#stocks making biggest moves in pre #markets - #Pfizer &amp; #BioNTech on new Covid19 vaccine, #DuPont #jobs cuts, #Wayfair beat revenue estimates, #ShakeShack on rebounding sales, #Starbucks to open 85% of locations, #Avis says June recovery &amp; more  @CNBC  https://t.co/CjUcU6uxSP