Well gold is the way to go if you want to diversify your investing. Both bitcoin and gold are very solid investments, although people tend to forget that.
Especially when it comes down to bitcoin, it's underestimated

For me I would chose both, although Gold's value will surely appreciate and it's stable I also believe that bitcoin has it's own market value. They are totally different and it should not be compared. So why chose when you can have both.