港交所在2005年引入基石投资者制度，该制度在中国香港的IPO过程中发挥着非常重要的作用。在基石投资者制度下，公司在IPO之前会与一些特定的投资者签订投资协议，这些投资者同意以发行价格购买公司一定份额的股票，并且同意在IPO之后的一定期限内不进行出售。这些投资者通常是一些大型机构或知名个人，包括资产管理基金、主权基金和香港富豪等。港股基石投资者的参与可以提高发行人的声誉和市场认可度，为公司提供稳定的募资基础，同时也有助于稳定市场，保护投资者利益。在学术界不乏有锚定投资者、Pre-IPO投资者、战略投资者等投资者对企业上市后价格稳定性影响的讨论，部分学者更是指出投资者的声誉认证效应缓解了抑价发行的现象，亦有部分学者认为投资者参与带来的市场力量放大了市场的涨跌幅度。本文主要针对于基石投资者制度，包括基石投资者的参与、参与的机构数量、认购的企业份额等关键被解释变量，对该被解释变量对企业在港股上市首日的价格波动影响进行了研究。另外，针对港股基石投资锁定期的要求，分析在锁定期满时证券价格的波动。研究方法采用的是多元回归模型，从一级发行市场和二级市场的多个指标对每一家在港交所主板上市的企业进行研究。研究结果表明基石投资者的参与可以有效降低企业IPO抑价率，使得其发行定价更趋近企业自身价值；同时，基石投资者在单一股票中参与的数量越多，认购的企业份额越高，其对于发行价格的稳定效应则越强。最后，通过总结本文针对基石投资者制度在港股的影响，对该制度给出了政策性的建议。
HKEX first introduced cornerstone investors in 2005, which plays a key role in the IPO process. Cornerstone investors usually sign investment agreements before an IPO, and promise to buy certain share of the company‘s stock at IPO price and are subjected to six month lockup periods. These investors are typically large institutions and high-profile individuals, including asset management funds, sovereign funds and Hong Kong tycoons. The participation of cornerstone investors can improve the reputation and market recognition of the company, provide a stable foundation for the company to raise funds, and also help stabilize the market and protect the interests of investors.There has been many discussions on the influence of anchor investors, Pre-IPO investors and strategic investors on the price stability of enterprises after listing. Some scholars even point out that the reputation certification effect of investors alleviates the phenomenon of IPO underpricing, and some scholars believe that the market power brought by investor participation magnifies market fluctuation. This paper mainly focuses on cornerstone investors, including the participation of cornerstone investors, the number of participating institutions and the shares of enterprises subscribed, and studies the influence of these explained variables on the price fluctuations of enterprises after listing. The research method adopts multiple regression model, and studies the impact of different primary and secondary market factors on enterprise listed on the main board of HKEX.The results show that the participation of cornerstone investors can effectively reduce the IPO underpricing rate and make the IPO pricing closer to the enterprise‘s value. At the same time, the more cornerstone investors participate in a single stock, the higher the share of the company subscribed, the stronger its stabilizing effect on the issue price. Finally, by summarizing the impact of cornerstone investors on HKEX, this paper gives some policy suggestions on cornerstone investor’s future development on HKEX.
