Value-at-risk methods which employ a linear (“delta only”) approximation to the relation between instrument values and the underlying risk factors are unlikely to be robust when applied to portfolios containing non-linear contracts such as options. The most widely used alternative to the delta-only approach involves revaluing each contract for a large number of simulated values of the underlying factors. In this paper we explore an alternative approach which uses a quadratic approximation to the relation between asset values and the risk factors. This method (i) is likely to be better adapted than the linear method to the problem of assessing risk in portfolios containing non-linear assets, (ii) is less computationally intensive than simulation using full-revaluation and (iii) in common with the delta-only method, operates at the level of portfolio characteristics (deltas and gammas) rather than individual instruments.

We argue that anomalies may experience prolonged decay after discovery and propose a Bayesian framework to study how that impacts portfolio decisions. Using the January effect and short-term index autocorrelations as examples of disappearing anomalies, we find that prolonged decay is empirically important, particularly for small-cap anomalies. Papers that document new anomalies without accounting for such decay may actually underestimate the original strength of the anomaly and imply an overstated level of the anomaly out of sample. We show that allowing for potential decay in the context of portfolio choice leads to out-of-sample outperformance relative to other approaches.

This paper analyzes the relation between agency conflicts and risk management. In contrast to previous contributions, our analysis incorporates not only stockholder-debtholder conflicts but also manager–stockholder conflicts. We show that the costs of both underinvestment and overinvestment are essential in determining the firm's hedging policy. In particular, firms that derive more of their value from assets in place (lower market-to-book ratios), although having lower costs of underinvestment, generally display larger costs of overinvestment. Thus, they may be more likely to hedge to control these overinvestment incentives. Our analysis explains why large profitable firms with fewer growth opportunities tend to hedge more (Bartram et al., 2004). It also provides a number of new predictions relating the benefits associated with risk management to various dimensions of the firm's economic environment.

Using NYSE short-sale order data, we investigate whether short sellers’ informational advantage is related to firm earnings and analyst-related events. With a novel decomposition method, we find that while these fundamental event days constitute only 12% of sample days, they account for over 24% of the overall underperformance of heavily shorted stocks. Importantly, short sellers use both public news and private information to anticipate news regarding earnings and analysts. Shorting’s predictive ability remains significant after controlling for information in analyst actions and displays no reversal patterns, indicating that short sellers know more than analysts, and the nature of their information is long term.

This article examines whether agency conflicts introduced by securitization affect servicers’ asset liquidation decisions. We find securitized loans are 25.4–28.5 percent less likely to be liquidated via short sales than portfolio loans. Securitized loan servicers’ bias against short sales does not represent an agency conflict if short sale and real estate owned (REO) liquidations are equally efficient. However, we find REOs have significantly lower average liquidation prices, higher average liquidation expenses, and longer average liquidation times than short sales. Although short sales benefit investors, securitized loan servicers have a financial incentive to pursue REOs.

This article provides a comprehensive history of default risk for newly originated home mortgages in the USA over the past quarter century. The loan-level source data include the entire guarantee book for Fannie Mae and Freddie Mac. We track many loan characteristics and produce a summary measure of risk. Among our many results, we show that mortgage risk had already risen in the 1990s, planting seeds of the financial crisis well before the actual event. Our results also cast doubt on explanations of the crisis that focus on borrowers with low credit scores. The aggregate series are available for download at https://www.fhfa.gov/papers/wp1902.aspx.