 Shares of CytoDyn Inc. CYDY, -4.11 fell 4.9 in trading on Tuesday, the same day that the Food and Drug Administration issued a warning letter to the company over a video that features the former CEO falsely claiming that the companys experimental drug, leronlimab, clinically benefits COVID-19 patients. CytoDyn announced Jan. 24 that the board terminated Nader Pourhassan, the former president and CEO cited in the letter. 