NEW YORK ( TheStreet) -- CHANGE IN RATINGSAsbury Automotive ( ABG) downgraded at Craig-Hallum from Buy to Hold, Craig-Hallum said. Valuation call, based on a $38 price target. Allison Transmission ( ALSN) downgraded at Piper from Overweight to Neutral, Piper Jaffray said. $24 price target. Company lowered its guidance. Alexion ( ALXN) downgraded at Lazard from Buy to Neutral, Lazard Capital Markets said. $102 price target. Stock appears attractive, following a 30% decline. AMN Healthcare Services ( AHS) is upgraded to buy at TheStreet Ratings. Capital One ( COF) downgraded at Guggenheim to Neutral, Guggenheim said. $59 price target. Recent trends will not support a multiple expansion. Deckers ( DECK) downgraded at Wedbush from Outperform to Neutral, Wedbush said. Valuation call, based on a $45 price target. HollyFrontier ( HFC) downgraded at Wells from Outperform to Market Perform, Wells Fargo said. Valuation call. Starwood Hotels ( HOT) downgraded at Jefferies to $66, Jefferies said. $66 price target. Valuation call. NVIDIA ( NVDA) is upgraded to buy at TheStreet Ratings. QLogic ( QLGC) is upgraded to buy at TheStreet Ratings. PNM Resources ( PNM) upgraded at Baird from Neutral to Outperform, Robert Baird said. $24 price target. San Juan appears back on track, which should improve earnings visibility. SAIC ( SAI) downgraded at JP Morgan from Overweight to Neutral, JP Morgan said. $12 price target. Valuation call, as the stock has outperformed its peers by 13% year-to-date. Sealed Air ( SEE) downgraded at JP Morgan from Overweight to Neutral, JP Morgan said. Valuation call, based on a $22.50 price target. Sealed Air downgraded at Wells from Market Perform to Underperform, Wells Fargo said. Company's cash generation is lagging. Sirona Dental ( SIRO) downgraded at Baird from Outperform to Neutral, Robert Baird said. $76 price target. Sales of new products may not ramp as quickly as expected. Staples ( SPLS) upgraded at Citigroup to Neutral from Sell, Citigroup said. $16 price target. Possible industry consolidation. Total System Services ( TSS) downgraded at Jefferies to Hold from Buy, Jefferies said. $23 price target. Surprising NTSP acquisition. Visteon ( VC) upgraded at JP Morgan to Overweight, JP Morgan said. Company is attractive on a sum-of-the-parts valuation. Minimum fair value of $73 price target. Windstream ( WIN) downgraded at UBS to Sell from Neutral, UBS said. $7.50 price target. Dividend payout not sustainable.