Analyst upgrades, downgrades and initiations: ABMD, TI, DKS, SCHW ...

Analyst upgrades:

Jefferies upgraded Abiomed (NASDAQ: ABMD) to Hold from Underperform on valuation as it believes concerns over the company's Impella heart pump are priced in at current levels. The firm lowered its target price to $7 from $8.
Suntrust upgraded Somanetics (NASDAQ: SMTS) to Neutral from Reduce. The firm believes most of the risk is out of Somanetics shares and that the Q1 report could be a positive catalyst.
Banc of America/Merrill upgraded shares of Telecom Italia (NYSE: TI) to Buy from Neutral on valuation and believes the company's revenue trends are improving.
China Petroleum & Chemical (NYSE: SNP) was raised to Buy from Neutral at UBS.
Hexcel (NYSE: HXL) and Johnson Controls (NYSE: JCI) were upgraded to Buy from Neutral at Goldman.

Analyst downgrades:

Jefferies downgraded shares of Energy XXI (NASDAQ: EXXI) to Underperform from Buy and Parallel Petroleum (NASDAQ: PLLL) to Hold from Buy to reflect the low commodity prices and believes the company must preserve liquidity. It lowered its price target on Energy XXI to 30c from $1 and lowered its target on Parallel Petroleum to $1 from $12.
Merriman downgraded Xoma (NASA: XOMA) to Neutral from Buy to reflect financial distractions after the company's independent accountants placed a going concern on it.
Piper downgraded Metabolix (NASDAQ: MBLX) to Neutral from Buy after the company announced another delay in the start-up of its first commercial-scale production facility.
Dick's Sporting Goods (NYSE: DKS) was cut to Neutral from Buy at Goldman.
American Tower (NYSE: AMT) was downgraded at Morgan Stanley to Equal Weight from Overweight.
Sunpower (NASDAQ: SPWRA) was downgraded to Underweight from Overweight at JP Morgan.

Analyst initiations:

Thomas Weisel said Supertex (NASDAQ: SUPX) faces near-term challenges from high DOI, inventory correction in medical, and lack of visibility in LED driver ramp. Shares were initiated with a Market Weight rating and $20 target.
Citigroup believes Charles Schwab (NASDAQ: SCHW) is the preeminent discount broking franchise and feels 2009's challenges are already priced into shares. Shares were assumed with a Buy rating and $16 target.
JMP Securities initiated Sequenom (NASDAQ: SQNM) with an Outperform rating and $25 target. The firm believes Sequenom is poised to become the leader in non-invasive prenatal diagnostics with its soon-to-be-launched SEQureDx test.
Allergan (NYSE: AGN) was initiated at Piper Jaffray with a Buy rating and $48 target.
Data Domain (NASDAQ: DDUP) was assumed with a Neutral rating at Merriman.
American Capital (NASDAQ: AGNC) was started at Keefe Bruyette with a Market Perform rating and $17.50 target.