NEW YORK ( TheStreet) -- CHANGE IN RATINGS Cavium ( CAVM) was initiated with an overweight rating at Morgan Stanley. $48 price target. Estimates also well ahead of consensus expectations, Morgan Stanley said. Cubist ( CBST) was upgraded at Leerink Swann to outperform from market perform. $76 price target. Acquisitions should drive near-term growth, Leerink Swann said. Tableau ( DATA) was initiated with an outperform rating at FBN Securities. $85 price target. Company is a pure play on Big Data, FBN said. Diodes ( DIOD) was downgraded to hold at TheStreet Ratings. Diamondback Energy ( FANG) was downgraded to hold at Canaccord Genuity. $47 price target. Valuation call, as the stock is up 129% year to date, Canaccord said. GOLD) was downgraded to hold at TheStreet Ratings. Lindsay ( LNN) was downgraded at William Blair to market perform from outperform. Expect declines in the irrigation business, Blair said. Masco ( MAS) was initiated with a hold rating at Jefferies. $24 price target. Best housing play, but recovery baked in, Jefferies said. Owens Corning ( OC) was initiated with a buy rating at Jefferies. $55 price target. Underappreciated franchise with significant earnings leverage, Jefferies said. Occidental ( OXY) was upgraded at Wells Fargo to outperform. Company can unlock value through restructuring, Wells Fargo said. Pharmacyclics ( PCYC) was initiated with an overweight rating at J.P. Morgan. J&J partnership should drive growth, J.P. Morgan said. POR) was upgraded at Wells Fargo to outperform from market perform. Company has lagged its peers in recent months, but has good long-term growth prospects, Wells Fargo said. Valmont ( VMI) was downgraded at William Blair to market perform. Estimates were also cut, as two segements will likely peak this year, Blair said.