Planet Fitness Inc (NASDAQ:PLNT) unveiled its latest quarterly earnings results Friday morning.

The fitness center chain saw its shares skyrocket as the company reported its fourth-quarter report, posting net losses of $3.5 million, amounting to roughly 4 cents per share. In the year-ago quarter, the company posted net income of $10 million, or 18 cents per share.

Planet Fitness’ end to fiscal 2017 was hit hard by a tax charge of $17.2 million, linked with changes in the U.S. tax code. On an adjusted basis, the company raked in earnings of 24 cents per share, which was better than the 23 cents per share than the figure analysts were calling for, according to data compiled by FactSet.

The fitness center operator’s revenue tallied up to $134 million, ahead of the $116.4 million it brought in during the fourth quarter of 2016. Analysts were calling for revenue of $109.3 million for Planet Fitness, according to data compiled by FactSet.

The company’s system-wide same-store sales were 11.6% better year-over-year for the quarter, while its full-year system-wide same-store sales rose 10.2% compared to the year-ago quarter. Its franchise segment revenue, including commission income, gained $33.7 million, or 28.9% year-over-year.

For its first quarter of fiscal 2018, Planet Fitness the Wall Street consensus estimate calls for adjusted earnings of 26 cents per share and revenue of $109.3 million. The company forecasts its full-year sales to increase by roughly 20% year-over-year, while adjusted earnings will surge by about 40%.

PLNT stock was up about 11.6% early afternoon Friday.