Cette thèse est composée de quatre chapitres qui contribuent à une meilleure connaissance des comportements d’échange des investisseurs individuels et de leur performance. Dans le premier chapitre, nous réalisons la première étude consacrée aux performances de portefeuille des investisseurs individuels français. A partir d’une base de données de plus de 8 millions de transactions réalisées par 56 723 investisseurs, nous montrons que les investisseurs français affichent des rentabilités ajustées au risque négatives sur leurs portefeuilles et font des choix d’investissement pénalisants. De plus, nous mettons en évidence que les investisseurs les plus sophistiqués ne sont pas plus performants que leurs pairs.Dans le second chapitre, nous montrons que l’aspiration individuelle constitue un déterminant clé pour expliquer l’hétérogénéité des performances de portefeuille. Nous définissons les aspirations selon la Théorie Comportementale du Portefeuille. Les investisseurs qui ont de fortes aspirations détiennent des portefeuilles plus risqués, échangent plus fréquemment et diversifient moins que les investisseurs ayant de faibles aspirations. En contrôlant de la fréquence des échanges, de la diversification et des facteurs de risque habituels, nous montrons que les investisseurs ayant de fortes aspirations sous-performent les investisseurs ayant de faibles aspirations.Dans le troisième chapitre nous analysons les performances des investisseurs individuels via des mesures adaptées à leurs préférences. Lorsque leurs performances sont évaluées avec ces mesures plutôt qu’avec le ratio de Sharpe, une plus grande part des investisseurs bat l’indice de marché. Cette observation jette un regard nouveau sur les capacités de gestion des investisseurs individuels. Cependant, nous montrons que l’amélioration des performances est liée à la skewness des portefeuilles plutôt qu’à une sélection de titres pertinente.Dans le dernier chapitre, nous explorons les comportements de rachat des investisseurs individuels. Nous montrons que les investisseurs préfèrent racheter (1) les titres pour lesquels ils ont réalisé une plus-value lors de la vente (2) les titres dont le prix a diminué depuis la vente. Nos tests excluent les explications rationnelles et confirment que l’évitement du regret est à l’origine de tels comportements. Sur la base d’une analyse de survie, nous montrons que les investisseurs sophistiqués sont moins sujets à ces préférences. / This dissertation is composed of four chapters that make a substantial contribution to existing knowledge of the trading behavior and performance of individual investors. The first chapter provides the most extensive study of the trading performance of French individual investors to date. Based on a large database of nearly 8 million trades realized by56,723 investors, we show that French investors exhibit negative risk-adjusted returns on their portfolios, and make penalizing choices in their trades. We find that more sophisticated investors do not perform better than their peers, and we conclude that investors would gain more from applying a passive strategy. In the second chapter, we evidence that individual aspiration is a key determinant of existing heterogeneity in portfolio performance. We define aspirations according to the Behavioral Portfolio Theory. Investors who have high aspirations hold riskier portfolios, trade more frequently and diversify less than investors who have low aspirations. After controlling for turnover, diversification and usual risk factors, we find that investors with high aspirations underperform investors with low aspirations.In the third chapter we highlight alternative measures of performance that efficiently convey the real preferences of investors. When they are evaluated with these alternative measures rather than with the Sharpe ratio, a higher proportion of investors beat the market index. This observation challenges the global evidence that individual investors are poor portfolio managers. However, our evidence suggests that the improvement of an investor’s performance is linked to portfolio skewness rather than relevant stock selection.In the last chapter, we explore the repurchase behavior of individual investors. We find that French investors prefer to repurchase (1) stocks that have been sold for a gain and (2) stocks that have lost value since their sale. Our tests exclude rational explanations for these preferences and confirm our hypothesis that such patterns can be traced to the avoidance of regret in trades. We use survival analysis to demonstrate that sophisticated investors suffer less from there purchase preferences.

Despite being the twelfth largest financial market in the world, approximately 90 per cent of the entire trading volume in the Taiwan stock market is accounted for by only a small, but widely dispersed, group of local investors actively participating in the local market during the 1995-1999 period (Barber, Lee, Liu and Odean, 2007); it is, however, also the case that these investors suffer from low levels of investor protection (La Porta, Lopez-de-Silances, Shleifer and Vishny, 1998). The discovery of a series of corporate scandals in Taiwan, between 16 June and 15 September 2004 (the event period), offers a unique opportunity to investigate the perceptions of investors on the value of corporate governance. The main line of reasoning in this study is that at times when news of scandals flows into the market, the perceptions of certain types of investors, particularly uniformed outsiders, will lead to a systematic change in their trading habits; thus, they may avoid trading in certain firms altogether, or their incentives to place aggressive orders may be considerably weakened, particularly where there is a likelihood of expropriation by controlling insiders. This dissertation undertakes a comprehensive analysis of trade and quote (TAQ) data for all investors on a sample of 94 firms listed on the Taiwan Stock Exchange (TSE), and provides evidence of extreme variations in the investment behavior of different types of investors. It is clear that during the event period, a substantial proportion of investors did cease trading altogether, with such cessation of trading even affecting their original non-scandal portfolios. This response was particularly discernible amongst small and medium-sized individual investors, who may often incur losses in firms with high cash-flow rights leverage. It seems that even the better-performed small-sized individual investors, who had previously enjoyed larger positive excess returns, tended to discard their previous trading strategy involving firms with no clear deviation between control rights and cash-flow rights. An examination of this deviation in trading behavior shows that most investors, with the exceptions of foreign institutions and large-sized individual investors, began to enter the market more passively during the event period, particularly in firms in which the ultimate controllers had separate control and cash-flow ownership. However, throughout the event period, the trading strategies of foreign institutions and large-sized individual investors involved more aggressive submission of orders for stocks in firms with strong cash-flow rights leverage. Finally, a direct test of the informativeness of aggressive orders placed by each category of investors, under different ownership structure portfolios, regardless of any order strategy, reveals that small-sized individual investors invariably performed badly during both the pre-event and event periods examined in this dissertation. Each line of our analysis shows that only foreign institutions and large-sized individual investors maintained acceptable returns; in comparative terms, these two groups of investors performed relatively well in portfolios with higher cash-flow rights leverage.

本文以事件研究法探討在公司治理程度不同的公司發布盈餘預測時， 不同類型的投資人在事件窗期中所反映的投資行為。首先以獨立董事與監 察人佔董監席次比例、董監事持股比例、大股東持股比例、經理人持股比 例、機構投資人持股比例、盈餘股份比以及董事長是否兼任總經理作為判 別公司治理程度的指標。再以公司發布盈餘預測的時點做區別，分別以當 年度首度預測是否由公司本身發布，與之後調高以及調低預測做為事件日。 實證結果顯示，當公司治理佳者發布盈餘預測時，外資會出現較多的買超 行為且獲得較高的異常報酬，散戶則持相反動作；而公司治理差者發布盈 餘預測時，散戶的買賣超變化量一般而言會較法人大，出現短期進出的情 形較多，且外資在其調高盈餘預測時，也不會馬上進行買進。整體而言， 外資在公司發布盈餘預測時所做出的交易行為，大致上與公司的治理程度 有正向關係，散戶則大多報持短線進出的態度。 / This study examines how different types of investors behave when entities with different corporate governances announce earnings forecasts. Using seven corporate governance indicators to categorize all of the samples and analyzing how the abnormal return, the results suggests foreign institutional investors are gaining more abnormal return by buying more stocks after earnings announcements of the entities with better corporate governance, and would not interact right after earnings announcements of the entities with worse corporate governance, when the individual investors are going the opposite way to the foreign institutional investors.

Die globale Finanzkrise unterstrich die Bedeutung von makrofinanziellen Verknüpfungen für Vermögenspreisdynamiken und Konjunkturschwankungen. Bei angebotsseitigen Finanzfriktionen werden hierbei Finanzintermediäre, insbesondere ihre Bilanz und ihre Risikotragfähigkeit, als zentral erachtet. Diese Dissertation wendet verschiedene Klassen von SVAR Modellen und neueste Identifizierungsmethoden an um empirische Belege für die Rolle von Finanzintermediären für Finanzmärkte und die Realwirtschaft zu liefern. Das erste Kapitel untersucht das regimeabhängige Handelsverhalten von Finanzintermediären auf dem Öl-Futures-Markt und zeigt, dass Finanzintermediäre während Krisenzeiten preisunelastischer werden und mehr ihren eigenen Interessen folgend handeln. Die Ergebnisse deuten auf eine nichtlineare Futures-Preissetzung von Intermediären hin, was die Volatilität im Markt während Krisenzeiten signifikant erhöht. Das zweite Kapitel legt dar, dass die meisten Händlergruppen in Rohstoff-Futures-Märkten eine antizyklische Investitionsstrategie verfolgen. Das einfache SVAR Modell eignet sich für die Analyse der Handelsstrategien verschiedener Händlergruppen sowie deren Auswirkungen für die Preisvolatilität in jedweden Vermögensmärkten. Kapitel 3 identifiziert in einem einzelnen Modell sektorspezifische Kreditangebotsschocks gegenüber Firmen und Haushalten und präsentiert empirische Belege über deren Effekte für die US-Wirtschaft. Die Ergebnisse zeigen, dass beide Kreditangebotsschocks wesentlich zum Konjunkturverlauf während des Beobachtungszeitraums beigetragen haben, wobei Kreditangebotsschocks gegenüber Haushalten klassischen Nachfrageschocks ähneln. Das letzte Kapitel analysiert die globalen Auswirkungen des Schuldenabbaus europäischer Banken und findet, dass europäische Bankbilanzschocks Bruttokapitalzuflüsse und das Kreditwachstum in fortgeschrittenen Ökonomien mit entwickelten Finanzmärkten beeinflussen, aber nur geringfügige Effekte auf das Wirtschaftswachstum haben. / The global financial crisis has demonstrated the importance of macrofinancial linkages for asset price dynamics and business cycles. Regarding supply-side financial frictions, financial intermediaries, in particular their balance sheet and risk-bearing capacity, are considered to be pivotal. This thesis applies different classes of SVAR models and state-of-the-art identification techniques to provide empirical findings on the role of financial intermediaries in financial markets and the real economy. The first chapter studies the state-dependent trading behavior of financial intermediaries in the oil futures market and shows that intermediaries become less price-elastic and trade more according to their own demand. The findings suggest that the futures pricing of intermediaries is nonlinear which significantly raises the volatility in the market during crisis times. The second chapter demonstrates that most trader groups in commodity futures markets employ contrarian strategies. The simple SVAR model can be applied for analyzing the trading strategies of different trader groups as well as their effects for price volatility in any asset market. Chapter 3 identifies sector-specific business and household loan supply shocks in one single model and provides empirical evidence on their effects for the U.S. macroeconomy. The results show that both loan supply shocks have contributed significantly to business cycle dynamics over the sample period, with household loan supply shocks resembling classical demand shocks. The last chapter analyzes the global effects of European bank deleveraging and finds that European bank balance sheet shocks significantly affect gross capital inflows and credit growth in in advanced economies with developed financial markets, but have only minor effects on output growth.

This paper investigates the investor trading behavior and the relationship between investor sentiment and stock returns. First we explore whether individual investors behave as the Disposition Effect stated — hold their losers too long while realize their winners too soon. Second, we apply four sentiment indicators — number of recommended stocks, margin purchase value, net fund redemption and odd-lot trade value — to examine relationship between investor sentiment and stock returns. We would like to see if past returns have anything to do with current sentiment, and if sentiment provides predictive power to future returns. First of all, from our analysis to over eight hundreds cash accounts trading records in two research periods, January to March and September to December in 2000, we found the Disposition Effect holds in average but not statistically. Second, the number of recommended stocks, weighted number of recommended stocks, margin purchase value, change in margin purchase value, net fund redemption and odd-lot trade value as proxies of investor sentiment are good at measuring the effect of past 4-week and 26-week returns on sentiment. Third, the margin purchase value, net fund redemption and odd-lot trade value provide predictive power to future 26-week returns in our study, which also implies there is likely underlying mean-reversion within half year during the research period. 　Finally, exploiting the change in margin purchase value as proxy of investor sentiment, we found the past 4-week returns volatility is inversely related with the indicator. That is, investors are scared on facing with high returns volatility.