NEW YORK ( TheStreet) -- CHANGE IN RATINGS Best Buy ( BBY) downgraded at Wedbush from Neutral to Underperform, Wedbush said. $14.50 price target. Fundamentals are deteriorating and the new CEO lacks retail experience. CF Industries ( CF) rated new Hold at Stifel Nicolaus. Valuation call. Centerpoint ( CNP) upgraded at Wells from Market Perform to Outperform, Wells Fargo said. Company is looking to invest in future growth. Group 1 Automotive ( GPI) downgraded at Keybanc from Buy to Hold, Keybanc said. Valuation call, given a slower growth outlook. Medicines Company ( MDCO) rated new Neutral at BofA/Merrill. $29 price target. Company faces multiple binary outcomes for its late-stage clinical products. Targa Resources ( TRGP) rated new Buy at UBS. $57 price target. Company is a regional leader with solid dividend growth. Yelp ( YELP) rated new Market Perform at JMP. Valuation call, based on a $19 price target. Zynga ( ZNGA) rated new Outperform at JMP. $4.50 price target. Stock appears washed out and there are early signs that metrics are improving.