SpaceX investors say the rocket company uses a 'very smart' internal stock market to keep workers happy in spite of long hours and 'mediocre' salaries

· A private investor in SpaceX says the rocket company, founded by Elon Musk, is in the middle of an internal tender offer for its employees.
· Employees can gradually buy vested stock in SpaceX. A former employee says staff get a 10% discount off the latest strike price.
· But to keep tight control of the company's...