Benzinga's Top Pre-Market Gainers

Cliffs Natural Resources, Inc

soared +2.65% to $20.89 in the pre-market trading. 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. Vodafone Group Plc

surged 1.36% to $29.10 in the pre-market session. Vodafone has joined hands with China Mobile Limited

to bid for mobile license in Myanmar. Vodafone has also announced plans to launch 4G services in Australia in June. Quest Diagnostics Inc

added 1.15% to $57.30 in the pre-market session. Quest Diagnostics has announced that it has completed the divestiture of its HemoCue diagnostics products business for approximately $300 million plus customary adjustments for cash balances. Ericsson

moved up 1.11% to $12.14 in the pre-market session. Ericsson has announced the acquisition of Microsoft's

Mediaroom business.