The Securities and Futures Commission warned of high shareholding concentration in Zhong An Intelligent Living Service (HKG:2271), according to a Wednesday Hong Kong bourse filing.
Shares of the firm were down over 26% in Thursday morning trade.
As of Aug. 27, 14 shareholders held 120.5 million shares, or 23.3% of the company, while controlling shareholder Zhong An Service owned 380 million shares, or 73.4%, the regulator said.
Together, this represented 96.7% of issued shares, leaving just 3.3% in public hands.
Zhong An Intelligent's shares jumped 252% to HK$4.22 by Aug. 27 and climbed further to HK$4.82 on Sept. 9, marking a 302% gain since mid-July.
In response, the company said the information in the SFC announcement had not been independently verified, apart from details of Chairman Shi Zhongan's holdings based on statutory disclosures.
It added that, to the best of the board's knowledge, at least 25% of shares remained in public hands as of Aug. 27 and that it complies with Hong Kong's public float requirements.