Analyst Upgrades

• SanDisk (SNDK) was upgraded to outperform from neutral at RW Baird.
• JPMorgan resumed Potash (POT) at overweight, up from neutral.
• Ariba (ARBA) was upgraded to buy from neutral at Roth Capital.
• Cirrus Logic (CRUS) was upgraded to buy from hold at Jefferies.
• Morgan Stanley upgraded Tesoro (TSO) to overweight from equal weight.
• Solarfun Power (SOLF) was upgraded to buy from hold at Auriga.
• Barclays upgraded Ciena (CIEN) to overweight from equal weight.
• Optimer Pharm (OPTR) was upgraded to outperform from market perform at JMP Securities.
• Argo Group (AGII) was upgraded to outperform from market perform at FBR Capital.
• BofA/Merrill upgraded Green Mountain (GMCR) to buy from underperform and Southern Company (SO) to neutral from underperform.

MOST NOTEWORTHY: The U.S. media sector, oil services, MercadoLibre and Horsehead Holdings were today's noteworthy initiations:

• Credit Suisse initiated coverage of the U.S. media sector with a Market Weight rating, shares of The Walt Disney Company (NYSE: DIS) with an Outperform rating and shares of Time Warner Inc (NYSE: TWX) and Viacom Inc (NYSE: VIA.B) with Neutral ratings.
  
• Bernstein initiated coverage of the oil services sector with a Positive Bias rating. The firm initiated Weatherford International Ltd (NYSE: WFT) with an Outperform rating and $84 target and Halliburton Company (NYSE: HAL), Baker Hughes Incorporated (NYSE: BHI) and Schlumberger Limited (NYSE: SLB) with Market Perform ratings and a $44 target, $103 target and $96 target, respectively.
  
• MercadoLibre Inc (NASDAQ: MELI) was initiated by American Technology with a Buy rating and $45 target, as the firm believes the e-commerce growth opportunity in Latin America is still in its infancy. Shares were also started at Pacific Crest with an Outperform rating and $37 target, as the firm believes the company should benefit from strong secular growth and company-specific drivers. MercadoLibre was also initiated at JP Morgan with an Overweight rating and at Merrill Lynch with a Buy rating and $35 target.
  
• Friedman Billings expects Horsehead Holding Corp's (NASDAQ: ZINC) EBITDA to increase even in a declining commodity environment and believes the company is well positioned to gain market share. Shares were started with an Outperform rating and $27 target also added to the firm's Top Pick List.

OTHER INITIATIONS:

• Citigroup started shares of Companhia Vale do Rio Doce (NYSE: RIO) with a Buy rating and shares of StealthGas Inc (NASDAQ: GASS) with a Hold rating and $20 target.
  
• Roth Capital started shares of Internap Network Services Corporation (NASDAQ: INAP) with a Buy rating and $19 target.
  
• Raymond James initiated Atmel Corporation (NASDAQ: ATML) with an Outperform rating and Argo Group Internaional Holdings Ltd (NASDAQ: AGII) with a Strong Buy rating.