Implied volatility forecasts in the grains complex

This article finds that the implied volatilities of corn, soybean, and wheat futures options 4 weeks before option expiration have significant predictive power for the underlying futures contract return volatilities through option expiration from January 1988 through September 1999. These implied volatilities also encompass the information in out‐of‐sample seasonal Glosten, Jagannathan, and Runkle (GJR;1993) volatility forecasts. Evidence also demonstrates that when corn‐implied volatility rises relative to out‐of‐sample seasonal GJR volatility forecasts, implied volatility substantially overpredicts realized volatility. However, simulations of trading rules that involve selling corn option straddles when corn‐implied volatility is high relative to out‐of‐sample GJR volatility forecasts indicate that none of the trading rules would have been significantly profitable. This finding suggests that these options are not necessarily overpriced. © 2002 Wiley Periodicals, Inc. Jrl Fut Mark 22:959–981, 2002     

Multivariate realized volatility forecasts of agricultural commodity futures

We forecast the multivariate realized volatility of agricultural commodity futures by constructing multivariate heterogeneous autoregressive (MHAR) models with flexible heteroscedastic error structures that allow for non-Gaussian distribution, stochastic volatility, and heteroscedastic and serial dependence. We evaluate the forecast performances of various models based on both statistical and economic criteria. The in-sample and out-of-sample results suggest that the proposed MHAR models allowing for flexible heteroscedastic covariance structures outperform the benchmark MHAR models. In addition, the proposed Bayesian MHAR models allowing for t innovations improve both in-sample and out-of-sample forecast performance of the corresponding MHAR models with Gaussian innovations.     

Predicting financial volatility: High‐frequency time‐series forecasts vis‐à‐vis implied volatility

Recent evidence suggests option implied volatilities provide better forecasts of financial volatility than time‐series models based on historical daily returns. In this study both the measurement and the forecasting of financial volatility is improved using high‐frequency data and long memory modeling, the latest proposed method to model volatility. This is the first study to extract results for three separate asset classes, equity, foreign exchange, and commodities. The results for the S&P 500, YEN/USD, and Light, Sweet Crude Oil provide a robust indication that volatility forecasts based on historical intraday returns do provide good volatility forecasts that can compete with and even outperform implied volatility. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:1005–1028, 2004     

Time series volatility of commodity futures prices

This article examines the pattern of volatility over time of a series of commodity futures prices, and focuses in particular on the futures price variability as the maturity date of the futures contract approaches. In a rational expectations model of asymmetric information, the article provides conditions under which the Samuelson hypothesis—that the variability of futures prices increases as maturity approaches—will be true. © 2000 John Wiley & Sons, Inc. Jrl Fut Mark 20: 127–144, 2000     

统计中时间数列的变动趋势分析

时间数列就是将反映社会经济现象数量特征的统计指标值按时间的先后顺序排列所形成的数列,又称动态数列.通过动态数列,可以揭示社会经济现象的数量变化趋势,以便进一步研究确定这种趋势和波动是否有规律性的反映.当有季度或月份资料的动态数列时,可以确定是否存在季节变动和季节变动的数量表现.     

The influence of strategic patterns of internationalization on the accuracy and bias of earnings forecasts by financial analysts

This paper examines how financial analysts’ earnings per share forecasts are affected by strategic patterns that multinational firms have used to expand abroad. Prior empirical studies have examined a firm's internationalization level as a one-dimensional construct involving increased task complexity for financial analysts’ forecasting and therefore resulting in lower accuracy and greater optimistic bias in earnings forecasts. In contrast, we use two strategic patterns of internationalization associated with geographic dispersion and cross-border integration to characterize a firm's international strategy, and find different empirical results using a sample of U.S. public companies with domestic and international operations. The empirical evidence suggests that geographic dispersion contributes to increases in forecasting accuracy and decreases in optimistic bias. Further, the results support that cross-border integration leads to decreases in forecasting accuracy. The two strategic patterns of internationalization are a consequence of managerial choices and therefore these results are important for managers, investors and shareholders as they help explain the linkages between international strategies and earnings forecasts by financial analysts.     

The impact of volatility derivatives on S&P500 volatility

This study investigates whether the newly cultivated platform of volatility derivatives has altered the volatility of the underlying S&P500 index. The findings suggest that the onset of the volatility derivatives trading has lowered the volatility of both the cash market volatility and the cash market index, and significantly reduced the impact of shocks to volatility. When big sudden events hit financial markets, however, the volatility of volatility seems to elevate in the U.S. equity market as a result of increased global correlations. Regardless of the period under examination and the estimator employed, long‐run volatility persistence is present. The latter drops significantly when the credit crunch period is excluded from the post‐event date sample period. The correlation between the broad equity index and the return volatility remains low, which in turn strengthens the role of volatility derivatives to facilitate portfolio diversification. The analysis also shows that volatility is mean reverting, whereas market data support the impact of information asymmetries on conditional volatility. In the post‐event date phase, no asymmetries are found when the recent crisis is not accounted for. Finally, comparisons with other international equity indices, with no volatility derivatives listed, unveil that these indices exhibit higher volatility and slower recovery from shocks than the S&P500 index. © 2009 Wiley Periodicals, Inc. Jrl Fut Mark 29:1190–1213, 2009     

The volatility effect in emerging markets

We examine the empirical relation between risk and return in emerging equity markets and find that this relation is flat, or even negative. This is inconsistent with theoretical models such as the CAPM, which predict a positive relation, but consistent with the results of studies for developed equity markets. The volatility effect appears to be growing stronger over time, which we argue might be related to the increased delegated portfolio management in emerging markets. Finally, we find that the volatility effect in emerging markets is only weakly related to that in developed equity markets, which argues against a common-factor explanation.     

The short‐time behavior of VIX‐implied volatilities in a multifactor stochastic volatility framework

We consider a modeling setup where the volatility index (VIX) dynamics are explicitly computable as a smooth transformation of a purely diffusive, multidimensional Markov process. The framework is general enough to embed many popular stochastic volatility models. We develop closed‐form expansions and sharp error bounds for VIX futures, options, and implied volatilities. In particular, we derive exact asymptotic results for VIX‐implied volatilities, and their sensitivities, in the joint limit of short time‐to‐maturity and small log‐moneyness. The expansions obtained are explicit based on elementary functions and they neatly uncover how the VIX skew depends on the specific choice of the volatility and the vol‐of‐vol processes. Our results are based on perturbation techniques applied to the infinitesimal generator of the underlying process. This methodology has previously been adopted to derive approximations of equity (SPX) options. However, the generalizations needed to cover the case of VIX options are by no means straightforward as the dynamics of the underlying VIX futures are not explicitly known. To illustrate the accuracy of our technique, we provide numerical implementations for a selection of model specifications.     

The HWWA econometric model for economic forecasts

Econometric models are often used to forecast economic developments. Does the use of computer-based econometric procedures help sharpen our view of the future or are we blinkered by the supposed ‘precision’ of such models? What problems arise when building national economic models and when these models are used for forecasting purposes? These issues are examined with reference to the HWWA model.     

The volatility effect of diaspora's location

Remittances can transmit volatility from host to home countries for some common patterns of diaspora's geographical distribution. In a migration portfolio model, the overall risk of volatility of any set of diaspora location is decomposed into a contagion and a concentration risks: a diaspora located in more volatile destinations induces a higher contagion risk, while a diaspora located in few destination countries increases the concentration risk. A series of estimations on a large panel of developing countries over 1995–2015 provide evidence for these two risks. Estimation of a structural model confirms that the geography of diaspora has an indirect impact on the origin country's aggregate instability through remittances.     

The new market for volatility trading

This study analyses the new market for trading volatility; VIX futures. We first use market data to establish the relationship between VIX futures prices and the index itself. We observe that VIX futures and VIX are highly correlated; the term structure of average VIX futures prices is upward sloping, whereas the term structure of VIX futures volatility is downward sloping. To establish a theoretical relationship between VIX futures and VIX, we model the instantaneous variance using a simple square root mean‐reverting process with a stochastic long‐term mean level. Using daily calibrated long‐term mean and VIX, the model gives good predictions of VIX futures prices under normal market situation. These parameter estimates could be used to price VIX options. © 2010 Wiley Periodicals, Inc. Jrl Fut Mark 30:809–833, 2010     

The log-moment formula for implied volatility

We revisit the foundational Moment Formula proved by Roger Lee fifteen years ago. We show that in the absence of arbitrage, if the underlying stock price at time T admits finite log-moments $\mathbb{E}[|\log S_T{|}^q]$ for some positive q, the arbitrage-free growth in the left wing of the implied volatility smile for T is less constrained than Lee's bound. The result is rationalized by a market trading discretely monitored variance swaps wherein the payoff is a function of squared log-returns, and requires no assumption for the underlying price to admit any negative moment. In this respect, the result can be derived from a model-independent setup. As a byproduct, we relax the moment assumptions on the stock price to provide a new proof of the notorious Gatheral–Fukasawa formula expressing variance swaps in terms of the implied volatility.     

基于时间序列聚类的多雷达数据融合

针对多雷达数据融合问题,提出了基于时间序列的聚类算法,用于实现航迹相关,即以时间序列为基础把聚类模型转化为基于特征匹配的聚类算法。进一步考虑到多目标密集时,部分来自不同目标的数据可能比来自同一目标的数据更接近,易导致关联错误,为此提出了基于时间序列的模糊聚类算法。对上述两种算法的聚类结果,应用卡尔曼滤波器实现滤波跟踪,在不同的情况下仿真后发现,在跟踪目标较少且相互位置较远的情况下,两种算法均有效,在跟踪目标较多且相互位置靠近的情况下,基于时间序列的模糊聚类算法更有效。     

The information content of implied volatility in light of the jump/continuous decomposition of realized volatility

In the framework of encompassing regressions, the information content of the jump/continuous components of historical volatility is assessed when implied volatility is included as an additional regressor. The authors' empirical application focuses on daily and intradaily data for the S&P100 and S&P500 indexes, and daily data for the associated VXO and VIX implied volatility indexes. The results show that the total explanatory power of the encompassing regressions barely changes when the jump/continuous components are included, although the weekly and monthly continuous components are usually significant. This evidence supports the view that implied volatility has very high information content, even when extended decompositions of past realized volatility are used. Moreover, adding GARCH‐type volatility forecasts in the regressions confirms these results. © 2007 Wiley Periodicals, Inc. Jrl Fut Mark 27:337–359, 2007     

The implied volatility smirk of commodity options

This paper studies the implied volatility (IV) smirks in four commodity markets by adopting Zhang and Xiang's methodology. First, we document the term structure and dynamics of IV smirks. Overall, the commodity IV curves are negatively skewed with a positive curvature. Then we analyze the commodity and S&P 500 returns' predictability based on in‐sample and out‐of‐sample tests and find that the information embedded in IV smirks can significantly predict monthly commodity and S&P 500 returns. For example, the risk‐neutral fourth cumulant (FC) from the crude oil market outperforms all of the standard predictors in predicting the S&P 500 returns.     

The Fed's policy decisions and implied volatility

This study examines how the Fed's monetary policy decisions affect the implied volatility of the S&P 500 index. The results show that stock market uncertainty is significantly affected by the Fed's policy decisions. In particular, we find that implied volatility generally decreases after FOMC meetings, while the relationship between target rate surprises and market uncertainty appears positive. However, our results also suggest that the apparent positive relationship between policy surprises and implied volatility is mostly driven by the volatility‐reducing effects of negative surprises. We further document that implied volatility is affected by both scheduled and unscheduled policy actions, with the scheduled path surprises having the strongest impact on volatility. Finally, our findings indicate that the impact of monetary policy decisions on implied volatility is more pronounced during periods of expansive policy. © 2010 Wiley Periodicals, Inc. Jrl Fut Mark