Portefeuille (finance) | EPFL Graph Search

Un portefeuille (en finance) désigne une collection d'actifs financiers détenus par un établissement ou un individu. Cela peut aussi désigner des valeurs mobilières détenues à titre d'investissements, de dépôt, de provision ou de garantie. Types de portefeuilles d'investissement Une caractéristique importante d'un portefeuille est son degré de diversification qui permet d'atteindre un juste milieu entre le risque, la volatilité et la rentabilité du portefeuille, tout en tenant compte de la durée prévue du placement (horizon de temps). La répartition du portefeuille, tant en types d'actifs qu'en actifs individuels, est un aspect crucial du placement boursier. Perdre de l'argent sur des valeurs boursières est un risque permanent, comme le montre l'éclatement de la bulle internet en 2000/2002. Cette répartition va dépendre du degré d'aversion au risque de l'investisseur.

On appelle portefeuille équilibré, un portefeuille qui prend peu de risques, mais qui peut assurer

The total benefit of alternative assets to pension fund portfolios

Anna Slavutskaya

Pension funds only quite recently have explored alternative assets, prodded by financial crises that devastated equity returns and led to low bond returns. We assess the addition of alternative assets to pension fund portfolios in terms of the total benefit derived from diversification, addition of positive skewness, and the elimination of left tails in returns. During 1994-2012, adding portfolios of hedge funds produced significantly higher total benefits than adding real estate, commodities, foreign equities, mutual funds, funds of funds, as well as some counter cyclical and non-cyclical assets. Conditioning on past total benefits improves the out-of sample performance even further. (C) 2016 Elsevier B.V. All rights reserved.

Elsevier Science Bv2016

Essays in Information-Based Asset Pricing

Michael Hasler

I started my Ph.D. studies in the Fall 2008, a period ex-post perceived as being at the core of the Financial Crisis. At that time my ideas were vague and I struggled to find a good research topic. As surprising as it might appear, in one single week the discussions I had with my relatives provided me with enough ideas needed to write my thesis. Indeed, during that single week my relatives contacted me and complained about the fact that they had lost money invested in the financial market. They wanted me to advise them. I simply told them to invest their money in relatively safe bonds. My relatives did not realize how fruitful their behavior was for me. Indeed, after having advised them I wondered whether their willingness to gather information in bad times was optimal or pure irrationality. This issue is addressed in the first chapter of my thesis. The last two chapters investigate the impact of the willingness to gather more information in bad times than in good times on the dynamics of asset prices. My thesis answers two very important questions: When should investors acquire information given that information-processing is costly and what is the impact of the optimal information acquisition strategy on asset price dynamics? Consequently, the main topic of my thesis is the transmission of acquired information in financial markets. In the first chapter I consider a dynamic portfolio choice and costly information acquisition problem. Consistent with my relatives behavior, I show that it is optimal to gather more information in bad times than in good times. As the state of the economy worsens, investors optimally re-balance their portfolio towards safer investment and spend more and more money to gather more and more accurate information regarding future market moves. This result derived in a purely rational setup helps to understand the empirical observation that people tend to pay fluctuating attention to news, focusing more in downturns than in upturns. To the best of my knowledge, this paper is the first to consider costly information acquisition in a dynamic setting. The main contribution is to provide insights on how investors should optimally allocate their wealth to the financial market on the one hand and to information market on the other hand given current market conditions. In the second chapter (with Daniel Andrei) we model the optimal information acquisition strategy obtained in the first chapter in a general equilibrium framework and we show that this strategy (fluctuating attention paid to news) has very interesting implications on the dynamics of asset prices. Our main contribution is to highlight a J-shaped relationship between attention and volatility. By constructing an empirical measure of attention to news, we show that the theoretical prediction of our model holds in the data. Moreover, we are the first to provide a theoretical foundation for the fact that the slope of the term structure of equity premia is pro-cyclical. In the third chapter I investigate the impact of fluctuating attention to news in a multi-asset general equilibrium framework. My main contribution is to show that fluctuating attention to news generates return and volatility spillover effects among financial markets. As a bad shock hits one market, investors raise their attention to that particular market. This implies a simultaneous increase in each market volatility and in each cross-market correlation, a phenomenon called financial contagion. Moreover, I document that the interconnection between attention and uncertainty generates persistence in cross-market correlations. This very interesting result proves that persistence can be generated through Bayesian learning. Finally, I am the first to provide a theoretical foundation for the observed shape of the term structure of correlation. Consistent with empirical findings, I show that fluctuating attention implies an upward sloping term structure of correlation where the shorthand is wider than the longhand.

EPFL2013

Essays on Equilibrium Asset Pricing

Rodolfo Javier Prieto Katunaric

This thesis consists of three chapters. The first chapter endogenizes technological change by introducing a stylized innovation process driven by a R&D–dependent Poisson process in a Cox, Ingersoll and Ross (1985) production economy. The model reproduces some of the features of the long-run risk literature, that is, endogenous consumption growth departs slightly from the i.i.d. framework, and shocks to realized and expected consumption growth are priced in equilibrium. Equilibrium dynamics suggest the use of general investment based measures, such as the R&D-to-capital ratio, to identify the long-run risk component in aggregate consumption growth. The second chapter examines the impact of risk-based portfolio constraints on asset prices in a standard exchange economy model where agents have different risk aversion. Constrained agents scale down their benchmark portfolio and behave locally like power utility investors with risk aversion that depends on current market conditions. The equilibrium is characterized using the consumption share of the constrained agents and allows for explicit existence results. The imposition of constraints on active market participants dampens fundamental shocks when they bind, a result that challenges recent studies that suggest that risk management rules serve to amplify aggregate fluctuations. The results also dispute the belief that capital regulations make financial crises larger and more costly, as constraints are more likely to bind in bad times. Constraints may give rise to equilibrium asset pricing bubbles, a result that is associated to the risk aversion distribution across agents and the severity of the constraint. The third chapter studies a pure exchange economy with three types of agents: constrained agents are subject to portfolio constraints, unconstrained agents are free to choose the composition of their portfolio and face a standard nonnegativity constraint on wealth, and arbitrageurs, who are unconstrained, and may incur in marked-to-market losses which are bounded by a state-dependent constraint. This credit condition is valuable when there are asset pricing bubbles, which arise endogenously because of the presence of constrained agents. The size of bubbles depends, primarily, on the ability of the arbitrageur to exploit the arbitrages available due to the mispriced assets, and hence, on the credit conditions. The bubble on the stock vanishes in the limit of infinite credit. Even though all agents have logarithmic utility, the stock price and volatility display the "leverage effect". The impact of the form of the wealth constraint on the results is also assessed.

EPFL2010