This looks like stock manipulation:
On February 10, Trump's FDA oddly declined to review Moderna's new flu vaccine. The stock then dropped from 37.95 to 32.22.
Then Moderna announced that this surprising move was "inconsistent with previous written communications" with the FDA, and they were now sorting this out. News then broke that the FDA would now review the vaccine, and sure enough, the stock is now back up.
If someone wanted to earn big on trading Moderna, this is what they would do.