Tandem Diabetes Care (TNDM 4.13%) followed the broader market and traded down on Tuesday, despite reporting quarterly results that featured an unexpected bottom-line profit.

The company, which makes insulin pumps and related products to help treat diabetes, booked sales of almost $108.4 million in its Q4 of fiscal 2019, which was 42% higher on a year-over-year basis. Net income fell to just under $2.7 million ($0.04 per share), from Q4 of fiscal 2018's nearly $3.7 million.

Vial of insulin with stethoscope.

Image source: Getty Images.

This produced a mixed quarter in relation to analyst estimates. Prognosticators following the stock had collectively anticipated a top-line result of $109 million but were expecting a net loss equating to $0.07 per share.

Tandem's sales have been rising precipitously thanks to its popular signature product line, the t:slim X2 insulin pump.

Sales growth of 42% in Q4 is down quite a bit from Q3's near doubling; according to Tandem this is due to clients who are waiting for the company's latest innovation to be approved by the Food and Drug Administration for use with the t:slim X2s. Called Control-IQ, this is a digital program that adjusts insulin levels for patients using those products.

The company also proffered guidance. It is forecasting sales of $450 million to $465 million, which would mean at least a 24% improvement on the fiscal 2019 result of $362 million. Adjusted EBITDA should land at 12% to 14% of sales; in 2019 this percentage landed at 13%.

Previous to this week's bear market, Tandem shares had generally been rising sharply. Even with Tuesday's 10%-plus decline, the healthcare stock is still up by almost 29% year to date.