The systematic risk of corporate bonds: default risk,term risk,and index choice

In this paper, we empirically examine the systematic risk of corporate bonds in the Euro area. Based on a unique sample of 784 bonds from 1999 to 2010, we show that the systematic risk of constructed bond portfolios and individual bonds—measured against three different market indices—depends on credit quality, term risk, and index choice. A significant increase in systematic risk for lower-rated bonds is observed following the start of the financial crisis. In multi-factor models, bond portfolios load significantly on default and term risk, which are included as additional factors. Conducting Fama and MacBeth cross-sectional tests, we find that default and term risk are priced with economically relevant premiums that range from 0.35 to 0.62 % per month. Our results are robust to the inclusion of characteristics such as rating and time to maturity.     

基于余弦相似度(CS)和最小生成树(MST)的基金市场复杂网络研究

以中国基金市场中123家基金公司持有的投资组合为样本,综合运用余弦相似度(CS)和最小生成树(MST)方法,考量基金市场复杂网络。结果显示：各家基金公司持有股票组合的相似程度比持有债券组合的相似程度更高,表明他们持有的债券组合较之股票组合更加多元化,基金公司持有的股票相对集中于市值大、成长性高的公司。同时,全部资产投资组合、股票投资组合和债券投资组合等三类基金MST网络的节点度均服从幂律分布,表明大多数基金公司以少数强影响力基金公司为中心聚集起来,彼此之间具有较强的业务关联。此种网络结构特征可能导致市场风险向基金聚集团体集中,其抵御系统性风险的能力偏弱,也不利于满足投资者的理财多元化需求。     

The cross-section of expected corporate bond returns: Betas or characteristics?

This paper finds that default betas are significantly related to the cross-section of average bond returns even after controlling for characteristics such as duration, ratings, and yield-to-maturity. Among characteristics, only yield-to-maturity is significantly related to average bond returns after controlling for default and term betas. The default and term factors are able to price the returns of beta-sorted portfolios better than they do the returns of yield-sorted portfolios. The magnitude of the ex ante Sharpe ratio generated by yield-sorted portfolios suggests non-risk-based explanations. Overall, given the elusive nature of systematic risk in empirical asset pricing, the central finding of our paper is that systematic risk matters for corporate bonds.     

Tracking bond indices in an integrated market and credit risk environment

Abstract

The management of credit risky assets requires simulation models that integrate the disparate sources of credit and market risk, and suitable optimization models for scenario analysis. In this paper we integrate Monte Carlo simulation models for credit risk with scenario optimization, and develop a methodology for tracking broadly defined corporate bond indices. Testing of the models shows that the integration of the multiple risk factors improves significantly the performance of tracking models. Good tracking performance can be achieved by optimizing strategic asset allocation among broad classes of corporate bonds. However, extra value is generated with a tactical model that optimizes bond picking decisions as well. It is also shown that adding small corporate bond holdings in portfolios that track government bond indices improves the risk/return characteristics of the portfolios. The empirical results to substantiate the findings of this study are obtained by backtesting the model over a recent 30 month period.     

Currency Hedging for International Portfolios

This paper examines the benefits from currency hedging, both for speculative and risk minimization motives, in international bond and equity portfolios. The risk-return performances of globally diversified portfolios are compared with and without forward contracts. Over the period 1974 to 1990, inclusion of forward contracts results in statistically significant improvements in the performance of unconditional portfolios containing bonds. Conditional strategies are also implemented, both in sample and out of sample, and are shown to both significantly improve the risk-return tradeoff of global portfolios and to outperform unconditional hedging strategies.     

The Riskiness of Corporate Bonds

We use an index of riskiness recently proposed by Aumann and Serrano ( 2008 ) to analyze how the riskiness of diversified portfolios of corporate bonds changes across rating classes and through time and how it compares to the riskiness of other financial instruments. We find that differences in riskiness among portfolios of bonds belonging to different rating classes are seldom statistically significant. We instead find significant time variation in riskiness, driven mainly by return volatility, inflation, and average bond yields. In particular, we find that increases in average bond yields have historically tended to reduce the riskiness of portfolios of corporate bonds by increasing their expected return and by lowering the probability of portfolio losses.     

Tranching and Rating

In this paper we analyse the source and magnitude of marketing gains from selling structured debt securities at yields that reflect only their credit ratings, or specifically at yields on equivalently rated corporate bonds. We distinguish between credit ratings that are based on probabilities of default and ratings that are based on expected default losses. We show that subdividing a bond issued against given collateral into subordinated tranches can yield significant profits under the hypothesised pricing system. Increasing the systematic risk or reducing the total risk of the bond collateral increases the profits further. The marketing gain is generally increasing in the number of tranches and decreasing in the rating of the lowest rated tranche.     

Diversified Portfolios with Jumps in a Benchmark Framework

This paper considers diversified portfolios in a sequence of jump diffusion market models. Conditions for the approximation of the growth optimal portfolio (GOP) by diversified portfolios are provided. Under realistic assumptions, it is shown that diversified portfolios approximate the GOP without requiring any major model specifications. This provides a basis for systematic use of diversified stock indices as proxies for the GOP in derivative pricing, risk management and portfolio optimization. 1991 Mathematics Subject Classification: primary 90A12; secondary 60G30; 62P20 JEL Classification: G10, G13     

Diversification with volatility products

Recent changes to clearing-house regulations have promoted exchange-traded products offering risk premia previously accessible only over-the-counter. Thus, as correlations increase between equity, bonds and commodities, a new strand of research questions the benefits of home-grown diversification using volatility products. First we ask: “What expected returns will induce equity and bond investors to perceive ex-ante diversification benefits from adding volatility?” We call this the optimal diversification threshold. We derive the theoretical thresholds for minimum-variance, mean-variance and Black–Litterman optimization. Empirical analysis of US and European markets shows that volatility diversification is frequently perceived to be optimal, ex-ante, but these apparent benefits are almost never realized, being eroded by high roll and transaction costs. Exchange-traded volatility only proved an effective diversifier during the banking crisis. At other times long equity and bond portfolios diversified with volatility futures have not performed as well as those without diversification, or even those diversified with commodities.     

The Variation of Economic Risk Premiums in Real Estate Returns

We examine the predictable components of returns on stocks, bonds, and real estate investment trusts (REITs). We employ a multiple-beta asset pricing model and find that there are varying degrees of predictability among stocks, bonds, and REITs. Furthermore, we find that most of the predictability of returns is associated with the economic variables employed in the asset pricing model. The stock market risk premium is highly important in capturing the predictable variation in stock portfolios, and the bond market risk premiums (term and risk structure of interest rates) are important in capturing the predictable variation in bond portfolios. For REITs, however, both the stock and bond market risk premiums capture the predictable variation in returns. REITs have comparable return predictability to stock portfolios. We conclude that there is an important economic risk premium for REITs that are not captured by traditional multiple-beta asset pricing models.     

HOW MANY SMALL FIRMS ARE ENOUGH?

Individual investors are undiversified, holding on average less than four securities in their personal portfolios. The small firm literature focuses on CAPM (systematic risk, full diversification concept) premia, and the actual performance of small firm portfolios held by investors is overstated because of the presence of unsystematic risk. This paper illustrates the magnitudes of total risk for small and large firms, and the behavior of such measures as portfolio size is altered. Small firms contain more risk as shown by the finding that a diversified portfolio of small firms has greater variability than a single, typical large firm. While small firms outperform large firms, investors should be aware of the implications for small firm undiversified portfolios. Because small firms contain large amounts of unsystematic risk, diversification is important if investors are going to capture the small firm premia reported in the literature.     

Hedging Corporate Bonds

We examine Treasury bond and stock index futures, the swap curve and two types of hypothetical corporate bond assets as alternative hedging instruments for portfolios of corporate bonds. Conducting ex post and ex ante tests we find evidence that credit quality and maturity are important sources of basis risk when hedging corporate bonds whose credit rating are below triple A. We conclude that a new corporate hedging instrument may be useful for those wishing to hedge corporate bond portfolios provided that transaction costs are not too high relative to existing futures contracts.     

Consumption risk and the cross-section of government bond returns

In this paper we provide a consumption-based explanation of risk in nominal US Treasury bond portfolios. We use a consumption-CAPM with Epstein–Zin–Weil recursive preferences. Our model introduces two sources of risk: uncertainty about current consumption (reflected in contemporaneous consumption growth) and uncertainty about prospects of consumption in a long run (reflected in innovations to expectations about future consumption growth). We use a novel approach to estimate pricing factors in our model: we employ a factor-augmented VAR model with common factors, extracted from a large panel of macroeconomic and financial data, as state variables. We find that the important source of risk in US bonds is related to uncertainty in prospects in future consumption and it induces a positive and significant risk premium. We find as well that covariance risk related to innovations in expectations about future consumption growth is greater for long term bond portfolios than for short term bond portfolios, which is consistent with a duration measure of risk and justifies why long term bonds require greater premium than short term bonds. Our model explains well the cross-sectional variation in average excess returns of bonds with different maturities over the period 1975–2011 and compares favorably with competing models.     

Trapped in diversification – another look at the risk of fund of hedge funds

Recent literature implies that despite being more diversified, fund of hedge funds (FOFs) are exposed to tail risk. We propose an explanation for this phenomenon; tail risk is a systematic risk factor for hedge funds, which by construction, explains the higher portion of the returns in the diversified portfolios. Our study suggests that not only an additional tail risk factor improves the explanatory power of the factor model, the relative importance of tail risk factor increases with the number of underlying hedge funds in an FOF portfolio. Furthermore, we demonstrate that FOFs with a short history, higher management fees, leverage and requiring shorter lockup periods are more sensitive to tail risk.     

Common risk factors in the cross-section of corporate bond returns

We investigate the cross-sectional determinants of corporate bond returns and find that downside risk is the strongest predictor of future bond returns. We also introduce common risk factors based on the prevalent risk characteristics of corporate bonds—downside risk, credit risk, and liquidity risk—and find that these novel bond factors have economically and statistically significant risk premiums that cannot be explained by long-established stock and bond market factors. We show that the newly proposed risk factors outperform all other models considered in the literature in explaining the returns of the industry- and size/maturity-sorted portfolios of corporate bonds.     

How does the corporate bond market value capital investments and accruals?

This paper examines whether the mispricing of accruals documented in equity markets extends to bond markets. The paper finds that corporate bonds of firms with high operating accruals underperform corporate bonds of firms with low operating accruals. In the first year after portfolio formation, the underperformance is 115 basis points using an accrual measure that includes capital investments and 93 basis points using an accrual measure that is based only on working capital investments. The Sharpe ratios of the zero-investment bond accrual portfolios are comparable to those of the corresponding zero-investment stock accrual portfolios. The results are also robust to risk adjustments based on both a factor model consisting of the Fama and French (J. Financial Econ 33 (1993) 3) stock and bond market factors and a characteristics model based on bond ratings and duration. Cross-sectional Fama–MacBeth regressions that use individual bond data and control for stock and bond issuances in addition to ratings and duration also confirm the time-series portfolio findings. Overall, our results reveal an accrual anomaly among bonds similar to that observed among stocks.

Diversified Portfolios in Continuous Time

We study a financial market containing an infinite number of assets, where each asset price is driven by an idiosyncratic random source as well as by a systematic noise term. Introducing asymptotic assets which correspond to certain infinitely well diversified portfolios we study absence of (asymptotic) arbitrage, and in this context we obtain continuous time extensions of atemporal APT results. We also study completeness and derivative pricing, showing that the possibility of forming infinitely well diversified portfolios has the property of completing the market. It also turns out that models where the all risk is of diffusion type are qualitatively quite different from models where one risk is of diffusion type and the other is of Poisson type. We also present a simple martingale based theory for absence of asymptotic arbitrage.     

Effects of securitization and covered bonds on bank stability

This paper empirically investigates the relationship of securitization and covered bonds with bank stability and highlights that this relationship varies with the level of a bank's involvement in a specific instrument. The study uses the data from 46 securitizing and covered bond issuing listed banks in Europe for 2000–2014. The initial results show that some banks have been heavily involved in securitization activity, while covered bond issuance does not go beyond a certain limit. The results obtained using a quadratic model and a generalized additive model show a U-shaped relationship between securitization and systemic risk of banks. However, some interesting results are obtained for covered bonds. Initial results do not show a significant impact of covered bonds on systemic risk, but further analysis shows the presence of a size effect. The systemic risk of smaller banks increases after the issuance of covered bonds, while larger banks remain unaffected. The study does not support imposing uniform limits on covered bond issuance; rather such limits should be linked to the bank size. However, some regulatory framework is needed to limit banks’ involvement in securitization.     

Stochastic durations,the convexity effect,and the impact of interest rate changes

This article shows that the equilibrium models of bond pricing do not preclude arbitrage opportunities caused by convexity. Consequently, stochastic durations derived from these models are limited in their ability to act as interest rate risk measures. The research of the present article makes use of an intertemporal utility maximization framework to determine the conditions under which duration is an adequate interest rate risk measure. Additionally, we show that zero coupon bonds satisfy those equilibrium conditions, whereas coupon bonds or bond portfolios do not as a result of the convexity effect. The results are supported by empirical evidence, which confirms the influence of convexity on the deviation of coupon bond returns from equilibrium.     

Household portfolio optimization with XTFs? An empirical study using the SHS-base

XTFs are plain-vanilla Exchange Traded Funds (ETFs) which replicate a broad, internationally diversified market index. We question, if XTFs can optimize the performance of households’ portfolios when taking multiple relevant asset classes into account, not only stocks. As opposed to most existing studies, we apply representative household portfolio data to estimate households’ portfolios. Households’ portfolios in our sample show similar compositions and can be grouped into one of three stylized portfolio compositions which exhibit asset class concentrations on cash/savings, mutual funds and individual stocks. For each stylized portfolio, we first investigate if an easily investable 60/40 stock/bond XTF portfolio which is risk-adjusted (including (de-)leverage costs) to the risk of the stylized portfolios, achieves higher returns than the stylized portfolios. This is the case for all stylized portfolios, even those with concentrations on cash/savings or mutual funds. Second, we examine risk/return-changes when replacing the entire risky assets of the stylized portfolios with the 60/40 stock/bond XTF portfolio including transaction costs. This leads to return enhancements in all stylized portfolios and particularly in the portfolio with high stock concentrations to risk reductions. Overall, we find that XTFs are generally suitable to optimize the performance of households’ portfolios under consideration of multiple relevant asset classes.