Market volatility and the demand for hedging in stock index futures

This study examines the relation between stock market volatility and the demand for hedging in S&P 500 stock index futures contracts. Open interest is used as a proxy for hedging demand. The analysis employs unique data that identify separately the open interest of large hedgers, large speculators, and smaller traders. Volatility estimates are decomposed into expected and unexpected components, to assess whether traders’ reactions to volatility depend upon its predictability. Results indicate that daily open interest for hedgers increases when unexpected volatility increases. Increases in unexpected volatility may cause hedgers to raise their estimates of future expected volatility, and hence increase their demand for hedging. Open interest of speculators is not related to expected volatility, and is only weakly related to unexpected volatility. The increase in the participation of hedgers in periods of higher volatility is significantly larger than the increase in the participation of speculators. The results suggest that increases in stock market volatility increase the demand for hedging. © 2000 John Wiley & Sons, Inc. Jrl Fut Mark 20: 105–125, 2000     

中国股市收益与经济增长背离现象的协整性检验

近年来很多专家学者已经注意到了中国股市收益与经济增长相背离的现象,并将这种现象称之为“股经背离”。应用计量经济学中的协整理论,对我国股市收益与经济增长的关系进行实证分析,结果表明,代表虚拟经济的股市和代表实体经济的经济增长之间并不具有长期的均衡关系,从而用计量经济学的方法进一步证实了“股经背离”现象的存在。     

The information content of option implied volatility surrounding the 1997 Hong Kong stock market crash

This study examines the information conveyed by options and examines their implied volatility at the time of the 1997 Hong Kong stock market crash. The author determines the efficiency of implied volatility as a predictor of future volatility by comparing it to other leading indicator candidates. These include volume and open interest of index options and futures, as well as the arbitrage basis of index futures. Using monthly, nonoverlapping data, the study reveals that implied volatility is superior to those variables in forecasting future realized volatility. The study also demonstrates that a simple signal extraction model could have produced useful warning signals prior to periods of extreme volatility. These results indicate that the options market is highly efficient informationally. © 2007 Wiley Periodicals, Inc. Jrl Fut Mark 27:555–574, 2007     

What do we know about individual equity options?

This paper examines the empirical literature on individual equity options, discussing results in areas of consensus, showing findings in areas of disagreement and providing a guide for future research (especially highlighting analyses that cannot be performed with index options). Key topics include the impact of equity option listings on the underlying stock market, option market efficiency, anomalies in equity option returns, option market microstructure, investors’ behavioral biases, option price discovery, and private information revealed in equity option markets. Some directions for future research include the determinants of equity option returns and the effect of algorithmic trading in option markets.     

The behavior and performance of major types of futures traders

This article examines the behavior and performance of speculators and hedgers in 15 U.S. futures markets. We find that after controlling for market risk factors, speculators are contrarians, but respond positively to market sentiment. In contrast, hedgers engage in positive feedback trading and trade against market sentiment. We also find that trades of speculators (hedgers) are positively (negatively) correlated with subsequent abnormal returns; however, it does not appear that speculators possess superior forecasting power. Therefore, hedging pressure effects likely explain the negative relation between the performance of speculators and hedgers. The positive feedback trading by hedgers together with their negative performance suggests that hedgers have a destabilizing impact on futures prices. © 2003 Wiley Periodicals, Inc. Jrl Fut Mark 23:1–31, 2003     

Pricing Stock Options in a Jump‐Diffusion Model with Stochastic Volatility and Interest Rates: Applications of Fourier Inversion Methods

Fast closed form solutions for prices on European stock options are developed in a jump‐diffusion model with stochastic volatility and stochastic interest rates. The probability functions in the solutions are computed by using the Fourier inversion formula for distribution functions. The model is calibrated for the S and P 500 and is used to analyze several effects on option prices, including interest rate variability, the negative correlation between stock returns and volatility, and the negative correlation between stock returns and interest rates.     

Volatility Spillovers and the Risk-Return Relation Between Stock and Foreign Exchange Markets in Brazil

We examine the evidence of mean and volatility spillovers between stock and foreign exchange markets in Brazil with multivariate GARCH models and nonlinear Granger causality tests. We also use a multivariate GARCH-in-mean model to assess the relationship between risk and return in these markets. The results indicate that the stock market leads the foreign exchange market in price formation and that nonlinear Granger causalities from the exchange market to the stock market do occur. Part of these nonlinear causalities are explained by volatility spillovers. We show that exchange rate volatility affects not only stock market volatility but also stock returns.     

Jump variance risk: Evidence from option valuation and stock returns

We study jump variance risk by jointly examining both stock and option markets. We develop a GARCH option pricing model with jump variance dynamics and a nonmonotonic pricing kernel featuring jump variance risk premium. The model yields a closed-form option pricing formula and improves in fitting index options from 1996 to 2015. The model-implied jump variance risk premium has predictive power for future market returns. In the cross-section, heterogeneity in exposures to jump variance risk leads to a 6% difference in risk-adjusted returns annually.     

The capital market spillover effect of product market advertising: Evidence from stock price synchronicity

We analyze whether product market advertising has a spillover effect on stock price synchronicity by transmitting firm-specific information to the capital market and attracting more investor attention. Using a sample of Chinese listed firms from 2009 to 2017, we find that firms with greater advertising expenditures have lower stock price synchronicity. The results are robust after we address endogeneity concerns. In accord with our hypothesis that product market advertising increases the amount of firm-level information capitalized into stock prices through the information channel, we find that the impact of advertising on synchronicity is more pronounced for firms with a higher degree of information asymmetry and firms in the consumer-product industry. Further tests show that product market advertising enhances the ability of current period returns to reflect future earnings, and thus rules out that the negative relationship between advertising and synchronicity is driven by noise trading. Our results imply that product market advertising plays an informative role and improves information efficiency in a capital market.     

通货膨胀幻觉对中国股市的影响分析

上海A股市价格波动无法用红利与无风险利率的变化来解释。通过实证分析发现,跟传统理论相反,中国股价跟通货膨胀呈现反向关系。其原因在于Fed模型的拥护者将E/P跟名义利率进行比较来判断股市估值是否合理。中国投资者中存在通货膨胀幻觉。通货膨胀幻觉假设在一定程度上能够解释上海A股市场价格变化,特别是该假设能解释1996-2001年的大牛市。     

国际股票市场收益率和波动率的长记忆性研究

股票市场长记忆性问题是金融学研究的一个热点问题,对于市场有效性的研究和系统非线性结构的分析有着重要的意义。本文运用修正R/S分析和V/S分析两种方法对世界上28个国家(地区)的股票指数的日、周收益序列和日、周收益波动序列进行了完整的长记忆性研究。结果表明:对于收益序列,以美国为代表的大多数发达国家股市一般不存在长记忆性,而中国等发展中国家大多存在显著的长记忆性,尤其中国股市的长记忆性最强;对于收益波动序列,所有国家(地区)都具有长记忆性,并强于收益序列。     

Abnormal trading volume and autoregressive behavior in weekly stock returns in the Saudi stock market

This paper examines the relationship between the abnormal change in trading volume of both individual stocks and portfolios and short-term price autoregressive behavior in the Saudi stock market (SSM). Our objective is to investigate the informational role that trading volume plays in predicting the direction of short-term returns. We evaluate whether the abnormal change in lagged, contemporaneous, and lead turnovers affects serial correlation in returns. Specifically, we examine if and when the change in volume produces momentum (positive correlation) or reversal (negative autocorrelation) in consecutive weekly stock returns.We find a reversal in weekly stock returns when conditioned on the change in lagged volume in the SSM. Our results are consistent for the whole sample, the two sub-sample periods, and the large- and small-firm portfolios. The results are consistent with Campbell, Grossman, and Wang [Campbell, J. Y., S. J. Grossman, and J. Wang, 1993, Trading volume and serial correlation in stock returns, Quarterly Journal of Economics, 108, 905–939], who present a model in which risk-averse market makers accommodate the selling pressure of liquidity or non-informational traders. We also find that reversal is more pronounced with the loser portfolio as specified by filter-based methodology. The overall result of this paper is also consistent with the empirical findings of Conrad, Hameed, and Niden [Conrad, J., A. Hameed, and C. Niden, 1994, Volume and autocovariances in short-horizon individual security returns, Journal of Finance 49, 1305–1329.] and Gebka [Gebka, B., 2005, Dynamic volume-return relationship: evidence from an emerging market, Applied Financial Economics, 15, 1019–1029] in which they report price reversal for stock with high trading volume.     

Weak-Form Market Efficiency of the Nigerian Stock Market in the Context of Financial Reforms and Global Financial Crises

The weak-form efficient market hypothesis for the Nigerian Stock Market (NSM) is explored using different statistical tests. The analyses use overall stock market returns collected over the period 2000–2010. It is shown that the NSM is not weak-form efficient which questions the benefits of the 2004 financial reforms. It is also shown that the degree of market inefficiency varies across the periods corresponding to the financial reforms and 2007 global financial crisis, for daily and monthly returns. The results are important to security analysts, investors, and security exchange regulatory agencies in their investment, stock market development, and policy-making decisions.     

Is There Long Memory in Indian Stock Market Returns? An Empirical Search

The issue of long memory, though has important theoretical and practical implications, has not received much attention in India. This article examines the issue of long memory in mean of the stock returns by employing a set of sophisticated time-series tests including a bias reduced log periodogram test of Andrews and Guggenberger. The study used daily values of 29 major indices including sectoral indices traded on the National Stock Exchange and Bombay Stock Exchange from April 2003 to March 2012, which provide insights into relation between composition of indices and long memory. The findings of the study suggest significant presence of long memory in mean returns of the medium- and small-sized indices and weaker evidences for large cap indices. Further, the study identifies a relationship between presence of long memory and market structure variables. The use of linear models in the presence of long memory would result in incorrect inferences, and this calls for investigation of appropriate long memory model to generate profits in Indian stock market.     

Stock option taxation: a missing piece in European innovation policy?

Europe continues to lag behind the USA in venture capital (VC) activity and in the creation of successful startups, and has recently been surpassed by China. This is despite the fact that many European countries have deep financial markets, strong legal institutions, and high R&D spending. We point to the tax treatment of employee stock options as an explanation for the stronger growth of the US VC sector. As a response to high uncertainty and transaction costs, VC financiers have developed a model in which founders and key recruitments are compensated with stock options under complex contracts. Low tax rates on employee stock options further raise the relative returns of working and investing in innovative entrepreneurial firms, and shift financial capital and talent to that sector. We measure the effective tax on stock options in VC-backed entrepreneurial firms in a number of developed economies. Countries with lower stock option taxation have higher VC activity and more high-growth expectation entrepreneurial activity. Based on these associations and the theoretical and empirical literature, we argue that more lenient taxation of gains on employee stock options can be a strategy for European countries to catch up in entrepreneurial finance. This tax policy would narrowly target entrepreneurial startups without requiring broad tax cuts. The favorable tax treatment of stock options allows the state to promote firms that rely on entrepreneurial finance and make use of these types of contracts without lowering taxes for other sectors of the economy.     

中国开放式基金表现的动态能力研究

本文以中信指数与中信债券指数的加权超额收益率为市场基准 ,以GDP增长率和消费物价指数的增长率以及广义货币供给增长率为条件变量 ,构建了证券投资基金表现的条件评价模型 ,对中国开放式证券投资基金的选股能力和市场时机把握能力进行了测度。计量方法上采用混合数据模型的回归方法以提高回归结果的有效性。研究结论为 :中国开放式基金不但具有一定的选股能力 ,而且具有良好的市场时机把握能力 ;条件模型的解释能力高于无条件模型。     

The information content in implied idiosyncratic volatility and the cross‐section of stock returns: Evidence from the option markets

Current literature is inconclusive as to whether idiosyncratic risk influences future stock returns and the direction of the impact. Earlier studies are based on historical realized volatility. Implied volatilities from option prices represent the market's assessment of future risk and are likely a superior measure to historical realized volatility. Implied idiosyncratic volatilities on firms with traded options are used to examine the relationship between idiosyncratic volatility and future returns. A strong positive link was found between implied idiosyncratic risk and future returns. After considering the impact of implied idiosyncratic volatility, historical realized idiosyncratic volatility is unimportant. This performance is strongly tied to small size and high book‐to‐market equity firms. © 2008 Wiley Periodicals, Inc. Jrl Fut Mark 28: 1013–1039, 2008     

股市收益和波动性长期记忆的国际比较——基于V/S的经验证据

现有研究运用经典和修正R/S分析探讨我国股票市场的长期记忆效应。本文运用更为稳健的V/S分析,对比研究上证股市和另外7个国家和地区的股票市场,分别诊断各股市日收益和周收益、及三种典型度量的收益波动的长期记忆效应。研究表明:股市日收益和周收益序列都不存在显著的长期记忆;三种典型度量的收益波动普遍存在显著的长期记忆;日收益波动比周收益波动的长期记忆更显著。     

The information content of implied volatility: Evidence from Australia

This study develops an implied volatility index for the Australian stock market, termed as the AVX, and assesses its information content. The AVX is constructed using S&P/ASX 200 index options with a constant time‐to‐maturity of three months. It is observed that the AVX has a significant negative and asymmetric relationship with S&P/ASX 200 returns. When evaluating the forecasting power of the AVX for future stock market volatility, it is found that the AVX contains important information both in‐sample and out‐of‐sample. In‐sample, the AVX significantly improves the fit of a GJR‐GARCH(1, 1) model. Out‐of‐sample, the AVX significantly outperforms the RiskMetrics approach and the GJR‐GARCH(1, 1) model, with its highest forecasting power at the one‐month forecasting horizon. © 2009 Wiley Periodicals, Inc. Jrl Fut Mark 30:134–155, 2010     

"利率通道"调控模式对我国利率市场化改革的启示

金融自由化理论的发展对各国金融改革提供了理论支持,我国正在进行的利率市场化改革,迫切需要构建适合实际和发展需要的利率调控模式,所以必须了解“利率通道”调控模式的运行机制,运用实证数据对“利率通道”调控模式进行模拟分析,从而建立以“利率通道”调控为主、公开市场操作调控为辅的利率调控模式作为我国利率市场化改革的选择。