Each share is currently backed by 0.9422 Oz of physical silver held in London. I wouldn't pay too much attention to JP Morgan as custodian. They hold the metal in trust for the unit holders. Do people think they would actually attempt to steal it? JP Morgan have a lot more to lose by breaking the law then getting their hands on a couple of bars of silver. The bars are independently audited every 6 months, to ensure the metal is actually there.
ETPMAG is currently holding 8,640,482 oz of physical silver. So by buying units you are drawing silver out of circulation. If you want to hold silver for 10 years, buy physical and avoid the 0.49% management fee. Otherwise if you would like to sell it within 5 years, I would look at the buy and sell spread offered by physical bullion dealers. ETPMAG is what 10 cents, add a couple 0.49% fees and you should come out way in front.
