PDE approach to valuation and hedging of credit derivatives

This paper presents a PDE approach in a Markovian setting to hedge defaultable derivatives. The arbitrage price and the hedging strategy for an attainable contingent claim are described in terms of solutions of a pair of coupled PDEs. For some standard examples of defaultable claims, we provide explicit formulae for prices and hedging strategies.     

Corporate cash flow and stock price exposures to foreign exchange rate risk

This paper estimates the foreign exchange rate exposure of 6917 U.S. nonfinancial firms on the basis of stock prices and corporate cash flows. The results show that several firms are significantly exposed to at least one of the foreign exchange rates Canadian Dollar, Japanese Yen and Euro, and significant exposures are more frequent at longer horizons. The percentage of firms for which stock price and earnings exposures are significantly different is relatively low, though it increases with time horizon. Overall, the impact of exchange rate risk on stock prices and cash flows is similar and determined by a related set of economic factors.     

企业套期保值研究及实证分析--基于基差复制技术的方法

文章针对企业套期保值过程中由于套保比率的设定以及入市点的错误选择使得企业面临亏损风险的问题而提出对策。笔者在套期保值比率问题上首次引入了寻找合理判断入市点的模型并给出了具体方法。利用金融工程中无套利的复制原理,复制出了一个远期的权益,从而得出了文章所认为的最优套保比率,为实务界经常运用的选择入市点问题给予理论支持。文章构建的模型得出,在套保比率的设定问题上不但要选择入市点,还要选择套保的时间因素。在买期保值上,当判断出市场行情有利时我们选择相对较大的保值比率,这样可以使我们能尽量获取基差上扬所带来的收益,另外又不至于把套保比率无限扩大使得套保变成投机,以防在万一出现行情错误的时候出现大幅亏损。在卖期保值上,当判断行情有利时,选择相对较低的保值比率,这样可以使我们能尽量获取基差下跌所带来的收益,另外又不至于把套保比率无限缩小甚至不保使得套保变成投机,以防在万一出现行情错误的时候亏损。     

The dynamic connectedness and hedging opportunities of implied and realized volatility: Evidence from clean energy ETFs

This paper aims to examine dynamic connectedness and hedging opportunities between the realized volatilities of clean energy ETFs and energy implied volatilities through Time-Varying Parameter Vector Autoregression Model (TVP-VAR) and Asymmetric Dynamic Conditional Correlation (ADCC) GARCH models. TVP-VAR analysis results show that dynamic connectedness increases during turbulence periods. We also determine that clean energy ETFs such as PBW, QCLN, SMOG, and TAN are net volatility transmitters. Surprisingly, OVX is a net volatility receiver, especially with the developments after the Paris Agreement in 2016.As a result of the ADCC GARCH analysis, we determine that the conditional correlation between clean energy ETFs and implied volatility ETFs is asymmetric, and negative information shocks increase the conditional correlation. Although OVX is a cheap alternative for hedging long position risks in clean energy ETFs, VXXLE is more effective than OVX in terms of hedging effectiveness. These findings provide insight for individual and institutional investors, and portfolio managers on how negative and positive shocks change the conditional correlation between assets at different levels.     

便利收益下碳排放动态套期保值效果

随机的碳排放价格变化直接导致资产组合的投资风险加剧，影响碳排放现货与期货资产的投资组合策略。依靠商品期货价格的期限结构，本文提出了一种新的在便利收益下动态套期保值比率及其套期保值效果评价方法。动态套期保值比率是由现货和便利收益的波动率、协方差及其相关系数、距离到期日时间、便利收益均值回复速度等参数存在紧密关联性。为了有效地规避碳排放现货价格剧烈波动所引发的市场风险，市场参与者利用便利收益的历史信息优化调整期货与现货的对冲比例，确定最优化的套期保值比率，可以有效规避现货资产的市场风险，实现资产投资组合最佳的投资收益。     

Intraday data and hedging efficiency in interest spread trading

Three government bond futures contracts and their respective 3-month interest rate futures contracts traded on LIFFE are examined. The data period covers three years of observations, January 1994-December 1996, sampled at half-hourly intervals. Borrowing from the calculation of minimum variance hedge ratios, half-hourly minimum variance spread ratios (the ratio of one contract to another, which provides the minimum variance) are estimated for the above contracts. The hypothesis under examination is whether there is any value-added in estimating minimum spread ratios based on intraday data. Three spread ratios are defined: two ratios calculated from daily data and a third one based on intraday data. Evidence tends to indicate that spread ratios calculated from intraday data exhibit a substantially lower variance than the other two spread ratio speciications. Thus, it is shown that intraday data, in comparison with daily data, allow for lower hedging costs. Moreover, the use of intraday-based spread ratios might be a contributing factor to reducing the maximum cumulative loss potentially incurred while holding a spread position.     

Optimal hedge ratios and alternative hedging strategies in the presence of cointegrated time-varying risks

This paper utilizes the inter-temporal relationship between the FTSE-100 stock index and its futures price level between 1992 and 1999 to examine the characteristics of several minimum variance hedge ratios and the performances of several alternative hedging strategies for dynamic portfolio management in the presence of cointegrated time-varying risks. Earlier studies neglected the importance of cointegration between the two variables which resulted in biased estimates. These studies, in general, also assume that the hedging period is the same as the estimation time interval. This paper also looks at several key issues when the holding period is longer than the estimation period, such as the construction of optimal minimum variance hedge ratios, and the trade-off between transaction costs and risk reduction.     

期货最优套期保值比率研究评述

套期保值、价格发现、资产配置是期货市场的三大基本职能。而在这三种职能中，最为重要的是套期保值，它是期货市场得以生存和发展的关键动因。在国内外套期保值研究中，最优套期保值比率的估计是套期保值研究最为核心的问题。而运用期货套期保值理论进行实践更是随着套期保值比率估计模型的不断优化、完善而向前发展的，本文通过对国内外套期保值研究相关文献进行分类，整理，综述，梳理出最优套期保值比率估计的研究思路和相关实证技术路线，概括出国内外最优套保比率的研究框架，以此来向国内相关研究学者指出未来的进一步研究方向，同时对国内期货交易主体进行套期保值操作提供了估计模型的选择建议。     

Efficiency tests with overlapping data: an application to the currency options market

This paper presents the results of an empirical study into the efficiency of the currency options market. The methodology derives from a simple model often applied to the spot and forward markets for foreign exchange. It relates the historic volatility of the underlying asset to the implied volatility of an option on the underlying at a specified prior time and then proceeds to test obvious hypotheses about the values of the coefficients. The study uses panel regression to address the problem of overlapping data which leads to dependence between observations. It also uses volatility data directly quoted on the market in order to avoid the biases which may occur when ‘backing out’ volatility from specific option pricing models. In general, the evidence rejects the hypothesis that the currency option market is efficient. This suggests that implied volatility is not the best predictor of future exchange rate volatility and should not be used without modification: the models presented in this paper could be a way of producing revised forecasts.