Analyst Upgrades

• Siemens (SI) to buy from hold at Deutsche Bank.
• Diamond Offshore (DO) to market perform from underperform at FBR Capital.
• MeadWestvaco (MWV) to conviction buy from neutral at Goldman.
• TD AmeriTrade (AMTD) and Cabot Oil & Gas (COG) to buy from neutral at BofA/Merrill.
• Janus Capital (JNS) to hold from sell at Citigroup.
• Motorola Mobility (MMI) to buy from neutral at UBS.
• Frontier Communications (FTR) to neutral from underperform at Macquarie.
• Humana (HUM) to buy from hold at Argus.

Analyst upgrades:

• Citigroup upgraded shares of Cadbury (NYSE: CBY) to Hold from Sell on the company's pricing initiatives and their expectations for margin expansion.
  
• Jefferies upgraded shares of Medicis (NYSE: MRX) to Buy from Hold and raised its target to $16 from $12.50 as they believe the company's settlement with Impax should lift valuation and drive higher earnings.
  
• Cowen upgraded Williams-Sonoma (NYSE: WSM) to Neutral from Underperform on valuation. Shares were also upgraded at Merrill Lynch to Buy from Underperform.
• Signet Group (NYSE: SIG) was raised to Neutral from Sell at Goldman.
  
• EMC Corp (NYSE: EMC) was upgraded to Buy from Accumulate at ThinkPanmure.
  
• DSP Group (NASDAQ: DSPG) was upgraded at RBC Capital to Sector Perform from Underperform.

Analyst downgrades:

MOST NOTEWORTHY: Some of today's noteworthy downgrades were Medimmune Inc (MEDI), J.B. Hunt (JBHT), Lockheed Martin (LMT), Komag (KOMG) and Victor Corp (VICR):

• Freidman Billings cut Medimmune inc (NASDAQ: MEDI) to Market Perform from Outperform on valuation. Prudential downgraded shares to Neutral from Overweight and recommended investors take profits in the company.
• J.B. Hunt Transport Services Inc (NASDAQ: JBHT) was downgraded to Peer Perform from Outperform at Bear Stearns citing valuation.
• Lockheed Martin (NYSE: LMT) was removed from Goldman Sachs Conviction Buy List and prefers L-3 Communication (LLL) over the large-cap aerospace/defense company.
• Komag Inc (NASDAQ: KOMG) was downgraded to Sell from Neutral at American Technology as they believe industry fundamentals have weakened and that the Seagate (STX) preannouncement will increase pricing pressure.

OTHER DOWNGRADES:

• Stifel downgraded Mercantile Bank (NASDAQ: MBWM) to Hold from Buy at Stifel.
• Soliel downgraded shares of Limited Brands (NYSE: LTD) to Hold from Buy.
• Matrix USA cut DSP Group (NASDAQ: DSPG) to Strong Sell from Hold.
• Brean Murray downgraded shares of Keithley Instruments (NYSE: KEI) to Sell from Buy with a $13 target following the company's Q2 pre-announcement.
• Needham cut Semitool Inc (NASDAQ: SMTL) to Hold from Buy.

Analyst summaries provided by TheFlyOnTheWall.com (subscription required).