"Cumulative percent changes" (below) shows the determined increase in December 2011 silver futures vs. gold futures from Sept. 1, 2010 to March 1, 2011. The intermediate peaks and troughs in the price of gold are matched in timing by silver, with some exaggeration especially noted in early November. Declines in silver vs. gold during January 2011 may be related to short sales of silver, while the increase in silver futures in February 2011 may be because of market resistance against short-selling silver. Attempts at manipulation of precious metal prices have been noted through history, although the turmoil in North African nations in early 2011 is probably the major cause of price escalation during January and February.
To see how well the percentage changes in the price of December 2011 silver futures are correlated with the changes in the price of gold futures, a regression analysis of the 123-day period of comparison is shown on "Silver and gold correlation" (below). The results of regression are: slope 1.80, y-intercept 0.0028, and correlation coefficient 0.84. Thus, the straight regression line rises and falls from a zero change in the price of gold futures, with changes in silver futures approximately 80% larger than changes in the gold futures price.