Shares of Labcorp Holdings Inc fell 5.43% in pre-market trading, even as the company reported better-than-expected second-quarter results and raised its full-year guidance. The decline suggests investors focused on a softer performance in the company's core diagnostics unit compared to a recently reported rival.

The company posted second-quarter revenue of $3.73 billion, slightly above the analyst consensus estimate of $3.71 billion, and adjusted earnings per share of $4.99, which topped expectations of $4.78. Labcorp also raised its 2026 adjusted earnings forecast to a range of $18.10 to $18.55 per share, with the midpoint exceeding Wall Street estimates.

However, according to a Reuters report citing Leerink Partners analyst Michael Cherny, investor focus was drawn to weaker-than-expected organic growth in the Diagnostics Laboratories segment. Revenue in this unit grew 5.5% to $2.90 billion, slightly missing the analyst estimate of $2.91 billion. This miss came after rival Quest Diagnostics raised its own forecast the previous week, setting a higher performance bar for the sector.