Analyst upgrades:

• Piper Jaffray upgraded PetMed Express (NASDAQ: PETS) to Overweight from Neutral following the better-than-expected Q1 results. The firm raised its target on shares to $22 from $19.
• Deutsche Bank upgraded International Paper (NYSE: IP) and Packaging Corp. (NYSE: PKG) to Buy from Hold to reflect stabilization in the containerboard industry. The firm raised its target price on Packaging Corp. to $24 from $14, and on International Paper to $24 from $16.
• Bernstein upgraded Human Genome Sciences (NASDAQ: HGSI) to Outperform from Market Perform following the positive Phase III data for Benlysta in lupus.
• IBM (NYSE: IBM) was upgraded to Hold from Sell at Societe Generale.
• British Airways (OTC: BAIRY) was upgraded to Buy from Sell at Goldman.
• Continental AG (OTC: CTTAY) was upgraded to Hold from Sell at Citigroup.

Analyst upgrades:

• Whole Foods (NASDAQ: WFMI) was upgraded to Neutral from Sell at UBS.
  
• Archer Daniels Midland (NYSE: ADM) was upgraded to Equal Weight from Underweight at Barclays.
• AutoZone (NYSE: AZO) was raised to Buy from Neutral at Merrill Lynch.
• B. Riley upgraded S&T Bancorp (NASDAQ: STBA) to Buy from Neutral and lowered its target to $35 from $38 on valuation, as they believe the sell-off post-Q3 results is overdone.
  
• Jefferies upgraded GSI Commerce (NASDAQ: GSIC) to Buy from Hold on valuation after Q4 revenue guidance was reset lower. The firm lowered their target to $13 from $18.
  
• JP Morgan upgraded shares of DHT Maritime (NYSE: DHT) and General Maritime (NYSE: GMR) to Overweight from Neutral on the company's valuation and dividend stability.

Analyst downgrades:

• HSBC cut Prudential (NYSE: PUK) to Neutral from Overweight as they believe capital has eroded and debt refinancing is increasingly difficult.
  
• Freeport McMoRan (NYSE: FCX) was downgraded to Neutral from Buy at Goldman.
  
• Logitech (NASDAQ: LOGI) was lowered to Hold from Buy at Citigroup and to Neutral from Outperform at Credit Suisse.

MOST NOTEWORTHY: S1 Corp, CME Group and Elizabeth Arden were today's noteworthy upgrades:

• Stephens upgraded shares of S1 Corp (NASDAQ: SONE) to Overweight from Equal Weight after meeting with management to reflect their increased confidence in the company's ability to execute. The firm maintains a $9 target on the stock.
  
• Citigroup upgraded shares of CME Group (NYSE: CME) to Buy from Hold as they find the risk/reward attractive with volumes picking up and consensus estimates at more rational levels. The firm maintains a $485 target.
  
• Oppenheimer raised Elizabeth Arden (NASDAQ: RDEN) to Outperform from Perform on valuation, as they believe the current share price does not adequately reflect potential earnings accretion from the company's licensing agreement with Liz Claiborne (NYSE: LIZ) or restructuring savings.

OTHER UPGRADES:

• Double Hull Tankers (NYSE: DHT) was raised to Neutral from Underweight at JP Morgan.
  
• Hovnanian (NYSE: HOV) was upgraded at UBS to Neutral from UBS.
  
• BMO Capital upgraded Xyratex (NASDAQ: XRTX) to Outperform from Market Perform.

MOST NOTEWORTHY: Double Hull Tankers, Comverge and Cardica were today's noteworthy initiations:

• Double Hull Tankers (NYSE: DHT) was initiated with a Buy rating and $20 target at Jefferies, as they believe shares are attractively valued given the company's time charter contract coverage and upside potential through profit sharing arrangement.
• Broadpoint views Comverge (NASDAQ: COMV) as the industry leader in the high-growth demand response market. The firm assumed coverage with a Buy rating.
• Oppenheimer expects Cardica's (NASDAQ: CRDC) proximal device, which is awaiting FDA approval, to change cardiothoracic surgery and that adoption should be rapid. The firm initiated shares with a Buy rating and $11 target.

OTHER INITIATIONS:

• Bear Stearns started Brady Corp (NYSE: BRC) with a Neutral rating and $40 target.
• Bill Barrett (NYSE: BBG) was initiated with a Market Perform rating and Morgan Keegan.
• William Blair initiated LKQ (NASDAQ: LKQX) with a Market Perform rating.