Stocks made little progress Wednesday as investors digested weak retail data from April. The S&P 500 and Dow closed flat. Owens-Illinois (OI) was the best performer on the S&P 500 after the company purchased Mexican glass manufacturer Vitro for $2.15 billion. Southwestern Energy (SWN) was the worst performer, losing alongside crude oil which gave back some of the gains achieved over a multi-session rally. DuPont (DD) pressured the Dow after activist investor Nelson Peltz failed to gain a board seat. Dutch telecom Vimpelcom (VIP) topped the Nasdaq on discussions of a merger with the Italian wireless business of holding company Hutchison.