact that in the past year Bitcoin more than doubled in price, while gold 'only' went up by 52%. You also cannot argue with the fact that on earth, there is a limited supply of gold. Gold is real, cryptocurrency is virtual. Bitcoin went up 220 times since 2013. If you bought $108 bitcoin in 2013, you'd have 22,800 today. If you bought gold in 2013, you would be up $100. So, if you are a risk taker: Bitcoin would have made you very rich. However, Bitcoin sold for $16,800 in 2017, and dropped to $3,400 on December 2015, so you'd have lost most of your money. With gold, it is mostly steady as she goes.
So... for diversification, I would get cryptocurrency, but not bitcoin at $22,800, maybe Ethereum (ETH) or one of the other lesser known, but solid 'coins' such as Litecoin (LTC) or Bitcoincash (BTC).
NEVER put all your eggs in one investment basket.