944 resultados para Stock index revision
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This paper investigates the impact of price limits on the Brazil- ian future markets using high frequency data. The aim is to identify whether there is a cool-off or a magnet effect. For that purpose, we examine a tick-by-tick data set that includes all contracts on the São Paulo stock index futures traded on the Brazilian Mercantile and Futures Exchange from January 1997 to December 1999. Our main finding is that price limits drive back prices as they approach the lower limit. There is a strong cool-off effect of the lower limit on the conditional mean, whereas the upper limit seems to entail a weak magnet effect on the conditional variance. We then build a trading strategy that accounts for the cool-off effect so as to demonstrate that the latter has not only statistical, but also economic signifi- cance. The resulting Sharpe ratio indeed is way superior to the buy-and-hold benchmarks we consider.
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This paper investigates the impact of price limits on the Brazilian futures markets using high frequency data. The aim is to identify whether there is a cool-off or a magnet effect. For that purpose, we examine a tick-by-tick data set that includes all contracts on the S˜ao Paulo stock index futures traded on the Brazilian Mercantile and Futures Exchange from January 1997 to December 1999. The results indicate that the conditional mean features a floor cool-off effect, whereas the conditional variance significantly increases as the price approaches the upper limit. We then build a trading strategy that accounts for the cool-off effect in the conditional mean so as to demonstrate that the latter has not only statistical, but also economic significance. The in-sample Sharpe ratio indeed is way superior to the buy-and-hold benchmarks we consider, whereas out-of-sample results evince similar performances.
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Este documento relata os resultados de pesquisa que objetivou testar se o investimento de longo prazo em ações no Brasil propicia a obtenção de maiores retornos e menores riscos, conforme sugerido por recomendações da imprensa financeira brasileira. Foram estudados os retornos mensais do Ibovespa, excedentes em relação à caderneta de poupança, no período de janeiro de 1969 a dezembro de 1998, contra vários horizontes de investimento. A evidência empírica constatada indica que "sabedoria convencional" tem algum suporte no que se refere a que o risco se reduz à medida que aumenta o horizonte do investimento, mas que o retorno não aumenta com o horizonte do investimento. No geral, os resultados não parecem ser sensíveis à consideração de que os investimentos se encerram em período de baixa ou de alta do mercado.
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A pesquisa objetivou testar a existência, no mercado futuro brasileiro, do fenômeno que a literatura batizou como a Hipótese de Samuelson, que postula que a volatilidade dos retornos de preços futuros aumenta à medida que o vencimento do contrato respectivo se aproxima. Para testar a hipótese em foco, foram utilizados dados dos seguintes contratos futuros, negociados na BM&F - Bolsa de Mercadorias & Futuros : contrato futuro de Ibovespa, contrato futuro de dólar comercial, contrato futuro de boi gordo e contrato futuro de café arábica. O período abrangido estendeu-se de 30 de junho de 1994 a 30 de abril de 1998. Aplicação de quatro testes distintos a cada contrato não autoriza afirmar-se que a Hipótese de Samuelson se observa no mercado futuro brasileiro.
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Os conceitos de Governança Corporativa não são novos, mas a gravidade de impactos financeiros gerados por escândalos corporativos estimula as empresas a adotarem melhores níveis de governança. Investidores profissionais se dispõem a pagar um ágio para investir em empresas com altos padrões de governança e que garantam um ambiente corporativo favorável ao retorno do seu investimento. A liquidez na qual o mundo viveu nos últimos anos propiciou um volume cada vez maior de recursos; não apenas para o Brasil, mas para grande parte dos mercados emergentes; para os mercados de capitais locais e em investimentos diretos. Esse capital, em grande parte externo, necessita de transparência, regulamentação e outros requerimentos de modo a reduzir os riscos relacionados às empresas alvo. Com base nas expectativas de mercado de indicadores macroeconômicos disponibilizadas pelo Sistema de Expectativas de Mercado do Banco Central do Brasil e nas informações fornecidas pela Bovespa e seus índices de mercado Ibovespa e IGC, este trabalho buscou uma associação entre variações nestas expectativas e valorização ou desvalorização da média de capitalização bursátil e índice de bolsa - Ibovespa e IGC. Observou-se que tanto o Ibovespa quanto o IGC e a média de capitalização bursátil da Bovespa e Ibovespa estão sujeitos as mesmas influências de variáveis macroeconômicas nacionais, mas em magnitudes diferentes. Entretanto, fez-se como exceção a média de capitalização bursátil do IGC, que sofreu influência de expectativas macroeconômicas diferentes dos demais. 6
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Apesar da diversidade de suas estratégias, os retornos dos fundos de investimentos multimercado geralmente exibem correlação positiva com índices de bolsa. Por outro lado, fundos de categorias distintas tendem a ser menos correlacionados entre si se comparados a fundos de mesma categoria. A ideia de diversificação entre fundos de baixa correlação é discutida recorrentemente pela literatura. Na prática, porém, poucos alocadores de portfólios otimizam suas carteiras através das linhas de Markowitz (1953) por exemplo. O objetivo deste estudo é buscar identificar o ponto ótimo de diversificação de ativos (fundos de investimentos) dentro de uma mesma categoria. Como metodologia, buscaremos a minimização do risco idiossincrático dos fundos de investimentos através de simulações com outros fundos de mesma categoria. O estudo contém análises para a escolha do número ideal de ativos em um dado portfólio. Esses resultados beneficiariam, principalmente, o processo decisório das empresas de Wealth Managements, das Consultorias de Investimentos e dos Private Bankers.
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Este artigo apresenta a utilização de Beta e variação de Beta dos ativos pertencentes ao Ibovespa como novos critérios para a construção de carteiras vencedoras e perdedoras em estratégias de momento. Os resultados mostram que as estratégias de momento, com base em critérios de maior ou menor Beta e de variação de Beta dos ativos pertencentes ao Ibovespa, geram retornos positivos ao longo de períodos subsequentes de 6 meses e 12 meses, porém apontam que estas estratégias, quando aplicadas e renovadas a cada mudança do principal índice bursátil brasileiro, apresentaram-se menos rentáveis do que as estratégias habituais baseadas no retorno total dos ativos no período entre 1995 a 2013.
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Neste trabalho, propomos uma especificação de modelo econométrico na forma reduzida, estimado por mínimos quadrados ordinários (MQO) e baseado em variáveis macroeconômicas, com o objetivo de explicar os retornos trimestrais do índice de ações IBRX-100, entre 2001 e 2015. Testamos ainda a eficiência preditiva do modelo e concluímos que o erro de previsão estimado em janela móvel, com re-estimação de MQO a cada rodada, e utilização de VAR auxiliar para projeção dos regressores, é significativamente inferior ao erro de previsão associado à hipótese de Random Walk para o horizonte de previsão de um trimestre a frente.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The primary purpose of the paper is to analyze the conditional correlations, conditional covariances, and co-volatility spillovers between international crude oil and associated financial markets. The paper investigates co-volatility spillovers (namely, the delayed effect of a returns shock in one physical or financial asset on the subsequent volatility or co-volatility in another physical or financial asset) between the oil and financial markets. The oil industry has four major regions, namely North Sea, USA, Middle East, and South-East Asia. Associated with these regions are two major financial centers, namely UK and USA. For these reasons, the data to be used are the returns on alternative crude oil markets, returns on crude oil derivatives, specifically futures, and stock index returns in UK and USA. The paper will also analyze the Chinese financial markets, where the data are more recent. The empirical analysis will be based on the diagonal BEKK model, from which the conditional covariances will be used for testing co-volatility spillovers, and policy recommendations. Based on these results, dynamic hedging strategies will be suggested to analyze market fluctuations in crude oil prices and associated financial markets.
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"GAO/GGD-88-38."
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This paper examines the measurement of long-horizon abnormal performance when stock selection is conditional on an extended period of past survival. Filtering on survival results in a sample driven towards more-established, frequently traded stocks and this has implications for the choice of benchmark used in performance measurement (especially in the presence of the well-documented size effect). A simulation study is conducted to document the properties of commonly employed performance measures conditional on past survival. The results suggest that the popular index benchmarks used in long-horizon event studies are severely biased and yield test statistics that are badly misspecified. In contrast, a matched-stock benchmark based on size and industry performs consistently well. Also, an eligible-stock index designed to mitigate the influence of the size effect proves effective.
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This study focuses on: (i) the responsiveness of the U.S. financial sector stock indices to foreign exchange (FX) and interest rate changes; and, (ii) the extent to which good model specification can enhance the forecasts from the associated models. Three models are considered. Only the error-correction model (ECM) generated efficient and consistent coefficient estimates. Furthermore, a simple zero lag model in differences which is clearly mis-specified, generated forecasts that are better than those of the ECM, even if the ECM depicts relationships that are more consistent with economic theory. In brief, FX and interest rate changes do not impact on the return-generating process of the stock indices in any substantial way. Most of the variation in the sector stock indices is associated with past variation in the indices themselves and variation in the market-wide stock index. These results have important implications for financial and economic policies.
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In this dissertation, I investigate three related topics on asset pricing: the consumption-based asset pricing under long-run risks and fat tails, the pricing of VIX (CBOE Volatility Index) options and the market price of risk embedded in stock returns and stock options. These three topics are fully explored in Chapter II through IV. Chapter V summarizes the main conclusions. In Chapter II, I explore the effects of fat tails on the equilibrium implications of the long run risks model of asset pricing by introducing innovations with dampened power law to consumption and dividends growth processes. I estimate the structural parameters of the proposed model by maximum likelihood. I find that the stochastic volatility model with fat tails can, without resorting to high risk aversion, generate implied risk premium, expected risk free rate and their volatilities comparable to the magnitudes observed in data. In Chapter III, I examine the pricing performance of VIX option models. The contention that simpler-is-better is supported by the empirical evidence using actual VIX option market data. I find that no model has small pricing errors over the entire range of strike prices and times to expiration. In general, Whaley’s Black-like option model produces the best overall results, supporting the simpler-is-better contention. However, the Whaley model does under/overprice out-of-the-money call/put VIX options, which is contrary to the behavior of stock index option pricing models. In Chapter IV, I explore risk pricing through a model of time-changed Lvy processes based on the joint evidence from individual stock options and underlying stocks. I specify a pricing kernel that prices idiosyncratic and systematic risks. This approach to examining risk premia on stocks deviates from existing studies. The empirical results show that the market pays positive premia for idiosyncratic and market jump-diffusion risk, and idiosyncratic volatility risk. However, there is no consensus on the premium for market volatility risk. It can be positive or negative. The positive premium on idiosyncratic risk runs contrary to the implications of traditional capital asset pricing theory.
Resumo:
In this dissertation, I investigate three related topics on asset pricing: the consumption-based asset pricing under long-run risks and fat tails, the pricing of VIX (CBOE Volatility Index) options and the market price of risk embedded in stock returns and stock options. These three topics are fully explored in Chapter II through IV. Chapter V summarizes the main conclusions. In Chapter II, I explore the effects of fat tails on the equilibrium implications of the long run risks model of asset pricing by introducing innovations with dampened power law to consumption and dividends growth processes. I estimate the structural parameters of the proposed model by maximum likelihood. I find that the stochastic volatility model with fat tails can, without resorting to high risk aversion, generate implied risk premium, expected risk free rate and their volatilities comparable to the magnitudes observed in data. In Chapter III, I examine the pricing performance of VIX option models. The contention that simpler-is-better is supported by the empirical evidence using actual VIX option market data. I find that no model has small pricing errors over the entire range of strike prices and times to expiration. In general, Whaley’s Black-like option model produces the best overall results, supporting the simpler-is-better contention. However, the Whaley model does under/overprice out-of-the-money call/put VIX options, which is contrary to the behavior of stock index option pricing models. In Chapter IV, I explore risk pricing through a model of time-changed Lévy processes based on the joint evidence from individual stock options and underlying stocks. I specify a pricing kernel that prices idiosyncratic and systematic risks. This approach to examining risk premia on stocks deviates from existing studies. The empirical results show that the market pays positive premia for idiosyncratic and market jump-diffusion risk, and idiosyncratic volatility risk. However, there is no consensus on the premium for market volatility risk. It can be positive or negative. The positive premium on idiosyncratic risk runs contrary to the implications of traditional capital asset pricing theory.