Com o crescimento da economia brasileira as operações de Fusões e Aquisições tem vivenciado um franco crescimento. Segundo trabalhos recentes sobre o tema, esse tipo de operação tem um componente estratégico muito superior ao simples ganho imediato de valor, tese que se justifica com os trabalhos empíricos atuais, que encontram fortes evidências que a empresa adquirente, frequentemente, perde valor de mercado, através da queda no preço das suas ações, nos dias seguintes à combinação empresarial. No entanto, a maioria dos trabalhos sobre o tema versam sobre operações de Fusões e Aquisições no mercado norte-americano e europeu, onde estruturas regulatórias e cultura de proteção aos acionistas minoritários divergem muito das situações encontradas no Brasil. Por outro lado, a economia brasileira após a implantação do Plano Real é relativamente recente, mas sendo permeada por crises internacionais e nacionais na década de 1990, além de um período de intenso programa de privatizações que fez surgir grandes grupos econômicos nacionais, tornando esse período um intervalo temporal único, e que as evidências encontradas nesse período possam não ter muita aderência à atual realidade brasileira. Através de um estudo de caso com 121 empresas listadas na BOVESPA, foi analisado a criação de valor para o acionista da empresa adquirente através de uma janela temporal de 20 dias antes e 20 dias após o anúncio do fato relevante que dá início a combinação empresarial. Foram utilizados dois métodos para observar a criação ou destruição de valor para o acionista, o método do retorno de mercado e o método do modelo de mercado ajustado, que demonstraram ser idênticos para a análise proposta. Analisando operações de combinação empresarial de 2001 a 2011, as empresas adquirentes foram agrupadas através da Classificação Nacional de Atividades Econômicas (CNAE) e submetidas a critérios de seleção da amostra que reduziu o grupo estudado a três setores econômicos, o da Indústria de Transformação, o de Informação e Comunicação e por fim o de Serviços Financeiros. Os resultados sugerem que os investidores tem informações sobre a operação de Fusão e Aquisição antes da divulgação do Fato Relevante pelas empresas, fazendo com que as ações experimentem altas em seus preços dias antes do anúncio, assim como foram encontradas evidências que o Setor Financeiro tem um comportamento que rejeita a hipótese de eficiência de mercado em sua forma semiforte. / In the past few years, with the growth of the Brazilian economy, operations of Mergers and Acquisitions had experienced significant growth. According to recent papers, this type of operation has a strategic component far superior to the simple gain of immediate value, a thesis justified with empirical work showing strong evidence that the acquiring company often loses market value, noticed by the falling prices of its shares in the days following the merger announcement. However, most studies on the subject deal with operations of Mergers and Acquisitions in the U.S. market and Europe, where regulatory structures and culture of protection of minority shareholders are much different from the situations we find in Brazil. On the other hand, the stability of the Brazilian economy, after the Real Plan, is relatively recent, being permeated by national and international crises in the 1990s. Through a case study with 121 companies listed on the BOVESPA, we analyzed the creation or value for shareholders of the acquiring company through a time window of 20 days before and 20 days after the announcement of the merger. Two methods were used to observe the creation or destruction of shareholder value, the method of the market return and the method of adjusted market model, which proved to be identical to the proposed analysis. Analyzing business combination transactions from 2001 to 2011, the acquiring companies were grouped by the National Classification of Economic Activities (CNAE) and subjected to a selection criteria that reduced the sample group to three economic sectors, the Manufacturing Industry, the Information and Communication and finally the Financial Services. The results suggest that investors have information about the operation of Merger and Acquisition before the announcement, causing stocks to experience increases in their prices days before the announcement, and evidence was found that the financial sector has a behavior that rejects the hypothesis of market efficiency in its semi-strong form.

Made available in DSpace on 2016-04-25T16:45:31Z (GMT). No. of bitstreams: 1 Regilane Lacerda Abreu.pdf: 2757231 bytes, checksum: bde3a61b38bf8099f9abd4fbd3aecfcd (MD5) Previous issue date: 2010-05-12 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aims at testing the semi-strong form of market efficiency, which presumes that the prices should reflect all publicly available information, and at verifying the effects of the anomaly of announcements determined by the behavioural finances, specifically, the announcement of share repurchase by the open companies in Brazil, analyzing its effects in the share market value of those companies listed on Bovespa through the application of event study whose data were obtained from both the Economatica database and the São Paulo Stock Exchange (Bovespa). The study concentrates in the verification of abnormal return on the announcement dates of share repurchase announced by the companies listed on Bovespa from 1998 to 2008. An event study methodology was applied using the logarithmic approach of continuous capitalization to estimate the returns of shares and the return of Ibovespa. Regarding that event, the return of shares of those companies in the Brazilian Stock Market was investigated in a period shorter than or longer than 20 days around the event, comparing it with the return of portfolio market represented by Ibovespa. It was possible to determine the presence of abnormal returns in the share prices statistically superior than the returns of Ibovespa, indicating that probably occurred a stronger valorization of the companies that announced share repurchase in the years studied according to the methodology adopted for this study. The t-Student test was applied for testing the statistical significance of the results, leading to the rejection of a null hypothesis that the abnormal variation in the return of the shares around the date of the repurchase announcement is equal to zero. The regression analysis certifies that the variation in the Ibovespa s portfolio market is not enough to explain the abnormal returns of the shares analysed. Those results lead to the rejection of the hypothesis that the semi-strong form of market was efficient in the period covered by this research since the presence of abnormal returns indicate that the market was not efficient in its semi-strong form after the share repurchase announcements in that period / Este estudo tem como objetivo testar a eficiência do mercado em sua forma semiforte, que pressupõe que os preços devem refletir toda informação publicamente disponível, e verificar os efeitos da anomalia de anúncios determinada pelas finanças comportamentais; neste caso, o anúncio de recompra de ações por parte das companhias abertas no Brasil, analisando seus efeitos no valor de mercado da ação das empresas listadas na Bovespa, por meio da aplicação do estudo de eventos cujos dados foram extraídos da base de dados Economática e da Bolsa de Valores de São Paulo (Bovespa). O estudo se concentra na verificação de retorno anormal em torno das datas de anúncios de recompra de ações divulgados pelas empresas listadas na Bovespa no período de 1998 a 2008. Neste contexto, utilizou-se a metodologia de estudo de evento, considerando a abordagem Logarítmica de capitalização contínua para estimar os retornos das ações e o retorno do Ibovespa. Considerando este evento, investigou-se o retorno das ações das respectivas empresas no mercado acionário brasileiro, em um período -20 e +20 dias em torno do evento, comparando-o com o retorno da carteira de mercado, representada pelo Ibovespa. Foi possível determinar a presença de retornos anormais nos preços das ações estatisticamente superiores aos retornos do Ibovespa, o que indica que provavelmente ocorreu uma maior valorização das companhias que anunciaram recompra de ações nos anos estudados, segundo a metodologia deste estudo. O teste t-Student foi utilizado para testar a significância estatística dos resultados, que levaram a rejeitar a hipótese nula de que a variação anormal no retorno das ações em torno da data de anúncio da recompra é igual a zero. A análise de regressão atesta que a variação na carteira de mercado, Ibovespa, não é suficiente para explicar os retornos anormais das ações estudadas. Esses resultados levam a rejeição da hipótese de que o mercado se mostra eficiente em sua forma semiforte no período da pesquisa, uma vez que a presença de retornos anormais indicam que o mercado não foi eficiente em sua forma semiforte após os anúncios de recompra de ações no período

O propósito dessa pesquisa é estudar a relação entre a revelação de informação corporativa e o comportamento de uma seleção de empresas com fortes políticas de revelação de informação e alto grau de capitalização do Mercado Acionário da Colômbia, para o ano 2014. Mediante esse estudo, é analisada a microestrutura utilizando informação de alta frequência e notícias corporativas publicadas na plataforma de Bloomberg Professional Services. A metodologia de análise para prover evidência da relação foi o estudo de eventos, testando a significância da diferença entre as médias e medianas pré-evento e pós-evento de alguns indicadores de liquidez, retorno e volatilidade. Os resultados permitem concluir que a disseminação de informação tem um impacto sobre a liquidez e a volatilidade do mercado. Percebe-se que no período posterior à publicação das notícias, o tamanho dos bid-ask spreads e a volatilidade do midquote diminui, os investidores negociam em média menores volumes e quantidade de operações e submetem menor quantidade de intenções de compra e venda. / The purpose of this investigation is to study the relationship between corporate disclosure and the behavior of a selection of companies, with strong disclosure policies and high market capitalization ratio of the Colombian Stock Market, for the entire year 2014. The idea of this investigation is to analyze the market microstructure using high frequency data and corporate information publicized through the Bloomberg professional services platform. The estimation technique to provide evidence of the relationship is the event study, testing the significance of the difference between the pre-event and post-event average and median of some indicators of return, liquidity and volatility. The results prove that the disemintation of information impact the market liquidity and volatility. It is noticed that in the post-event window, bid-ask spreads and volatility of the midquote decreases, traders negociate on average lower volums and number of transactions and submit fewer buy and sell order intentions.

Ao se tratar de mercado de capitais, dentre seus principais fatores de análise, encontra-se a discussão a respeito da teoria de eficiência de mercado que é uma teoria que diverge em relação ao comportamento do preço dos ativos, no que diz respeito à sua linearidade ou não. Neste sentido, este trabalho teve como objetivo analisar o comportamento dos principais índices das dez maiores bolsas de valores do mercado, durante o período de junho de 1999 a junho de 2009. Para realização de tal análise foi utilizada a estatística R/S e o cálculo do Expoente de Hurst, por sua vez, validado pelo Teste Estatístico de Wald. A utilização desta metodologia permitiu investigar a presença da memória longa persistente, anti-persistente ou a identificação de um passeio aleatório. Os resultados evidenciaram que, de modo geral, os índices apresentaram presença de memória longa persistente na maior parte do período analisado, devendo-se ressaltar que apenas no período próximo à crise financeira de 2008 foi possível identificar forte presença de um comportamento aleatório. Assim, foi possível aceitar a hipótese de que os mercados são ineficientes na maioria das séries históricas de retornos dos índices. / When it comes to the capital market, among its main factors of analysis, it´s found the debate concerning the market efficiency theory, which is a theory that differs in relation to the behavior of the asset´s price, concerning its linearity or not. In this way, this work aims to analyse the behavior of the main index of the ten major stock market, from june 1999 until june 2009. To the achievement of such analysis it was used the R/S statistics and the Hurst Exponent, which was, validadet by the Wald Test Statistics. The employment of such methodology allowed to investigate the presence of the long persistence memory, anti-persistence or the identification of a random walk. The results showed that, on the whole, the indexes showed the presence of the long persistence memory most of the analysed period, saying the only in the period close to the financial crisis of 2008, it was possible to identify a relevant presence of a random behavior. So, it was possible to accept the hipothesis that the markets are ineffectual in most of the historical series of restoration of indexes.

The paper reacts to tremendous increase in popularity of FX trading among retail investors in recent years, caused mainly by easy accessibility through numerous online trading platforms and dramatic fall in trading costs. One of the accompanying trends along with increasing trading speed is a departure from fundamental analysis and shift towards more technical approach. In reaction to that, the paper aims to review the most popular technical trading rules and puts the findings in contrast with existing empirical literature and efficient market hypothesis. Although being far from discovering an ultimate trading formula, the paper concludes that selected trading strategies do demonstrate a certain degree of predictability of future exchange rate movements.

abstract: 中国商品期货市场经历30年发展，已初备协调资源分配、对冲经营风险的功能。但受产业自身和期货市场发展的制约，各期货品种市场有效性参差不齐。随着我国经济从增量阶段过渡到存量阶段，期货作为企业的价格管理和风险控制工具的重要性日益凸显，因此研究我国商品期货市场有效性具有非常好的现实意义。 本文开创性的从期货的基本功能——资源配置的角度出发，提出有效市场是指其期货价格能够对本行业社会资源起到合理的调配作用的市场。在内容安排上，本文首先总结了现有国际成熟期货品种的特点并找出能够反映期货对资源配置能力的四个指标假说，分别为期现回归性、利润波动性、库存波动性以及现金流变化，然后通过数学模型证明指标数据和品种成熟度的关联，最后应用该套指标对我国商品市场有效性进行检验。数学方法上，本文先采用Bai-Perron内生多重结构突变模型对时间序列进行突变点检验，然后对断点时间序列分别进行多元回归，并在剔除季节性和周期性后，通过平稳性检验、ARCH效应检验结果来确定相应的Garch模型，并用Garch模型来描述时间序列的波动性。 通过数学验证，我们认为期现回归性、利润波动性、库存波动性以及现金流变化这四个指标可以作为反映期货成熟度的检验指标，用该套方法对国内部分活跃品种检验后发现大连豆粕期货已经具备成熟品种的特征，本文认为豆粕期货市场是有效的；PTA、玉米淀粉期货的四个检验指标在近年来表现出时间序列优化的特点，但因时间较短尚不稳定，可以认为是接近成熟的品种；而螺纹钢和铝期货在多数指标上表现不佳，表明他们对社会资源配置能力较差，因此本文认为螺纹钢和铝期货市场是活跃但非有效的。通过进一步分析，本文认为品种的期现回归性差是制约其资源配置能力发挥的关键因素，而交易标的不明确、 仓单制作难度大、产业参与度低以及期货设计中的其他限制因素又是导致期现回归性差的重要原因。 / Dissertation/Thesis / Doctoral Dissertation Business Administration 2019

The cryptocurrency market is continuously growing but is still a relatively unexplored field within academic research. The ambition with this thesis is to increase existing research on market efficiency of cryptocurrencies, by studying the risk exposure of identical investments between different cryptocurrency exchanges. The study includes four cryptocurrencies and nine different exchanges, the data is tested on a full sample period and two subsample periods. The results reveal significant Sharpe ratio differences for identical investments on selected exchanges, but also improved efficiency between the first and second subsample periods. The study concludes that there are significant market inefficiencies on the cryptocurrency market, but the results also suggests that the market is becoming more efficient over time.

The U.S. National Market System (NMS), the largest marketplace in the world for securities and exchange traded funds, suffers from geographic market fragmentation which leads to reduced market efficiency. Communication lines transmit price updates and other information between geographically isolated exchanges at varying speeds, bounded above by the speed of light. Market participants have access to federally mandated information provided by the Securities Information Processor (SIP) and privately offered information provided by the exchanges, often called direct feeds. These feeds are quantitatively and qualitatively distinct, with the direct feeds tending to provide more information at a faster rate than the SIP feed. Differences between the SIP and direct feeds can lead to information asymmetries between market participants, which in turn create arbitrage opportunities. Under the market conditions of the NMS in 2016, these arbitrage opportunities occur regularly and many can be captured by market participants with fast connectivity. Several methods exist which allow market participants to reduce their communication latency with trading centers, including the practice of co-location where market participants pay to have their trading infrastructure located in the same building as the matching engines of an exchange. Such regularly occurring and executable arbitrage opportunities run counter to the Efficient-Market Hypothesis (EMH) in all forms, where even the weak form of the EMH claims that market participants should not be able to systematically profit from market inefficiencies. This thesis investigates the market inefficiencies and related effects introduced by geographic market fragmentation in two baskets of stocks: the Dow Jones Industrial Average (Dow), and the 30 largest stocks by market capitalization in the Standard \& Poor's 500 index (S&P 30).

<p>The Chinese stock market is a remarkable emerging market, the two stock markets Shanghai and Shenzhen Stock Exchanges were both established in 1990, and since then they have been playing a very important role in Chinese economy. More and more attention is focused on the emerging Chinese market, and investors have been trying to find the opportunity to achieve abnormal returns through the Chinese stock market. We name this phenomenon market efficiency anomaly, one pattern of which is seasonality effect. In our study, we would like to choose the seasonality effect as the approach.</p><p>This study focuses on Shanghai Stock Exchange Composite Index, and we settle two research questions: Does seasonality effect exist in Chinese Stock exchange? Is the seasonality effect persistent over times?We try to test the seasonality in Chinese stock market by day of the week effect, January effect and semi-month effect. Deductive approach and quantitative research method are used in this thesis. To analyze seasonality effect, the data has been collected from Shanghai Stock Exchange Index and has been tested in four periods: 1992-1996,1997-2001, 2002-2006 and the whole period 1992-2006. Null hypothesis and T-test with α=0.05 is used to test the seasonality effect. The results show that seasonal anomalies like Day of the week effect, positive March effect, and negative July effect exist in the Chinese stock market, while semi-month effect does not occur significantly; but the existing seasonal effect is not persistent over times. The above indicates that the Chinese stock market is not fully efficient yet. Investors may have opportunities to make use of the seasonal anomalies to earn abnormal return.</p>

<p>This paper investigates whether the traditional accrual based trading strategy first documented by Sloan (1996) can be refined using fundamental analysis. Specifically, this is done by implementing the composite signal F_SCORE introduced by Piotroski (2000) to identify financially strong or weak firms. We find that by applying both investment models simultaneously, in a model we call P_KOMB, the mean market-adjusted return earned by an investor exploiting the accrual anomaly can be increased by 14.8% annually. This is achieved by taking a long position in strong firms (as defined by the composite signal) in the lowest accrual portfolio, while an offsetting short position is taken in weak firms in the highest accrual portfolio, repeated annually between 1997 and 2007. Consistent with prior studies, positive market-adjusted returns can be attained through assessment of accruals as well as key value drivers found in historical financial data. Moreover, our results indicate that accruals are a more powerful determinant for future return than the fundamentals in the composite signal. The evidence suggests, however, that the accrual anomaly is best exploited in combination with the fundamental signals to maximise returns.</p>