Why Gilead Scinces Stock Tumbled on Tuesday

On some negative news about one of its investigational programs, the stock of pharmaceutical company Gilead Sciences (NASDAQ: GILD) took some hits on Tuesday. Investors traded it down by more than 2%, comparing unfavorably to the 0.6% gain of the benchmark S&P 500 (SNPINDEX: ^GSPC).

The FDA puts on the red light

That morning, the U.S. Food and Drug Administration (FDA) ordered a halt to Gilead's testing of a two-drug combination to treat human immunodeficiency viruses (HIV), the cause of acquired immunodeficiency syndrome (AIDS).

Where to invest $1,000 right now? Our analyst team just revealed what they believe are the 10 best stocks to buy right now. Learn More »

Image source: Getty Images.

The regulator ordered the company to pause its current trials of the pair, GS-1720 and GS-4182, after some participants were found to have low levels of CD4+ T-cells (a type of white blood cell). It was unclear what triggered the deficiencies.

Gilead was putting the two drugs through their paces in a series of clinical trials, which were at various stages. The ones in the mid-to-late cycles were testing the pair against its currently commercialized HIV pill, Biktarvy.

GS-4182 is a pill version of the company's HIV treatment lenacapavir (sold in commercial form as Sunlenca). GS-1720 is a drug in development that is administered once per week.

In an article on the FDA's move published by Reuters, the news agency wrote that Gilead stated it has numerous other HIV combination treatments under development that are not affected by the agency's hold.

A drop in the bucket

Given that, the pause mandated by the FDA doesn't feel like a monster setback. We should also bear in mind that not only is Gilead actively developing next-generation HIV treatments, it also has quite a wide pipeline, spanning 58 investigational programs.

Should you invest $1,000 in Gilead Sciences right now?

Before you buy stock in Gilead Sciences, consider this:

The Motley Fool Stock Advisor analyst team just identified what they believe are the 10 best stocks for investors to buy now… and Gilead Sciences wasn’t one of them. The 10 stocks that made the cut could produce monster returns in the coming years.

Consider when Netflix made this list on December 17, 2004... if you invested $1,000 at the time of our recommendation, you’d have $660,341!* Or when Nvidia made this list on April 15, 2005... if you invested $1,000 at the time of our recommendation, you’d have $874,192!*

Now, it’s worth noting Stock Advisor’s total average return is 999% — a market-crushing outperformance compared to 173% for the S&P 500. Don’t miss out on the latest top 10 list, available when you join Stock Advisor.

See the 10 stocks »

*Stock Advisor returns as of June 9, 2025

Eric Volkman has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Gilead Sciences. The Motley Fool has a disclosure policy.