价格异常与不对称相关结构下套期保值策略——来自亚洲股指期货市场的实证

在不对称相关结构下,尾部区域期货和现货价格联动模式异常复杂,传统套期保值策略在极端价格行为下将不可避免地出现系统性偏差。为此,恰当的连接函数被引入描述尾部区域的价格联动模式,依据MV框架构建局部套期保值策略,以解决极端价格行为下的套期保值问题。对亚洲市场日经指数和恒生指数期货套期保值的实证研究表明:(1)采用Rotated Gumbel连接函数,在传统MV策略(全局策略)下,虽然在降低套保组合方差方面没有明显优势,但日经指数和恒生指数期货的套期保值成本将显著下降,套保组合收益/组合方差的比率显著上升;(2)如果套期保值者能够对未来形成可靠预期,套期保值的成本将进一步下降,并且现货价格风险也得到有效控制。     

Asymmetric effect of basis on dynamic futures hedging: Empirical evidence from commodity markets

The dynamic minimum variance hedge ratios (MVHRs) have been commonly estimated using the Bivariate GARCH model that overlooks the basis effect on the time-varying variance–covariance of spot and futures returns. This paper proposes an alternative specification of the BGARCH model in which the effect is incorporated for estimating MVHRs. Empirical investigation in commodity markets suggests that the basis effect is asymmetric, i.e., the positive basis has greater impact than the negative basis on the variance and covariance structure. Both in-sample and out-of-sample comparisons of the MVHR performance reveal that the model with the asymmetric effect provides greater risk reduction than the conventional models, illustrating importance of the asymmetric effect when modeling the joint dynamics of spot and futures returns and hence estimating hedging strategies.     

模糊厌恶下股指期货风险对冲策略设计及实证分析

投资者对股指期货与现货有着不同的模糊厌恶,本文首先将此假设条件引入带交易成本的Garleanu and Pederson (2013)投资模型中,并以指数基金对冲策略为例,构建了一个股指期货动态对冲的理论模型。与非对冲策略相比,基于上述模型设计的对冲策略投资绩效更好,动态最优成交额占目标交易额的比例更小,目标成交额对收益率预测因子的敏感性更大。借助上述模型,本文选取2010年4月至2021年6月的中国ETF指数基金和股指期货数据,并以2015年9月股指期货管理措施实施为界进行区间划分,实证研究发现:(1)中国A股市场的ETF投资组合进行股指期货对冲显著提升了投资绩效,但股指期货管理会削弱该作用;(2)投资绩效改善主要来源于交易成本的下降与目标成交额因子敏感性的提升,该机制受到股指期货管理的约束;(3)与Garleanu and Pederson (2013)、Zhang et al. (2017)相比,本文对冲策略保留“抗跌”特点的同时增加了“易涨”特性。本文研究结果表明,在当前大力发展机构投资者的背景下应不断丰富股指期货、股指期权产品谱系,降低股指期货交易成本并完善持仓约束。     

Bank Funding Risks,Risk Aversion,and the Choice of Futures Hedging Instrument

Currently, theories of financial futures hedging are based on either a portfolio-choice approach or a duration approach. This article presents an alternative: a firm-theoretic model of bank behavior with financial futures. Assuming the bank is uncertain about cash CD interest rates and the quantity of CDs it needs in the future, expressions for the optimal futures hedge are derived under constant absolute risk aversion and constant relative risk aversion. The performance of these two strategies is estimated from 1981–1983 using either the recently developed CD futures contract or the T-Bill futures contract. These results are also compared with the performance of a portfolio-choice strategy and a routine hedging strategy. The analysis indicates that the CD futures market can serve a hedging purpose that is not served by the previously established T-Bill futures market.     

Hedging Long-Term Forwards with Short-Term Futures: A Two-Regime Approach

In this paper we investigate Metallgesellschafts problem of hedging long-term forwards with short-term futures. Very different hedging strategies have been proposed in the literature. We attribute these differences to the underlying valuation approaches for oil futures and empirically compare five model-based hedging strategies. In particular, we consider a strategy which results from a two-regime pricing model. This continuous-time equilibrium model reflects the observation that prices of oil futures exhibit a very different behavior for low and high oil prices. Our empirical study shows that time diversification is the dominant effect for an effective hedging of long-term oil forwards with short-term futures. JEL classification G13, G30     

Size effect,methodological issues and ‘risk-to-default’: evidence from the UK stock market

The hedging effectiveness of dynamic strategies is compared with static (traditional) ones using futures contracts for the five leading currencies. The traditional hedging model assumes time invariance in the joint distribution of spot and futures price changes thus leading to a constant optimal hedge ratio (OHR). However, if this time-invariance assumption is violated, time-varying OHRs are appropriate for hedging purposes. A bivariate GARCH model is employed to estimate the joint distribution of spot and futures currency returns and the sequence of dynamic (time-varying) OHRs is constructed based upon the estimated parameters of the conditional covariance matrix. The empirical evidence strongly supports time-varying OHRs but the dynamic model provides superior out-of-sample hedging performance, compared to the static model, only for the Canadian dollar.     

股指期货与股指期权套期保值组合的Delta中性动态模拟——基于沪深300股指期货仿真交易的分析

沪深300股指期货的推出,在为市场提供套保工具和流动性的同时,也带来新的风险。本文运用同一指数的股指期权与股指期货组成多种动态套期保值组合,分析股指期货的风险对冲策略。结果表明所构造的组合都能为股指期货提供有效的套期保值;不论多头股指期货还是空头股指期货,保护性策略的风险控制能力更强。     

Benefits from Asia-Pacific Mutual Fund Investments with Currency Hedging

This study presents empirical evidence on the efficiency and effectiveness of hedging U.S.-based international mutual funds with an Asia-Pacific investment objective. The case for active currency risk management is examined for a passive and a selective hedge, which is constructed with currency futures in the major currencies. Both static and dynamic hedging models are used to estimate the risk-minimizing hedge ratio. The results show that currency hedging improves the performance of internationally diversified mutual funds. Such hedging is beneficial even when based on prior optimal hedge ratios. Further, efficiency gains from hedging, as measured by the percent change in the Sharpe Index, are greatest under a selective portfolio strategy that is implemented with an optimal constant hedge ratio.     

SELECTIVE HEDGING OF BANK ASSETS WITH TREASURY BILL FUTURES CONTRACTS

The recent volatility of interest rates, the associated profit pressures imposed on banks, and the surge in the development of new contracts have stimulated a desire to understand and apply financial futures hedging to banking operations. This paper models interest rate futures contracts in a theory of bank behavior to illustrate the hedging of bank loans as well as government securities. The model predicts the hedge will be greater (1) the greater the expected rise in interest rates and (2) the greater the effect of disintermediation on bank deposits. A simulation of the financial futures trading strategy is reported for banks of various asset sizes using data from the Eleventh Federal Reserve District. Depending on bank risk aversion and interest rate expectations, hedging the bank's total interest rate exposure with T-bill futures reduces the variability of unhedged profits by 80 percent.     

INTEREST RATE HEDGING: AN EMPIRICAL TEST OF ALTERNATIVE STRATEGIES

For hedging, financial and agricultural futures contracts differ in their usefulness. This paper presents a new hedging approach uniquely appropriate to financial futures that better fits the typical hedging situation confronted by those wishing to hedge interest rate risk. The superiority of this new hedging strategy is demonstrated empirically by comparing the strategy with several other methods currently in use.     

Limits to arbitrage and hedging: Evidence from commodity markets

We build an equilibrium model of commodity markets in which speculators are capital constrained, and commodity producers have hedging demands for commodity futures. Increases in producers' hedging demand or speculators' capital constraints increase hedging costs via price-pressure on futures. These in turn affect producers' equilibrium hedging and supply decision inducing a link between a financial friction in the futures market and the commodity spot prices. Consistent with the model, measures of producers' propensity to hedge forecasts futures returns and spot prices in oil and gas market data from 1979 to 2010. The component of the commodity futures risk premium associated with producer hedging demand rises when speculative activity reduces. We conclude that limits to financial arbitrage generate limits to hedging by producers, and affect equilibrium commodity supply and prices.     

Hedging effectiveness under conditions of asymmetry

We examine whether hedging effectiveness is affected by asymmetry in the return distribution by applying tail-specific metrics, for example, value at risk, to compare the hedging effectiveness of short and long hedgers. Comparisons are applied to a number of hedging strategies including OLS and both symmetric and asymmetric generalised autoregressive conditional heteroskedastic models. We apply our analysis to a dataset consisting of S&P500 index cash and futures containing symmetric and asymmetric return distributions chosen ex post. Our findings show that asymmetry reduces out-of-sample hedging performance and that significant differences occur in hedging performance between short and long hedgers.     

A note on managing deposit flows with cash and futures market decisions

As deposit market become less regulated, financial intermediaries must focus more of their attention on the explicit pricing of deposit accounts. An implication of pricing deposits is that the intermediary faces a random source of funds when future deposit supplies are unknown. This note shows that financial futures contracts can be used to hedge the risk of deposit withdrawals, allowing the financial firm to set lower deposit rates than it would without futures trading. A model of risk averse banking behavior is constructed to determine the relationship between hedging deposit withdrawals and setting deposit rates. Using the certificate of deposit futures contract to hedge demand and savings deposit withdrawals, an empirical application of the model reveals that the possible gains in profitability from setting deposit rates and hedging withdrawals are small but statistically significant.     

中国期货市场套期保值绩效实证研究

为了研究中国期货市场的套期保值绩效，本文利用确定套期保值比率的OLS、B-VAR、ECHM和EC—GARCH四个模型和套期保值绩效的衡量指标，对中国期货的小麦、大豆、铜和铝的套期保值比率和绩效进行了实证研究，使用1998～2004年中国期货与现货价格的周数据来进行单位根和协整检验等计量分析。研究显示，金属期货品种的套期保值比率和绩效比农产品期货品种的套期保值比率和绩效都要高。考虑了协整关系的ECHM和EC—GARCH模型的套期保值比率和绩效比没有考虑协整关系的OLS和B—VAR模型高，样本区间外的套期保值绩效优于样本区间内的绩效。本文认为采用ECMH和EC—GARCH模型进行套朔保值是最佳的策略。     

Analyzing hedging strategies for fixed income portfolios: A Bayesian approach for model selection

During the recent European sovereign debt crisis, returns on EMU government bond portfolios experienced substantial volatility clustering, leptokurtosis and skewed returns as well as correlation spikes. Asset managers invested in European government bonds had to derive new hedging strategies to deal with changing return properties and higher levels of uncertainty. In this environment, conditional time series approaches such as GARCH models might be better suited to achieve a superior hedging performance relative to unconditional hedging approaches such as OLS. The aim of this study is to test innovative hedging strategies for EMU bond portfolios for non-crisis and crisis periods. We analyze single and composite hedges with the German Bund and the Italian BTP futures contracts and evaluate the hedging effectiveness in an out-of-sample setting. The empirical analysis includes OLS, constant conditional correlation (CCC), and dynamic conditional correlation (DCC) multivariate GARCH models. We also introduce a Bayesian composite hedging strategy, attempting to combine the strengths of OLS and GARCH models, thereby endogenizing the dilemma of selecting the best estimation model. Our empirical results demonstrate that the Bayesian composite hedging strategy achieves the highest hedging effectiveness and compares particularly favorable to OLS during the recent sovereign debt crisis. However, capturing these benefits requires low transactions cost and efficiently functioning futures markets.     

Alternative settlement methods and Australian individual share futures contracts

Individual share futures contracts have been introduced in Australia since 1994. Initially, the contracts were settled in cash. In 1996, cash settlement was gradually replaced by physical delivery. This study investigates the effects of the settlement method change on Australian individual stock and its futures markets. Specifically, we examine whether return and volatility of each market, correlation between the two markets, basis behavior, and hedging performance of futures markets differ across cash settlement period and physical delivery period. We find that, after the switch from cash settlement to physical delivery, the futures market, the spot market, and the basis all become more volatile. However, each individual share futures contract becomes a more effective hedging instrument. The improvement in hedging effectiveness is particularly impressive for the most recently established individual share futures contracts.     

Hedging Pressure Effects in Futures Markets

We present a simple model implying that futures risk premia depend on both own-market and cross-market hedging pressures. Empirical evidence from 20 futures markets, divided into four groups (financial, agricultural, mineral, and currency) indicates that, after controlling for systematic risk, both the futures own hedging pressure and cross-hedging pressures from within the group significantly affect futures returns. These effects remain significant after controlling for a measure of price pressure. Finally, we show that hedging pressure also contains explanatory power for returns on the underlying asset, as predicted by the model.     

Cross hedging under multiplicative basis risk

Cross hedging price risk in an incomplete financial market creates basis risk. We propose a new way of modeling basis risk where price risk and basis risk are combined in a multiplicative way. Under this specification, positive prudence is a necessary and sufficient condition for underhedging in an unbiased market. Using the example of cross hedging jet fuel price risk with crude oil futures, we show that the new specification is superior in describing the price series and that optimal cross hedges differ significantly from those derived under the traditional additive cross hedging model.     

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。     

Can modeling the natural gas futures market as a threshold cointegrated system improve hedging and forecasting performance?

The calculation of the hedge ratio, and therefore the effectiveness of the hedge, is dependent upon the correct specification of the relationship between the futures and spot price. Likewise, a forecast of the future spot or futures price is dependent upon the model specification. This article investigates the appropriateness of using a threshold cointegrated model of the natural gas markets as the basis for hedging and forecasting. The findings suggest that the threshold model is more appropriate for longer contract length and that the threshold model does not offer much improvement in hedging or forecasting efficiency.