E-commerce giant joins Dow's blue chips, bumps Walgreens ahead of Walmart stock split
                                
                                
                                    (Newser) -
                                    Amazon is joining the ranks of one of Wall Street's oldest and most exclusive stock indexes: the Dow Jones Industrial Average. The e-commerce pioneer will officially take its position in the 30-company Dow before the open of trading Monday, replacing drugstore operator Walgreens Boots Alliance, per the  AP . S&...