What happened 

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.

So what

Quarterly revenue was up 9.4%, to $2.86 billion, and net income was up 142%, to $237 million, or $4.16 per share. Analysts were only expecting $3.44 per share in earnings, so this was a huge earnings beat. 

Worker managing warehouse inventory.

Image source: Getty Images.

The bigger shocker was that management increased the bottom end of 2018 sales guidance to $11.0 billion, with the top end staying at $11.3 billion. Better yet, earnings-per-share guidance was increased from $14.30 to $15.30 per share to a range of $15.05 to $16.05 per share. 

Now what

Management said that large- and medium-sized business customers are driving the company's growth and operating leverage is helping profitability. The leverage will continue throughout the year, which is why earnings guidance was up significantly.

A strong business environment continues to be a tailwind for WW Grainger. As long as the economy continues to hum along, the company should be a great stock for investors.