Apple Watch 'killer' to 5G: What to watch out for at MWC By: CNBC.com News February 20, 2015 at 09:15 AM EST CNBC runs you through the five biggest themes at Mobile World Congress in Barcelona which officially kicks off on March 2. Read More >> Related Stocks: Alibaba Group Holding Ltd Comtech Telecom Company Lenovo Group Ltd ADR Volkswagen Ag Pfd Sh