Companies have endured financial meltdowns, civil wars and natural disasters. But nothing in modern memory has dented both demand and supply so quickly for so many industries as the coronavirus…

Conferences are getting canceled, from the Geneva International Motor Show to Facebook Inc.’s F8 developer gathering in California. Disneyland Tokyo is closed. Auto suppliers are warning of parts shortages. Generic drug manufacturers are paying 50% more for some raw materials.

The widespread nature of the epidemic and related uncertainty will put a hold on large corporate investments, mergers and hiring, said Stanford University economist Nicholas Bloom, who has researched the impact of uncertainty on business cycles.

“A lot of the damage is already being inflicted purely from major decisions being delayed,” Mr. Bloom said. “I can’t see many firms green-lighting any projects until they can figure out what is going on.”