RSUs have a $0 cost basis - these aren't options we're talking about. Yes it's technically a $600K downside risk but if you recognize anywhere close to that your company went bankrupt and that won't factor into the conversation since you won't have a job anymore.
This kind of up-front grant is a wonderful asymmetric bet. You get $600K skin in the game on day 1. If the stock goes up 20% you get a 20% gain on the whole amount before you even own it. If it goes down materially, you're welcome to quit - but more often what happens is actually the company issues a refresh grant to make up for it - since they don't want you to quit. If it goes back up you now have a ton more stock on the way back up.
You get to earn appreciation on the whole amount before you earn it so up to 4 years early. You have nothing of your own at risk except your time. Things go well, you can do amazingly well. If things go bad, you lost a year or two and you can wander down the street for another lotto ticket.
This kind of up-front grant is a wonderful asymmetric bet. You get $600K skin in the game on day 1. If the stock goes up 20% you get a 20% gain on the whole amount before you even own it. If it goes down materially, you're welcome to quit - but more often what happens is actually the company issues a refresh grant to make up for it - since they don't want you to quit. If it goes back up you now have a ton more stock on the way back up.
You get to earn appreciation on the whole amount before you earn it so up to 4 years early. You have nothing of your own at risk except your time. Things go well, you can do amazingly well. If things go bad, you lost a year or two and you can wander down the street for another lotto ticket.