Causal and Dynamic Relationships among Stock Returns,Return Volatility and Trading Volume: Evidence from Emerging markets in South-East Asia

This paper examines the causal and dynamic relationships among stock returns, return volatility and trading volume for five emerging markets in South-East Asia—Indonesia, Malaysia, Philippines, Singapore and Thailand. We find strong evidence of asymmetry in the relationship between the stock returns and trading volume; returns are important in predicting their future dynamics as well as those of the trading volume, but trading volume has a very limited impact on the future dynamics of stock returns. However, the trading volume of some markets seems to contain information that is useful in predicting future dynamics of return volatility.     

融资融券对我国股市波动性的影响

本文采集股价指数月收益率和融资融券交易额每月日平均变化率的数据,针对融资融券对我国股市波动性的影响,进行实证检验,并对结果做进一步的解释。     

Forecasting Stock Index Futures Price Volatility: Linear vs. Nonlinear Models

The study examines the relative ability of various models to forecast daily stock index futures volatility. The forecasting models that are employed range from naïve models to the relatively complex ARCH-class models. It is found that among linear models of stock index futures volatility, the autoregressive model ranks first using the RMSE and MAPE criteria. We also examine three nonlinear models. These models are GARCH-M, EGARCH, and ESTAR. We find that nonlinear GARCH models dominate linear models utilizing the RMSE and the MAPE error statistics and EGARCH appears to be the best model for forecasting stock index futures price volatility.     

Information Asymmetry and the Bid‐Ask Spread: Evidence From the UK

Abstract:   The generally accepted factors that determine the bid‐ask spread are volatility, trading volume and market value ( Atkins and Dyl, 1997 ; Glosten and Harris, 1988 ; and Menyah and Paudyal, 2000 ). Following Kim and Verrecchia (1994) we include a measure of the disagreement in analysts' earnings forecasts in our model of the bid ask spread. This measure serves as a proxy for the informational disadvantage of market makers with respect to informed traders. Market makers respond to the additional risk by increasing the bid‐ask spread. We find that the disagreement amongst analysts is significant for horizons up to and including six months (and with the hypothesised sign) in explaining FTSE 100 company spreads, rendering strong empirical support for our model.     

The Impact of Information Release on Stock Price Volatility and Trading Volume: The Rights Offering Case

This paper examines whether information released via rights offering announcements induces changes in price volatility and trading volume of underlying stock. The results of this paper provide support for the release of new information via offering announcements and evidence of its effects on price volatility and volume of underlying stock. Specifically, utilization of the announced information by investors is evidenced by greater trading volume following the announcement date than during the pre-announcement period. We interpret this result to mean that informedness dominates consensus. However, stock price volatility decreased from the pre-announcement period to the post-expiration period of rights offerings.     

Are Economically Significant Stock Returns and Trading Volumes Driven by Firm‐specific News Releases?

This paper explores whether firm‐specific information events drive economically relevant positive and negative stock price changes and trading volume and, if so, the nature of such information. We find that no less than 65% of significant price changes and trading volume movements in our sample of FTSE 350 companies can be readily explained by public domain information contradicting the thesis that corporate news is not a primary driver, and that share price changes and trading volume activity are driven by factors unrelated to information flows per se. In addition, we find that a parsimonious set of news categories represent the key drivers. Sell‐side analyst stock recommendations and earnings forecast revisions as a class, unaccompanied by other news releases, dominate all other news categories in terms of significant market reaction. However, taking into account the relative magnitude of market response to different news releases, firms' formal accounting disclosures dominate within this domain. As such, we conclude these are not fully anticipated by apparently more timely market disclosures, and that the existence of news services and the activities of the sell‐side analyst are not substitutes for a firm's interim and preliminary results.     

Insider trading and future stock returns in firms with concentrated ownership levels

We investigate the relationship between insider trading and stock returns in firms with concentrated ownership. To this end, we employ data from East Asian countries which span the period January 2003 to May 2012. Consistent with the previous literature, we find a significantly negative relation between the selling activity of insiders and stock returns. However, contrary to studies which focus on highly developed markets, we find that the buying activity of insiders is also inversely related to future stock returns. Our analysis shows that top directors with higher ownership levels drive this result, suggesting that the trading activity of insiders is not always associated with profit-making motives and can be explained by their level of ownership. Furthermore, we demonstrate that a trading strategy which focuses solely on purchases made by top directors with high ownership levels yields negative returns. The paper has important implications for outside investors who mimic the trading activity of insiders with the aim to realise profits.     

股指期货到期日效应在中国存在吗

本文选取1分钟高频数据作为研究对象,采用带有虚拟变量的自回归模型对沪深300股指期货合约是否具有到期日效应展开实证研究。研究的主要结论有：第一,股指期货合约到期日时,现货市场并没有出现交易量异常放大的现象,反而在到期日的最后两个小时,现货市场的交易量出现异常减少的现象;第二,股指期货合约到期日时,现货市场的波动率并没有出现异常的变化。由以上两个结论来看,沪深300股指期货合约并没有出现所谓的到期日效应,这与我国设计合理的交割结算价确定机制以及特殊的期货市场投资者结构有关。     

Corporate Sales, Equity Trading, and Risk

This paper proposes and investigates an explanation for a positive association between the signed value of common share returns and trading activity. The mixture of distributions model for stock returns and trading is applied with the added assumption that product sales for a firm is the directing process which generates the flow of information to equity markets. Because trading depends upon information arrival, sales and trading are positively related. Also, because contribution margin is positive, cash flows increase with sales. Dependence of both cash flows and trading on sales implies that returns and trading are also positively related. This explanation is tested in this paper.     

Volatility Spillovers Between Stock Returns and Exchange Rate Changes: International Evidence

We investigate interdependencies between stock returns and exchange rate changes for six industrialised countries, namely the US, the UK, Japan, Germany, France and Canada, by testing for volatility spillovers using a bivariate EGARCH model. Volatility spillovers from stock returns to exchange rate changes are found for all countries except Germany. These spillovers are symmetric in nature. No evidence is found of volatility spillovers from exchange rate changes to stock returns for any country. Spillovers from stock returns to exchange rate changes have increased since October 1987. This finding is consistent with the notion that international financial markets have become increasingly integrated.     

Market Structure and Return Volatility: Evidence from the Hong Kong Stock Market

There is no consensus about the cause for higher volatility at the market open than at the market close in the U.S. market. As an order–driven, nonspecialist market, the Hong Kong stock market provides a useful setting for an examination. If halt of trade were the major cause of higher open–to–open volatility, the open–to–open volatility in the Hong Kong market would be higher. However, this is not observed. The autocorrelation of the open–to–open return series also indicates that the temporary price deviation at the market opening is not significant. We view these findings as consistent with the specialist argument.     

The calm after the storm: implied volatility and future stock index returns

This article explores the predictive power of five implied volatility indices for subsequent returns on the corresponding underlying stock indices from January 2000 through October 2013. Contrary to previous research, very low volatility levels appear to be followed by significantly positive average returns over the next 20, 40 or 60 trading days. Rolling trading simulations show that positive adjusted excess returns can be achieved when long positions in the stock indices are taken on days of very low implied volatility. This may be a hint that market inefficiencies exist in some markets, especially outside the USA. The excess returns measured against a buy and hold benchmark are significant for the German and Japanese market when tested with a bootstrap methodology. The results are robust against a broad spectrum of specifications.     

机构投资者大幅增减仓对股票价格的影响研究--基于2014年中报数据的实证分析

运用事件研究法,选取2014年中报不同类型机构投资者大幅增减仓幅度、股票的超额收益率、同方向操作的机构数量等作为被研究变量,通过Stata12、Excel软件分析机构大幅增减仓在中短期内对股票价格的影响。研究发现,不同机构大幅增减仓对股价的影响有较大差异,机构大幅增仓比大幅减仓对股票的正面影响明显更大,但减仓的股票整体上也存在超额收益率;机构投资者增减仓幅度与股票超额收益率正相关,机构同买同卖的行为存在一定程度的“羊群效应”。因此,国家需进一步鼓励机构投资者的发展,引入更多的QFII,促进保险、券商、信托与基金发行差异化理财产品,机构应当理性投资,挖掘优质股票,避免羊群行为以减少对股票价格的冲击。     

A multivariate nonparametric test for return and volatility timing

This paper develops a novel approach to simultaneously test for market timing in stock index returns and volatility. The tests are based on the estimation of a system of regression equations with indicator variables and provide detailed information about the statistical significance of alternative market timing components.     

Do insiders trade on innovation?

We find that pure insider share purchases—which we define as insider purchases over two successive years without any corresponding sales—are a strong predictor of a firm’s patent applications. The predictability increases with the quality of the patent: Applications for the highest-quality, breakthrough patents increase by 21% in the year following pure insider purchases in our sample. These purchases are associated with large abnormal stock returns of 1.1% per month (14% annualized) over the subsequent three-year period. We also document that stock price responds less to the subsequent announcement of the grant of patent if the application for the patent has been preceded by pure insider purchases, consistent with the idea that insider purchases reveal information about future firm innovation. Our evidence has implications for understanding insider trading within technology companies that have become a dominant feature of US stock markets in recent decades.     

Stock prices and the flow of information in the Athens Stock Exchange

The paper investigates the dynamics of price changes and information flow to the market in the Athens Stock Exchange in Greece using daily data over the period 1988 to 1993. A generalised autoregressive conditional heteroskedastic (GARCH) model in stock returns is shown to reflect time dependence in the process generating information flow to the market. Using daily trading volume or value as proxies for information flow, we find them to be significant in explaining the variance of daily returns and to reduce GARCH effects substantially. This has implications for the informational efficiency of the market.     

Empirical Analysis of Stock Returns and Volatility: Evidence from Seven Asian Stock Markets Based on TAR-GARCH Model

This paper investigates the time-series behavior of stock returns for seven Asian stock markets. In most cases, higher average returns appear to be associated with a higher level of volatility. Testing the relationship between stock returns and unexpected volatility, the evidence shows that four out of seven Asian stock markets have significant results. Further analyzing the relationship between stock returns and time-varying volatility by using Threshold Autoregressive GARCH(1,1)-in-mean specification indicates that the null hypothesis of no asymmetric effect on the conditional volatility is rejected for the daily data. However, the null cannot be rejected for the monthly data.