Bragging rights to Hong Kong, for now.

The city's equity market overtook Japan earlier this week to be the world's third largest in value, behind only the U.S. and mainland China, courtesy of a rebound in Hong Kong stocks after their worst year since 2011.

Hong Kong's market cap was $5.78 trillion as of Tuesday, compared with $5.76 trillion for Japan, according to data compiled by Bloomberg based on where primary securities are listed. The Asian city's Hang Seng Index climbed 17 percent this year through Tuesday, when it closed at its highest since June 15. Internet giant Tencent Holdings Ltd. has been the main driver, with a 22 percent gain. Japan's Topix Index advanced 8.3 percent in that period.

Both markets declined Wednesday, as an economic outlook from the International Monetary Fund renewed concern about a slowdown in global growth and after the U.S. threatened tariffs on the European Union.