The Dow Jones Industrial Average (^DJI 0.16%) was down again Friday morning, although the index recovered a bit in the first hour of trading. By 10:40 a.m. EST, the Dow was 1.7% lower. Globally, the novel coronavirus outbreak has now surpassed 100,000 cases. In the U.S., the virus continues to spread to new states.

Almost every Dow component was down Friday morning. Shares of Intel (INTC 0.02%) slumped after rival Advanced Micro Devices (AMD -2.94%) laid out an aggressive growth plan for the data center. American Express (AXP 0.27%) stock was also down as virus fears escalated.

Intel faces stiff competition

Semiconductor giant Intel holds a dominant share of the CPU market. In terms of units, Intel controlled roughly 95% of the server CPU market, 83% of the desktop CPU market, and 84% of the laptop CPU market in the fourth quarter of last year. That data comes from Mercury Research.

Intel Xeon processors and a wafer.

Image source: Intel.

AMD has long played second fiddle to Intel, and even with a series of successful product launches over the past few years, it remains far behind the market leader. However, the company has been growing its market share across all segments. AMD now has an advantage in terms of manufacturing, using a 7-nanometer process from a third party, and the company's products are no longer disadvantaged when it comes to performance.

During AMD's Financial Analyst Day event on Thursday, the company laid out a plan to aggressively grow its data center business. Server CPUs have been a growth engine for Intel, particularly due to growing demand from cloud computing providers. That segment will likely come under even more pressure as AMD tries to expand its presence.

AMD is targeting total annual revenue growth of around 20% as part of its long-term model. That target is premised on the company boosting its data center revenue from 15% of total revenue today to greater than 30% of total revenue in the future. The company's EPYC server chips have been slow to gain share, partly because enterprise IT decisions take time. Market share gains will have to accelerate for AMD to hit its target.

Already Intel has been forced to slash prices on its server chips to keep its products competitive. The company initiated a de facto price cut in February by launching a new lineup of second-generation Xeon Scalable Processors that effectively cut prices by as much as 70%. Price cutting won't be good for Intel's margins.

Intel stock was down 2.2% Friday morning, although the broad market sell-off may be mostly to blame.

American Express leads Dow lower

Shares of American Express were down 3.6% Friday morning, putting in one of the worst performances in the Dow. There wasn't any company-specific news, but investors are clearly getting worried about the impact on consumer spending of the novel coronavirus outbreak.

Other credit card companies have already warned about the outbreak. Visa warned earlier this month that a sharp slowdown in the cross-border business would reduce its revenue growth in the second quarter by between 2.5 and 3.5 percentage points. That estimate assumes continued deterioration in March, but the company was clear that the impact during the rest of March was impossible to predict.

In late February, Mastercard updated its guidance to reflect the coronavirus outbreak. The company expects an impact of 2 to 3 percentage points on its first-quarter revenue growth, which will lead to revenue growth between 9% and 10% year over year. For the full year, Mastercard expects percentage revenue growth in the low teens if the impact is limited to the first quarter.

American Express is likely in the same boat. If the virus spreads widely in the U.S., forcing businesses to close in some cities to contain the outbreak, credit card spending could tumble. If the outbreak leads to a recession, credit card charge-off rates could soar.

American Express stock is now down about 22% from its 52-week high.