Following a big gain on Wednesday for the Dow Jones Industrial Average (^DJI -0.17%), the index declined sharply on Thursday. By 11:40 a.m. EST, the Dow was down 2.36%. The novel coronavirus outbreak in the U.S. is raising fears of a major economic disruption. There are now more than 160 confirmed cases in the U.S. and 11 deaths.

One area already hit hard is travel, with multiple airlines warning about weakening demand. That's not good news for Boeing (BA -0.26%). Shares of ExxonMobil (XOM -0.95%) were also under pressure on Thursday after the company updated its growth plans.

Boeing sinks as airlines hit hard

Shares of airplane and defense company Boeing were down 5.1% Thursday morning, underperforming a weak market. While there was no company-specific news, the plight of the major airlines as the novel coronavirus outbreak spreads seems to be weighing on the stock.

An airplane in flight over clouds

Image source: Getty Images.

Boeing is already struggling as it tries to get the 737 Max flying again after two fatal crashes grounded the plane. With the outbreak crimping travel, Boeing may soon have a demand problem as well as a supply problem.

United Airlines (UAL 3.50%) announced on Wednesday that it was cutting its U.S. and Canada flights by 10% in April, along with a 20% cut to international flights. Some larger planes will be taken out of service as the airline tries to bring capacity in line with reduced levels of demand. United has also instituted a hiring freeze through at least June 30, excluding critical roles.

On Thursday, Southwest Airlines (LUV -0.21%) updated its guidance for the first quarter to reflect a significant decline in demand, as well as an increase in trip cancellations. Southwest expects to take a revenue hit between $200 million and $300 million in the first quarter, and operating revenue per available seat mile growth is now expected between negative 2% and positive 1%. Previously, Southwest had expected this metric to grow by 3.5% to 5.5%.

While it's too early to tell whether this slump in travel demand will cause airlines to pull back on plane orders, investors are nonetheless punishing Boeing.

ExxonMobil updates on strategy

Energy giant ExxonMobil was also down big on Thursday, with the already beaten-down stock losing another 4.6%. This move lower came after the company gave an update on its long-term growth strategy.

Exxon expects to spend between $30 billion and $35 billion on capital expenditures annually through 2025, with around $33 billion of spending this year. "We are taking advantage of a favorable cost environment and investing in advantaged projects -- underpinned by the long-term fundamentals of growing demand," said CEO Darren Woods.

In terms of individual projects, the company expects its production in Guyana to exceed 750,000 gross barrels of oil per day by 2025. In the Permian Basin, the company sees over 1 million oil equivalent barrels of production per day by 2024, although Exxon said that it was evaluating the pace of near-term development due to market conditions.

While oil prices have plunged this year, Exxon expects energy demand to continue to grow in the long run due to population growth and an expanding global middle class.