After suffering through stock selloffs this summer, China’s internet giants are working hard to regain favor with authorities and global investors as the companies try to chart paths back to normalcy. Shares of two large Chinese online retailers, Pinduoduo Inc. and JD.com Inc., have jumped about 20% or more this week—recouping a chunk of their heavy losses since July—after the companies reported healthy sales increases in the second quarter and highlighted their contributions to Chinese society. Their performance took some of the focus away from [Beijing’s widening regulatory crackdown](//www.wsj.com/articles/china-unveils-new-rules-targeting-anticompetitive-practices-by-internet-companies-11629199116?mod=article_inline) , which has turned many investors off the once-hot internet sector....