Jim Chanos, head of Kynikos Associates, spoke Wednesday at the Delivering Alpha conference in New York. Chanos discussed his bets against Mednax and Envision Healthcare. "These businesses are earning nothing," he said.

James Chanos, Founder & Managing Partner, Kynikos Associates. David A. Grogan | CNBC

Chanos has previously disclosed his bets against the two companies, with his position against Mednax in place since mid-2017 and his Envision short going since the beginning of 2018. Share prices for both dropped after Chanos presented his remarks. Chanos has called the companies "rent seekers" in the health-care system and charged again Wednesday that they are shuffling money to cover up how poorly the businesses are performing.