Indeed, May's joint sell-off in commodities and equities echoes similarly timed declines in 2010 and 2011.

ECONOMIST: Making sense of the fall in commodity prices

Easing likely would help other commodities and equities on hopes that it would help speed up an economic recovery.

FORBES: Precious Metals, Other Markets To Take Cue From Bernanke Speech Friday

Hackett said the divergence between commodities and equities is not unlike what happened in 2007, but in reverse, when investors fled stocks and ran to commodities.

FORBES: FOCUS: Falling Commodity Prices, Slowing Global Growth Stir Deflation Thoughts