The BIS source is impeccable, unfortunately they hardly assume a global regulatory role, except for occasional warnings and issuing global banking best practice accounting rules (Basel II) with which as yet not many banks are compliant for reasons we all know.

The silver derivatives represent some 15'447'154'472 (15 billion) ounces or 480460 tonnes at $12.3 per ounce this represents approx 17 years global silver mine production (2007 global figures 894.5 million ounces) not counting a declining silver mine production and physical inventories going close to just in time stocks.

http://www.silverinstitute.org/suppl...

What would be interesting to know who places these bets and who are the counterparties, most likely the are the same and are the central banks as the biggest market interventionists, manipulators through their conduit trading partners e.g. JP Morgan for the Fed, Deutsche Bank for the ECB, etc. Vital is that it remains undercover, hence the strong continuing driving forces for light regulation so they can remain under the radar screen.

For recollection the JP Morgan silver derivatives represent 353'983'740 ounces or 11010 tonnes. Table 9: $4.354 billion in precious metals

http://www.occ.gov/ftp/release/2009-...

The figures for silver, gold and other derivatives have detached from any economic reality. A deleveraging has become virtually impossible without a systemic failure of the central banks and the system, this is the fundamental reason of their continuing desperate further market interventions, until the last man standing, as their (paper) means are unlimited this can still go on for quite a while. Until physical take off by industry, jewelry, the ETFs, silver coins and on the Comex overwhelms the paper manipulation at some point in the future. Physical take off at the Comex will be key.