投資型商品連動於特定資產，保險人除了面臨原有的核保風險，更需承擔部分的財務風險。傳統保險商品的純保費價格等於其預期損失，而投資型商品的保險給付依據投資標的波動，保險人的預期損失不易估算，傳統精算的評價方法不完全適用於投資型商品。保證最低給付的給付結構使得投資型商品其有選擇權的特質，Brennan與Schwartz(1976)首先利用選擇權定價理論探討附有保證最低給付投資型商品之價值與避險策略，爾後亦有許多文獻以此方向加以著墨，但選擇權定價理論是基於市場為完全市場的假設，保險市場為不完全市場，以完全市場假設之理論評定保險商品之價值實不合理。本為假設保險人面臨的風險為核保風險及財務風險，財務市場為完全市場，保險人可以藉由市場上的各種金融商品建構避險組合規避財務風險；而預期死亡人數與實際死亡人數所產生的核保誤差，保險人無法利用避險組合完全地規避，因此保險市場為不完全市場。 在不完全市場中請求權的價值牽涉投資者主觀的風險偏好，不存在唯一的平賭測度，請求權的價格也不唯一，最適避險策略依請求權的價格調整，所以投資型保險商品的價格不再等於其公平價值，真正的成交價格應落於買賣價差之中。本文引用Mercurio(1996)的結果，利用二次效用函數，以極大化保險人期末財富之效用為目標，建構生存險的合理價格範圍。以二元樹模型描述股票的波動，分別模擬五年、十年及十五年投資型生存險之價差範圍，保險人的風險規避程度、保單期限以及保證金額的高低將影響商品價差範圍的大小。 關鍵字：不完全市場、效用函數，買賣價差、最適避險策略 / Investment-linked life (LIL) insurance policies integrate the attributes from the mutual fund by introducing the investment options to the policyholders and life insurance through the benefit payments shielding the unexpected events of the insured. Since the execution of the implied options depends on the policyholder's health status. Actuarial equivalent principal and non-arbitrage pricing theory are used in evaluating the prices for LIL insurance policies. Brennan and Schwartz (1976) initially employ the option pricing theory in examining the pricing and hedging strategy for LIL insurance policies with minimum guarantees. Most published literatures are focusing on this issue adopting the B-S methodology. Since the values of the LIL policies cannot be replicated uniquely through the self-financing strategies due to underwriting risks of the insurance market. Insurance market does not satisfy the completeness assumptions, Due to lack of a unique martingale measure under market incompleteness, the utility assumption of the policyholder is involved in the pricing issue. Insurance pricing must consider the risk attitude of the investors in the market. Hence the cost the LIL insurance policies are not necessarily equal to the fair market prices. The market value should fall within the range of the bid and ask prices. In this study, we follow the approach in Mercurio (1996) by adopting the quadratic utility function and compute the reasonable range of the prices based on maximizing the terminal health utility function. Binary tree method is used in modeling the asset dynamics. Then the numerical computations are performed using endowment LIL insurance policies with 5, 10 and 15 years of duration. Based on the results, we find that the risk attitude of the policyholder, the policy duration and minimum amounts of the guarantees significantly affect the bid-ask price spread of LIL insurance policies. Keywords: market incompleteness; utility function; bid-ask spread; optimal hedging strategy.

This thesis is devoted to the study of the applications of the error theory using Dirichlet forms. Our work is split into three parts. The first one deals with the models described by stochastic differential equations. After a short technical chapter, an innovative model for order books is proposed. We assume that the bid-ask spread is not an imperfection, but an intrinsic property of exchange markets instead. The uncertainty is carried by the Brownian motion guiding the asset. We find that spread evolutions can be evaluated using closed formulae and we estimate the impact of the underlying uncertainty on the related contingent claims. Afterwards, we deal with the PBS model, a new model to price European options. The seminal idea is to distinguish the market volatility with respect to the parameter used by traders for hedging. We assume the former constant, while the latter volatility being an erroneous subjective estimation of the former. We prove that this model anticipates a bid-ask spread and a smiled implied volatility curve. Major properties of this model are the existence of closed formulae for prices, the impact of the underlying drift and an efficient calibration strategy. The second part deals with the models described by partial differential equations. Linear and non-linear PDEs are examined separately. In the first case, we show some interesting relations between the error and wavelets theories. When non-linear PDEs are concerned, we study the sensitivity of the solution using error theory. Except when exact solution exists, two possible approaches are detailed: first, we analyze the sensitivity obtained by taking "derivatives" of the discrete governing equations. Then, we study the PDEs solved by the sensitivity of the theoretical solutions. In both cases, we show that sharp and bias solve linear PDE depending on the solution of the former PDE itself and we suggest algorithms to evaluate numerically the sensitivities. Finally, the third part is devoted to stochastic partial differential equations. Our analysis is split into two chapters. First, we study the transmission of an uncertainty, present on starting conditions, on the solution of SPDE. Then, we analyze the impact of a perturbation of the functional terms of SPDE and the coefficient of the related Green function. In both cases, we show that the sharp and bias verify linear SPDE depending on the solution of the former SPDE itself

No description available.

När en företagsobligation och en statsobligation har samma löptid och har en skillnad i avkastning, så kallas denna skillnad för kreditspread. Ett känt koncept inom finansvärlden är att risk har en stark koppling till avkastning. När emittenten av obligationen inte kan återbetala överenskommen utdelning eller principiellt lånebelopp så klassas detta som en betalningsinställelse. Eftersom det generellt sett är större risk för en betalningsinställelse för ett företag än för en stat, så vill investerare bli kompenserade för den extra risken de tar sig an. Den totala risken som utgör skillnaden i avkastning kan i sin tur delas upp i flera olika riskkomponenter. Syftet med vår uppsats är att undersöka ifall likviditetsrisk, ränterisk och kreditrisk har en effekt på kreditspread för företagsobligationer på den svenska marknaden. Med detta som bakgrund så har vi samlat in historiska data på förfallna obligationer under de senaste 10 åren via databaserna Thomson Reuter Datastream och Eikon. Vi har sedan laddat ned obligationsspecifika egenskaper i form av finansiella nyckeltal för samtliga obligationer. Dessa nyckeltal har valts för att till bästa förmåga representera och mäta respektive risk. Exempelvis så har vi använt oss av nyckeltalet “bid-ask-spread” för att mäta likviditetsrisk hos en obligation. För att undersöka sambandet mellan våra valda risker och kreditspread så genomförde vi ett hypotestest. Vi skapade en nollhypotes och en alternativhypotes som vi sedan testade med hjälp av en multipel regression. Nollhypotes (H0): Studiens utvalda variabler har inte en effekt på den kreditspread hos svenska företagsobligationer Alternativhypotes (Ha): Studiens utvalda variabler har en effekt på den kreditspread hos svenska företagsobligationer Slutsatsen var att vi kunde statistiskt påvisa ett positivt samband mellan riskernas storlek och storleken på obligationens kreditspread. Detta gjordes både för riskerna var för sig och för modellen när den blev testad i sin helhet. Den bakomliggande teorin bakom variablerna kunde därför antas vara korrekt även vid applicering på svenska marknaden för det senaste decenniet. Vi har som ambition att denna studie skall kunna agera som ett verktyg för fundamental analys för framtida investerare samt vidare studier inom området obligationer på svenska marknaden

In dieser Dissertation befassen wir uns mit ökonometrischen Modellen und empirischen Eigenschaften von Intra-Tages (Hochfrequenz-) Aktienmarktdaten. Der Fokus liegt hierbei auf der Analyse des Einflusses, den die Veröffentlichung von Wirtschaftsnachrichten auf die Aktienmarktaktivität hat, der Vorhersage der Geld-Brief-Spanne sowie der Modellierung von Volatilitätsmaßen auf Intra-Tages-Zeitintervallen. Zunächst quantifizieren wir die Marktreaktionen auf Marktneuigkeiten innerhalb eines Handelstages. Zu diesem Zweck benutzen wir linguistisch vorab bearbeitete Unternehmensnachrichtendaten mit Indikatoren über die Relevanz, Neuheit und Richtung dieser Nachrichten. Mit einem VAR Modell für 20-Sekunden Marktdaten der London Stock Exchange weisen wir durch Nachrichten hervorgerufene Marktreaktionen in Aktienkursrenditen, Volatilität, Handelsvolumina und Geld-Brief-Spannen nach. In einer zweiten Analyse führen wir ein long memory autoregressive conditional Poisson (LMACP)-Modell zur Modellierung hoch-persistenter diskreter positivwertiger Zeitreihen ein. Das Modell verwenden wir zur Prognose von Geld-Brief-Spannen, einem zentralen Parameter im Aktienhandel. Wir diskutieren theoretische Eigenschaften des LMACP-Modells und evaluieren rollierende Prognosen von Geld-Brief-Spannen an den NYSE und NASDAQ Börsenplätzen. Wir zeigen, dass Poisson-Zeitreihenmodelle in diesem Kontext signifikant bessere Vorhersagen liefern als ARMA-, ARFIMA-, ACD- und FIACD-Modelle. Zuletzt widmen wir uns der optimalen Messung von Volatilität auf kleinen 20 Sekunden bis 5 Minuten Zeitintervallen. Neben der Verwendung von realized volatility-Ansätzen konstruieren wir Volatilitätsmaße durch Integration von spot volatility-Schätzern, sodass auch Beobachtungen außerhalb der kleinen Zeitintervalle in die Volatilitätsschätzungen eingehen. Ein Vergleich der Ansätze in einer Simulationsstudie zeigt, dass Volatilitätsmaße basierend auf spot volatility-Schätzern den RMSE minimieren. / In this thesis we present econometric models and empirical features of intra-daily (high frequency) stock market data. We focus on the measurement of news impacts on stock market activity, forecasts of bid-ask spreads and the modeling of volatility measures on intraday intervals. First, we quantify market reactions to an intraday stock-specific news flow. Using pre-processed data from an automated news analytics tool we analyze relevance, novelty and direction signals and indicators for company-specific news. Employing a high-frequency VAR model based on 20 second data of a cross-section of stocks traded at the London Stock Exchange we find distinct responses in returns, volatility, trading volumes and bid-ask spreads due to news arrivals. In a second analysis we introduce a long memory autoregressive conditional Poisson (LMACP) model to model highly persistent time series of counts. The model is applied to forecast quoted bid-ask spreads, a key parameter in stock trading operations. We discuss theoretical properties of LMACP models and evaluate rolling window forecasts of quoted bid-ask spreads for stocks traded at NYSE and NASDAQ. We show that Poisson time series models significantly outperform forecasts from ARMA, ARFIMA, ACD and FIACD models in this context. Finally, we address the problem of measuring volatility on small 20 second to 5 minute intra-daily intervals in an optimal way. In addition to the standard realized volatility approaches we construct volatility measures by integrating spot volatility estimates that include information on observations outside of the intra-daily intervals of interest. Comparing the alternative volatility measures in a simulation study we find that spot volatility-based measures minimize the RMSE in the case of small intervals.

Cette thèse est consacrée à l'étude des applications de la théorie des erreurs par formes de Dirichlet. Notre travail se divise en trois parties. La première analyse les modèles gouvernés par une équation différentielle stochastique. Après un court chapitre technique, un modèle innovant pour les carnets d'ordres est proposé. Nous considérons que le spread bid-ask n'est pas un défaut, mais plutôt une propriété intrinsèque du marché. L'incertitude est porté par le mouvement Brownien qui conduit l'actif. Nous montrons que l'évolution des spread peut être évalué grâce à des formules fermés et nous étudions l'impact de l'incertitude du sous-jacent sur les produits dérivés. En suite, nous introduisons le modèle PBS pour le pricing des options européennes. L'idée novatrice est de distinguer la volatilité du marché par rapport au paramètre utilisé par les traders pour se couvrir. Nous assumons la première constante, alors que le deuxième devient une estimation subjective et erronée de la première. Nous prouvons que ce modèle prévoit un spread bid-ask et un smile de volatilité. Les propriétés plus intéressantes de ce modèle sont l'existence de formules fermés pour le pricing, l'impact de la dérive du sous-jacent et une efficace stratégie de calibration. La seconde partie s'intéresse aux modèles décrit par une équation aux dérivées partielles. Les cas linéaire et non-linéaire sont analysés séparément. Dans le premier nous montrons des relations intéressantes entre la théorie des erreurs et celui des ondelettes. Dans le cas non-linéaire nous étudions la sensibilité des solutions à l'aide de la théorie des erreurs. Sauf dans le cas d'une solution exacte, il y a deux approches possibles: On peut d'abord discrétiser l'EDP et étudier la sensibilité du problème discrétisé, soit démontrer que les sensibilités théoriques vérifient des EDP. Les deux cas sont étudiés, et nous prouvons que les sharp et le biais sont solutions d'EDP linéaires dépendantes de la solution de l'EDP originaire et nous proposons des algorithmes pour évaluer numériquement les sensibilités. Enfin, la troisième partie est dédiée aux équations stochastiques aux dérivées partielles. Notre analyse se divise en deux chapitres. D'abord nous étudions la transmission de l'incertitude, présente dans la condition initiale, à la solution de l'EDPS. En suite, nous analysons l'impact d'une perturbation dans les termes fonctionnelles de l'EDPS et dans le coefficient de la fonction de Green associée. Dans le deux cas, nous prouvons que le sharp et le biais sont solutions de deux EDPS linéaires dépendantes de la solution de l'EDPS originaire.

Cette thèse est composée de quatre chapitres. Le premier chapitre traite de l'évaluation de produits financiers dans un modèle comportant un saut pour l'actif risque. Ce saut représente la faillite de l'entreprise correspondante. On étudie alors l'évaluation des prix d'options par indifférence d'utilité dans un cadre d'utilité exponentielle. Par des techniques de programmation dynamique on montre que le prix d'un Bond est solution d'une équation différentielle et le prix d'options dépendantes de l'actif est solution d'une équation aux dérives partielles d'Hamilton-Jacobi-Bellman. Le saut dans la dynamique de l'actif risque induit des différences avec le modèle de Merton que nous tentons de quantifier. Le second chapitre traite d'un marché comportant des sauts : les paris sur le football. Nous rappelons les différentes familles de modèles pour un match de football et introduisons un modèle complet permettant d'évaluer les prix des différents produits apparus sur ce marché ces dix dernières années. La complexité de ce modèle nous amène à étudier un modèle simplifié dont nous étudions les implications et calculons les prix obtenus que l'on compare à la réalité. On remarque que la calibration implicite obtenue génère de très bons résultats en produisant des prix très proches de la réalité. Le troisième chapitre développe le problème de fixation des prix par un teneur de marche monopolistique dans le marché des paris binaires. Ce travail est un prolongement direct au problème introduit par Levitt [Lev04]. Nous généralisons en effet son travail aux cas des paris européens et proposons une méthode pour estimer la méthode de cotation utilisée par le book-maker. Nous montrons que deux hypothèses inextricables peuvent expliquer cette fixation des prix. D'une part, l'incertitude du public sur la vraie valeur ainsi que le caractère extrêmement risque-averse du bookmaker. Le quatrième chapitre prolonge quant à lui cette approche au cas de produits financiers non binaires. Nous examinons différents modèles d'offre et de demande et en déduisons, par des techniques de programmation dynamique, des équations aux dérivées partielles dictant la formation des prix d'achat et de vente. Nous montrons finalement que l'écart entre prix d'achat et prix de vente ne dépend pas de la position du teneur de marche dans l'actif considère. Cependant le prix moyen dépend lui fortement de la quantité détenue par le teneur de marche. Une approche simplifiée est finalement proposée dans le cas multidimensionnel / This thesis is composed of four chapters. The first one deals with the pricing of financial products in a single jump model for the risky asset. This jump represents the bankrupcy of the quoted firm. We study the pricing of derivatives in the context of indifference of utility with an exponential utility. By means of dynamic programming we show that the bond price is solution of an ordinary differential equation and that stock price dependent options are solutions of an equation with partial derivatives of Hamilton-Jacobi-Bellman type generalizing the Black-Scholes one. We then try to quantify differences in the price obtained here and the one from Merton model without jump. The second chapter deals with a specific jump market : the soccer betting market. We recall the different model families for a soccer match and introduce some full model which allows to price the products recently born in this market in last ten years. Nevertheless the model complexity leads us to study a simplified model introduced by Dixon and Robinson from which we are able to derive closed formulas and simulate prices that we compare to market prices. We remark that implicit calibration gives pretty goof fit of market data. Third chapter developps the approach of Levitt [Lev04] on price formation in binary betting market held by a monopolistic market-maker operating in a one time step trading. We generalize Levitt results with european format of betting. We show that prices are distorded on the pressure of demand and offer, that phenomena introducing a market probability that allows to price products under this new measure. We identify some best model for demand and offer and market maker strategy and show that probability change is obvious in case of imperfect information about the value of the product. Fourth chapter generalizes this approach to the case of general payoffs and continuous time. The task is more complex and we just derive partial derivative equations from dynamic programming that enable us to give the bid-ask prices of the product traded by the market-maker. One result is that, in most models, bid-ask spread does not depend on the inventory held by the dealer whereas mid-quote price strongly reflects the unbalance of the dealer

[pt] Esta tese investiga a estimação de curvas de juros sob o ponto de vista de métodos não-paramétricos. O texto está dividido em dois blocos. O primeiro investiga a questão do critério utilizado para selecionar o método de melhor desempenho na tarefa de interpolar a curva de juros brasileira em uma dada amostra. Foi proposto um critério de seleção de método baseado em estratégias de re-amostragem do tipo leave-k-out cross validation, onde K k £ £ 1 e K é função do número de contratos observados a cada curva da amostra. Especificidades do problema reduzem o esforço computacional requerido, tornando o critério factível. A amostra tem freqüência diária: janeiro de 1997 a fevereiro de 2001. O critério proposto apontou o spline cúbico natural -utilizado com método de ajuste perfeito aos dados - como o método de melhor desempenho. Considerando a precisão de negociação, este spline mostrou-se não viesado. A análise quantitativa de seu desempenho identificou, contudo, heterocedasticidades nos erros simulados. A partir da especificação da variância condicional destes erros e de algumas hipóteses, foi proposto um esquema de intervalo de segurança para a estimação de taxas de juros pelo spline cúbico natural, empregado como método de ajuste perfeito aos dados. O backtest sugere que o esquema proposto é consistente, acomodando bem as hipóteses e aproximações envolvidas. O segundo bloco investiga a estimação da curva de juros norte-americana construída a partir dos contratos de swaps de taxas de juros dólar-Libor pela Máquina de Vetores Suporte (MVS), parte do corpo da Teoria do Aprendizado Estatístico. A pesquisa em MVS tem obtido importantes avanços teóricos, embora ainda sejam escassas as implementações em problemas reais de regressão. A MVS possui características atrativas para a modelagem de curva de juros: é capaz de introduzir já na estimação informações a priori sobre o formato da curva e sobre aspectos da formação das taxas e liquidez de cada um dos contratos a partir dos quais ela é construída. Estas últimas são quantificadas pelo bid-ask spread (BAS) de cada contrato. A formulação básica da MVS é alterada para assimilar diferentes valores do BAS sem que as propriedades dela sejam perdidas. É dada especial atenção ao levantamento de informação a priori para seleção dos parâmetros da MVS a partir do formato típico da curva. A amostra tem freqüência diária: março de 1997 a abril de 2001. Os desempenhos fora da amostra de diversas especificações da MVS foram confrontados com aqueles de outros métodos de estimação. A MVS foi o método que melhor controlou o trade- off entre viés e variância dos erros. / [en] This thesis investigates interest rates curve estimation under non-parametric approach. The text is divided into two parts. The first one focus on which criterion to use to select the best performance method in the task of interpolating Brazilian interest rate curve. A selection criterion is proposed to measure out-of-sample performance by combining resample strategies leave-k-out cross validation applied upon the whole sample curves, where K k £ £ 1 and K is function of observed contract number in each curve. Some particularities reduce substantially the required computational effort, making the proposed criterion feasible. The data sample range is daily, from January 1997 to February 2001. The proposed criterion selected natural cubic spline, used as data perfect-fitting estimation method. Considering the trade rate precision, the spline is non-biased. However, quantitative analysis of performance determinant factors showed the existence of out-of-sample error heteroskedasticities. From a conditional variance specification of these errors, a security interval scheme is proposed for interest rate generated by perfect-fitting natural cubic spline. A backtest showed that the proposed security interval is consistent, accommodating the evolved assumptions and approximations. The second part estimate US free-for-floating interest rate swap contract curve by using Support Vector Machine (SVM), a method derived from Statistical Learning Theory. The SVM research has got important theoretical results, however the number of implementation on real regression problems is low. SVM has some attractive characteristics for interest rates curves modeling: it has the ability to introduce already in its estimation process a priori information about curve shape and about liquidity and price formation aspects of the contracts that generate the curve. The last information set is quantified by the bid-ask spread. The basic SVM formulation is changed in order to be able to incorporate the different values for bid-ask spreads, without losing its properties. Great attention is given to the question of how to extract a priori information from swap curve typical shape to be used in MVS parameter selection. The data sample range is daily, from March 1997 to April 2001. The out-of-sample performances of different SVM specifications are faced with others method performances. SVM got the better control of trade- off between bias and variance of out-of-sample errors.

Cette thèse est consacrée à l'étude des applications de la théorie des erreurs par formes de Dirichlet. Notre travail se divise en trois parties. La première analyse les modèles gouvernés par une équation différentielle stochastique. Après un court chapitre technique, un modèle innovant pour les carnets d’ordres est proposé. Nous considérons que le spread bid-ask n'est pas un défaut, mais plutôt une propriété intrinsèque du marché. L'incertitude est portée par le mouvement Brownien qui conduit l'actif. Nous montrons que l'évolution des spread peut être évaluée grâce à des formules fermées et nous étudions l'impact de l'incertitude du sous-jacent sur les produits dérivés. En suite, nous introduisons le modèle PBS pour le pricing des options européennes. L'idée novatrice est de distinguer la volatilité du marché par rapport au paramètre utilisé par les traders pour se couvrir. Nous assumons la première constante, alors que le deuxième devient une estimation subjective et erronée de la première. Nous prouvons que ce modèle prévoit un spread bid-ask et un smile de volatilité. Les propriétés plus intéressantes de ce modèle sont l’existence de formules fermés pour le pricing, l'impact de la dérive du sous-jacent et une efficace stratégie de calibration. La seconde partie s'intéresse aux modèles décrit par une équation aux dérivées partielles. Les cas linéaire et non-linéaire sont analysés séparément. Dans le premier nous montrons des relations intéressantes entre la théorie des erreurs et celui des ondelettes. Dans le cas non-linéaire nous étudions la sensibilité des solutions à l’aide de la théorie des erreurs. Sauf dans le cas d’une solution exacte, il y a deux approches possibles : on peut d’abord discrétiser l’EDP et étudier la sensibilité du problème discrétisé, soit démontrer que les sensibilités théoriques vérifient des EDP. Les deux cas sont étudiés, et nous prouvons que les sharp et le biais sont solutions d’EDP linéaires dépendantes de la solution de l’EDP originaire et nous proposons des algorithmes pour évaluer numériquement les sensibilités. Enfin, la troisième partie est dédiée aux équations stochastiques aux dérivées partielles. Notre analyse se divise en deux chapitres. D’abord nous étudions la transmission de l’incertitude, présente dans la condition initiale, à la solution de l’EDPS. En suite, nous analysons l'impact d'une perturbation dans les termes fonctionnelles de l’EDPS et dans le coefficient de la fonction de Green associée. Dans le deux cas, nous prouvons que le sharp et le biais sont solutions de deux EDPS linéaires dépendantes de la solution de l’EDPS originaire / This thesis is devoted to the study of the applications of the error theory using Dirichlet forms. Our work is split into three parts. The first one deals with the models described by stochastic differential equations. After a short technical chapter, an innovative model for order books is proposed. We assume that the bid-ask spread is not an imperfection, but an intrinsic property of exchange markets instead. The uncertainty is carried by the Brownian motion guiding the asset. We find that spread evolutions can be evaluated using closed formulae and we estimate the impact of the underlying uncertainty on the related contingent claims. Afterwards, we deal with the PBS model, a new model to price European options. The seminal idea is to distinguish the market volatility with respect to the parameter used by traders for hedging. We assume the former constant, while the latter volatility being an erroneous subjective estimation of the former. We prove that this model anticipates a bid-ask spread and a smiled implied volatility curve. Major properties of this model are the existence of closed formulae for prices, the impact of the underlying drift and an efficient calibration strategy. The second part deals with the models described by partial differential equations. Linear and non-linear PDEs are examined separately. In the first case, we show some interesting relations between the error and wavelets theories. When non-linear PDEs are concerned, we study the sensitivity of the solution using error theory. Except when exact solution exists, two possible approaches are detailed: first, we analyze the sensitivity obtained by taking “derivatives” of the discrete governing equations. Then, we study the PDEs solved by the sensitivity of the theoretical solutions. In both cases, we show that sharp and bias solve linear PDE depending on the solution of the former PDE itself and we suggest algorithms to evaluate numerically the sensitivities. Finally, the third part is devoted to stochastic partial differential equations. Our analysis is split into two chapters. First, we study the transmission of an uncertainty, present on starting conditions, on the solution of SPDE. Then, we analyze the impact of a perturbation of the functional terms of SPDE and the coefficient of the related Green function. In both cases, we show that the sharp and bias verify linear SPDE depending on the solution of the former SPDE itself / Questa tesi é dedicata allo studio delle applicazioni della teoria degli errori tramite forme di Dirichlet, il nostro lavoro si divide in tre parti. Nella prima vengono studiati i modelli descritti da un’equazione differenziale stocastica: dopo un breve capitolo con risultati tecnici viene descritto un modello innovativo per i libri d’ordini. La presenza dei differenziali denarolettera viene considerata non come un’imperfezione, bensi una proprietà intrinseca dei mercati. L’incertezza viene descritta come un rumore sul moto Browniano sottostante all’azione; dimostriamo che l’evoluzione di questi differenziali puó essere valutata attraverso formule chiuse e stimiamo l’impatto dell’incertezza del sottostante sui prodotti derivati. In seguito proponiamo un nuovo modello, chiamato PBS, per il prezzaggio delle opzioni di tipo europeo: l’idea innovativa consiste nel distinguere la volatilità di mercato dal parametro usato dai trader per la copertura. Noi supponiamo la prima constante, mentre il secondo diventa una stima soggettiva ed erronea della prima. Dimostriamo che questo modello prevede dei differenziali lettera-denaro e uno smile di volatilità implicita. Le maggiori proprietà di questo modello sono l’esistenza di formule chiuse per il princing, l’impatto del drift del sottostante e un’efficace strategia per la calibrazione. La seconda parte è dedicata allo studio dei modelli descritti da delle equazioni alle derivate perziali. I casi lineare e non-lineare sono trattati separatamente. Nel primo caso mostriamo interessanti relazioni tra la teoria degli errori e quella delle wavelets. Nel caso delle EDP non-lineari studiamo la sensibilità della soluzione usando la teoria degli errori. Due possibili approcci esistono, salvo quando la soluzione è esplicita. Possiamo prima discretizzare il problema e studiare la sensibilità delle equazioni discretizzate, oppure possiamo dimostrare che le sensibilità teoriche verificano, a loro volta, delle EDP dipendenti dalla soluzione della EDP iniziale. Entrambi gli approcci sono descritti e vengono proposti degli algoritmi per valutare le sensibilità numericamente. Infine, la terza parte è dedicata ai modelli descritti da un’equazione stocastica alle derivate parziali. La nostra analisi é divisa in due capitoli. Nel primo viene studiato l’impatto di un’incertezza, presente nella condizione iniziale, sulla soluzione dell’EDPS, nella seconda si analizzano gli impatti di una perturbazione dei termini funzionali dell’EDPS del coefficiente della funzione di Green associata. In entrambi i casi dimostriamo che lo sharp e la discrepanza sono soluzioni di due EDPS lineari dipendenti dalla soluzione dell’EDPS iniziale

Submitted by Gustavo Silva Araujo (00araujogs@gmail.com) on 2013-12-11T15:36:37Z No. of bitstreams: 1 tese Gustavo Araujo.pdf: 1480340 bytes, checksum: 7f293b1022a44c6056c471633c80981d (MD5) / Approved for entry into archive by ÁUREA CORRÊA DA FONSECA CORRÊA DA FONSECA (aurea.fonseca@fgv.br) on 2013-12-16T12:31:03Z (GMT) No. of bitstreams: 1 tese Gustavo Araujo.pdf: 1480340 bytes, checksum: 7f293b1022a44c6056c471633c80981d (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2013-12-19T16:32:32Z (GMT) No. of bitstreams: 1 tese Gustavo Araujo.pdf: 1480340 bytes, checksum: 7f293b1022a44c6056c471633c80981d (MD5) / Made available in DSpace on 2013-12-19T16:32:47Z (GMT). No. of bitstreams: 1 tese Gustavo Araujo.pdf: 1480340 bytes, checksum: 7f293b1022a44c6056c471633c80981d (MD5) Previous issue date: 2011-03-31 / This thesis is dedicated to studies in finance. The topics are distributed in two subareas, microstructure and asset pricing. There is also an insertion of the study in corporate finance, since we deal with the corporate governance of firms. In the first chapter I estimate the adverse selection cost component embedded in the spreads of Brazilian stocks. I also study the patterns of spreads and adverse selection costs as a function of the size and time of the trade. In chapter two, I implement an extensive research through a series of regressions in order to determine characteristics of the companies that are correlated with the adverse selection component and the spread. In particular, we analyze the relationship between the adverse selection and corporate governance levels. In the third chapter I detect which corporate governance mechanisms cause an opposite relationship between the returns of Brazilian stocks and corporate governance levels, as shown by Carvalhal and Nobili (2011). In this analysis, I emphasize the ownership concentration of Brazilian companies, which is extremely high when compared with more developed countries. / Esta tese se dedica a estudos na área de finanças. Os estudos se subdividem nas subáreas de microestrutura e apreçamento de ativos, mas há uma inserção do trabalho em finanças corporativas, uma vez que trato da governança corporativa das empresas. No primeiro capítulo estimo o coeficiente de assimetria de informação embutido no spread de compra e venda de ações brasileiras. Além disso, verifico se há padrões para esse coeficiente e para o próprio spread em relação ao tamanho da transação e à hora de negociação. No capítulo dois, eu investigo quais características ligadas às empresas têm relação com as variáveis estimadas no capítulo 1, o coeficiente de assimetria de informação embutido no spread de compra e venda de ações brasileiras e o próprio spread. A governança corporativa das empresas é uma das características examinadas. No terceiro capítulo, eu observo quais mecanismos de governança corporativa fazem com que haja uma relação antagônica entre os retornos das ações brasileiras e o índice de governança corporativa, conforme mostrado por Carvalhal e Nobili (2011). Nesta investigação, dou ênfase à concentração acionária das empresas brasileiras que, em comparação com países mais desenvolvidos, é extremamente alta.