Uniqlo had closed about 350 of its casual clothing stores in China, as well as closures at some partner factories, a month ago.
The closures have raised fears of a major hit to Uniqlo's profits. China has been a key growth market for the company, which faces a saturated market and weak consumer spending in Japan.
Fast Retailing shares closed on Monday at 46,000 yen, down nearly 30 percent since the beginning of the year.
Jefferies on Monday raised its rating on Fast Retailing to "hold" from "underperform", saying the company was resilient and had enough liquidity to survive a possible recession.
"China and Korea both appear to have gained control of the virus and many people appear to be returning to work," analyst Michael Jon Allen said in a note to clients.
"We think the worst for Fast Retailing's overseas operations is already in the past, and a slow but steady recovery has begun."
A Fast Retailing spokeswoman said it had not yet decided on any closures in North America, where it has about 60 shops.
Retailers including Nike Inc and Lululemon Athletica Inc have said they were closing stores in the United States as the highly contagious respiratory illness has spread beyond China.
By Ritsuko Ando