Most investors don't truly understand the long-term case for owning gold, according to Crumb. "People want to bean count gold like it's oil or copper," Crumb says. That's misguided.

There's roughly $7 trillion of gold money stock and inventory, he says, and, unlike other commodities, gold is scarce and non-perishable. So that $7 trillion in inventory is basically the last 5,000 years of production.

"I like the math of gold. It's got this deep simplicity" as money stock, Crumb says.