Muddy Waters takes short position in NMC Health, stock tanks

(Reuters) - U.S. short-selling firm Muddy Waters said on Tuesday it has acquired a short position in NMC Health Plc , citing "serious doubts" about the hospital operator's financial statements, including its asset values, cash balance and reported profits.Shares of the FTSE 100 firm plunged more than 20% and were on track for their worst day ever.NMC Health was not immediately available for comment.