"Fiduciary duty" is the term you'll be looking for. Its a legal requirement for the fiduciary (an executive in this case) to act in the best interest of the beneficiary (the shareholder in this case).
If I'm not mistaken, case law covers the basics like acting in good faith, trust, candor, etc but one of the biggest requirements is acting in the best financial interest of shareholders.
If I'm not mistaken, case law covers the basics like acting in good faith, trust, candor, etc but one of the biggest requirements is acting in the best financial interest of shareholders.