Risk arising from single issuer credit events
So far we have described a rather intuitive way of combining individual views in a portfolio. Top-down and bottom-up analyses have determined the overall strategy for the portfolio, spread class and sector selection and finally issuer weightings. This qualitative methodology does not require estimates of returns, risks and correlations between the investments, and therefore is easy to implement. Yet, it is not able to capture the full benefits of diversification and to tailor the expected risk/return profile of the portfolio to the preferences of the investor. Since the seminal work of Markowitz (1952), diversification is a central tenet of modern investment theory. In the context of credit portfolios it plays a crucial role, because it helps to control downside risk arising from single issuer credit events. Since the mid-1990s debt-financed M&A activities, share buybacks, and the introduction of new technologies have fueled the new issue pipeline and broadened the corporate bond universe. Meanwhile, the European corporate bond market offers sufficient market breadth and depth for institutional investors to construct thoroughly diversified portfolios. If the portfolio manager is capable of quantifying the risk and return characteristics of his investment alternatives, portfolio optimization approaches present a formalized and thus objective way of deriving investment recommendations. This applies irrespective of the performance target of the investor. Portfolio optimization can be used with respect to portfolios that are managed in absolute risk/ return terms as well as portfolios that are managed relative to a benchmark index.. Various constraints can be included, for example a short sales restriction for real money investors, maximum concentration limits or desired duration ranges.
Assessments of an issuer’s credit quality
The rating agencies have been criticized for being too slow to react to changes in the credit quality of an issuer, leading to serially correlated rating patterns and limiting the value of ratings as a risk management tool. As a reaction, Moody’s decided to put its rating process under review, and acquired KMV to be able to provide investors with additional, marketbased assessments of an issuer’s credit quality. The feedback from market participants was surprising. Since investors themselves tend to use spreads and spread volatility as indicators for credit risk, the vast majority does not want Moody’s or the other rating agencies to switch to a more marketbased approach when assessing the credit quality of an issuer. There is really a need for, according to the feedback, more transparency with regard to the rating process. This would allow investors to use rating agency information in their risk management most efficiently.
Perceived credit quality and risk exposure
For purposes of risk management bonds are often grouped according to agency ratings based on the assumption that bonds with similar ratings tend to show a high degree of comovement. Breger et al. (2003) examine whether the correlation between individual bonds increases if they are grouped by implied ratings, that is by spread classes rather than by agency ratings. The rationale for this would be that market valuations are a better indicator for the drivers of credit spread changes, namely perceived credit quality and risk exposure, than are agency ratings. In their empirical study they find that bonds of the same spread class are more similar than bonds with the same rating from a risk/return perspective. Breger et al. (2003) conclude that the classification of bonds based on market data provides a more reliable basis for modeling return relationships than does a classification by agency ratings. However, one has to note that the motivation behind this study differs significantly from the rating agencies’ approach. The objective is not to predict default risk, but rather to improve the classification of corporate borrowers and provide a basis for reliable spread risk forecasts.
When payday translation risk arises
When financial accounts are converted from one currency to another, translation risk arises. Typically, the financial accounts of foreign subsidiaries have to be translated back in the reporting currency to be included in the consolidated financial accounts. Since most companies do not hedge translation risk, significant changes in exchange rates during the reporting period can cause volatility in revenues and operating income. Usually companies present constant exchange rate revenues as an addition to reported revenues, to allow investors and creditors to analyze the effect of currency fluctuations.
However, a secular depreciation of the US dollar positively affects those European companies with part of their liabilities denominated in US dollars. Not only the amount of debt shown on the balance sheet is reduced, but also the associated interest burden is lessened. In terms of credit ratios, the issuance of debt in a currency, in which part of the revenues are generated, can provide an effective natural hedge against exchange rate volatility. For example, if profits of a European company operating in the United States were reduced by a weakening US dollar, it may be offset by a contemporaneous reduction of the level of US dollar denominated debt. In this case, credit ratios as well as interest coverage ratios could remain constant or even improve. It should be noted that revenues and earnings typically accrue gradually, hence they are translated at average exchange rates, while balance sheet figures are usually determined at the end of reporting period spot rates.