UnitedHealth Group has announced the resignation of CEO Andrew Witty, who stepped down for personal reasons as the company grapples with higher-than-expected medical costs. In light of these developments, UnitedHealth has suspended its financial outlook for 2025, which has led to a significant drop in its stock value. Stephen Hemsley has been reappointed as the new CEO as part of this leadership transition. The shift comes amidst growing concerns in the health insurance sector, prompting a downturn in stocks not just for UnitedHealth, but across health insurers.