The investment bank said the company is strongly positioned as a leader in the transplant diagnostics market with tests that serve an unmet need.
An analyst said the DetermaVu test could potentially be best in class for lung cancer diagnosis and that CMS could begin reimbursing for it in late 2020.
The firm said net product revenues fell 11 percent year over year in the fourth quarter.
UBS initiated coverage of Quest with a Neutral raing and a $90 price target on its shares. It gave LabCorp a Buy rating and a $169 price target.
The improvement in the 360Dx Index was modest compared to 2017, but it still outpaced the broader markets, which fell dramatically in the last month of the year.
The investment bank called Genomic Health a leader in diagnostic testing and said Invitae will benefit from growth trends in the genetic testing sector.
The company attributed the lower revenue growth to lower volume growth in diagnostics, which is expected to continue for the rest of the year.
The firm said genomic testing volume rose 23 percent year over year, and raised its revenue guidance for full-year 2018.
Analysts cited Guardant's strong liquid biopsy testing portfolio, specifically its Guardant360 assay, as reasons for their optimistic views.
The investment bank expects Abbott's Diagnostic division to grow in the mid-single digits driven in part by global launches of its Alinity systems.