Analyst upgrades, downgrades and initiations: COMS, GOLD, STT, SVNT, TXN

Analyst upgrades

Oppenheimer upgraded Savient Pharmaceuticals (NASDAQ: SVNT) to Perform from Underperform after the FDA's Arthritis Advisory Committee voted 14-1 in favor of approving Krystexxa for gout.
Banc of America/Merrill upgraded Texas Instruments (NYSE: TXN) to Buy from Underperform and raised its target to $27 from $18 based on expectations that margin expansion will be higher than Street expectations.
UBS said Nvidia (NASDAQ: NVDA) has limited downside risk given the improved outlook for the graphics processor market and professional solutions business. Shares were upgraded to Neutral from Sell and its target was raised to $11.50 from $8.
BHP Billiton (NYSE: BHP) was upgraded to Outperform from Neutral at Macquarie.
Neutral Tandem (NASDAQ: TNDM) was upgraded to Outperform from Neutral at Baird.
Central Garden & Pet (NASDAQ: CENT) was upgraded to Buy from Neutral at SunTrust.

Analyst downgrades

UBS downgraded Cummins (NYSE: CMI) to Neutral from Buy and lowered its target to $36 from $38 based on valuation and weak freight conditions.
Bernstein downgraded 3Com (NASDAQ: COMS) to Market Perform from Outperform but raised its target to $5 from $4 based on valuation and concerns regarding competition in China.
TD Newcrest downgraded Silver Wheaton (NYSE: SLW) to Hold from Buy based on lower production forecast. The firm has a $10 target on the stock.
Swiss Reinsurance (OTC: SWCEY) was downgraded to Hold from Buy at Deutsche Bank.
Packaging Corp. (NYSE: PKG) was downgraded to Underweight from Neutral at JPMorgan.
Rangold Resources (NASDAQ: GOLD) was downgraded to Sector Perform from Outperform at RBC Capital.

Analyst initiations

Stephens believes Rehabcare (NYSE: RHB) is well positioned in an environment where reimbursement is more episodic and not venue driven. Shares were initiated with an Overweight rating and $27 target.
JMP Securities initiated Savient Pharmaceuticals (NASDAQ: SVNT) with an Outperform rating and $15 target. The firm believes Savient's Krystexxa will be approved this year for the treatment of refractory gout.
Wunderlich believes OGE Energy (NYSE: OGE) has above-average earnings growth prospects, solid transmission expansion, and an attractive valuation. The firm started shares with a Buy rating and $32 target.
Ormat Technologies (NYSE: ORA) was initiated with an Outperform rating and $50 target at Baird.
Main Street Capital (NASDAQ: MAIN) was initiated with a Neutral rating and $12.50 target at Janney Montgomery.
State Street (NYSE: STT) was initiated with a Buy rating and $68 target at SunTrust.