CommoditiesThe Shanghai Exchange piles on silver, hiking margin rates and increasing the daily limit for...May 12, 2011 7:10 AM ETSLV, DBS, AGQ, ZSL, SIVRBy: Stephen Alpher, SA News Editor1 Comment The Shanghai Exchange piles on silver, hiking margin rates and increasing the daily limit for price moves. Silver is at its lows of the session, -8.0% at $32.68/oz. Recommended For YouTrending AnalysisTrending News