本研究旨在研究行動支付業務對美國電商產業的公司風險與報酬的影響機制。首先本文採用事件研究法研究單家公司宣告行動支付相關動態時會產生異常報酬。同時，本文以美國電商行業為樣本，建立跨期模型及預測模型，探究行動支付業務對公司風險及股票報酬的影響。本研究針對金融、傳統零售與其他行業分別進行迴歸，探究由於產業不同所帶來影響效果之差異。本文所使用的樣本為2013年至2016年間在美國上市的電商類企業。實證結果顯示，行動支付業務對公司風險有顯著正向影響，但是只有金融業公司行動支付業務對股票報酬有顯著正向影響。最後，跨期模型與預測模型也表明行動支付業務將對公司未來的風險與報酬也有顯著影響。

This paper is to study the impact of the MP business on corporate risk and stock return in the US e-commerce industry. Initially, our paper uses the method of event study and finds that the abnormal return shows up as a company that announces something about MP. Besides, this paper establishes measurement models, inter-temporal models and forecasting models to explore the impact of MP services on corporate risk and stock returns. This paper takes the US e-commerce industry as a sample, establishes an inter-temporal model and a predictive model, and explores the impact of the MP business on corporate risk and stock returns. Our research also discusses the differences between industries. The sample used in this paper is an e-commerce company listed in the US between 2013 and 2016. The empirical results reveal that the MP business has a significant positive impact on corporate risk, but only the financial industry company's MP business has a significant positive impact on stock returns. More vitally, the inter-temporal model and forecasting model also indicate that the MP business has an impact on the firm's future risks and stock returns.

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