The chairman and CEO of Pfizer, Albert Bourla, sold $5.6 million worth of stock in the pharmaceutical company on Monday. The sale took place on the same day Pfizer announced that its experimental coronavirus vaccine candidate was found to be more than 90% effective. Bourla's sale of Pfizer stock was part of a trading plan set months in advance. Known as 10b5-1 plans, they essentially put stock trades on autopilot. Executives are supposed to adopt these plans only when they are not in possession of inside information that can affect a company's stock price. On Aug. 19, Bourla implemented his stock-trading plan. The next day, Aug. 20, Pfizer issued a press release ... confirming that Pfizer and its German partner, BioNTech, were "on track to seek regulatory review" for its vaccine candidate. Daniel Taylor, an expert in insider trading ... told NPR that the close timing between the adoption of Bourla's stock plan and the press release looked "very suspicious." "It's wholly inappropriate for executives at pharmaceutical companies to be implementing or modifying 10b5-1 plans the business day before they announce data or results from drug trials," Taylor said. The stock sales by Pfizer's CEO brought to mind similar concerns with another coronavirus vaccine-maker, Moderna. Multiple executives at Moderna adopted or modified their stock-trading plans just before key announcements about the company's vaccine. Those executives have sold tens of millions of dollars in Moderna stock.