The main purpose of this thesis is to assess the potential of emerging stock markets and commodity markets in attracting the attention of international investors who utilize various portfolio diversification strategies to reduce the cumulative risk of their portfolio. A successful portfolio diversification strategy requires low correlation among financial markets. However, it is now well documented that the correlations among financial markets in developed countries are very high and hence the benefits of international portfolio diversification among these markets have been very limited. This fact suggests that investors should look for alternative markets whose correlations with developed markets are low (or even negative if possible) and which have high growth potentials. In this thesis, two emerging countries&#039 / stock markets and two commodity markets are considered as alternative markets. Among emerging countries, Turkey and China are chosen due to their promising growth performance since the mid-2000s. As commodity markets, agricultural commodity and precious metal markets are selected because of the outstanding performance of the former and the &quot / safe harbor&quot / property of the latter. The structures and properties of dependence between these markets and stock markets in developed countries are examined by modeling the conditional correlation in the dynamic conditional correlation framework. The results reveal that upward trend hypothesis is valid for almost all correlations among market pairs and market volatility plays significant role in time varying structures of correlations.

The purpose of this study is to examine the volatility spillover among a country&rsquo / s foreign exchange, bond and stock markets and the volatility transmission from the global bond, stock and commodity markets to these local financial markets. The sample for the study includes data from both emerging and developed economies in the time period between 2004 and 2011. A multivariate GARCH methodology with the BEKK representation is applied for the local financial markets and global variables are included as exogenous variables into the model. The volatility integration of the financial markets of the emerging economies is stronger compared to the integration of the developed economies. Global variables have a spillover effect on the developed markets only after the global financial crisis, whereas they significantly affect the volatility in emerging markets for both the pre- and post-crisis period. North American countries in the sample, U.S. and Mexico, have low local volatility integration in the pre-crisis era and the integration rises in the post-crisis period. Moreover, they are more open to the internal and global short-term shocks in the post-crisis period. Germany and Turkey are the representatives of the EMEA (Europe, Middle East and Africa) region and they have high local market integration and are open to global shocks for both sub-periods. Far Eastern markets, Japan and Korea, also have high local market integration and their vulnerability to the global effects is large and getting larger for the post-crisis period. The most important limitation of this thesis is the difficulty of reaching sharp generalizations due to the small number of countries analyzed. This limitation can be addressed by the inclusion of a larger number of geographically dispersed countries. The most noteworthy originality of this study is the addition of the exogenous global variables for modeling volatility spillovers. Furthermore, comparison of results for emerging versus developed markets and the pre- versus post-crisis periods is another contribution of this study to the existing literature. The findings of this study can be used by investors interested in assessing the risks of investing internationally.

This thesis analyzes the optimal strategies of rational agents in incomplete financial markets. The incompleteness may arise from the stochastic volatility of stock prices, in which case we study the optimal pricing and hedging strategies of an option trader. We introduce a new concept that we call the relative indifference price, which is the price at which a trader is indifferent to trade in an additional option, given that he is currently holding and dynamically hedging a portfolio of options. We find that the appropriate volatility risk premium depends on the trader's risk aversion coeffcient and his portfolio position before selling or buying the additional option. More generally, the incompleteness of the market may arise from both the drift and volatility of the stock being driven by a correlated factor. In this setting, we study the optimal consumption and investment policies of CARA, conservative CRRA and aggressive CRRA agents. In particular, we provide interpretations of the non-myopic investment in terms of martingale measures and the risk monitoring strategy of a path-dependent option. / text

This thesis consists of three essays. The first essay, “A Theory of Bank Illiquidity and Default with Hidden Trades”, develops a theory of banking to explore how the availability of trading opportunities for both banks and individual investors affects the link between illiquidity and default in the financial system. The results show that default emerges only in the presence of systemic risk, and when an unpredicted crisis hits the economy. Moreover, in contrast to the previous literature, default is not an efficient outcome of the economy. The second essay, “Financial Liberalization with Hidden Trades”, studies how the availability of unregulated market-based channels for the circulation of liquidity in the financial system affects the process of financial integration, and the efficiency of the corresponding equilibrium, in a two-country economy with comparative advantages. The results show that the only level of integration which the two countries are able to coordinate is the one where the two banking systems are autarkic, but international hidden trades are possible. Moreover, the resulting consumption allocation is constrained efficient. The third essay, “Bank Liquidity, Stock Market Participation, and Economic Growth”, develops a dynamic growth model with fully microfounded banks and markets to explain the observed decreasing trend in the relative liquidity of many financial systems around the world. The main result characterizes the threshold after which the agents in the economy are rich enough to access the market, where the relative liquidity is lower, and shows that the relative liquidity of the whole financial system (banks and markets) drops because of the increasing market participation. Some evidence consistent with this theoretical prediction is provided: a one-unit increase in an index of securities market liberalization leads to a drop in the relative liquidity of between 13 and 22 per cent.

This work is an extension of the classical Cox-Ross-Rubinstein discrete time market model in which only one risky asset is considered. We introduce another risky asset into the model. Moreover, the random structure of the asset price sequence is generated by bivariate finite state Markov chain. Then, the interest rate varies over time as it is the function of generating sequences. We discuss how the model can be adapted to the real data. Finally, we illustrate sample implementations to give a better idea about the use of the model.

Despite the extent of a theoretical framework in financial market studies, a vast majority of the traders, investors and computer scientists have relied only on technical and timeseries data for predicting future prices. So far, the forecasting models have rarely incorporated macro-economic and market fundamentals successfully, especially with short-term predictions ranging less than a month. In this investigation on the predictability of certain financial markets, an attempt has been made to incorporate a un-exampled and encompassing set of parameters into an Artificial Neural Network prediction system. Experiments were carried out on three market instruments ??? namely currency exchange rates, share prices and oil prices. The choice of parameters for inclusion or exclusion, and the time frame adopted for the experimental sets were derived from the market literature. Good directional prediction accuracies were achieved for currency exchange rates and share prices with certain parameters as inputs, which consisted of predicting short-term movements based on past movements. These predictions were better than the results produced by a traditional least square prediction method. The trading strategy developed based on the predictions also achieved a higher percentage of winning trades. No significant predictions were observed for oil prices. These results open up questions in the microstructure of the markets and provide an insight into the inputs required for market forecasting in the corresponding time frame, for future investigation. The study concludes by advocating the use of trend based input parameters and suggests ways to improve neural network forecasting models.

Orientador: Antonio Fernando Crepaldi / Banca: Fernando Fagundes Ferreira / Banca: Jair Wagner de Souza Manfrinato / Resumo: Estudos que proporcionem conhecer de forma mais adequada o mercado de capitais brasileiro são uma necessidade para um país que a cada dia tem a sua importância no cenário internacional acentuada. Compreender a dinâmica das flutuações do mercado de ações é um desafio científico possibilitado, no Brasil, por dois aspectos importantes: disponibilidade de dados de alta frequencia sobre os preços praticados no mercado e a utilização de métodos computacionais. O objetivo dessa pesquisa é verificar e analisar os principais fatos estilizados observados em séries temporais financeiras: agrupamento de volatilidade, distribuições de probabilidade com caudas gordas e a presença de memória de longo alcance na série temporal dos retornos absolutos. Para isso, foram utilizadas e analisadas as cotações intraday de ações de dez companhias negociadas na Bolsa de Valores, Mercadorias e Futuros que correspondem juntas a uma participação de 52,1%, para a data de 01/09/2009, no Ìndice Bovespa. Verificou-se a existência de vários fatos estilizados em todas as ações da amostra, bem como se procedeu a caracterização desses comportamentos por meio de gráficos e medidas estatísticas / Abstract: Studies that provide to know in a more suitable way the Brazilian money market are a necessity for a country that has its importance increased in the international scenery every day. Understanding the dynamics of the stock market fluctuation is a scientific challenge possible, in Brazil, because of two important aspects: availability of high frequency data on the prices practiced in the stock market and the use of computing methods. The objective of this survey is to verify and analyze the stylized facts observed in financial seasonal series: gathering of volatility, probability distribution with fat tails and the presence of high reaching memory in the seasonal series of abolute recurrence. For this, it was used and analyzed the intraday quotations over stocks of ten enterprises in the stock exchange, commodities and futures that correspond together to a participation of 52,1% to th data of 09/01/2009, in the Bovespa index. It was verified the existence os several stylized fact in all stock samples and how it was preceded the characterization of this behavior by graphic displays and statistical measures / Mestre

Esta dissertação apresenta uma proposta de modelo de mercado financeiro artificial que reproduz séries de retornos com propriedades estatísticas universais semelhantes às observadas em séries reais. Dentre as propriedades, também chamadas de fatos estilizados na Economia, as séries artificiais de retornos exibiram ausência de autocorrelação para os retornos simples, leis de potência para autocorrelação para os retornos absolutos e quadráticos, excesso de curtose nas distribuições de retorno, gaussianidade agregacional e volatilidade clusterizada. Cabe salientar, que não há na literatura um outro mercado artificial que reproduziu tantos fatos estilizados conjuntamente. O modelo dinâmico e síncrono é baseado em agentes que transacionam ativos com risco como ações de empresa através de ordens de compra e venda enviadas ao mercado a cada período de tempo. O preço de mercado das ações é calculado da média ponderada pelo volume das ordens negociadas entre os agentes. O objetivo dos agentes é maximizar sua riqueza e, para isso, seguem ou a estratégia fundamentalista utilizando os dividendos para calcular os preços das ações ou a estratégia técnica baseada em análise de séries temporais. A principal contribuição da modelagem foi acrescentar às estratégias um fator de aprendizado em que o agente considera sua habilidade individual passada de previsão de riqueza esperada para calcular os retornos futuros. Este trabalho também mediu o coeficiente de Gini para descobrir como algumas variáveis de mercado afetavam a distribuição de riqueza dos agentes e, além disso, estudou quais valores de dividendo tornavam uma estratégia mais eficiente que outra. Por fim, incorporaram-se características evolutivas aos agentes possibilitandoos a trocar de estratégias no decorrer da simulação e, com isso, os resultados mostraram aumento da riqueza dos agentes. / This work presents a new artificial stock market model for reproducing price time series of assets in such market model. For a suitable validation of the model, we verified several statistical and universal properties (called stylized facts in the Economics Literature) and similar results are obtained with data extracted from real stock markets. We investigate several properties including absence of autocorrelation for simple returns and the power behavior law of autocorrelation for absolute and quadratic returns, excess of kurtosis, aggregational gaussianity, and clustered volatility. It is important to mention that no other similar artificial model has investigated so many statistical universalities. Our synchronous model is based on agents negotiating risk assets through purchase and sale orders. These orders are stored in books for each simulation step. The weighted average volume of all orders negotiated by the agents determines the price of an asset. For the sake of simplicity, our model considers two kinds of strategies: 1. Fundamentalist - where one uses the dividends to calculate the expected return of an asset; 2. Trend predictor - where one obtains the expected returns directly from an analysis of the price time series. One of the main contributions of our model was to add a term that works as the expected wealth of an agent. This is considered an important psychological factor in the decision making process. In addition, we consider an income inequality index to analyze the wealth distribution of the agents: the Gini-coefficient, which predicts an inequality interval of [0 (society completely fair),1 (society completely unfair)]. We also study the influence of the dividends and risk free assets parameters on this coefficient. Finally, some evolutionary features of the model are analyzed. Our results show an increase in agent’s wealth when strategies are updated according to the following criteria: if expected wealth does not reach a given threshold, the agent changes his strategy from Fundamentalist to Trend Predictor or vice-versa. If the expected wealth reaches the specified threshold, the agent keeps his initial strategy. We tested different threshold values in this analysis and the conclusion was confirmed in all cases studied.

La montée du poids de la finance est, pour une part au moins, une réponse à la mise en place et en œuvre de stocks de capital productif toujours plus importants et à l’accumulation, qui en est la contrepartie, d’une masse toujours plus grande d’actifs financiers. A ce premier facteur qui fait de la montée du poids de la finance une conséquence en partie « mécanique » du développement économique, s’en est toutefois ajouté un autre : une montée incontestable du rôle des marchés financiers qui est venue modifier en profondeur la façon dont les risques liés au financement de cette accumulation de capital productif sont désormais portés. Le mécanisme d’allocation de l’épargne et de prise de risques mis à disposition de nos économies par les marchés financiers n’a toutefois ni la puissance ni la robustesse que lui prêtent les tenants de la libéralisation financière. La masse de risques qu’un système financier peut porter est fonction des contraintes de prudence imposées par les régulateurs, mais aussi de l’attitude face au risque des acteurs financiers. Le caractère cyclique de cette dernière a une incidence majeure sur la stabilité financière : le système peut brutalement ne plus parvenir à trouver seul son équilibre. / The rise of finance in developed economies is, for a part at least, a response to the provision and use of an ever growing volume of productive capital stocks and to the accumulation of an ever growing amount of financial assets, which is its counterpart. It is, however, far from being only a mechanical consequence of the development of the real sphere of the economy: the development of financial markets has also radically altered the way financial risks associated with the financing of the accumulation of capital stocks are now borne. The mechanisms allocating savings and redistributing financial risks at the disposal of our economies have, however, neither the efficiency nor the robustness advocated by the proponents of financial liberalization. The mass of risks a financial system can absorb depends not only on prudential regulatory constraints, but also on financial agents’ attitude towards risk. The pro-cyclical nature of the latter has a major impact on financial stability: the system can suddenly be unable to strike a balance on its own.

[pt] Apresentamos um estudo empírico comparativo para o problema de Execução Otimizada de Transações nos mercados financeiros modernos. Construímos um simulador dos mercados financeiros, e então, baseado nessa ferramenta, comparamos o desempenho de algumas estratégias propostas na literatura. Os melhores resultados foram obtidos por estratégias que usam técnicas de aprendizado de máquina. / [en] We present a comparative empirical study for the Optimized Trade Execution problem in moderns financial markets. We build a financial market simulator and then, based on this tool, we compare the performance of many strategies available in the literature. The best results were achieved by strategies that make use of machine learning techniques.