Shares of Gilead Sciences climbed Monday on a rough day for the overall market after CVS Health said Gilead’s pricey hepatitis C treatments will become a preferred treatment on several of its pharmacy benefits management plans.

CVS Health, which is one of the nation’s largest pharmacy benefits managers, said Gilead’s Harvoni and Sovaldi will become exclusive starting Wednesday for its Medicare and Medicaid formularies, as well as for some commercial coverage. Formularies are lists of drugs covered by a pharmacy benefits manager. They are often broken down into different payment tiers.

CVS Health Corp. is one of the country’s largest pharmacy benefits managers. A spokeswoman said via email that the company made its decision after reviewing treatments for the liver-destroying virus.

She did not immediately respond to a question about how this designation may affect out-of-pocket costs for consumers taking the drug.

Sovaldi was hailed as a groundbreaking new therapy when it hit the market late in 2013. But Sovaldi and the more recently approved Harvoni have generated criticism for their high price tags. Both drugs cost more than $80,000 each for a full course of treatment.

Gilead executives have said that their drugs are cost effective, despite their price tags, because they cure more patients in less time than older drugs, and they prevent catastrophic problems like liver failure.

Shares of Foster City, California-based Gilead Sciences Inc. climbed nearly 2 percent, or $1.83, to $96.74 in afternoon trading while the Dow Jones industrial average fell 1.7 percent.

Gilead’s stock had plunged last month after the nation’s largest pharmacy benefits manager, Express Scripts Holding Co., said it would restrict coverage of Sovaldi and Harvoni to limited circumstances. It made AbbVie Inc.’s Viekira Pak the preferred treatment for patients who have the most common form of hepatitis C, genotype 1.