(Bloomberg) -- Once the toast of millennials, the LaCroix brand of carbonated water is losing some sparkle for its billionaire owner.

Nick Caporella, the octogenarian chairman and founder of LaCroix parent National Beverage Corp., has lost $2.7 billion -- more than half of his net worth -- in the past nine months. The stock tumbled 62% through Tuesday amid slumping sales, increased competition and a whistle-blower lawsuit alleging its cans contain toxic chemicals.

Excluding News Corp. Chairman Rupert Murdoch, who transferred the bulk of his fortune to his children, Caporella is the biggest loser in percentage terms among all people tracked by the Bloomberg Billionaires Index over that span. Shares of National Beverage slid an additional 0.7% to $44.84 at 9:42 a.m. in New York.

Last month, Guggenheim Securities analyst Laurent Grandet cut his price target on National Beverage shares, saying industry data show sales are “effectively in free fall.” On Tuesday, the stock tumbled 4.8% after Business Insider reported on the whistle-blower complaint. The suit alleges that the founder’s son, company President Joseph Caporella, planned to lie about whether its products contained toxic chemicals.

“False statements were made in litigation brought by a former employee seeking to extract a monetary recovery from the company,” Fort Lauderdale, Florida-based National Beverage said in an email. “We intend to vigorously defend our company and our brands against false claims brought by this disgruntled former employee.”

In January, LaCroix faced claims in a proposed class-action lawsuit that the sparkling water was wrongfully labeled “all natural."

The son of Italian immigrants, Caporella grew up poor in rural Pennsylvania. He had early success building and selling construction businesses and formed National Beverage in the 1980s. He added LaCroix to his portfolio of mostly regional drink brands a decade later. He owns almost three-quarters of National Beverage shares, which trade on the Nasdaq Stock Market under the ticker symbol FIZZ.

Caporella’s net worth peaked at $4.7 billion in September, when he ranked as high as No. 383 on Bloomberg’s list of the world’s 500 wealthiest people.

(Updates with share price in third paragraph.)

--With assistance from Jack Witzig.

To contact the reporters on this story: Devon Pendleton in New York at dpendleton@bloomberg.net;Sophie Alexander in New York at salexander82@bloomberg.net

To contact the editors responsible for this story: Pierre Paulden at ppaulden@bloomberg.net, Peter Eichenbaum, Steven Crabill

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