5
May
Silver falls to one-month low after COMEX margin hike
5 May 2011 Reuters

Silver prices fell 1 percent on
Thursday to a one-month low, after the CME Group hiked margin
requirement on COMEX silver again, while gold held steady.
http://www.reuters.com/article/2011/05/05/markets-precious-idUSL3E7G501P20110505