Healthcare stocks were hit hard yesterday following a tweet by Democratic Presidential candidate Hillary Clinton about the pricing of drugs. While biotech stocks were more affected by the tweet with the NASDAQ Biotechnology index shedding 4.41%, pharma stocks were also not spared with the NYSE ARCA Pharmaceutical Index losing 1.47%. (Read how Hillary Clinton Crushed ETFs)

The “Price Gouging” Tweet That Triggered the Slide

“Price gouging like this in the specialty drug market is outrageous. Tomorrow I’ll lay out a plan to take it on.” – this is the tweet that triggered the slide in the biotech sector. Clinton was responding to a tweet by The New York Times about a 5,000% hike in the price of a drug, Daraprim (pyrimethamine) that was approved by the FDA way back in 1953.

Turing Pharmaceuticals, headed by ex-hedge fund manager, Martin Shkreli, had acquired rights to Daraprim from Impax Laboratories just last month and reportedly hiked its price from $13.50 to $750 per tablet. Needless to say, this caused a major furor considering growing concerns regarding the pricing and affordability of prescription drugs.

Last year too, the biotech sector had seen a selloff when lawmakers had questioned Gilead Sciences, Inc.’s (GILD – Analyst Report) pricing of its hepatitis C virus (HCV) treatment, Sovaldi. The $84K price tag for a 12-week treatment period was considered too expensive and came under heavy criticism.

Biotech Stocks Affected by Clinton’s Vow

Although most biotech stocks saw their share prices sliding yesterday, here is a look at five large biotech companies that were hit by Clinton’s vow to fight drug pricing.

Biogen Inc. (BIIB – Analyst Report) – Cambridge, MA-based Biogen, well known for its multiple sclerosis (MS) treatments, saw its shares slide 5.56% yesterday. It’s been a challenging year for the company which is facing a slowdown in the growth rate of its oral MS treatment, Tecfidera. To make matters worse, the emergence of a few cases of progressive multifocal leukoencephalopathy (PML), a serious brain infection, in patients using Tecfidera, will continue to weigh on the stock.