[Traster]

It's quite simple, these trial results don't just get automatically published. He knows he has a sale date coming up, if the results are good, he times the announcement just before his sale - causing a pop to his stock (that likely will mean revert eventually) causing the peak share price to occur around the time he sells. If the results are bad he delays the announcement to the day after his sale, making sure he secures a good price before the inevitable drop. The CEO of Pfizer shouldn't be timing market moving evens based on his personal stock trading.