(Bloomberg) –It’s been a long week for the Shetty family.

The billionaire clan behind hospital operator NMC Health Plc and financial services firm Finablr Plc has seen its fortune drop by about $820 million since short-seller Carson Block issued a report Tuesday criticizing the medical company’s accounts and disclosing a short position.

Read: Billionaire BR Shetty’s NMC Health Plans Review After Short Seller Attack

NMC shares tumbled 32% on Tuesday in response to the report, which the company called “principally unfounded.” They continued sliding Thursday when a buy-back program failed to convince investors and slumped again Friday by 13% at 10:18 am in London after the Financial Times reported NMC held talks to raise off-balance sheet debt to fund growth. NMC said the claims are “based on false information.”

To make matters worse, shares of Finablr are also down 19% since Block’s Muddy Waters Capital launched its attack on NMC, prompting the firm to confirm it’s on track to hit expected financial results.

Bavaguthu Raghuram Shetty, 77, founded NMC in 1975 after moving to Abu Dhabi from his native India. It’s now the United Arab Emirates’ biggest private health-care provider. He created Finablr in 2018 to consolidate his finance brands and listed the company on the London Stock Exchange this year. The family’s stakes in Finablr are worth about $1 billion.

Read: Muddy Waters Short Report Sends NMC Health to Record Plunge

Block, 43, earned his reputation as a short seller a decade ago by targeting U.S.-listed Chinese companies that he claimed were frauds. More recently, his San Francisco-based firm targeted British litigation-finance firm Burford Capital Ltd. and Japanese biotech stock PeptiDream Inc. Short sellers seek to benefit from a decline in a company’s share price.

Muddy Waters didn’t disclose the size of its short position in NMC.

–With assistance from Lisa Pham and Filipe Pacheco.