Of the 28 companies in the index, 16 companies' share prices increased while the share values of 12 declined month over month.
Natera discussed its cancer and transplant rejection testing businesses, while Exact Sciences explained how it will benefit from its Genomic Health acquisition.
Though the firm's top-line figures fell just shy of analysts' estimates, its installed base of ePlex analyzers grew 49 percent year over year.
Gainers in the index outpaced the decliners 19 to nine, and the index outpaced the Dow Jones Industrial Average and Nasdaq Biotechnology Index but lagged the Nasdaq.
Pressure associated with competition and reimbursement may erode GenMark's market share and product pricing, JP Morgan said.
The firm said that ePlex revenues grew 98 percent compared to Q3 2018, and the firm placed 51 net new ePlex analyzers.
Companies in the AMR space have met resistance from investors and clinicians as a result of conflicting hospital priorities and perceived technology shortcomings.
The Carlsbad, California-based molecular diagnostics firms reported $18.4 million in revenues, up from 14.9 million in Q2 of 2018.
The guidelines provide recommendations for what CYP2C9 variant alleles should be included in clinical pharmacogenomic tests assessing that gene.
GenMark Diagnostics received clearance for a third BCID panel that the firm said paves the way for a customizable approach to sepsis MDx.