What happened

Shares of Boeing (NYSE:BA) and General Electric (NYSE:GE) each opened down more than 11% Monday morning, and shares of Lockheed Martin (NYSE:LMT) were down more than 6%, as COVID-19 fears continue to rattle the market. The ripple effects of the outbreak are going to be substantial and could eat into a number of sectors in the months to come.

So what

The coronavirus sell-off has been going on for a number of weeks now, but Monday's open was ugly even by recent standards. The S&P 500 opened down 7%, immediately triggering a market halt.

Aerospace giants were caught up in the selling. Commercial aerospace figures to be among the sectors hardest hit by a coronavirus-related slowdown, as airlines have been scrambling to cut flights and reduce capacity in response to falling demand.

An airplane landing at night

Image source: Getty Images.

Less flying means fewer airplanes are needed, and fewer GE engines. Despite the market panic, it seems unlikely the airlines will experience any permanent drop-off in demand, but a prolonged downturn could mean airlines deferring new planes scheduled for delivery in 2020, which if nothing else will delay revenue for Boeing and GE.

General Electric also has significant exposure to the energy sector and is likely feeling the impact of a collapse in the price of crude oil. GE is also facing this slowdown in the middle of a multiyear turnaround that could get delayed further if end markets dry up.

Boeing and fellow defense contractors, including Lockheed Martin, aren't as directly affected by coronavirus, as the United States is likely to continue to buy warplanes and helicopters even as the virus spreads. But the larger the crisis gets, the more it is likely to cost the government. In an environment where the Pentagon was already being pushed to make difficult decisions to conserve cash, that's worrisome news for defense investors.

Now what

This is a tough market, and until the coronavirus is deemed under control, it is going to be hard to find a bottom. Things could get worse before they get better.

That said, there is nothing to suggest that the fundamentals of these businesses have changed. Lockheed Martin remains one of the best-run businesses in the defense sector, while GE is progressing but potentially had "limited upside" even without the virus concerns. Boeing investors meanwhile need to remain focused on the company's effort to navigate through the 737 MAX crisis.

It's hard to focus on the big picture on a day when stocks are plunging, but for those with the stomach to ride out the turbulence -- or at least not check stock prices while the outbreak scare plays out -- the current chaos is sure to create opportunities.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.