As the Q1 earnings season wraps, let’s dig into this quarter’s best and worst performers in the testing & diagnostics services industry, including RadNet (NASDAQ: RDNT) and its peers.

The testing and diagnostics services industry plays a crucial role in disease detection, monitoring, and prevention, serving hospitals, clinics, and individual consumers. This sector benefits from stable demand, driven by an aging population, increased prevalence of chronic diseases, and growing awareness of preventive healthcare. Recurring revenue streams come from routine screenings, lab tests, and diagnostic imaging, with reimbursement from Medicare, Medicaid, private insurance, and out-of-pocket payments. However, the industry faces challenges such as pricing pressures, regulatory compliance, and the need for continuous investment in new testing technologies. Looking ahead, industry tailwinds include the expansion of personalized medicine, increased adoption of at-home and rapid diagnostic tests, and advancements in AI-driven diagnostics that enhance accuracy and efficiency. However, headwinds such as reimbursement uncertainties, competition from decentralized testing solutions, and regulatory scrutiny over test validity and cost-effectiveness may impact profitability. Adapting to evolving healthcare models and integrating automation will be key for sustaining growth and maintaining operational efficiency.

The 5 testing & diagnostics services stocks we track reported a strong Q1. As a group, revenues beat analysts’ consensus estimates by 3.2%.

Luckily, testing & diagnostics services stocks have performed well with share prices up 12.7% on average since the latest earnings results.

Weakest Q1: RadNet (NASDAQ: RDNT)

With over 350 imaging facilities across seven states and a growing artificial intelligence division, RadNet (NASDAQ: RDNT) operates a network of outpatient diagnostic imaging centers across the United States, offering services like MRI, CT scans, PET scans, mammography, and X-rays.

RadNet reported revenues of $575.6 million, up 22.1% year on year. This print exceeded analysts’ expectations by 3%. Despite the top-line beat, it was still a slower quarter for the company with a significant miss of analysts’ EPS estimates.

Dr. Howard Berger, President and Chief Executive Officer of RadNet, commented, “After being impacted by severe winter weather conditions in the Northeast during January and February which reduced Revenue and Adjusted EBITDA(1) by an estimated $13 million and $9 million, respectively, our business strongly rebounded in March, resulting in a Total Company Revenue increase of 22.1% and a Total Company Adjusted EBITDA(1) increase of 36.3% from last year’s first quarter. The record first quarter performance was driven by aggregate advanced imaging (MRI, CT and PET/CT) growth of 19.7% and same-center advanced imaging growth of 8.2% as compared with the first quarter of last year. The growth in MR, CT and PET/CT contributed to a 235 basis point shift in RadNet’s advanced imaging procedural volume mix (relative to routine imaging) as compared with the same quarter last year, increasing from 26.9% in last year’s first quarter to 29.3% in the first quarter of 2026. Imaging Center Adjusted EBITDA(1) margin increased by 52 basis points, after adjusting for lost Revenue and Adjusted EBITDA(1) from the severe winter weather in this year’s first quarter and the severe winter weather and California wildfires in last year’s first quarter.”

The market seems disappointed with the results as the stock is down 9% since reporting and currently trades at $52.96.

Read our full report on RadNet here, it’s free.

Best Q1: Guardant Health (NASDAQ: GH)

Pioneering the field of "liquid biopsy" with technology that can identify cancer-specific genetic mutations from a simple blood draw, Guardant Health (NASDAQ: GH) develops blood tests that detect and monitor cancer by analyzing tumor DNA in the bloodstream, helping doctors make treatment decisions without invasive biopsies.

Guardant Health reported revenues of $301.7 million, up 48.3% year on year, outperforming analysts’ expectations by 8.4%. The business had an exceptional quarter with an impressive beat of analysts’ revenue estimates and full-year revenue guidance exceeding analysts’ expectations.

Guardant Health achieved the biggest analyst estimate beat and fastest revenue growth among its peers. The market seems happy with the results as the stock is up 44.7% since reporting. It currently trades at $133.50.

Is now the time to buy Guardant Health? Access our full analysis of the earnings results here, it’s free.

Labcorp (NYSE: LH)

With over 600 million tests performed annually and involvement in 90% of FDA-approved drugs in 2023, Labcorp (NYSE: LH) provides laboratory testing services and drug development solutions to doctors, hospitals, pharmaceutical companies, and patients worldwide.

Labcorp reported revenues of $3.54 billion, up 5.8% year on year, exceeding analysts’ expectations by 0.9%. It was a satisfactory quarter as it also posted a narrow beat of analysts’ full-year EPS guidance estimates but organic revenue in line with analysts’ estimates.

Labcorp delivered the highest full-year guidance raise but had the weakest performance against analyst estimates and slowest revenue growth in the group. Interestingly, the stock is up 1.5% since the results and currently trades at $261.

Read our full analysis of Labcorp’s results here.

NeoGenomics (NASDAQ: NEO)

Operating a network of CAP-accredited and CLIA-certified laboratories across the United States and United Kingdom, NeoGenomics (NASDAQ: NEO) provides specialized cancer diagnostic testing services, including genetic analysis, molecular testing, and pathology consultation for oncologists and healthcare providers.

NeoGenomics reported revenues of $186.7 million, up 11.1% year on year. This print surpassed analysts’ expectations by 1.2%. Overall, it was a strong quarter as it also produced EPS in line with analysts’ estimates and a narrow beat of analysts’ revenue estimates.

The stock is up 26.2% since reporting and currently trades at $11.38.

Read our full, actionable report on NeoGenomics here, it’s free.

Quest (NYSE: DGX)

Processing approximately one-third of the adult U.S. population's lab tests annually, Quest Diagnostics (NYSE: DGX) provides laboratory testing and diagnostic information services to patients, physicians, hospitals, and other healthcare providers across the United States.

Quest reported revenues of $2.90 billion, up 9.2% year on year. This result beat analysts’ expectations by 2.7%. It was a strong quarter as it also recorded a solid beat of analysts’ revenue estimates and a beat of analysts’ EPS estimates.

The stock is flat since reporting and currently trades at $196.16.

Read our full, actionable report on Quest here, it’s free.

Market Update

Late in 2025 into early 2026, there was hand-wringing around artificial intelligence. For software companies, the fear was that AI would erode pricing power and compress margins as new tools made it easier to replicate what once required expensive enterprise platforms. Crypto investors had their own version of the same anxiety: if AI agents could trade, allocate capital, and manage wallets autonomously, what exactly was the long-term value of today’s crypto infrastructure?

These concerns triggered a noticeable rotation away from these sectors and into safer havens. But markets rarely dwell on one narrative for long. Spring 2026 came, and the focus shifted abruptly from technological disruption to geopolitical risk. The US’ conflict with Iran became the dominant driver of market psychology, and when geopolitics takes center stage, the script changes quickly. Investors stop debating growth rates and start worrying about oil supply, inflation, and global stability.

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