2020年证监会发布的再融资新规对非公开发行股票的要求做出修改，包括发行对象数量的增加、可选择的定价基准日增多、折价率放宽、锁定期缩短、发行规模限制放宽等。总体来说，新规减少了对定向增发的限制，这既增加了上市公司融资决策的自主性，也为内部人、特别是大股东侵占中小股东利益留出更多的余地。

根据监督理论（monitoring）和认证假说（certification），定向增发引入更多机构投资者，有利于加强对公司内部人的监督，并且向市场传递出公司价值被低估的信号，新规使得原本融资约束更高的上市公司更容易通过定向增发筹集所需资金，因此新规出台后定向增发的短期市场回报会更高；然而，鉴于中国投资者保护环境较差，内部人控制严重，新规出台后，大股东及其关联方也更容易通过如劣质资产注入、高折价定向增发进一步侵占中小投资者利益，因此新规出台后定向增发的市场反应也可能更负面。本文基于我国A股上市公司2006-2022年的定向增发数据，实证检验了2020年再融资新规出台后，我国上市公司定向增发公告日的短期市场反应的变化。研究结果发现，新规出台后，定向增发公告的短期市场反应虽依然为正，但不显著，且累计超额收益（CAR）显著低于新规前。这一结果表明，在中国市场上放宽对定向增发的发行要求后，中小投资者担心受到大股东利益侵犯的负面效应抵消了监督和认证带来的正面效应。

进一步的研究结果显示，高成长性企业在新规后有更高的短期累计超额收益，投资者相信高成长性公司定向增发的监督和认证效果，因为成长性高的上市公司更可能因为信息不对称问题严重而选择定向增发，从而及时缓解其高成长投资项目的资金需求；股权集中度较高的企业，其定向增发的股价短期反应与新规是否实施的负相关关系更明显，因为中小投资者认为在股权集中度较高的企业中，大股东通过定向增发进行利益输送的可能性更大，定向增发更容易成为大股东利益输送的手段。

本文丰富了现有关于定向增发的文献，同时有利于帮助学术及实务界深化对在中国制度背景下上市公司融资活动的理解，对后续相关研究起到一定的理论帮助。同时检验了新规出台对促进定向增发市场发展的实际成效，为后续的政策施行和金融监管提供了一些建议。

The new regulations on refinancing issued by China Securities Regulatory Commission in 2020 will revise the requirements for non-public offerings of shares, including increasing the number of issuing objects, increasing the number of optional pricing base days, relaxing the discount rate, shortening the lockup period and relaxing the restrictions on the size of issuance. Generally speaking, the new rules reduce the restrictions on private placement, which not only increases the autonomy of listed companies in financing decisions, but also leaves more room for insiders, especially major shareholders, to seize the interests of minority shareholders.

According to the monitoring theory and certification hypothesis, the introduction of more institutional investors in private placement is conducive to strengthening the supervision of company insiders and sending signals to the market that the value of the company is undervalued. The new rules make it easier for listed companies with higher financing constraints to raise needed funds through private placement. Therefore, after the introduction of the new regulations, the short-term market return of private placement will be higher; However, in view of the poor protection environment for Chinese investors and the serious insider control, after the introduction of the new regulations, major shareholders and their related parties are more likely to further encroach on the interests of small and medium investors through the injection of inferior assets and high discount private placement, so the market reaction of private placement after the introduction of the new regulations may be more negative. Based on the data of private placement of Chinese A-share listed companies from 2006 to 2022, this paper empirically tests the change of short-term market reaction on the announcement date of private placement of Chinese listed companies after the introduction of new regulations on refinancing in 2020. The results show that the short-term market reaction of private placement announcement is still positive, but not significant, and the cumulative excess return (CAR) is significantly lower than before the new regulation. This result shows that after the relaxation of the issuance requirements for private placement in the Chinese market, the negative effect of small and medium investors' fear of being infringed by the interests of major shareholders offsets the positive effect of monitoring and certification.

Further research results show that high-growth enterprises have higher short-term cumulative excess returns after the new regulation. Investors believe in the supervision and certification effect of private placement of high-growth companies, because listed companies with high growth are more likely to choose private placement due to the serious problem of information asymmetry, so as to timely alleviate the capital needs of their high-growth investment projects. For enterprises with high concentration of ownership, the short-term stock price reaction of private placement has a more obvious negative correlation with the implementation of the new regulation, because small and medium investors believe that in enterprises with high concentration of ownership, it is more likely for major shareholders to transfer benefits through private placement, and private placement is more likely to become a means to transfer benefits of major shareholders.

This paper enriches the existing literature on private placement, and helps the academic and practical circles to deepen their understanding of the financing activities of listed companies under the background of the Chinese system, and plays a certain theoretical help for the subsequent relevant research. At the same time, it examines the effect of the new regulations on the development of private placement market, and provides some suggestions for the subsequent policy implementation and financial supervision.