Baystreet Staff - Thursday, April 11, 2013 Cliffs Natural Resources (CLF) drops with S&P placement Cliffs Natural Resources, Inc (NYSE: CLF) fell back 3.6% to $19.62. Pinnacle West Capital Corp has taken over from Cliffs Natural Resource as #236 in the S&P 500 most shorted component, while CLF has fallen to the #357 spot. Share volume was 627,000