RSAs and RSUs are types of equity that companies award to employees and other service providers. While a stock option gives you the right or “option” to buy a set number of shares at the designated strike price, you don’t own the shares until you exercise your option to buy them. With RSAs and RSUs, you’re the legal owner of the shares from the date they are issued to you (although exactly when the underlying shares are issued depends on the type of equity award).