Quest Diagnostics (DGX) shares surged 11.54% during intraday trading on Thursday, as investors reacted to a powerful combination of better-than-expected second-quarter results and a significant upward revision to the company's full-year outlook.

The diagnostic testing giant reported adjusted earnings per share of $3.12 for the second quarter, easily surpassing the analyst consensus estimate of $2.83 and marking a 19% increase from the prior-year period. Revenue climbed 10% to $3.04 billion, exceeding Wall Street forecasts of $2.97 billion. The strong performance was fueled by broad-based organic growth across the company's physician, hospital, and consumer channels, along with double-digit expansion in advanced diagnostics including Alzheimer's blood tests and cardiometabolic testing.

Management raised its full-year 2026 adjusted EPS guidance to a range of $11.05 to $11.25, well above the FactSet consensus of $10.75, and lifted its revenue forecast to between $11.95 billion and $12.05 billion, compared with analysts' estimates of $11.85 billion. The upbeat results and bullish outlook underscored robust demand for routine diagnostic services and reinforced investor confidence in the company's growth trajectory.