Thinking about buying stock in Portola Pharmaceuticals, Norwegian Cruise Line, Tetra Technologies, Wayfair, or Chegg? PR Newswire NEW YORK, May 5, 2020 NEW YORK , May 5, 2020 /PRNewswire/ -- InvestorsObserver issues critical PriceWatch Alerts for PTLA, NCLH, TTI, W, and CHGG. To see how InvestorsObserver's proprietary scoring system rates these stocks, view the InvestorsObserver's PriceWatch Alert by selecting the corresponding link. PTLA:...