Employee gifted shares

Asalamu Alaykum,

Company a few years ago gave shares that were to vest after certain time period. The company does permissible work but likely has income from interest etc. What to do when the shares vest? Options I can think of:

  1. Don’t accept them they’re impermissible
  2. Cash them but only keep the value that they were on the day they were promised (as if it was a cash gift)
  3. Cash them and keep the gain too (if the price is higher than when promised)

What would be permissible?
JazakAllah khair