Shares of Vertex Pharmaceuticals Inc. VRTX fell nearly 11% after the company stated that it is going to stop developing an experimental drug after it was found unlikely to be effective against AAT Deficiency disease.Royal Caribbean Group’s RCL shares fell 0.6% after the company stated that two passengers aboard its Celebrity Millennium Cruise ship had tested positive for COVID-19.American Airlines Group Inc.’s AAL shares rose 0.3% after the company said that it is going to invest $25 million into Vertical Aerospace, a flying taxi startup company.Protagonist Therapeutics, Inc.’s PTGX shares rose 17.1% after the company announced updated results from its ongoing Phase 2 study of rusfertide for polycythemia vera, which is a type of blood cancer, at the European Hematology Association 2021 Virtual Congress session.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Royal Caribbean Cruises Ltd. (RCL): Free Stock Analysis Report Vertex Pharmaceuticals Incorporated (VRTX): Free Stock Analysis Report American Airlines Group Inc. (AAL): Free Stock Analysis Report Protagonist Therapeutics, Inc. (PTGX): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research