“We must curb the tendency for greed,” Xiaomi CEO Lei Jun told the South China Morning Post in April.

Which may explain the humbling of Xiaomi's long-awaited IPO. In May, Xiaomi filed for an IPO on the Hong Kong Stock Exchange, hoping to raise as much as $10 billion. That would have made it the largest IPO since Alibaba raised $22 billion in September 2014.

Instead, Xiaomi raised $4.7 billion in an IPO that the Wall Street Journal dissed as “hapless.” The amount could rise if underwriters sell an overallotment of shares set aside for the offering. At $4.7 billion, Xiaomi's offering won't even rank in the 10 largest global IPOs since Alibaba went public...