Analyst upgrades:

• Citigroup upgraded shares of Sovereign Bancorp (NYSE: SOV) to Buy from Hold on their belief Sovereign will merge with Banco Santander (NYSE: STD) according to the terms on their October 13 agreement.
  
• Jefferies upgraded Whole Foods (NASDAQ: WFMI) to Hold from Underperform on valuation as they believe the capital infusion from Leonard Green limits downside risk. The company's target was raised to $11 from $9.50.
  
• Banc of America upgraded Max Capital (NASDAQ: MXGL) to Buy from Neutral on valuation, the company's strategic changes to lower earnings volatility and their belief it is well positioned to benefit from an improved P&C marketplace.
• Qimonda (NYSE: QI) was upgraded to Neutral from Underperform at Cowen.
  
• Health Net (NYSE: HNT) was raised to Neutral from Sell at Goldman.
  
• Parkway Properties (NYSE: PKY) was lifted to Market Perform from Underperform at Wachovia.

Analyst downgrades:

Analyst upgrades:

• PepsiCo (NYSE: PEP) was upgraded to Buy from Hold at Deutsche Bank.
• Fortress (NYSE: FIG) was upgraded at Citigroup to Hold from Sell.
• Prudential (NYSE: PUK) was lifted to Overweight from Neutral at JP Morgan.
• Keefe Bruyette upgraded Franklin Resources (NYSE: BEN) to Outperform from Market Perform and added shares to their Best Ideas List on valuation as they see an attractive risk/reward at current levels.
• UBS upgraded ASML Holding (NASDAQ: ASML) to Buy from Neutral on valuation as they believe the company remains a market leader.
• Oppenheimer raised Seattle Genetics (NASDAQ: SGEN) to Outperform from Perform on valuation following the recent weakness as they expect positive clinical news flow beginning in December.

Analyst downgrades:

• UBS downgraded U.S. Steel (NYSE: X) to Sell from Buy and lowered its target to $30 from $60 citing deteriorating U.S. conditions and concerns about the company's high fixed costs in a falling steel price environment.
• Royal Dutch Shell (NYSE: RDS.A) was downgraded to Underperform from Neutral at Credit Suisse.
  
• China Unicom (NYSE: CHU) was lowered to Underweight from Neutral at JP Morgan.

MOST NOTEWORTHY: First Solar, Pride International and EnerSys were today's noteworthy downgrades:

• Friedman Billings downgraded First Solar (NASDAQ: FSLR) to Underperform from Market Perform citing margin risk concerns, as the company aggressively pursues utility-scale projects in the US. The firm said risks are not reflected in share valuation near $300 and could be a source of disappointment but could also lead to downside EPS risk.
  
• Wachovia said Pride International (NYSE: PDE) has the least potential EPS upside vs. peers given the company has contracted the highest percentage of its floater days into 2012E. Additionally, the firm views a takeout by Seadrill as unlikely. Shares were cut to Underperform from Market Perform.
  
• Merriman downgraded shares of EnerSys (NYSE: ENS) to Neutral from Buy as they believe the strong Q4 results were driven by a one-time benefit from lead procurement mechanics and that data does not support the company's sustained margin expansion story.

OTHER DOWNGRADES:

• Citigroup lowered Intuit (NASDAQ: INTU) to Hold from Buy.
  
• UBS downgraded Nucor (NYSE: NUE) to Neutral from Buy.
  
• Smart Modular (NASDAQ: SMOD) was downgraded at Oppenheimer to Perform from Outperform.
  
• The Airlines Sector was cut by Soleil to Neutral from Outperform.

Stock screeners are tools that let investors filter through a large number of stocks according to chosen criteria. It is important to remember that a stock screener is just a tool and every investment should be analyzed on its own merits to make sure it fits with your personal portfolio and risk characteristics. My weekly column finds interesting investment opportunities with the help of our Stock Screener.

Since two of the stocks I covered in the Stock Screener section had such wild movements in such a short time, I've decided to quickly take a look at all the stocks I've covered here, see what major news recently affected them and how they reacted. All returns are as of May 2nd close.

Solar Energy Stocks

On March 27th, I went over some solar energy stocks. I looked at Trina Solar Ltd. (NYSE: TSL) and Suntech Power Holdings Co., Ltd. (NYSE: STP), concluding with: "I think it may not be too late to jump on the Trina bandwagon. Suntech could prove a long-term solid player as well."

Since then, TSL returned over 24% and STP returned 5.8%.
The main catalyst in the solar energy stock was a court ruling that could pave the way to more regulations and have a positive impact on alternative energy stocks.