Depends on your goals, risk tolerance and time frame you're investing. You can expect gold will hold its value +/- 20% next month, but bitcoin has higher upside and lower downside. You can double your money in gold in 3 years maybe if you're lucky, but you can't lose more than 30% or 50%. In bitcoin you could make 5x your investment or lose 80%.
Gold is moderately speculative and bitcoin is highly speculative, so you should diversify and decide which is more important, huge returns or safety