What happened

Shares of Dexcom (NASDAQ:DXCM), a leader in the growing market for blood sugar trackers, jumped 47.4% in November, according to data from S&P Global Market Intelligence. Another quarterly report filled with positive signals was the spark that started the rally.

So what 

Glucose monitors that sync with smartphones are gaining popularity fast, and Dexcom's third-quarter earnings report suggests its G6 system is leading the pack. Compared with the prior-year period, revenue grew 49% to $396 million.

Beneath the top line, it looks like the company's easy-to-use solutions are flying off shelves all by themselves. Third-quarter operating expenses rose just 23% to $191 million.

Upward sloping stock chart and a man with a jetpack.

Image source: Getty Images.

Dexcom also raised its expectations for the rest of 2019. Instead of a range of $1.33 billion to $1.38 billion, total revenue is expected to reach between $1.43 billion and $1.45 billion this year. On the bottom line, adjusted operating earnings are expected to reach 9% of total sales instead of the 7% operating margin the company had been expecting just a few months earlier.

Now what

There's no shortage of glucose monitoring options for diabetes patients to choose from, but Dexcom's devices could command a leading share of the market for the foreseeable future. In October, the company officially started selling everything needed to begin using a G6 to Medicare patients in partnership with Walgreens.

Keeping glucose levels in a normal range has been shown to reduce the risk of problems common among diabetes patients, such as vision loss. That means Medicare can save a bundle over the long run by providing Dexcom's devices.