Tracking stock sales of executives involved in Covid-19 drug developments

Pfizer CEO Albert Bourla sold almost $5.6 million worth of stock on Monday, the same day the drugmaker announced positive early data on its experimental coronavirus vaccine that sent shares soaring. But Bourla isn't the only executive officer of a pharmaceutical company involved in the race for Covid-19 vaccine and treatments who are selling stocks. CNBC's Meg Tirrell reports.