CME's Criminally-Timed Silver Margin Increase-They Pulled Out Every Dirty Trick
SPAN is handy, but it is a tool for analysis. Also, the exchanges set the parameters that are fed into SPAN in order to run its analysis. The CME does not automatically adjust margin requirements according to the daily results of SPAN reports.
Think about it, what changed so much in one day that the SPAN report said that silver futures margins had to be raise by <30%> the NEXT day?
Seriously. Stop. Think about it. If the CME were running off SPAN they should have had a series of small margin increases for the last couple of months, not two back to back large increases in a week.