Major US Companies From Apple to Walt Disney See Revenue Hit by Coronavirus

People wearing protective masks are seen in an Apple Store, as China is hit by an outbreak of the new coronavirus, in Shanghai, China, on Jan. 29, 2020. Aly Song/Reuters

WASHINGTON—American companies have begun lowering their revenue and earnings estimates to reflect the potential effects on their businesses of China’s deadly coronavirus outbreak.

Nearly 40 percent of S&P 500 companies that released fourth-quarter earnings ending Dec. 31 warned about COVID-19, highlighting concerns in financial markets about the impact of the epidemic.