(Bloomberg) -- WW International, better known as WeightWatchers, shares plummeted after the company said it has lost its largest shareholder.

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The stock fell 19% Thursday after the company announced that investment firm Artal Group sold its remaining stake in the wellness company in a Rule 144 block trade. Artal was one of its longest investors, having purchased the stock in 1999 from Heinz and maintained a controlling interest from its initial public offering in 2001 through 2018, a press release said. Artal had owned nearly 15 million shares of WW, according to data compiled by Bloomberg.

“We have been privileged to have overseen and participated in the Company’s development over the past 24 years, which is one of the longest holdings in our 38 year history,” Artal Group CEO Ray Debbane said in a press statement, adding that he has full confidence in WW’s current leadership team as they evolve the business.

WeightWatchers and Artal Group did not respond to Bloomberg’s request for further comment.

It’s been a rocky year for the company. Shares surged last month on news of WeightWatchers’ acquisition of Sequence, a telehealth provider that will help the company tap into the growing market for new obesity drugs, but since then it has struggled to hold onto gains.

Read more: Weight Loss Drugs Are a Golden Ticket for Health-Linked Stocks

The company has had a difficult time maintaining revenue and member growth since 2018, when shares hit an all-time closing high of about $103. Today, shares are trading shy of $7.

Wall Street is largely neutral on WW. The company has two buys, three holds and one sell rating, according to data compiled by Bloomberg. The average analyst target price for the stock is $7.90, implying a roughly 18% upside from Thursday’s close at $6.73.

(Updates stock prices throughout for market close.)

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