What happened

Shares of Insulet (NASDAQ:PODD) rocketed 25.4% higher in August, according to data from S&P Global Market Intelligence. The stock has pumped out a gain of 108% in 2019 through Sept. 3, making it one of the year's best-performing medical device stocks within the broader healthcare arena

The Boston-area company is the leader in tubeless insulin pump technology with its Omnipod pump.

Insulet stock's August performance is even more impressive when you consider that the market had a down month. The S&P 500, including dividends, fell 1.6% last month, and has returned 17.5% so far this year.

A two-pane image with the top pane showing an Omnipod attached to a woman's lower stomach and the bottom pane showing the handheld control for the device.

Image source: Getty Images.

So what

We can attribute Insulet stock's strong performance last month to the company's Aug. 5 release of its second-quarter results, which were better than Wall Street and many investors were expecting, and to management once again increasing full-year 2019 revenue guidance. Shares surged 21.4% on the day following the release and continued to move somewhat higher throughout the remainder of the month.

In Q2, Insulet's revenue soared 43% year over year to $177.1 million, easily beating the $164 million Wall Street was looking for. Earnings per share came in at $0.02 -- versus a loss of $0.03 per share in the year-ago period -- hitting the consensus estimate on the bull's-eye. 

Now what

For the third quarter, Insulet guided for revenue growth of about 15% to 20% year over year. And for full-year 2019, it expects revenue to increase about 24% to 27%, up solidly from its previous outlook of 18% to 22% growth. The company doesn't provide earnings guidance.