British boss of US healthcare giant UnitedHealth quits for ‘personal reasons’ - The move comes five months after one of the company’s top executives was killed after being shot as he walked to an investor conference in New York.

Stephen Hemsley ran UnitedHealth Group for more than a decade. It's a different company after four years with Andrew Witty in charge.

Hemsley, 72, had led the company for more than a decade until 2017 and is re-taking the reins following a series of setbacks.

Stephen Hemsley hasn’ t been CEO at UnitedHealth Group in nearly a decade yet he’ s never really left. Since that day, the company’ s stock has fallen from $610 a share to $308 on Tuesday, an unprecedented decline for the company that culminated in this week’ s CEO transition.

UnitedHealth has faced several headwinds in the recent past, ranging from a cyberattack, which had greater than initially realized impacts, to the tragic killing of its CEO, which caused the company to suffer harsh public backlash over the company's and industry practices.

UnitedHealth's stock has plunged nearly 40% year-to-date as the company has battled a series of crises. Can the healthcare giant turn it around? Seeking Alpha analysts weigh in.

Even UnitedHealth will struggle to overcome parasitic medical costs that Warren Buffett once called a tapeworm eating away at U.S. economic competitiveness. The $300 billion healthcare conglomerate reinstalled Chairman Stephen Hemsley as CEO and yanked its financial guidance.

Stephen Weiss, who frequently appears on CNBC, noted on the network yesterday that he was holding onto his position in UnitedHealth Group Incorporated (UNH) after UNH’s CEO, Andrew Witty, resigned, citing “personal reasons.