Testing & Diagnostics Q1: RadNet (RDNT) Misses EPS, Guardant Health (GH) Leads Revenue Growth

The testing and diagnostics services sector posted strong Q1 2026 results overall, with aggregate revenues beating analyst estimates by 3.2%. However, individual stock performance diverged sharply. RadNet (NASDAQ:RDNT) saw revenue jump 22.1% to $575.6 million, exceeding expectations by 3%, but a significant EPS miss sent shares down 9% to $52.96. CEO Howard Berger cited severe winter weather cutting an estimated $13 million from revenue, though operations rebounded in March. In contrast, Guardant Health (NASDAQ:GH) surged, with revenue up 48.3% to $301.7 million—an 8.4% beat—and raised full-year guidance. The stock soared 44.7% to $133.50. Labcorp (NYSE:LH) and Quest Diagnostics (NYSE:DGX) posted more muted beats, while NeoGenomics (NASDAQ:NEO) rose 26.2%. The industry benefits from AI diagnostics and aging demographics, but faces reimbursement pressures and competition from decentralized testing.