Its on their site... There is no more risk to this on the short term than any other play. I would only use this if you are debating on trading any gains to another stock, which is where this shines. If you are LONG for a few years, or thinking retirment, just buy the real thing since you wont care about immediate swings. See APMEX
For me, Im going to roll gains to the real thing and keep the rest in the ETF to play with. GLTA.