UnitedHealth Stock Rallies on Improved Medical Costs and Raised Guidance

UnitedHealth's stock price has surged by 21% since its July earnings report, where it posted revenue of $112 billion and adjusted EPS of $6.38, both beating expectations.

The key factor behind this rally is the company's improved medical care ratio, which measures how much premium revenue goes toward paying medical claims. This ratio has decreased to 86.7%, down from a year ago, indicating lower medical costs.

As a result of this trend, UnitedHealthcare's operating margin nearly doubled to 4.6%, while Optum's operating margin rose to 6.2%. If medical cost trends continue into the back half of the year, the raised guidance looks achievable rather than aspirational.