I 摘要 2018年10月全国人民代表大会常务委员会对《中华人民共和国公司法》中 关于股份回购的条款进行专项修改，赋予上市公司股票回购更多的灵活性和自 主权，国内资本市场掀起股份回购热潮。2019年我国A股上市公司实施股份回 购的公司家数和股份回购规模再创新高，2019年实施股份回购的上市公司数量 为1077家，回购股份数量为172.25亿股，回购资金为1298.48亿元。股票回购 已成为上市公司资本运作的重要手段之一。 文章首先从研究背景、研究意义及技术路线等方面介绍本次的研究框架。其 次，对股份回购理论及国内外学者关于股份回购的研究成果进行综述和整理，发 现国内外学者一致认为股份回购公告能对市场带来正向的效应，无论短期效应 还是长期效应。但是，基于证券市场的有效性及证券市场发展背景，关于回购股 份的动机以及股份回购市场效应的影响因素研究结果存在差异。第三部分，从政 策法规及实际案例两个方面回顾我国股份回购的发展历程，国家积极鼓励公司 实施股票回购、不断扩大《公司法》中股票回购的允许范围。目前我国A股上 市公司股份回购业务的特点为回购规模大、回购目的多样化、回购资金来源多元 化，集中竞价交易为主、流通股与限售股共存，所有行业的公司积极参与。第四 部分，从2013年至2019年实施股票回购的A股上市公司中选取214家作为研 究样本采用事件研究法进行实证分析。研究发现样本公司总体在股票回购预案 公告日实现事件窗口期内的最大平均超额收益率，股票回购公告能对市场产生 短期的显著正向效应，同时也发现事件日前1天的平均超额收益率和累计超额 收益率异常下降，存在内幕信息泄露的问题。按照不同事件窗口、不同回购目的、 不同回购资金来源、不同回购比例分组进行实证分析，发现公告日后事件窗口的 累计超额收益率最大，以市值管理为目的的股票回购在公告日的平均超额收益 率最大，以实施股权激励为目的股票回购公告对市场的效应更稳定。但是，以股 权激励基金回购股票的公告对市场产生反向的效应，这与其他所有组的结果完 全相反，还发现股票回购比例与平均超额收益率大小无明显的相关性。第五部分， 摘要 II 本文引入回购特征、公司治理、财务情况三个方面的8个变量，运用多元回归分 析对股票回购公告的市场效应进行解释，研究发现股票回购数量与累计超额收 益率呈显著的正向相关性，闲置现金指数与累计超额收益率呈显著的反向相关 性，股票回购比例、第一股东持股比例、资产负债率、摊薄的净资产收益率、市 盈率及总资产均与累计超额收益率无显著相关性。所以，我们认为股份回购公告 的短期市场效应仅与股票回购数量、公司闲置现金数量有关，公众投资者研究判 断股票回购公告时主要考虑回购股票本身的信息并未考虑公司治理、经营情况 等额外信息。文章最后，对本文的研究成果进行总结，鼓励上市公司认真履行信 息披露的义务、制定合理的股票回购计划，提醒公众投资者提升对股票回购的认 知、提高理性投资的意识。 关键词：股票回购；市场效应；回购动机 Abstract I Abstract In October 2018, the Standing Committee of the National People's Congress made special amendments to the provisions on share repurchase in the Company Law of the People's Republic of China. The amendments grants listed companies with more flexibility and autonomy in stock repurchase.The move has set off an upsurge in share buybacks in the domestic capital market. In 2019, the number of companies and the scale of share repurchase implemented by A-share listed companies in China reached a new record high.In 2019, the number of listed companies implementing Stock Repurchase was 1077, the number of shares actually repurchased was 17.225 billion, with the repurchase fund was 129.848 billion yuan. Stock repurchase has become one of the important means of capital operation of listed companies. The first part of this article introduces the research framework from the research background, research significance and technical route. Secondly, it summarizes and collate the research results of share repurchase theory and domestic and foreign scholars on stock repurchase, and finds that domestic and foreign scholars agree that the share repurchase announcement can bring positive effects to the market, no matter short-term effect or long-term effect.Based on the effectiveness of the securities market and the background of the development of the securities market, there are differences in the motivation of the repurchase stock and the factors influencing the stock repurchase market effect.The third part reviews the development history of China's share repurchase from two aspects: policies, regulations and practical cases.The state actively encourages the company to implement stock repurchase and expand the permitted scope of stock repurchase in the company law. At present, the characteristics of share repurchase business of A-share listed companies in China are characterized by large scale of repurchase, diversification of repurchase purpose, diversified sources of repurchase funds, centralized bidding transactions as main, tradable shares and restricted stock coexistence, and all sectors of the company actively participate in the fourth part.From 2013 to 2019, a total of 214 selected A-share listed companies with Abstract II stock repurchase were selected as the research samples. The case study method was used to conduct an empirical analysis. The study found that the overall average excess return of the Sample Firms in the event window period on the stock repurchase announcement day was realized, and the stock repurchase announcement could produce a short-term significant positive effect on the market.At the same time, it was also found that the average excess return and cumulative excess return rate on the one day before the event dropped abnormally, and there was the problem of insider information leakage. According to the different events window, different repurchase purposes, different repurchase fund sources and different repurchase ratio groups, we found that the cumulative return rate of the event window after the announcement was the largest.The average return rate of stock repurchase on the day of announcement is the largest, and the effect of stock repurchase announcement on stock market is more stable on the day of announcement. However, the announcement of stock repurchase fund repurchase shares has a reverse effect on the market, which is totally contrary to the results of all his group.It is also found that there is no obvious correlation between the share repurchase ratio and the average excess return. The fifth part introduces 8 variables in three aspects, such as repurchase characteristics, corporate governance and financial situation, and uses multiple regression analysis to explain the market effect of stock repurchase announcements. It is found that there is a significant positive correlation between the number of stock repurchases and cumulative excess return.There is a significant inverse correlation between the idle cash index and the cumulative excess return. There is no significant correlation between the stock repurchase ratio, the first shareholder's shareholding ratio, the asset liability ratio, the diluted net assets yield, the P / E ratio and the total assets. Therefore, we believe that the short-term market effect of the share repurchase announcement is only related to the amount of stock repurchase and the amount of idle cash in the company.When the public investors study and judge the stock repurchase announcement, they mainly consider the information of the repurchase stock itself without taking into account the Abstract III additional information such as corporate governance and operating conditions. Finally, the paper summarizes the research results in this paper, and encourages listed companies to conscientiously fulfill their obligations to disclose information and to formulate reasonable stock buyback plans.Remind public investors to enhance their awareness of stock repurchase and enhance their sense of rational investment. Key Words: Share Repurchase;Market Effect;Repurchase Motivation 目录 I 目 录 第一章 绪论 .............................................. 1 第一节 研究背景及研究意义 ....................................... 1 一、研究背景 ............................................................ 1 二、研究意义 ............................................................ 2 第二节 研究内容方法、技术线路及创新 ............................. 3 一、研究内容和研究方法 .................................................. 3 二、研