Editor's Note: Green and red arrows refer to intraday stock price movement.NEW YORK ( TheStreet) -- CHANGE IN RATINGS TD Ameritrade ( AMTD) rated new Neutral at UBS. $23 price target. Company is a market leader, but appears fully valued at current levels. Babcock & Wilcox ( BWC) downgraded at Keybanc from Buy to Hold, Keybanc said. Valuation call. Babcock & Wilcox ( BWC) numbers raised at Goldman. Shares of BWC now seen reaching $34, according to Goldman Sachs. Estimates also increased, given higher emissions control demand. Neutral rating. Cognex ( CGNX) upgraded at Piper from Neutral to Overweight, Piper Jaffray said. $34 price target. Stock has pulled back 24% since earnings. Coventry Health ( CVH) upgraded at Stifel to Buy. Estimates also raised, as the company is seeing lower medical costs. $38 price target. Discovery Communications ( DISCA) initiated at Credit Suisse with a $45 price target and Neutral rating. Pure play cable programmer with faster than average top line growth, Credit Suisse said. General Growth Properties ( GGP) upgraded at Credit Suisse to Outperform from Neutral. Best positioned for the CMBS recovery, Credit Suisse said. Maintain $18 price target. Nalco ( NLC) upgraded at JP Morgan from Neutral to Overweight, JP Morgan said. Valuation call, based on a $30 price target. Stock is down 20% this year, largely because of the Berkshire overhang. Olin ( OLN) upgraded at UBS from Sell to Neutral, UBS said. $19 price target. JV acquisition is a good strategy. PPL ( PPL) estimates upped at Morgan Stanley through 2013, Morgan Stanley said. Overweight rating and $28 price target. PPL ( PPL) upgraded at FBR from Market Perform to Outperform, FBR Capital Markets said. $29 price target. Stock has pulled back, even though the recent acquisition should add to earnings. Taubman Centers ( TCO) downgraded at Credit Suisse to Neutral from Outperform. Valuation call, Credit Suisse said. Maintain $39 price target. UnitedHealth ( UNH) upgraded at Stifel to Buy. $56 price target. Estimates also boosted, because of lower expected medical costs. United Rentals ( URI) rated new Buy at Goldman. Company is in the early stages of a pricing recovery and can deliver above-average earnings growth. Wellpoint ( WLP) upgraded at Stifel to Buy. $85 price target. Business fundamentals are improving. Watts Water ( WTS) upgraded at BB&T to Buy, BB&T Capital said. $47 price target. End-market demand will eventually come around and drive above-average growth.