Shares of supply company WW Grainger Inc (NYSE: GWW) jumped as much as 12.1% in trading Wednesday after the company announced second-quarter 2018 results. At 2:55 p.m. EDT, shares were holding gains, up 10.1% on the day.Quarterly revenue was up 9.4%, to $2.86 billion, and net income was up 142%, to $237 million, or $4.16 per share.