Hong Kong — Chinese e-commerce site Pinduoduo (PDD) plans to raise at least $1bn in a US initial public offering, as it fights for market share against giants like Alibaba.

The Shanghai-based firm’s revenue more than tripled to $278m in 2017, according to its filing to the US Securities and Exchange Commission, under the name Walnut Street Group Holding. Losses rose 55% to $79.5m while transaction volumes reached 141.2-billion yuan ($21bn).

PDD has become one of the fastest-growing start-ups in China by creating a Facebook-Groupon mashup, where people spot deals on products then recruit friends to buy at a discount. It offers merchandise at up to 20% cheaper than market price by letting consumers buy directly from manufacturers, cutting out middlemen, advertising and acquisition costs.

It had 55.9-million daily active users in June, according to research from Shenzhen-based consultant Jiguang.

PDD’s valuation jumped about 10 times in its previous round of fundraising in April. It raised more than $1bn, at a valuation of about $15bn, sources said.