The divergence could be geographical as well. I am assuming that the majority of the gold companies on the GDX are part of the western exchanges. If you are Chinese or Indian or ???? there could be a prepencity to buy bullion as a safe haven trade . I would also assume that Equities of any kind would not be considered safe haven. Also I have been reading that a lot of Central Banks are buying gold and I am sure that they are not interested in equities.