The correlation coefficient
between gold futures
started out negative for a few years, but after Feb '14 they began to move together. BTC
have now been in a five year cycle where the correlation will jump to +72, then drop to a higher low, then up to +72 again, over and over. It seems reasonable that the correlation could soon become stronger than +72 at this rate.
It adds validity to the "Bitcoin is digital gold" idea. They are both being traded in an increasingly similar way.