News sentiment and volatility dynamics: a HAR-X analysis of Brazilian stock markets
| Ano de defesa: | 2025 |
|---|---|
| Autor(a) principal: | |
| Orientador(a): | , |
| Banca de defesa: | |
| Tipo de documento: | Dissertação |
| Tipo de acesso: | Acesso aberto |
| Idioma: | eng |
| Instituição de defesa: |
Não Informado pela instituição
|
| Programa de Pós-Graduação: |
Não Informado pela instituição
|
| Departamento: |
Não Informado pela instituição
|
| País: |
Não Informado pela instituição
|
| Palavras-chave em Português: | |
| Palavras-chave em Inglês: | |
| Link de acesso: | https://hdl.handle.net/10438/37244 |
Resumo: | The objective of this work is to apply to stocks traded on the Brazilian stock exchange the Heterogeneous Autoregressive model integrated with the use of news sentiment scores as an exogenous variable in order to estimate the effect of news on stock volatility. The volatility of the assets is obtained from the opening, minimum, maximum, and closing prices over one-hour intervals, using the Garman-Klass estimator. The sentiment scores are derived from a zero-shot classifier and proposed hypotheses, using as input approximately 2500 financial news from May 2023 to March 2025, with the intention of estimating the impact of news on stocks. Machine learning metrics such as R 2 and Mean Squared Error were compared between the models with and without exogenous variables for each evaluated asset. The inclusion of sentiment scores led to an overall improvement in performance. Furthermore, the analysis revealed a consistent lag structure across all evaluated stocks, characterized by similar linear coefficients associated with the lagged news sentiment variables. This pattern held irrespective of the industry in which each company operates, suggesting a generalized temporal response to news sentiment in volatility modeling. |
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Cambraia, Nicolas BeharEscolas::EESPAndrade, Douglas Coimbra dePinto, Afonso de CamposBotelho, Marcos Antonio2025-07-21T20:06:25Z2025-07-21T20:06:25Z2025-06-24https://hdl.handle.net/10438/37244The objective of this work is to apply to stocks traded on the Brazilian stock exchange the Heterogeneous Autoregressive model integrated with the use of news sentiment scores as an exogenous variable in order to estimate the effect of news on stock volatility. The volatility of the assets is obtained from the opening, minimum, maximum, and closing prices over one-hour intervals, using the Garman-Klass estimator. The sentiment scores are derived from a zero-shot classifier and proposed hypotheses, using as input approximately 2500 financial news from May 2023 to March 2025, with the intention of estimating the impact of news on stocks. Machine learning metrics such as R 2 and Mean Squared Error were compared between the models with and without exogenous variables for each evaluated asset. The inclusion of sentiment scores led to an overall improvement in performance. Furthermore, the analysis revealed a consistent lag structure across all evaluated stocks, characterized by similar linear coefficients associated with the lagged news sentiment variables. This pattern held irrespective of the industry in which each company operates, suggesting a generalized temporal response to news sentiment in volatility modeling.O objetivo deste trabalho e aplicar aos ativos negociados na bolsa de valores brasileira o modelo Heterogeneous Autorregressive (HAR) integrado com o uso de escores de sentimento extraídos de notícias como variável exógena, com o intuito de estimar o efeito das notícias sobre a volatilidade das ações. A volatilidade dos ativos é obtida a partir dos preços de abertura, mínima, máxima é fechamento em intervalos de uma hora, utilizando o estimador de Garman-Klass. Os escores de sentimento são derivados de um classificador zero-shot e hipótese propostas, com cerca de 2.500 notícias financeiras como entrada, abrangendo o período de maio de 2023 a março de 2025, visando estimar o impacto das notícias sobre os ativos. Métricas de aprendizado de máquina, como R 2 e erro quadrático médio (MSE), foram comparadas entre os modelos com e sem variáveis exógenas, para cada ativo avaliado. A inclusão dos escores de sentimento resultou em uma melhoria geral de desempenho. Ademais, a análise revelou uma estrutura de defasagens consistente entre todas as ações avaliadas, caracterizada por coeficientes lineares semelhantes associados as variáveis de sentimento de notícias. Esse padrão foi observado independentemente do setor de atuação das empresas, o que pode indicar uma resposta temporal generalizada ao ˜ sentimento de notícias no contexto da modelagem da volatilidade.engHAR-XVolatility forecastingNews sentimentPrevisão de volatilidadeSentimento de notíciasEconomiaMercado de capitais - BrasilMercado de ações - PrevisãoVolatilidade (Finanças)Processo decisórioNews sentiment and volatility dynamics: a HAR-X analysis of Brazilian stock marketsinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional do FGV (FGV Repositório Digital)instname:Fundação Getulio Vargas 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| dc.title.eng.fl_str_mv |
News sentiment and volatility dynamics: a HAR-X analysis of Brazilian stock markets |
| title |
News sentiment and volatility dynamics: a HAR-X analysis of Brazilian stock markets |
| spellingShingle |
News sentiment and volatility dynamics: a HAR-X analysis of Brazilian stock markets Cambraia, Nicolas Behar HAR-X Volatility forecasting News sentiment Previsão de volatilidade Sentimento de notícias Economia Mercado de capitais - Brasil Mercado de ações - Previsão Volatilidade (Finanças) Processo decisório |
| title_short |
News sentiment and volatility dynamics: a HAR-X analysis of Brazilian stock markets |
| title_full |
News sentiment and volatility dynamics: a HAR-X analysis of Brazilian stock markets |
| title_fullStr |
News sentiment and volatility dynamics: a HAR-X analysis of Brazilian stock markets |
| title_full_unstemmed |
News sentiment and volatility dynamics: a HAR-X analysis of Brazilian stock markets |
| title_sort |
News sentiment and volatility dynamics: a HAR-X analysis of Brazilian stock markets |
| author |
Cambraia, Nicolas Behar |
| author_facet |
Cambraia, Nicolas Behar |
| author_role |
author |
| dc.contributor.unidadefgv.por.fl_str_mv |
Escolas::EESP |
| dc.contributor.member.none.fl_str_mv |
Andrade, Douglas Coimbra de |
| dc.contributor.author.fl_str_mv |
Cambraia, Nicolas Behar |
| dc.contributor.advisor1.fl_str_mv |
Pinto, Afonso de Campos Botelho, Marcos Antonio |
| contributor_str_mv |
Pinto, Afonso de Campos Botelho, Marcos Antonio |
| dc.subject.eng.fl_str_mv |
HAR-X Volatility forecasting News sentiment |
| topic |
HAR-X Volatility forecasting News sentiment Previsão de volatilidade Sentimento de notícias Economia Mercado de capitais - Brasil Mercado de ações - Previsão Volatilidade (Finanças) Processo decisório |
| dc.subject.por.fl_str_mv |
Previsão de volatilidade Sentimento de notícias |
| dc.subject.area.por.fl_str_mv |
Economia |
| dc.subject.bibliodata.por.fl_str_mv |
Mercado de capitais - Brasil Mercado de ações - Previsão Volatilidade (Finanças) Processo decisório |
| description |
The objective of this work is to apply to stocks traded on the Brazilian stock exchange the Heterogeneous Autoregressive model integrated with the use of news sentiment scores as an exogenous variable in order to estimate the effect of news on stock volatility. The volatility of the assets is obtained from the opening, minimum, maximum, and closing prices over one-hour intervals, using the Garman-Klass estimator. The sentiment scores are derived from a zero-shot classifier and proposed hypotheses, using as input approximately 2500 financial news from May 2023 to March 2025, with the intention of estimating the impact of news on stocks. Machine learning metrics such as R 2 and Mean Squared Error were compared between the models with and without exogenous variables for each evaluated asset. The inclusion of sentiment scores led to an overall improvement in performance. Furthermore, the analysis revealed a consistent lag structure across all evaluated stocks, characterized by similar linear coefficients associated with the lagged news sentiment variables. This pattern held irrespective of the industry in which each company operates, suggesting a generalized temporal response to news sentiment in volatility modeling. |
| publishDate |
2025 |
| dc.date.accessioned.fl_str_mv |
2025-07-21T20:06:25Z |
| dc.date.available.fl_str_mv |
2025-07-21T20:06:25Z |
| dc.date.issued.fl_str_mv |
2025-06-24 |
| dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
| dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
| format |
masterThesis |
| status_str |
publishedVersion |
| dc.identifier.uri.fl_str_mv |
https://hdl.handle.net/10438/37244 |
| url |
https://hdl.handle.net/10438/37244 |
| dc.language.iso.fl_str_mv |
eng |
| language |
eng |
| dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
| eu_rights_str_mv |
openAccess |
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reponame:Repositório Institucional do FGV (FGV Repositório Digital) instname:Fundação Getulio Vargas (FGV) instacron:FGV |
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Fundação Getulio Vargas (FGV) |
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FGV |
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FGV |
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Repositório Institucional do FGV (FGV Repositório Digital) |
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Repositório Institucional do FGV (FGV Repositório Digital) |
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Repositório Institucional do FGV (FGV Repositório Digital) - Fundação Getulio Vargas (FGV) |
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biblioteca.digital@fgv.br |
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1866369147503378432 |