NEW YORK ( TheStreet ) -- Shares of PetSmart ( PETM ) are tumbling in pre-market trading on Wednesday, falling 3.1% to $65. Earlier, the specialty retailer received a downgrade from UBS to "neutral" from "buy" with a price target of $72. The investment bank said the rating change was driven by the departure of chief operating officer Joseph O'Leary and difficulty in gaining market share with an already sizable position. Last week, Deutsche Bank downgraded the stock to "sell" from "hold" with a price target of $65, pointing to slower traffic trends and increased competition. TheStreet Ratings team, however, reiterates PETSMART INC as a Buy with a ratings score of A. The team has this to say about their recommendation: "We rate PETSMART INC (PETM) a BUY. This is based on the convergence of positive investment measures, which should help this stock outperform the majority of stocks that we rate.