Producer prices barely rose in February, resulting in the smallest annual increase in more than 1-1/2 years, yet another indication of benign inflation. By Caroline Valetkevitch NEW YORK, March 13 () - U.S. stocks rose on Wednesday, led by gains in healthcare shares, and Boeing edged upward even as the United States joined other nations in grounding the company's 737 MAX jets. The grounding gives Boeing time to address any problems and not face another potential disaster, said Tim Ghriskey, chief investment strategist at Inverness Counsel in New York.