Guardant Health (GH) Stock Surges 42.6% on Q1 Revenue Beat; Testing & Diagnostics Sector Outperforms

Guardant Health (NASDAQ:GH) reported Q1 revenue of $301.7 million, soaring 48.3% year-on-year and beating analyst estimates by 8.4%. Shares of the liquid biopsy specialist have surged 42.6% to $131.53 since its May 29, 2026, report. The broader testing and diagnostics services group also performed strongly, with five tracked companies collectively exceeding consensus revenue forecasts by 3.2% and seeing average share-price gains of 11.2%. NeoGenomics (NEO) posted an 11.1% revenue increase to $186.7 million, narrowly topping estimates. RadNet (RDNT) grew revenue 22.1% to $575.6 million but missed EPS expectations, sending its stock down 3.6%. Labcorp (LH) reported $3.54 billion in revenue, up 5.8%, while Quest Diagnostics (DGX) delivered $2.90 billion, a 9.2% rise, both modestly exceeding projections. Sector tailwinds include aging demographics and AI-driven diagnostics, though reimbursement uncertainty and pricing pressures remain headwinds. Guardant Health delivered the fastest growth but issued the group’s weakest full-year guidance update, even as investor enthusiasm persisted.