Shares of Fitbit tumbled Thursday, a day after the maker of wearable fitness trackers posted disappointing earnings outlook for the current quarter.

The company said late Wednesday that it expects earnings between 8 cents and 11 cents per share for the quarter ending in June. That's far below the 26 cents per share analysts expected, according to FactSet. Fitbit said it expects second-quarter revenue between $565 million and $585 million, above the $531.5 million analysts expected.

Shares of Fitbit Inc. fell $2.53, or 15 percent, to $14.57 in midday trading Thursday. The company's stock is down nearly 30 percent since Fitbit became a public company in June.

Also late Wednesday, the company reported first-quarter earnings and revenue that beat Wall Street expectations. The company said it sold 4.8 million devices in the first three months of the year, up 23 percent from the same period a year before.