Abstarct: This study analyzes the impact of sentiments disseminated on the platform X (formerly Twitter) on Bitcoin price volatility. Financial markets, particularly cryptocurrency markets, are significantly influenced by news and public sentiment. In this research, daily data on Bitcoin prices and tweets posted by 23 influential users on the X platform were collected over the period from January 1, 2021, to July 27, 2025. The data include the emotional content of tweets and the number of likes, used to evaluate the extent of sentiment influence on market behavior. After categorizing the tweets, analyses were conducted using a Markov-Switching Model, which modeled the Bitcoin market into three sentiment regimes: negative, neutral, and positive. Results indicate that negative sentiments lead to a decline in Bitcoin prices, while positive sentiments result in price increases. Furthermore, different sentiment regimes exert distinct effects on market returns and volatility. Additionally, an Event Study Model was employed to examine the impact of sentiment-driven events on abnormal and cumulative returns of the Bitcoin market. Findings show that the release of emotionally charged tweets—whether positive or negative—induces short-term market reactions and leads to increased price volatility. This research, by combining sentiment analysis with advanced econometric methods—particularly the Event Study Model—aims to provide deeper insights into the influence of social media sentiments and news on Bitcoin price fluctuations. The results can assist analysts, investors, and policymakers in better understanding cryptocurrency market dynamics and forecasting price changes in response to social media news and public sentiment.