Theory and evidence on the dynamic interactions between sovereign credit default swaps and currency options

Using sovereign CDS spreads and currency option data for Mexico and Brazil, we document that CDS spreads covary with both the currency option implied volatility and the slope of the implied volatility curve in moneyness. We propose a joint valuation framework, in which currency return variance and sovereign default intensity follow a bivariate diffusion with contemporaneous correlation. Estimation shows that default intensity is much more persistent than currency return variance. The market price estimates on the two risk factors also explain the well-documented evidence that historical average default probabilities are lower than those implied from credit spreads.     

Understanding the term structure of credit default swap spreads

The shape of the term structure of credit default swap (CDS) spreads displays large variations over time and across firms. Consistent with the predictions of structural models of credit risk, we find that the slope of CDS spread term structure increases with firm leverage and volatility, but decreases with the level and the slope of the Treasury yield curve. However, these variables together have rather limited explanatory power for CDS slope and there is a significant common component in the regression residuals. In addition, we find that CDS slope predicts future changes in the CDS spreads, even after controlling for the contemporaneous variables that determine changes in the CDS spreads according to the structural models. Our results suggest that while structural models are qualitatively useful for understanding the shape of credit term structure, there are missing factors that importantly affect the term structure of CDS spreads.     

Evaluating corporate credit risks in emerging markets

Corporate leverage among emerging market firms went up considerably after the 2007–09 Global Financial Crisis (GFC). We investigate how the increased emerging market corporate leverage in the post-GFC period (2010–15) impacted the underlying credit risk, compared to the pre-GFC (2002–2006) and GFC (2007–09) periods. Using firm-level credit risk, financial, and balance sheet data for 350 firms in 23 emerging markets, we find that leverage growth leads to a significant increase in corporate credit default swap (CDS) spreads only in the post-GFC period, and the incremental effect is mainly evident among risky firms (firms with high leverage and idiosyncratic volatility). In contrast, emerging market CDS spreads during the GFC period are mainly driven by global market risk factors. The post-GFC corporate debt vulnerability is mitigated for high growth prospect firms and firms domiciled in countries with high net capital inflows and superior governance. While corporate leverage growth impacts aggregate corporate credit risk, there is no evidence that it increases sovereign credit risk. Our paper contributes to the recent literature on potential sources of default risk in emerging markets.     

The information content of CDS implied volatility and associated trading strategies

Using the theoretical link between put options and credit default swaps (CDS) in a very general setting, we develop a robust measure of CDS implied volatility (CIV) that captures the information content of CDS markets. Specifically, we use the unit recovery claim to bridge CDS and deep out-of-the-money put options of the same firm and then back out CIV via the binomial tree. Our CIV measure strongly co-moves with the option implied volatility (OIV), with a correlation coefficient of 0.8. Based on the standardized difference between CIV and OIV, we construct CDS and option trading strategies. Without taking transaction costs into account, the long–short CDS trading strategy achieves an annualized return of 58.29% and a Sharpe ratio of 2.97, which cannot be explained by non-parametric skewness and volatility risk.     

Extreme risk spillovers from commodity indexes to sovereign CDS spreads of commodity dependent countries: A VAR quantile analysis

Given the financialization of commodities and the increase in the CDS markets' size and structure, we examine the co-movement and dependence structure between four commodity indexes and sovereign credit risk via an extreme volatility risk spillover methodology. We use the daily change in sovereign CDS data between October 1, 2010 to March 31, 2020 for ten commodity-dependent countries and four commodity indexes (agricultural, precious and industrial metals, and energy). The results of White et al.'s (2015) VAR for Value at Risk (VaR) and the pseudo quantile impulse response function (QIRF) show that the volatility of the primary commodity export category (e.g., agriculture, mineral, and energy) substantially influences the volatility of sovereign spreads (except for two agriculture-dependent exporters). Still, it does not always have the strongest risk spillover effect when other commodity indixes are included in the analysis. When drilling down on the data and examining the single commodity index (i.e., gold, corn, etc.), our results indicate that the primary commodity exports significantly influence the volatility of its sovereign CDS spreads. Based on the results of the QIRF, most shocks are absorbed within 30 days. Most risk spillover from the volatility of sovereign CDS spreads to the volatility of commodity indexes is found to be insignificant.     

Option-implied correlation between iTraxx Europe Financials and Non-Financials Indexes: A measure of spillover effect in European debt crisis

This paper proposes an analytic method to estimate the option-implied correlation embedded in options on the iTraxx Europe CDS indexes. The option-implied correlation is suggested as a measure of the spillover effect of default risk between the financial and corporate sectors in Europe. In particular, the correlation between the iTraxx Financials and Non-Financials sub-indexes is estimated from options on the iTraxx Main Index, which is considered as a basket option with the two sub-indexes being its underlyings. The abrupt changes of the realized correlation anticipated information of the corresponding option prices. The sovereign default risk, funding liquidity risk, level of risk aversion, and equity market performance are identified to be significant determinants of the option-implied correlation, implying inter-dependence amongst various markets during the European debt crisis.     

Credit default swap spreads and annual report readability

This paper investigates whether annual report readability matters to CDS market participants and how it affects their evaluation on a firm’s credit risk, as measured by CDS spreads. We find that the less readable the annual reports, the higher the CDS spreads. Furthermore, the impact of readability on CDS spreads is more concentrated on firms with high information asymmetry and with investment grade ratings. Our results suggest that investors take into account the readability in their view of the firms’ credit risk. Creditors appear to suffer higher cost on CDS protection of the debts if the underlying firms have less readable annual reports.     

Informed Trading in Stock and Option Markets

We investigate the contribution of option markets to price discovery, using a modification of Hasbrouck's (1995) "information share" approach. Based on five years of stock and options data for 60 firms, we estimate the option market's contribution to price discovery to be about 17% on average. Option market price discovery is related to trading volume and spreads in both markets, and stock volatility. Price discovery across option strike prices is related to leverage, trading volume, and spreads. Our results are consistent with theoretical arguments that informed investors trade in both stock and option markets, suggesting an important informational role for options.     

Implied volatility skews and stock return skewness and kurtosis implied by stock option prices

The Black-Scholes* option pricing model is commonly applied to value a wide range of option contracts. However, the model often inconsistently prices deep in-the-money and deep out-of-the-money options. Options professionals refer to this well-known phenomenon as a volatility ‘skew’ or ‘smile’. In this paper, we examine an extension of the Black-Scholes model developed by Corrado and Su that suggests skewness and kurtosis in the option-implied distributions of stock returns as the source of volatility skews. Adapting their methodology, we estimate option-implied coefficients of skewness and kurtosis for four actively traded stock options. We find significantly nonnormal skewness and kurtosis in the option-implied distributions of stock returns.     

Market conditions,default risk and credit spreads

This study empirically examines the impact of the interaction between market and default risk on corporate credit spreads. Using credit default swap (CDS) spreads, we find that average credit spreads decrease in GDP growth rate, but increase in GDP growth volatility and jump risk in the equity market. At the market level, investor sentiment is the most important determinant of credit spreads. At the firm level, credit spreads generally rise with cash flow volatility and beta, with the effect of cash flow beta varying with market conditions. We identify implied volatility as the most significant determinant of default risk among firm-level characteristics. Overall, a major portion of individual credit spreads is accounted for by firm-level determinants of default risk, while macroeconomic variables are directly responsible for a lesser portion.     

Optimal asset allocation using a combination of implied and historical information

This paper investigates the contribution of option-implied information for strategic asset allocation for individuals with minimum-variance preferences and portfolios with a variety of assets. We propose a covariance matrix that exploits a mixture of historical and option-implied information. Implied variance measures are proposed for those assets for which option-implied information is available. Historical variance and correlation measures are applied to the remaining assets. The performance of this novel approach for constructing optimal investment portfolios is assessed out-of-sample using statistical and economic measures. An empirical application to a sophisticated portfolio comprised by a combination of equities, fixed income, alternative securities and cash deposits shows that implied variance measures with risk premium correction outperform variance measures constructed from historical data and implied variance without correction. This result is robust across investment portfolios, volatility and portfolio performance metrics, and rebalancing schemes.     

Volatility spreads and earnings announcement returns

Prior research documents that volatility spreads predict stock returns. If the trading activity of informed investors is an important driver of volatility spreads, then the predictability of stock returns should be more pronounced during major information events. This paper investigates whether the predictability of equity returns by volatility spreads is stronger during earnings announcements. Volatility spreads are measured by the implied volatility differences between pairs of strike price and expiration date matched put and call options and capture price pressures in the option market. During a two-day earnings announcement window, the abnormal returns to the quintile that includes stocks with relatively expensive call options is more than 1.5% greater than the abnormal returns to the quintile that includes stocks with relatively expensive put options. This result is robust after measuring volatility spreads in alternative ways and controlling for firm characteristics and lagged equity returns. The degree of announcement return predictability is stronger when volatility spreads are measured using more liquid options, the information environment is more asymmetric, and stock liquidity is low.     

The information content of implied volatilities and model-free volatility expectations: Evidence from options written on individual stocks

We measure the volatility information content of stock options for individual firms using option prices for 149 US firms and the S&P 100 index. We use ARCH and regression models to compare volatility forecasts defined by historical stock returns, at-the-money implied volatilities and model-free volatility expectations for every firm. For 1-day-ahead estimation, a historical ARCH model outperforms both of the volatility estimates extracted from option prices for 36% of the firms, but the option forecasts are nearly always more informative for those firms that have the more actively traded options. When the prediction horizon extends until the expiry date of the options, the option forecasts are more informative than the historical volatility for 85% of the firms. However, at-the-money implied volatilities generally outperform the model-free volatility expectations.     

Understanding Delta-Hedged Option Returns in Stochastic Volatility Environments

In this paper, we provide a novel representation of delta-hedged option returns in a stochastic volatility environment. The representation of delta-hedged option returns provided in this paper consists of two terms: volatility risk premium and parameter estimation risk. In an empirical analysis, we examine delta-hedged option returns based on the result of a historical simulation with the USD-JPY currency option market data from October 2003 to June 2010. We find that the delta-hedged option returns for OTM put options are strongly affected by parameter estimation risk as well as the volatility risk premium, especially in the post-Lehman shock period.     

Sovereign CDS Spreads,Volatility, and Liquidity: Evidence from 2010 German Short Sale Ban

The paper examines global impact of 2010 German short sale ban on sovereign credit default swap (CDS) spreads, volatility, and liquidity across 54 countries. We find that CDS spreads continue rising after the ban in the debt crisis region, which suggests that the short selling ban is incapable of suppressing soaring borrowing costs in these countries. However, we find that the ban helps stabilize the CDS market by reducing CDS volatility. The reduction in CDS volatility is greater in the eurozone than that in the non‐eurozone. Furthermore, we find that the CDS market liquidity has been impaired during the ban for the PIIGS (Portugal, Ireland, Italy, Greece, and Spain) countries. In contrast, there are no dramatic changes in the market liquidity for non‐PIIGS eurozone and non‐eurozone samples. The findings suggest that the short sale ban is ineffective to reduce sovereign borrowing costs in the debt crisis region if the underlying economy has not been significantly improved.     

Individual stock-option prices and credit spreads

This paper introduces measures of volatility and jump risk that are based on individual stock options to explain credit spreads on corporate bonds. Implied volatilities of individual options are shown to contain useful information for credit spreads and improve on historical volatilities when explaining the cross-sectional and time-series variation in a panel of corporate bond spreads. Both the level of individual implied volatilities and (to a lesser extent) the implied-volatility skew matter for credit spreads. Detailed principal component analysis shows that a large part of the time-series variation in credit spreads can be explained in this way.     

Factor decomposition of the Eurozone sovereign CDS spreads

In the present study, we examine the factors driving Eurozone sovereign credit default swap (CDS) spreads during the Eurozone sovereign debt crisis. For identifying factors we utilize independent component analysis (ICA), a technique similar to principal component analysis (PCA). We identify three factors that impact spreads and capture the features specific to the crisis such as the breakup risk of the Eurozone: peripheral factor, global factor, and Eurozone common factor. In contrast, when PCA is applied, only a single factor is identified. Moreover, using ICA with a GARCH model, we show that the source of volatility for CDS spreads shifted from the global factor in 2009 and the peripheral factor in 2010 to the Eurozone common factor in 2012, and that the dynamic correlation reflects the decoupling between low credit risk countries such as Germany and high credit risk countries such as Greece. We also show that the goodness-of-fit of the ICA-based model is better than other models used such as the Student's t copula model.     

A jump to default extended CEV model: an application of Bessel processes

We develop a flexible and analytically tractable framework which unifies the valuation of corporate liabilities, credit derivatives, and equity derivatives. We assume that the stock price follows a diffusion, punctuated by a possible jump to zero (default). To capture the positive link between default and equity volatility, we assume that the hazard rate of default is an increasing affine function of the instantaneous variance of returns on the underlying stock. To capture the negative link between volatility and stock price, we assume a constant elasticity of variance (CEV) specification for the instantaneous stock volatility prior to default. We show that deterministic changes of time and scale reduce our stock price process to a standard Bessel process with killing. This reduction permits the development of completely explicit closed form solutions for risk-neutral survival probabilities, CDS spreads, corporate bond values, and European-style equity options. Furthermore, our valuation model is sufficiently flexible so that it can be calibrated to exactly match arbitrarily given term structures of CDS spreads, interest rates, dividend yields, and at-the-money implied volatilities.     

Executive compensation and corporate risk-taking: Evidence from private loan contracts

We examine how management stock options affect corporate risk taking. We exploit exogenous variation in stock option grants generated by FAS 123R and use loan spreads to infer risk taking. Using a difference-in-differences approach, we find that the spreads of loans taken by firms that did not expense options before FAS 123R (treated firms) significantly decrease after FAS 123R relative to firms that either did not issue stock options or voluntarily expensed stock options before 123R (control firms). We also find that the effect is stronger for firms with high agency conflicts associated with risk-shifting. Furthermore, loans taken by the treated firms are less likely to contain collateral requirements and are less likely to have covenants restricting capital investment post FAS 123R.     

The pricing of idiosyncratic risk: evidence from the implied volatility distribution

A recent strand in the literature has investigated the relationship between idiosyncratic risk and future stock returns. Although several authors have found significant predictive power of idiosyncratic volatility, the magnitude and direction of the dependence is still being debated. Using a sample of all S&P 100 constituents, we identify positive risk premia for option-implied idiosyncratic risk. Depending on the model used to identify unsystematic risk, we observe a statistically and economically significant average annual premium of 1.72 percent. To investigate whether this impact is driven by the definition of idiosyncratic risk, we extend the pricing kernel by implied skewness. Using a double-sorting procedure, we show that the compensation of unsystematic risk is mainly driven by firms with high positive implied skewness.