The purpose of this dissertation is to examine the direct impact of cryptocurrencies, primarily Bitcoin, on stock returns, as well as to analyze the characteristics of some of the companies which Bitcoin has a large impact on stock returns and the reasons why these phenomena occur. The study examines the returns of three variables, NSDQ100 Index, Bitcoin price, and stock prices of 101 enterprises within NSDQ100 by analyzing the monthly ended figures over the past five years. As the nature of Bitcoin that cannot be directly linked to stock returns, the direct impact of Bitcoin on stock return was discussed and analyzed through two regression analyses of NSDQ100 returns and stock returns, as well as NSDQ100 returns, bitcoin returns and stock returns. This study concludes that the direct impact of Bitcoin on the stock returns of companies in the Technology and Consumer Discretionary sectors, which involve consumer goods, is significant; whereas its impact on the stock returns of companies in the Health Care sector and Consumer Discretionary sector that do not directly provide products is small. / Business Administration/Finance