Gold rose more than $70 this week after finally cracking the psychologically important $1,800 an ounce level.
Many say there is momentum for higher prices, with growing inflation fears triggering risk-off trade into gold.
The bank is not ruling out copper hitting $20,000 a tonne as the market deals with significant supply crunch and growing demand.
It has costs to store, and yet when you see the debasement of the currency, you say, ‘what am I going to hold onto?'” Zell told Bloomberg.