Sentiment-aware realized volatility forecasting in financial markets

This study evaluates the effects of -news sentiment data on volatility prediction, and how further boost the capabilities of the garch model. Also taken into account are the effect of the attention (news flow), and a macroeconomic variable (EPU). We develop a parsimonious GARCH(1,1)-X framework with...

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Detalles Bibliográficos
Autor: González Monge, Víctor
Tipo de recurso: tesis de maestría
Fecha de publicación:2025
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/445183
Acceso en línea:https://hdl.handle.net/2117/445183
Access Level:acceso abierto
Palabra clave:Econometrics
Emotions
Artificial Intelligence
Volatility prediction
Sentiment
Econometria
Emocions
Intel·ligència artificial
Àrees temàtiques de la UPC::Informàtica::Intel·ligència artificial
Descripción
Sumario:This study evaluates the effects of -news sentiment data on volatility prediction, and how further boost the capabilities of the garch model. Also taken into account are the effect of the attention (news flow), and a macroeconomic variable (EPU). We develop a parsimonious GARCH(1,1)-X framework with sign-separated sen- timent and optional attention/macro terms, and we compare hundreds of specifi- cations across four U.S. large companies in different sectors. Main findings. 1. Sentiment materially improves volatility forecasts. Across firms, adding polarity shows improved models over a price-only GARCH baseline. One thing of note to notice was how for out data the positive-polarity term add more importance than the negative one, even though the papers men- tion the contrary. This difference could be due to the difference datasets used and the methodology followed. For a general prediction using the ('unique','WeightedMean') with the polarityRob with different EMA can wield good results for most companies. 2. Volume of news Attention features (volume/RCV) yield small average gains, without the sentiment they are not worth adding, and even with the polarity the model did not show a significant improvement, which again does not coincide with what the papers mentioned. 3. Macro is stock-specific. EPU shows the expected correlation with realized volatility but delivers limited incremental predictive power. 4. Diagnostics. Standardized residuals exhibit no residual autocorrelation, indicating that mean/variance dynamics are well captured. QQ-plots show fat tails, so Gaussian errors understate extreme moves. This means sentiment alone is not enough to have completely reliable models 56 Limitations. We focus on a daily horizon, Gaussian innovations, and an additive variance link (GARCH-X). These choices emphasize interpretability, testing and tractable comparison across many aggregation/EMA variants, but might miss the possible details that could be gained from testing other models. Future work. (i) Test with other garch model variants. (ii) Test with different news sources to see the effect of the volume of news. (iii) Test with other macroe- conomic variables. (iv) Test the effect of the sentiment for smaller companies, which present higher volatilities.