RSU grants are afaik usually on a per unit basis based on the price when you start. So if the current stock price is $20/share and you get $20k worth of RSUs then that means you get 1k shares. If the value per share goes up to $100 then your RSUs are now worth $100k. This is why some tech company employees have massive stock compensations, the stock has gone up a lot since their initial offer.