SpaceX allows its employees to cash out some of their shares by selling to company-authorized outside investors around every 6 months. This article discusses an internal document from SpaceX about such a tender offer from 2022. Investors paid $70 per share to employees in the offer, an enormous discount compared to the $270 per share during the primary sale that year. The main reason for the price discrepancy comes from employees owning common stock - investors who buy into primary rounds typically buy preferred stock, which entitles them to dividends and liquidation preferences.