They're your shares. They are held in an account sponsored by the employer, but they are yours just like if you bought them from schwab.com. I don't know what

They're your shares. They are held in an account sponsored by the employer, but they are yours just like if you bought them from schwab.com. I don't know what happens if a brokerage goes out of business, but I imagine you're in the same boat as all the people who bought those shares with cash on the open market. Once the stock vests, it's yours.