Alibaba Stock Slides Again as Growth Prospects Ebb

A disappointing growth forecast from Alibaba Group Holding Ltd. helped push down the internet giant’s shares again while those of rival Inc. shares jumped, reflecting the two Chinese e-commerce companies’ diverging fortunes.

When they reported quarterly results Thursday—shortly after China’s annual Singles Day shopping festival, which ran through Nov. 11—Alibaba lowered an annual sales forecast it had put out just six months earlier, blaming rising competition and a slowdown in consumer spending. posted better-than-expected results.