What happened

Shares of some healthcare companies couldn't escape the wrath of COVID-19, the disease caused by the novel coronavirus. NuVasive (NUVA) closed down 13% on Thursday, while Exelixis (EXEL 0.74%) slumped 12% and Natus Medical (NTUS) dropped a whopping 17%. The broader S&P 500 index only fell 9.5% on Thursday.

So what

It's been a rough week for NuVasive, having also registered a double-digit decline on Monday. Part of the issue is likely that investors are profit taking, with the spine technology company having risen 56% in 2019.

It's likely COVID-19 will have some short-term affects on the rate of spine surgeries performed using NuVasive's minimally invasive lateral systems, but those backs aren't going to fix themselves. The patients will eventually need surgeries, and NuVasive will be there to continue to take market share from traditional spine surgery companies.

Man with clenched fists looking atstock charts

Image source: Getty Images.

Exelixis is the most puzzling of the three since it sells cancer treatments. Patients are still going to need their medication no mater what COVID-19 brings. The biotech does have an upcoming binary event with the CheckMate 9ER trial testing its Cabometryx drug plus Bristol-Myers Squibb's (BMY -0.59%) Opdivo in kidney cancer. The results, which are due out in the first half of this year, could reaccelerate Cabometryx's growth, but with the broader market having issues, investors may be selling to reduce their exposure to risk.

Natus sells a variety of products including newborn hearing tests, neurology products, and hearing aid fittings. While it's squarely in the healthcare space, it's foreseeable that Natus could see a slowdown in demand for some of its products. If COVID-19 pushed the U.S. into a recession, for example, the birth rate might temporarily go down, reducing spending on its hearing tests. And with COVID-19 affecting older patients to a higher degree, they may choose to stay home and put off getting hearing aids, although some of that revenue could be captured later once things settle down.

Now what

In these trying times, it can be hard to stay the course, but investors should be looking to areas like healthcare where revenues are less likely to be affected than in other sectors, where a recession -- if COVID-19 pushes us there -- might have a greater affect on discretionary spending.