The GenomeWeb Index, which now has 32 companies, lost 2.6 percent in September while the Dow Jones Industrial Average gained 2 percent over the same period.
The agency has approved the use of Exact's Cologuard test for average-risk individuals aged 45 and older.
The study said that Cologuard was an "inefficient screening option" for colorectal cancer given its cost as compared to other CRC screening methods.
The index, which underperformed the Dow Jones and the Nasdaq, gave back the 11 percent gain it made in June.
Financial analysts seemed convinced of the long-term advantages of the deal but noted that investors may remain skeptical in the near term.
The company's total revenues were $114.1 million compared with $95.6 million in the same quarter last year, beating analysts' expectations.
Exact said it will pay $72 per share for Genomic Health for a total transaction price of $2.8 billion in cash and stock.
Invitae said this week that it completed its acquisition of Singular Bio on June 19.
Exact Sciences and the Mayo Clinic are working to develop a blood test for pancreatic cancer that might be able to diagnose patients with early-stage disease.
The FLASH method, which depletes unwanted DNA from samples, allows labs to perform deep metagenomic sequencing on smaller, less expensive instruments.
23andMe has a holiday popup shop at a mall and could open additional stores, Bloomberg reports.
By studying koalas and a retrovirus that infects them, researchers may have uncovered a new sort of 'immune response' that occurs at the genomic level, Agence France Presse reports.
NPR reports that the first person in the US given a gene editing-based therapy for a genetic disorder is heading home.
In Science this week: ancient genomes reveal social inequality within individual households, new method for quantifying genetic variation in gene dosage, and more.