当瑞幸咖啡在2020年4月2日正式承认其财务造假行为时，瑞幸咖啡在导致自身股价腰斩的同时也导致了其他中概股的股价受到负面影响，对它们产生负面的溢出效应。不仅如此，瑞幸咖啡的财务造假事件同时也推动了美国在2020年通过，2021年正式生效《外国公司问责法案》，并且赋予美国证监会能够将连续三年拒绝向美国公众公司会计监督委员会提供审计报告在内的诸多敏感公司与消费者数据的公司进行强制退市的权利。作为近年来针对中概股的一系列国内国外政策的导火索，瑞幸咖啡财务造假案例应该通过不同的研究方法以及研究视角进行深度解析。本论文在对瑞幸咖啡与中概股现状进行了介绍与分析后对溢出效应与财务造假的相关文献进行了陈述与总结。通过使用事件研究法，本文通过测量2020年4月2日前后几天的累计超额收益率对瑞幸咖啡财务造假中对其他中概股造成的溢出效应进行了分析。之后，本文通过多元回归模型的方式尝试以国内国外文献中描述的公司特征作为解释变量去解释中概股的累计超额收益率。回归模型的最终结果显示累计超额收益率与公司大小负相关并且与收入增长率、盈利能力、以及流动性正相关。虽然在美上市的中国公司将难以避免《外国公司问责法》以及潜在的退市危机，中国公司应该加强内部审计流程并且改善公司内部治理结构。同时，政府机关以及监管机构也应当增强社会监管与审计力度并且加强财务造假方面的法律惩罚力度，提高财务造假的机会成本。
When Luckin Coffee committed financial fraud on April 2nd, 2020, the company not only affected its own stock performances, but also caused a spillover effect that led to collective fall in prices of China-concept stocks. In addition, the incident also had a direct impact on the passing of the Holding Foreign Companies Account Act (HFCAA), which will give US regulators the rights to delist Chinese companies that refuse to give the US Public Company Accounting Oversight Board (PCAOB). As the starting point of many following policies targeting China-concept stocks, the Luckin Coffee financial scandal is an event and its effect on other Chinese companies should be examined and researched through different methodologies and point of views. In this thesis, we begin by summarizing researches on spillover effects and financial fraud, and then introduced our research methodology. We first conducted an event study on the days before and after April 2nd, 2020 to measure abnormal returns from the event, and then we ran a regression in an attempt to describe the abnormal returns. Regression results suggest that bigger size and leverage decrease cumulative abnormal returns (CAR) while high revenue growth rate, profitability and liquidity increase CAR.While it is impossible to avoid the inevitable, companies should be act responsibly for themselves and for other China-concept stocks by implementing tight internal controls. While it is understandable that the Chinese government refuses to provide the US with sensitive consumer data of Chinese companies, regulators in China should also continue working towards enhancing external control measures and increasing the opportunity costs of committing illegal behavior so that companies like Luckin Coffee are discouraged from fraudulent behavior.
