(Yicai Global) Nov. 21 -- Pinduoduo's shares gained 16.6 percent yesterday after China's leading online group discounter released strong figures for annual gross merchandise volume.

Pinduoduo had an almost fivefold increase in gross merchandise volume to CNY344.8 billion (USD49.6 billion) in the year ended Sept. 30, the Shanghai-based company said in its third-quarter earnings report. Its shares [NASDAQ:PDD] ended trading at USD23.14 in New York.

Average annual spending among the platform's active buyers doubled to CNY894.4 billion (USD128.8 million), which was 17.7 percent higher than the previous quarter. The number of active buyers jumped 144 percent to 385.5 million, driven by brand building and advertising. Monthly active users averaged 231.7 million, an annual gain of 226 percent.

Major competitor Alibaba Group Holding, China's biggest e-commerce player, reported a 25 million jump in active users to 601 million in the same period thanks to increased activity in China's less-developed regions, a key market for Pinduoduo.

"The gap between the two will shrink, if Pinduoduo's user numbers and per customer transactions continue to jump in the next few quarters and overtake those of Alibaba," Cao Lei, director of China E-Commerce Research Center, told Yicai Global.

Pinduoduo, which went public at the end of July, saw its sales and marketing expenses reach CNY3.2 billion in the third quarter, a more than sevenfold gain from the year-earlier period.

Third-quarter revenue soared almost eightfold to CNY3.4 billion as online marketing and technological service sales gained nearly 11 times to CNY3 billion, based on which net cash flow from business activities swung into the black at CNY249.7 million (USD36 million), compared with a loss of CNY682.1 million a year earlier.