Somanetics (SMTS) was the most advancing stock in the Nasdaq Wednesday morning, with shares up more than 31%, or nearly $6 to $24.85. Shares reacted to news that Covidien (COV) is buying Somanetics, acquiring all of the outstanding shares of Somanetics for $25.00 per share in cash, a 32% premium to Tuesday's close. Covidien will pay a total of $250 million, for a total transaction value of approximately $300 million.

Covidien, a drug and medical devices maker, is already the distributor for Somanetics' noninvasive diagnostic equipment called INVOS (In-Vivo Optical Spectroscopy) Cerebral/Somatic Oximeter in Europe, the Middle East and Africa. INVOS monitors patients and continuously measures blood oxygen levels in the brain and in the body to help detect and correct complications.

Analyst Upgrades

• UBS upgraded Potash (POT) to buy from neutral and raised its price target to $112 from $106. UBS raised its 2011 potash production estimates based on expectations for a tighter market and notes the potential for China to import substantial amounts of corn.
• BMO Capital upgraded Peabody Energy (BTU) to outperform from market perform. The firm, which has a $49 target on the stock, cites valuation for the upgrade.
• Janney Montgomery upgraded City Holding (CHCO) to buy from neutral with a $37 price target, citing the recent pullback in shares.
• Boston Scientific (BSX) was upgraded to sell from conviction sell at Goldman.
• Pegasystems (PEGA) was upgraded to buy from hold at Roth Capital.
• Wendy's/Arby's (WEN) was upgraded to buy from neutral at SunTrust.

Analyst Upgrades

• UBS upgraded JPMorgan (JPM) to buy from neutral and has a $50 price target on the stock. The firm cites valuation for the upgrade.
• Morgan Joseph upgraded Deere (DE) to buy from hold, citing strong U.S. demand for combines and tractors, favorable fundamentals in Brazil, and expectations for improved domestic construction-equipment demand. The firm has a $75 price target on the stock.
• Wells Fargo upgraded Venoco (VQ) to outperform from market perform to reflect increased confidence in the company's Monterey Shale potential.
• GlaxoSmithKline (GSK) was upgraded to buy from hold at Jefferies.
• Tenet Healthcare (THC) was upgraded to positive from neutral at Susquehanna.
• Agnico-Eagle (AEM) was upgraded to outperform from sector perform at RBC Capital.

Analyst Upgrades

• Deutsche Bank upgraded U.S. Steel (X) to buy from hold after raising its steel forecasts and upped its target price on shares to $77 from $44. Note, the firm also downgraded AK Steel.
• Credit Suisse upgraded Philip Morris (PM) to outperform from neutral based on a better international outlook.
• JPMorgan upgraded ev3 Inc. (EVVV) to overweight from neutral. The firm sees upside potential to ev3's consensus estimates for 2010 and raised its target price on shares to $19 from $15.
• Vale (VALE) was upgraded to overweight from equal weight at Barclays.
• Xilinx (XLNX) was raised to outperform from sector perform at RBC Capital.
• Shuffle Master (SHFL) was upgraded at KeyBanc to buy from hold.

Analyst upgrades:

• Baird upgraded Carlisle (NYSE:CSL) to Outperform from Neutral and lowered their target to $25 from $33 following the company's Q4 results citing attractive valuation and solid execution.
  
• Citigroup upgraded Talbots (NYSE:TLB) to Hold from Sell on valuation as they believe the company's cash flow is improving and does not expect the company to face bankruptcy in next three years.
  
• Jefferies upgraded shares of Spectra Energy (NYSE:SE) to Hold from Underperform on valuation following the company's Q4 results and raised their target price to $15 from $11.75.
• Costco (NASDAQ:COST) was upgraded to Buy from Neutral at UBS.
  
• AU Optronics (NYSE:AUO) and LG Display (NYSE:LPL) were upgraded to Buy from Neutral at Banc of America/Merrill.
  
• Alpha Natural (NYSE:ANR) was raised to Buy from Hold at Natixis.

MOST NOTEWORTHY: EV3, Steel Dynamics and Sonic were today's noteworthy initiations:

• JP Morgan initiated EV3 (NASDAQ: EVVV) with a Neutral rating. The firm sees risk to guidance and finds it too early to recommend the stock.
  
• Steel Dynamics (NASDAQ: STLD) was assumed with an Overweight rating at Morgan Stanley.
  
• Lehman initiated Sonic (NASDAQ: SONC) with an Overweight rating.

OTHER INITIATIONS:

• HSBC initiated Rostelecom (NYSE: ROS) with an Underweight rating and $36.50 target.
  
• Keefe Bruyette assumed German American Bancorp (NASDAQ: GABC) with a Market Perform rating and $13 target.
  
• JP Morgan initiated Perdigao (NYSE: PDA) with an Overweight rating.

MOST NOTEWORTHY: UQM Technologies, Blue Nile, NPS Pharmaceuticals, Massey Energy and Hartford Financial were today's noteworthy downgrades:

• Merriman downgraded shares of UQM Technologies Inc (AMEX: UQM) to Neutral from Buy after Phoenix Motorcars delayed its electric vehicle manufacturing ramp, as they view the company's Phoenix Motorcars relationship as the primary driver for near-term growth.
• Citigroup downgraded shares of Blue Nile Inc (NASDAQ: NILE) to Sell from Hold on valuation as they believe near-term risks outweigh rewards. They see risk to Q3 revenue estimates and their analysis suggests an in-line quarter at best.
• NPS Pharmaceuticals Inc (NASDAQ: NPSP) was downgraded to Neutral from Buy at Oppenheimer and to Hold from Buy at Jefferies. Oppenheimer lowered shares following disappointing Gattex data; Jefferies believes the P3 GATTEX results in short bowel syndrome make the chances of successful low-dose approval unpredictable.
• Friedman Billings downgraded Massey Energy Company (NYSE: MEE) to Underperform from Market Perform based on valuation, 2008/2009 outlook, spinoff of Patriot Coal appears to be a better investment option, and another blow to mountaintop mining and permit issues.
• JP Morgan removed The Hartford Financial Services Group Inc (NYSE: HIG) from their Focus List; however, they believe the company's fundamental outlook remains positive and expects strong Q3 results.

OTHER DOWNGRADES:

• Morgan Stanley downgraded EV3 Inc (NASDAQ: EVVV) to Underweight from Equal Weight.
• Business Objects SA (NASDAQ: BOBJ) was downgraded to Hold from Buy at Roth Capital.
• Goldman downgraded The Nasdaq Stock Market Inc (NASDAQ: NDAQ) to Neutral from Buy.
• Banc of America downgraded The Pepsi Bottling Group Inc (NYSE: PBG) to Neutral from Buy.