Gerald Beeson, chief operating officer of Citadel Advisors LLC. (Kyle Grillot/Bloomberg)The billionaire’s right-hand man started his career as an intern at the now-prolific hedge fund. Gerald Beeson is the chief operating officer of Citadel LLC, the giant hedge fund that is the sibling company of Citadel Securities, both owned by billionaire Ken Griffin. Beeson, considered to be Griffin’s right-hand man, has been working at Citadel since its earliest days.