WRONG! The silver ETF, SLV is *NOT* a futures based ETF. The prospectus is quite clear that they buy and hold actual silver.
One of the reasons the silver futures market is so tight is that the silver ETF has a huge amount of physical silver in their vaults.
Now, SLV *could* be lying, but it would be an amazingly bold faced lie. For instance, they have the serial number of the silver bars that they claim to have in inventory available on a weekly basis listed on their site.
I don't *think* you are claiming that they are running a completely fake Maddoff style Ponzi scheme, I think you really just don't know what you are talking about.
But if you do have some secret information that SLV is a ponzi scheme please share it with us.
Otherwise, please stop making wild unsubstantiated false statements.
Many of those same contracts state explicitly that the holder of the contract cannot request physical delivery. Look into it.