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The Impact of News on Videogame Stock Market Prices and Volatility
Mertová, Veronika ; Čech, František (advisor) ; Kukačka, Jiří (referee)
The thesis investigates the impact of social media and news headline sentiment on stock prices, specifically comparing gaming firms to companies from other industries. Tweets and news headlines containing keywords referring to four selected gaming and four non-gaming companies were collected over 5 and 3 months, respectively. Both tweets and news collected came from the general users or media rather than focusing solely on financial ones. The data were aggregated into daily values. Daily stock price data were also collected for each examined company to derive returns and volatility. The data were analysed using a vector autoregression model in combination with Granger causality. The study found no significant differences between gaming and non-gaming sectors. The polarity of sentiment showed no effect on stock prices. However, when sentiment was divided into different emotions, some significance was observed, although the findings varied across individual firms regardless of their sectors. It was concluded that when using sentiment for market predictions, it is beneficial to either utilize specifically financial media or determine the specific type of sentiment that influences a particular stock. JEL Classification G14, G17, C32, C58 Keywords Tweets, News Headlines, Gaming Industry, Sentiment...
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Analysis of stock market sentiment with social media
Čermák, Vojtěch ; Baruník, Jozef (advisor) ; Vacek, Pavel (referee)
In the thesis, we explored prospects of extracting sentiment contained in Twitter messages. We proposed novel approach consisting of directly predicting the volatility on stock market by features obtained from the text documents using suitable document representation. We compared the performance of standard document vectorisation methods as well as a novel approach based on aggregating word vectors created by word embeddings. We showed that direct modelling of a market variable is possible with most of the proposed vectorisation techniques. In particular, the strong predictive power of aggregated word embeddings suggests that they are excellent sentiment representation, because they are independent of message volume and they capture well the semantical information in the tweets. Besides, our findings suggest that aggregating word embeddings vectorisation is viable approach even for large documents.
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Predictability of security returns using Twitter sentiment
Fremunt, Marek ; Baruník, Jozef (advisor) ; Kukačka, Jiří (referee)
This work concentrates on exploring the influence of social networks to financial markets. We have introduced a novel approach to Twitter sentiment analysis, in which we collect continuous stream of data and analyze it. Our original data set contains over 200 million English written Tweets from the period between July 1, 2014 and October 9, 2014. Twitter sentiment is used as a good representative of investors' mood. On hourly data we investigate how investors are influenced by basic emotions, moods and sentiment in their decision making processes as well as the influence of keywords related to specific securities and FOREX symbols. Particularly, we examine the relationships between Twitter-based variables and returns as well as volatility of several financial instruments on a wide range of data including commodities, currencies and S&P 500 Cash Index. We show that Twitter sentiment influences volatility of securities' returns, tested and shown on both conditional and realized volatility models. We also describe the effect of Twitter sentiment on securities' returns. Moreover, we reveal the influence of basic emotions on investors' decision making processes. Our results suggest that investors are influenced by emotions and moods, especially at longer investment horizons. The impact of emotions at shorter...
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