股票名称作为投资者最直观了解上市公司基本信息和主营业务领域的第一道门槛，对于企业的重要性不言而喻，上市公司出于多种目的也由此也引发了股票市场上的更名热潮。本文通过研究我国上市公司股票名称变更事件对股票超额收益的影响，既有利于帮助普通投资者增强对市场信息的分辨力，减少非理性投资，保护其合法权益，也有利于减少上市公司通过更名引发的投机行为，使企业专注自身发展，提升行业竞争力，达到实体经济与股票市场的平衡发展，同时对于监管机构来说，有利于完善上市公司信息披露制度，减少市场信息不对称所带来的隐患，也有助于整治股票更名热潮，使我国股票市场更加成熟、健康发展。 

本文选取2017年至2019年三年共计264家主动更改股票名称的上市公司作为研究样本。首先，按照股票名称变更年份、原因、公司的行业特点分别进行描述性统计分析；其次，运用事件研究法，设定研究窗口期，对总样本股票名称变更与股票超额收益水平进行分析，并通过显著性检验分析对比实质性更名与非实质性更名所产生的的市场反应差异；然后，对于上市公司股票实质性更名原因做细分，从资产重组、实际控制人或控股股东变更、主营业务变更三种更名类型分析更名事件对超额收益率的影响；最后分析上市公司股票名称变更存在的问题。

研究结果表明：1.股票主动更名事件会带来负的超额收益；2.实质性股票更名事件相对于非实质性股票更名事件会产生的更强的市场效应；3.当股票更名事件对市场产生负向效应时，实际控制人或控股股东变更引发的股票更名事件在不同类型更名事件中产生的负向市场效应最强；分行业样本的研究结果与总样本保持一致。

政策建议：对于监管机构来说，需要加强对上市公司股票名称变更现象的监管力度，建立健全相关制度；对于投资者来说，在挑选股票时应该更多的关注公司基本面情况，不应该只盲从、抱有投机心理，应当理性思考，合理投资；对于上市公司来说，在发展中应该更多关注主营业务的情况而不能期望通过炒作来吸引投资者和合作方，公司的经营业绩以及未来的发展空间等实质性内容才是决定公司今后发展走向的重要因素。

As the first threshold for investors to understand the basic information of listed companies and the main business areas, stock names are self-evident to the company. Listed companies for a variety of purposes, which also triggered the stock market renaming craze. This paper studies the impact of the change of stock name on the excess return of stock in China's listed companies, which not only helps ordinary investors to enhance the resolution of market information, reduce irrational investment, and protect their legitimate rights and interests, but also for listed companies, it can eliminate the speculation caused by renaming, so that enterprises can focus on their own development, enhance the competitiveness of the industry and achieve the balanced development of the real economy and the stock market, at the same time, for regulatory agencies, is conducive to improving the information disclosure system of listed companies, reducing the hidden dangers caused by market information asymmetry, and also helps to rectify the upsurge of stock renaming, so that China's stock market is more mature and healthy development.

This paper selects 264 listed companies that actively change their stock names from 2017 to 2019 as the research sample. Firstly, descriptive statistical analysis is conducted according to the year, reason and industry characteristics of the change of stock name. Secondly, the event study method is used to set the research window period to analyze the change of stock name and the level of stock excess return of the total sample. The difference of market reaction between substantive name change and non substantive name change is analyzed and compared through significance test. After that, the paper subdivides the reasons for the substantial renaming of the listed company's stock, analyzes the impact of the renaming event on the excess return rate from three renaming types: asset restructuring, change of actual controller or controlling shareholder, and change of main business. Finally, it analyzes the problems existing in the change of the listed company's stock name.

The results show that: 1. The active change of name of stock will bring negative excess return; 2. The substantial change of name of stock will produce stronger market effect than the non substantial change of name of stock; 3. When the change of name of stock has negative effect on the market, the change of actual controller or controlling shareholder will produce the strongest negative market effect in different types of change of name and the results of the sub-industry samples are consistent with the total samples。

Policy recommendations: For regulatory agencies, it is necessary to strengthen the supervision of the phenomenon of listed company stock name changes and establish and improve related systems. For investors, when choosing stocks, they should pay more attention to the fundamentals of the company. They should not only blindly follow and have a speculative mentality, but should think rationally and invest rationally. For listed companies, in their development, they should pay more attention to the main business rather than expect to attract investors and partners through speculation. The substantive contents of the company's business performance and future development space are the important factors that determine the future development direction of the company.