Joseph Tsai says his purchase last year of NBA’s Brooklyn Nets—along with their home arena—is meant to capitalize on the growing worldwide appeal of basketball. “Basketball is a global sport because it is easily accessible and its urban street culture is appealing to young people. Fans from all over the world, from China to Southeast Asia to Europe to the U.S., form a deep bond over this cultural phenomenon, led by the NBA and its stars,” Tsai, 56, says in an email through an Alibaba spokesman.