Among the stock activity stories for Friday, Jan. 11, from AP Business News:
— Shares of J.C. Penney Co. Inc. fell after a UBS analyst downgraded the retailer's stock to a "Sell' rating, amid a deteriorating earnings outlook.
— Shares of Dendreon Corp. soared following a rating upgrade by a Bernstein analyst who saw a brighter future for the company's prostate cancer treatment drug, Provenge.
