(Retail winners and losers article updated with additional stock movements and retail company news.)NEW YORK ( TheStreet) -- Retail is off to an active start in 2011. Office Depot ( ODP) is among some of the biggest gainers in the sector after being upgraded by Janney Capital Markets to buy from neutral. Analyst David Strasser cited the appointment of a new CEO, an improving job market, potential consolidation within the office supply sector, and the company's moves to cut cost, increase private label sourcing and improve merchandise, as catalysts for the upgrade. Strasser also lifted his rating on rival Staples ( SPLS) to buy from neutral. Shares of Office Depot are rising 6.7% to $5.77 and Staples is up 3.9% to $23.66. OfficeMax ( OMX) is riding on its peers' coat-tails, also gaining 5.4% to $18.66 in morning trading. But while the office supply sector is seeing a boost, several specialty retailers are starting off the New Year on a less joyous note. Jefferies & Co. lowered its rating on several retailers, including Under Armour ( UA), Coach ( COH), Tiffany ( TIF), Urban Outfitters ( URBN), Rue21 ( RUE) and Talbots ( TLB). "Given such sizable outperformance in 2010 along with a lack of positive (first-half) catalysts, more difficult compares, and less compelling valuations, we think the (specialty retail) group is due for early year declines," analyst Randal Konik said in a report. " However we would look for a meaningful pullback in the group as a buying opportunity to get back in as our fundamental outlook is still positive. " AnnTaylor Stores ( ANN) was downgraded by Piper Jaffray to neutral from overweight, sending shares down 6.4% to $25.65. But Zale ( ZLC) is shaping up to be one of the biggest losers of the day, with shares plunging 9.4% to $3.86. The jewelry retailer is giving up its gains from last week, when it hit a new 52-week high.