On December 11, shares of UnitedHealth Group (UNH) fell by 5.60%, marking the lowest intraday level since July 2024. The downturn follows the tragic incident involving UnitedHealth Insurance's CEO, Brian Thompson, who was fatally shot on December 4 in Manhattan, New York.

Brian Thompson's untimely death shocked both the business community and the broader public. The suspect, Luigi Mangione, was apprehended on December 9 in Pennsylvania. At the time of his arrest, Mangione was found with a handwritten note expressing grievances against the U.S. health insurance system. This note provided insights into his possible motives.

According to Joe Kenny, an investigator with the New York City Police Department, Mangione's notes suggested his dissatisfaction with the American healthcare system, deemed the most expensive globally, with the U.S. ranking 42nd in life expectancy. Although UnitedHealth stands as the largest private health insurer in the U.S., these systemic issues reportedly drove Mangione to the extreme act against Thompson.

It is understood that Mangione has been suffering from chronic back pain, a condition that potentially fueled his frustration. He reportedly shared his physical and emotional struggles on social media, which included an X-ray image of a spine reinforced with surgical implants. While it remains unclear whether Mangione received formal treatment for his condition, including surgery, his distress was palpable in his online presence.