What happened

Shares of Guardant Health (GH -3.60%) were rising 8.6% higher as of 1:25 p.m. EDT on Thursday after dropping as much as 11% earlier in the day and later jumping as much as 15.1%. How did the liquid biopsy company manage to defy gravity as the overall stock market plunged on worries about COVID-19? The most likely reason is that investors recognize the pandemic in no way hurts Guardant Health's business prospects.

So what

Very few stocks are rising today in the wake of the market bloodbath. Many of these, like Guardant Health, for all practical purposes have businesses that are immune to the effects of the coronavirus. And yet the stocks are falling nonetheless.

One bright white arrow pointing up with four other arrows pointing down

Image source: Getty Images.

It seems likely that one or more institutional investors have decided to take advantage of Guardant Health's pullback over the last few days to buy the healthcare stock at a discount. Why they're not doing so with other stocks is a mystery. But it's no mystery why Guardant Health would be attractive.

Sales for the company's liquid biopsy products Guardant360 and GuardantOMNI continue to skyrocket. Guardant Health's Lunar assays are waiting in the wings and could be even bigger winners over the long run than its current commercial products. And the prospects for all of these liquid biopsies shouldn't be dented in the slightest by COVID-19.

Now what

Will investors retain their sanity with respect to Guardant Health? Maybe, maybe not. In the current market environment, anything could happen. However, this bright spot on a very dark day for the stock market underscores an important point: There are stocks still worth buying. Guardant Health is definitely one of them.