沪港股市收益波动性的实证研究

由于受地理位置、经济文化等因素的影响,沪港股票市场在收益率波动性上存在相关性。本文利用ARCH族模型及Granger非因果检验对沪港股市收益波动性进行了实证研究,结果表明:沪港股市的收益率波动存在中等程度的正相关性;港市收益率对沪市收益率具有一期前导作用;两市的收益波动仅存在显著的港市对沪市的单向"溢出效应";而且两市的收益波动均存在明显的"杠杆效应"。     

沪港股市收益波动性的实证研究

由于受地理位置、经济文化等因素的影响,沪港股票市场在收益率波动性上存在相关性。本文利用ARCH族模型及Granger非因果检验对沪港股市收益波动性进行了实证研究,结果表明:沪港股市的收益率波动存在中等程度的正相关性;港市收益率对沪市收益率具有一期前导作用;两市的收益波动仅存在显著的港市对沪市的单向"溢出效应";而且两市的收益波动均存在明显的"杠杆效应"。     

基于ARCH族模型的白银市场与黄金市场收益率波动性研究

本文选取上海黄金交易所2006年10月至2015年12月的白银与黄金合约产品的日交易数据,通过运用ARCH族模型,分析白银市场与黄金市场的ARCH效应、杠杆效应与波动溢出效应。结果发现白银与黄金日收益率序列具有明显的ARCH效应,利好消息比利空消息在白银市场上能产生更大的影响,而利空消息在黄金市场会产生更大的市场波动。白银市场与黄金市场存在双向影响,但黄金市场对白银市场的影响更加明显。     

股票市场与外汇市场收益率波动溢出效应研究——基于多元BEKK-GARCH模型

用多元BEKK-GARCH模型检验了股票市场与外汇市场收益率的波动溢出效应,结合LR似然比检验和Wald检验,实证研究股票市场和外汇市场收益率的波动关系。研究表明:股票市场与外汇市场收益率序列都存在ARCH效应和GARCH效应,即都具有时变方差特征;且两市的波动具有较高的持续性。股票市场和外汇市场收益率存在单向的,不对称的溢出效应,即汇市对股市有波动溢出效应,反之则不然。     

基于GARCH模型对我国创业板波动性的实证研究

本文选取了2014年1月6日至2017年2月14日的创业板指数作为样本,分别运用ARCH模型、GARCH模型对创业板指数收益率的波动性以及波动的非对称性进行了初步研究。实证分析显示:创业板指数存在杠杆效应,其波动表现出集群现象和持久性,而且序列波动具有显著的非对称性。最后,本文根据我国创业板指数的波动特征,提出了相应的应对措施和建议。     

我国债市和汇市溢出效应的实证研究——基于VAR-GARCH-BEKK模型

利用VAR-GARCH-BEKK模型,研究了我国债市和汇市之间的价格和波动溢出效应。实证研究表明,债市和汇市收益率都呈现高峰厚尾的非正态分布,波动聚集特征显著;债市和汇市存在单向溢出效应,仅汇市对债市有价格和波动溢出效应;债市和汇市收益率序列总体呈现负相关,相关性较弱,样本期内两市场动态相关系数具有显著的时变性。     

国际石油价格波动对中国股票市场的风险溢出效应

由于交易时间上的不对称,采用非对称性调整方法对上证指数进行了滞后1期的调整,在此基础上,对非对称性调整前后的数据分别采用了Granger因果关系检验、向量自回归(VAR)模型、脉冲响应函数(IRF)、预测误差方差分解(FEVD)的方法以及MGARCH-BEKK(1,1)模型对纽约商业交易所(NYMEX)的西德克萨斯州中质油现货价格日对数收益率和上证指数日对数收益率之间的均值溢出效应和波动率溢出效应进行分析研究。研究结果表明,总体来说,两市收益率之间的风险溢出效应十分微弱和不稳定,但从2007年开始,这种风险溢出效应变得更显著,主要表现在WTI原油市场对上证指数具有正的均值溢出效应和正的波动率溢出效应。     

中国债券市场与股票市场间波动溢出效应——基于SJC-Copula模型的分析

本文基于SJC-Copula模型分析债券市场和股票市场间的波动溢出效应,并以此进一步分析波动溢出效应对债券市场风险规避能力的影响。研究选取2003年3月31日至2009年8月31日中信标普国债指数日数据和上证指数日数据,验证了两市波动溢出效应的存在性,同时发现波动溢出效应显著增强了债券市场规避风险的能力。     

我国上证A股指数收益波动性的研究

本文运用ARCH族模型对我国上证A股股指日收益率及波动性进行实证研究,探索我国A股股指收益率波动特征。实证研究结果发现:上证A股股指日收益率呈现明显的波动集群性特征,因此我国证券市场表现出的波动幅度和风险性要远远大大高于国外成熟的资本市场;我国股票市场存在显著的信息非对称性和杠杆效应,尤其是股票市场好消息导致的市场波动比同等大小的坏消息引起的波动要小。研究结果显示回归模型存在自回归条件异方差,这表明我国股票市场波动具有条件异方差效应。     

我国上证A股指数收益波动性的研究

本文运用ARCH族模型对我国上证A股股指日收益率及波动性进行实证研究,探索我国A股股指收益率波动特征。实证研究结果发现:上证A股股指日收益率呈现明显的波动集群性特征,因此我国证券市场表现出的波动幅度和风险性要远远大大高于国外成熟的资本市场;我国股票市场存在显著的信息非对称性和杠杆效应,尤其是股票市场好消息导致的市场波动比同等大小的坏消息引起的波动要小。研究结果显示回归模型存在自回归条件异方差,这表明我国股票市场波动具有条件异方差效应。     

上海金属期货市场的非线性波动特征研究

期货市场是一个典型的非线性动力系统,通过对上海期货交易所(SHFE)的铜、铝期货合约进行非线性波动特征检验,采用基于GED(广义误差分布)的GARCH族模型考察期货收益率的ARCH效应、杠杆效应,并用R/S分析法检验期货收益率和波动率的长期记忆性,得到的实证结果表明:铜、铝期货价格波动有明显的集丛性,铜期货收益率波动没有"杠杆效应",而对铝期货来说,"利好"对条件方差的冲击大于"利空"的冲击.R/S分析结果显示:铜、铝期货收益率均呈现长期记忆性,铜期货有一个约43个日历月的非周期循环,而铝期货并没有明显的非周期循环.更重要的是,实证结果表明期货收益波动率有明显的长期记忆性,因此,在对期货市场波动率建模时应充分考虑这一点.     

Evaluating the Forecast Accuracy of Emerging Market Stock Returns

This paper analyzes the forecast performance of emerging market stock returns using standard autoregressive moving average (ARMA) and more elaborated autoregressive conditional heteroskedasticity (ARCH) models. Our results indicate that the ARMA and ARCH specifications generally outperform random walk models. Models that allow for asymmetric shocks to volatility are better for in-sample estimation (threshold autoregressive conditional heteroskedasticity for daily returns and exponential generalized autoregressive conditional heteroskedasticity for longer periods), and ARMA models are better for out-of-sample forecasts. The results are valid using both U. S. dollar and domestic currencies. Overall, the forecast errors of each Latin American market can be explained by the forecasts of other Latin American markets and Asian markets. The forecast errors of each Asian market can be explained by the forecasts of other Asian markets, but not by Latin American markets. Our predictability results are economically significant and may be useful for portfolio managers to enter or leave the market.     

中国股市开、收盘波动性的比较研究

利用EGARCH模型,对2000年1月至2007年4月间沪深两市具有代表性的股票及指数的开收盘收益率的波动性进行实证分析,结果表明收益率序列有明显的ARCH效应,其波动性具有显著的非对称性的冲击的持续性;在样本期内,上交所的个股和指数未能观察到开盘波动性高于收盘波动性的现象,而深交所个股在2006年7月实施收盘集合竞价机制之后比较明显地观察到开盘波动性高于收盘波动性的现象。     

中国股票市场波动性研究：模型选择及实证

以日收盘数据计算出的市场日收益率作为研究的基础数据,利用准极大似然估计方法QML估计三种ARCH类模型(GARCH、T-GARCH和E-GARCH)对中国股市波动性与稳定性的运行效果进行了实证研究的结果,得出EGARCH(1,1)模型是最优的拟合模型。运用最优模型实证发现中国股市不仅波动性很大,而且波动是不对称的。     

国际商品市场与股票市场的溢出效应——基于中美数据的VAR-MGARCH分析

基于VAR-MGARCH-BEKK模型,对国际商品市场与中美股票市场之间的均值与波动溢出效应进行了经验分析。结果表明,国际商品市场与中美股票市场之间存在着相互的均值溢出效应,国际商品市场对中美股票市场存在波动溢出效应,同时,美国股票市场对国际商品市场存在波动溢出效应;另外,中国应该尽快编制科学合理并适合自身国情的商品指数。     

VOLATILITY FORECASTS,TRADING VOLUME,AND THE ARCH VERSUS OPTION‐IMPLIED VOLATILITY TRADE‐OFF

We investigate empirically the role of trading volume (1) in predicting the relative informativeness of volatility forecasts produced by autoregressive conditional heteroskedasticity (ARCH) models versus the volatility forecasts derived from option prices, and (2) in improving volatility forecasts produced by ARCH and option models and combinations of models. Daily and monthly data are explored. We find that if trading volume was low during period t?1 relative to the recent past, ARCH is at least as important as options for forecasting future stock market volatility. Conversely, if volume was high during period t?1 relative to the recent past, option‐implied volatility is much more important than ARCH for forecasting future volatility. Considering relative trading volume as a proxy for changes in the set of information available to investors, our findings reveal an important switching role for trading volume between a volatility forecast that reflects relatively stale information (the historical ARCH estimate) and the option‐implied forward‐looking estimate.     

Volatility forecasts and at-the-money implied volatility: a multi-component ARCH approach and its relation to market models

This article explores the relationships between several forecasts for the volatility built from multi-scale linear ARCH processes, and linear market models for the forward variance. This shows that the structures of the forecast equations are identical, but with different dependencies on the forecast horizon. The process equations for the forward variance are induced by the process equations for an ARCH model, but postulated in a market model. In the ARCH case, they are different from the usual diffusive type. The conceptual differences between both approaches and their implication for volatility forecasts are analysed. The volatility forecast is compared with the realized volatility (the volatility that will occur between date t and t + ΔT), and the implied volatility (corresponding to an at-the-money option with expiry at t + ΔT). For the ARCH forecasts, the parameters are set a priori. An empirical analysis across multiple time horizons ΔT shows that a forecast provided by an I-GARCH(1) process (one time scale) does not capture correctly the dynamics of the realized volatility. An I-GARCH(2) process (two time scales, similar to GARCH(1,1)) is better, while a long-memory LM-ARCH process (multiple time scales) replicates correctly the dynamics of the implied and realized volatilities and delivers consistently good forecasts for the realized volatility.     

Good News,Bad News,Volatility, and Betas

We investigate the conditional covariances of stock returns using bivariate exponential ARCH (EGARCH) models. These models allow market volatility, portfolio-specific volatility, and beta to respond asymmetrically to positive and negative market and portfolio returns, i.e., “leverage” effects. Using monthly data, we find strong evidence of conditional heteroskedasticity in both market and non-market components of returns, and weaker evidence of time-varying conditional betas. Surprisingly while leverage effects appear strong in the market component of volatility, they are absent in conditional betas and weak and/or inconsistent in nonmarket sources of risk.     

The quality of market volatility forecasts implied by S&P 100 index option prices

This study examines the performance of the S&P 100 implied volatility as a forecast of future stock market volatility. The results indicate that the implied volatility is an upward biased forecast, but also that it contains relevant information regarding future volatility. The implied volatility dominates the historical volatility rate in terms of ex ante forecasting power, and its forecast error is orthogonal to parameters frequently linked to conditional volatility, including those employed in various ARCH specifications. These findings suggest that a linear model which corrects for the implied volatility's bias can provide a useful market-based estimator of conditional volatility.     

The dynamic interaction between volatility and returns in the US stock market using leveraged bootstrap simulations

One of the most important stylized facts in finance is that stock index returns are inversely related to volatility. The theoretical rationale behind the proposition is still controversial. The causal relationship between returns and volatility is investigated in the US stock market over the period 2004-2009 using daily data. We apply a bootstrap test with leveraged adjustments that is robust to non-normality and ARCH. We find that the volatility causes returns negatively and returns cause volatility positively. The policy implications of our findings are discussed in the main text.