Analyst upgrades:

• Merriman upgraded Sunpower (NASDAQ: SPWRA) two levels to Buy from Sell after transitioning coverage. The firm believes Sunpower is emerging from the current recession as the CleanTech leader and has a $38-$48 price range on shares.
• Citigroup upgraded Varian Medical (NYSE: VAR) to Buy from hold as it believes capex pressure and health care reform uncertainty is priced into shares, and demand will return as hospital budgets stabilize. Citi raised its target on shares to $45 from $36.
• FBR Capital upgraded Gap (NYSE: GPS) to Outperform from Market Perform following the Q2 results to reflect product improvement and ongoing inventory control. The firm raised its target on shares to $24 from $18.
• Schnitzer Steel (NASDAQ: SCHN) was upgraded to Neutral from Sell at UBS.
• UDR Inc. (NYSE: UDR) was upgraded to Market Perform from Underperform at Wells Fargo.
• The Buckle (NYSE: BKE) was upgraded to Buy from Hold at Roth Capital.

Analyst upgrades:

• Goldman upgraded SanDisk (NASDAQ: SNDK) to Buy from Neutral and raised their target to $22 from $16 citing the renegotiated royalty agreement with Samsung.
• Goldman also upgraded Starwood Hotels (NYSE: HOT) to Buy from Sell and raised their target to $27 from $11 citing strong operating leverage as RevPAR recovers.
• KeyBanc upgraded Werner Enterprises (NASDAQ: WERN) to Hold from Underweight citing a recent improvement in freight demand.
• J.C. Penney (NYSE: JCP) was upgraded to buy from Underperform at Banc of America/Merrill.
• Savvis (NASDAQ: SVVS) was raised to Outperform from Perform at Oppenheimer.
• Sanofi-Aventis (NYSE: SNY) was upgraded at Citigroup to Buy from Hold.

Analyst upgrades:

• Jefferies upgraded NeuStar (NYSE:NSR) to Hold from Underperform on valuation following the recent weakness and raised their target price to $15 from $12.
  
• Oppenheimer upgraded Adobe Systems (NASDAQ:ADBE) to Outperform from Perform on valuation as they believe the recent pullback has created an attractive entry point into the name. The firm has a $27 target on the stock.
  
• UBS upgraded Pfizer (NYSE:PFE) and Wyeth (NYSE:WYE) to Buy from Neutral based on valuations. Pfizer's price target remains $18 and Wyeth's was raised to $50 from $38.
• Methanex (NASDAQ:MEOH) was upgraded to Sector Outperformer from Sector Performer at CIBC.
  
• BHP Billiton (NYSE:BHP) was raised to Buy from Hold at RBS.
  
• Anadys Pharma (NASDAQ:ANDS) was upgraded to Buy from Neutral at Piper Jaffray.

Analyst upgrades:

• Citigroup raised Ann Taylor (NYSE: ANN) to Hold from Sell. The firm upgraded shares following the company's Q2 upside and believes guidance for the second half of 2008 is appropriately conservative.
  
• Jefferies upgraded China Sunergy (NASDAQ: CSUN) based on valuation,and improved liquidity and silicon supply outlook.
  
• Stephens upgraded infoUSA (NASDAQ: IUSA) shares to Overweight from Equal Weight to reflect the stock's valuation, new management, improvements in expense controls and the potential to become a takeover target.
  
• Citigroup raised BB&T (NYSE: BBT) to Buy from Hold.
• Stifel upgraded Leggett & Platt (NYSE: LEG) to Buy from Hold.

Analyst downgrades:

• Citigroup downgraded Cablevision (NYSE: CVC) to Sell from Buy as they do not expect the company's structural moves to unlock value.
  
• Wachovia dropped Knight Transportation (NYSE: KNX) to Market Perform from Outperform based on valuation.
  

Citigroup cut Cablevision (NYSE: CVC) to Sell from Buy, according to MarketWatch. The financial sites also reports that Jefferies upgraded China Sunergy (NASDAQ: CSUN) to Buy from Hold.

Citigroup upgrades Ann Taylor (NYSE: ANN) to Hold from Sell, according to Briefing.com. The news service also reports that Merrill Lynch upgraded Bemis (NYSE: BMS) to Neutral from Underperform.

Douglas A. McIntyre is an editor at 247wallst.com.

Rival home improvement chains Home Depot Inc. (NYSE: HD) and Lowe's Companies Inc. (NYSE: LOW) are scheduled to report quarterly results this week. Not surprisingly, given the ongoing housing slump, analysts surveyed by Thomson Financial on average expect both companies to post earnings lower than in the same period a year ago. For Home Depot, that's 61 cents per share, down 20.8%, and for Lowe's, 56 cents per share, down 16.4%. Meanwhile, cabinet maker American Woodmark Corp. (NASDAQ: AMWD), for whom Home Depot and Lowe's are major distributors, is also expected to report lower earnings: 11 cents per share, down 67.6%.

The presidential campaigns have prompted much discussion of energy policy and alternative energy sources. Some solar-energy-related concerns are scheduled to report this week, and expectations seem to be high. Trina Solar Ltd. (NYSE: TSL) is expected to report 81 cents per share earnings, up 67.9%; ReneSola Ltd. (NYSE: SOL) is expected to post earnings of 32 cents per share, up 62.5%; and Suntech Power Holdings Co. (NYSE: STP) is expected to have earnings of 32 cents per share, up 21.9%. Even China Sunergy Co. Ltd. (NASDAQ: CSUN) is expected to have swung to a profit of 3 cents per share, from a per-share loss of 14 cents a year ago.

MOST NOTEWORTHY: Micron, China Sunergy and Medtronic were today's noteworthy upgrades:

• Deutsche Bank upgraded shares of Micron (NYSE: MU) to Buy from Hold as they believe improved pricing and the company's cost reductions should drive a strong margin recovery. The firm raised MU's target to $11 from $7.
  
• Jefferies raised China Sunergy (NASDAQ: CSUN) to Hold from Underperform following the company's Q1 beat to reflect its improved outlook for the production of higher efficiency cells and better controls over cash flow measures.
  
• Goldman raised Medtronic (NYSE: MDT) to Buy from Neutral based on potential earnings upside from strong market share and broad distribution.

OTHER UPGRADES:

• UBS upgraded National Fuel Gas (NYSE: NFG) to Buy from Neutral.
  
• Arris (NASDAQ: ARRS) was raised to Outperform from Market Perform at Friedman Billings.
  
• Piper upgraded Central Garden & Pet (NASDAQ: CENT) to Buy from Neutral.

Jazz Technologies (AMEX: JAZ) is up 77% on a buyout by Tower Semiconductor.

China Sunergy (NASDAQ: CSUN) is up over 6% on strong earnings.

Amkor (NASDAQ: AMKR) is up almost 6% after announcing that it CFO would speak at a large investor conference.

Thornburg Mortgage (NYSE: TMA) is off 8% on news that its will have a sharp loss for the last quarter.

Douglas A. McIntyre is an editor at 247wallst.com.

Suntech Power (NYSE: STP) closed at $47.12 Thursday.

STP is scheduled to report Q1 EPS on May 22.

STP June option implied volatility of 80 is above its 26-week average of 73 according to Track Data, suggesting larger price movement.

China Sunergy (NASDAQ: CSUN), a manufacturer of solar cell products in China, closed at $12.58 Thursday.

CSUN is expected to report Q1 EPS on May 20.

Cowen says: "Key issues: Ramp of new cells, expense control, liquidity."

CSUN June option implied volatility of 111 is above its 26-week average of 100 according to Track Data, suggesting larger price risk.

Option Update is provided by Stock Specialist Paul Foster of theflyonthewall.com

"I can't believe I won," cried Jordin Sparks, winner of last year's American Idol. Within seconds, industry and non-industry drones alike began formulating ways to attach themselves to her in some way, crazy in anticipation of the inevitable riches.

Months later, several Wall Street types were overheard saying, "I can't believe oil keeps going higher, alternative energy stocks are going to be hot, hot, hot," and thousands of investors went wild buying shares of the dozen or so solar stocks, crazy in anticipation of the inevitable riches.

Each industry has its stars: Kelly Clarkson, Carrie Underwood and Clay Aiken -- as determined by album sales -- for American Idol, First Solar (NASDAQ: FSLR), Sunpower (NASDAQ: SPWR) and MEMC Electronic Materials (NYSE: WFR) -- as determined by stock performance -- for the solar industry.

MOST NOTEWORTHY: Dreamworks Animation (NYSE: DWA), BlackRock (BLK), Mariner Energy (ME) and Franklin Resources (BEN) and RightNow Technologies (RNOW) were today's noteworthy initiations:

• Stifel expects Dreamworks Animation's (NYSE: DWA) fundamental outlook for film to improve given a more accommodating home entertainment market, while next-gen DVD format adoption and the introduction of 3D exhibition in theaters creates incremental opportunities for film studios. The firm started shares off with a Buy rating.
  
• Wachovia believes BlackRock (NYSE: BLK) is one of the best-positioned managers in both product and geographic perspectives and initiated shares with an Outperform rating.
  
• BMO Capital believes Mariner Energy (NYSE: ME) has a number of catalysts that could push shares higher, but feels current trading levels are not attractive. BMO started shares with a Market Perform rating.
  
• William Blair views Franklin Resources (NYSE: BEN) as a premier global firm with an advantage in many attractive international markets and started shares with an Outperform rating.
  
• Cantor believes RightNow Tech's (NASDAQ: RNOW) transition creates significant execution risk, initiated shares with a Hold rating...

OTHER INITIATIONS:

• China Sunergy (NASDAQ: CSUN) was initiated with a Neutral rating at Cowen.
  
• Banc Of America initiated shares of The Stanley Works (NYSE: SWK) with a Neutral rating.
  
• Yamana Gold (NYSE: AUY) was started with a Buy rating and Credit Suisse.
  
• Deutsche Bank initiated Cree (NASDAQ: CREE) with a Hold rating.

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

MOST NOTEWORTHY: Oracle Corp (ORCL), Helicos BioSciences (HLCS), Clean Energy Fuels (CLNE) and China Sunergy (CSUN) topped today's noteworthy initiations:

• Benchmark started Oracle Corp (NASDAQ: ORCL) with a Hold rating.

• JP Morgan initiated Helicos BioSciences (NASDAQ: HLCS) with a Neutral rating based on the potential of its single-molecule genetic sequencing platform but noted that commercialization carries near-term risk.

• Hambrecht believes Clean Energy Fuels' (NASDAQ: CLNE) total addressable market is over $20B given the company's focus on natural gas vehicle fuel for return-to-base applications and started shares with a Buy rating.

• Jefferies wants to see China Sunergy (NASDAQ: CSUN) demonstrate that its silicon wafer suppliers can meet aggressive ramping plans before becoming more positive on the stock, starting shares off with a Hold rating...

OTHER INITIATIONS:

• Lehman started Greenlight Capital Re (NASDAQ: GLRE) with an Equal Weight rating.

• Cellcom Israel (NYSE: CEL) and Partner Communications (NYSE: PTNR) were initiated with Buy ratings at Citigroup.

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