“Horrible” is how the macro hedge-fund manager Stephen Jen described it late last week, as he worked at home in London and watched markets for gold, bond yields and stocks whipsaw on his Bloomberg screen.

“The moves were absolutely incredible in size, in magnitude, in speed, and the triggers were not very clear,” he said.

On March 9, at the regular Monday meeting for Blackstone’s global team, Christopher Heady, who runs the firm’s real estate business in Asia and worked in Hong Kong when the coronavirus swept through China, tried to reassure colleagues that things would remain calm. By that evening, 14th-floor workers at the West Side Manhattan offices of Point72, which is led by Steven Cohen, were instructed to work from home, as their space was deep-cleaned after a back-office employee’s confirmed infection.

For those who have remained in the office, the dwindling numbers are palpable. Company cafeterias have at times been empty, as on a summer Friday, and restaurants closed by local authorities to prevent the virus’s spread have thinned the options for food takeout or delivery.

Will Hunter, a portfolio manager at the Manhattan-based Neuberger Berman, said last week that while empty subways were “eerie” to ride, there was a “sense of solidarity” at his office.

Owners of small businesses around downtown Manhattan, who depend on financial-firm employees, said they feared the coming weeks.

“Business this week is very slow,” Mohd Islam, who has run a corner newsstand near the Goldman building for two years, said last week. “Very slow. I don’t know, God knows, if next week,” he added, will be “down, down, down, down.”