What happened

Many companies on the hardware side of the tech sector had a very bad day on Monday. Machine vision specialist Cognex (CGNX -0.59%) closed the day 10.9% lower, automated testing systems expert National Instruments (NATI) fell 11.2%, and NCR (VYX -1.32%), which makes barcode scanners and ATM kiosks, took a 16.4% hit at the end of the day.

So what

None of these companies had any significant news of their own to share today. All of them were pulled down by a marketwide panic about a further reach of the novel coronavirus. The COVID-19 disease has now been found in more than 110,000 people around the world, with particularly heavy outbreaks in China, Italy, and Iran. Schools are closing in Spain, and the entire country of Italy is now on lockdown.

The disease is stopping millions of people from going to work, which is bad news for companies like Cognex and National Instruments, which depend on activity across the manufacturing sector. When factories slow down or even stop their manufacturing lines, they're not investing in their product-testing infrastructure. NCR's barcode-scanning systems also cater to this market. NCR is in the midst of a high-level strategy shift toward providing software and services supporting its kiosks and scanners, and those revenue streams can slow down in a hurry when the global economy slows down.

A technician uses a multimeter and an oscillator to examine a printed circuit board.

Image source: Getty Images.

Now what

All three of these stocks were trading near their 52-week highs in the middle of February, when the coronavirus hit news wires around the globe. The virus scare has driven National Instruments shares 20% lower in three weeks. Cognex stock fell 24% over the same period and NCR has taken an even deeper cut of 39%.

These stocks are not known to be particularly vulnerable to short-term market shifts. NCR's stock rose 52% in 2019 despite relatively modest 6% year-over-year revenue growth. Fellow Fool Lee Samaha handpicked Cognex as a key robotics stock to buy at the start of 2020. National Instruments beats analyst expectations like a drum, quarter by quarter.

All of these high-quality companies are hoping for a quick end to the coronavirus panic, allowing manufacturing workers to get back to work, but they should also be able to survive even a lengthy downturn. Cognex and National Instruments sport fantastically healthy balance sheets, and NCR's sector-leading return on equity points to a highly efficient business model. Buying these stocks on large dips like this one could be a winning strategy for patient long-term investors.