Determinants of idiosyncratic volatility: Evidence from the Indian stock market

This paper investigates whether firm-specific characteristics explain idiosyncratic volatility in the stocks of non-financial firms traded in the Indian stock market. It employs the linear time series five-factor model, augmented with a liquidity factor and the conditional EGARCH model, to extract yearly idiosyncratic volatility. We estimate a panel data regression to quantify the relationship between firm-specific characteristics and the volatility of individual securities. The results show that idiosyncratic volatility is significant in emerging markets such as India, and that cross-sectional return variations of firms are associated with firm-specific characteristics such as firm size, book-to-market ratio, momentum, liquidity, cash flow-to-price ratio, and returns on assets. We find that the idiosyncratic risk documented in this study is associated with smaller size of company, higher liquidity, low momentum, high book-to-market ratio, and low cash flow-to-price ratio. The findings suggest need to develop alternative tools to make investment decisions in emerging markets.     

Block ownership and firm-specific information

This study examines the impact of block ownership on the firm’s information environment. Previous research shows that stock price efficiency depends on the cost of acquiring private information, as well as on the precision of this information. Blockholders have a clear advantage over diffuse, atomistic shareholders in terms of the precision and acquisition cost of their private information. We hypothesize that this informational advantage will manifest itself primarily in the firm-specific component of stock returns. Our empirical findings confirm that blockholders increase the probability of informed trading and idiosyncratic volatility, and decrease the firm’s stock return synchronicity. These results hold for both inside and outside blockholders, but are insignificant for blocks controlled by employee stock ownership plans (ESOPs). Overall, our findings support the contention that ownership structure plays a significant role in shaping the firm’s information environment.     

Insider trading,stock return volatility,and the option market's pricing of the information content of insider trading

We find strong evidence that net insider selling is positively associated with future stock return volatility, consistent with insider selling increasing outside investors’ uncertainty. The positive effect of net insider selling is significantly stronger when the volatility is measured around the earnings announcement. Apparently, option prices do not fully reflect the information content of insider trading for future volatility. More specifically, we find no evidence that option traders adjust the implied volatility for the insider trading effect in a timely manner. Consequently, net insider selling is significantly associated with future option straddle returns and delta neutral returns.     

Overconfidence among option traders

The investor overconfidence theory predicts a direct relationship between market‐wide turnover and lagged market return. However, previous research has examined this prediction in the equity market, we focus on trading in the options market. Controlling for stock market cross‐sectional volatility, stock idiosyncratic risk, and option market volatility, we find that option trading turnover is positively related to past stock market return. In addition, call option turnover and call to put ratio are also positively associated with the past stock market return. These findings are consistent with the overconfidence theory. We also find that overconfident investors trade more in the options market than in the equity market. We rule out explanations other than investor overconfidence, such as momentum trading and varying risk preferences, for our findings.     

Is information risk priced? Evidence from abnormal idiosyncratic volatility

We propose a new, price-based measure of information risk called abnormal idiosyncratic volatility (AIV) that captures information asymmetry faced by uninformed investors. AIV is the idiosyncratic volatility prior to information events in excess of normal levels. Using earnings announcements as information events, we show that AIV is positively associated with informed return run-ups, abnormal insider trading, short selling, and institutional trading during pre-earnings-announcement periods. We find that stocks with high AIV earn economically and statistically larger future returns than stocks with low AIV. Taken together, our findings support the notion that information risk is priced.     

市场摩擦对特质风险溢价的影响效应——基于A股主板市场的实证分析

与国外发达市场相比,我国A股主板市场的市场摩擦因素对市场微观结构和资产定价的影响更大。在防范和化解系统性风险的过程中,进一步分析市场摩擦如何作用于特质风险定价效应的问题具有重要的理论和现实意义。本文通过采用多维市场摩擦指标来代理信息不对称、交易成本、买卖限制、卖空限制、风险对冲和外部冲击,检验中国股市特质风险和预期收益率的关系,并判断出市场摩擦因素间的差异性影响机制。回归发现,市场摩擦和特质风险因子(特质波动率和特质偏度)都具有定价效应。各维度市场摩擦因素降低了股票流动性,进而增强了特质波动率的负向定价效应,部分解释了“特质波动率之谜”,但市场摩擦对特质偏度因子溢价的影响较为微弱。同时,基于特质波动率和特质偏度因子的投资策略能够产生超越CAPM、三因子和五因子模型的绝对收益,并印证了市场摩擦对特质风险因子绝对收益的影响作用。     

The Impact of Firm-Specific Public News on Intraday Market Dynamics: Evidence from the Turkish Stock Market

This study attempts to discover the intraday firm-specific news announcements and return volatility relation in the Turkish stock market. The GARCH framework is utilized to investigate the impact of firm-specific public news announcements on volatility persistence with and without trading volume. For the majority of the stocks in the sample, the volatility persistence diminishes with the inclusion of firm-specific news, implying that news is impounded rapidly into prices. This effect is more pronounced for larger stocks. When there is no news, the trading volume does not appear to reduce the volatility persistence for the majority of stocks, possibly due to the presence of private information possessed by informed traders.     

The Information Content of Insider Call Options Trading

We examine the information content of two forms of insider trading, insider buy-, and sell-call transactions. We find that the information carried by stand-alone call purchases has only a short-term impact on stock prices, but over a longer term, call purchases accompanied by stock purchases have a positive impact. Call purchases accompanied by stock sales signal negative information about the firm, suggesting that some insiders use complicated trading strategies to manipulate the market. Insider sell-call transactions are followed by negative returns, indicating these transactions are driven by negative information about the firm.     

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.     

Idiosyncratic volatility and cross‐sectional stock returns in Southeast Asian stock markets

We examine the role of idiosyncratic risk in five ASEAN markets of Malaysia, Singapore, Thailand, Indonesia, and the Philippines. Our research was motivated by the findings of Ang et al. (2006, 2009) of a ‘puzzling’ negative relation between idiosyncratic volatility and 1‐month ahead stock returns in developed markets and the suggestion of the ubiquity of these results in other markets. In contrast, we find no evidence of an idiosyncratic volatility puzzle in these Asian stock markets; instead, we document a positive relationship between idiosyncratic volatility and returns in Malaysia, Singapore, Thailand, and Indonesia and no relationship in the Philippines. The idiosyncratic volatility trading strategy could result in significant trading profits in Malaysia, Singapore, Thailand, and to some extent in Indonesia. Our study underscores the fact that generalizing empirical results obtained in developed stock markets to new and emerging markets could potentially be misleading.     

Tax noncompliance and insider trading

This paper explores whether insiders who have shown noncompliance with the tax law (‘noncompliant insiders’) are more prone to exploit their information advantage in insider trading, compared to other insiders (‘compliant insiders’). Our empirical results from analyzing archival data of all insider trades in Sweden show that noncompliant insiders use more of their information advantage to trade their insider stocks shortly before significant stock price changes, compared to compliant insiders. These results remain similar after controlling for various insider- and firm-specific determinants of insider returns, including firm and year fixed effects. We believe that our results are of interest for academics and regulatory authorities monitoring and screening insider trading activity.     

Insider trading in takeover targets

We examine open market stock trades by registered insiders in about 3700 targets of takeovers announced during 1988–2006 and in a control sample of non-targets, both during an ‘informed’ and a control period. Using difference-in-differences regressions of several insider trading measures, we find no evidence that insiders increase their purchases before takeover announcements; instead, they decrease them. But while insiders reduce their purchases below normal levels, they reduce their sales even more, thus increasing their net purchases. This ‘passive’ insider trading holds for each of the five insider groups we examine, for all three measures of net purchases, and is more pronounced in certain sub-samples with less uncertainty about takeover completion, such as friendly deals, and deals with a single bidder, domestic acquirer, or less regulated target. The magnitude of the increase in the dollar value of net purchases is quite substantial, about 50% relative to their usual levels, for targets' officers and directors in the six-month pre-announcement period. Our finding of widespread profitable passive trading by target insiders during takeover negotiations points to the limits of insider trading regulation. Finally, our finding that registered insiders of target firms largely refrain from profitable active trading before takeover announcements contrasts with prior findings that insiders engage in such trading before announcements of other important corporate events, and points to the effectiveness of private over public enforcement of insider trading regulations.     

投资者分歧、异常交易量和股票横截面收益率预测——基于中国股票市场的经验证据

本文定义月度异常交易量为本月与上个月交易金额的比值,发现中国市场月度收益率与滞后一个月的异常交易量显著负相关。在控制了公司规模、账面市值比、流动性以及动量效应等指标后仍然具有显著的解释作用。进一步研究表明,在出现高异常交易量后的12个月内,换手率和特质性波动率都有大幅上升。本文认为,交易量上升代表着市场分歧程度和受关注程度的增加,在卖空约束下会使得股票价值高估,从而造成未来收益率下降。     

Insider Trading Activity,Different Market Regimens,and Abnormal Returns

This paper show that corporate insiders earn abnormal returns by adjusting their own firm's stock trading to future market movements. Insider trading activity in bear markets is characterized by decreases in insider sales and increases in purchases, consistent with the view that those markets are followed by improved economic conditions. Conversely, insider sales increase and purchases decrease in bull markets, consistent with the view that inferior market conditions tend to follow those periods.     

Corporate insider trading and return skewness

Corporate insider trades predict idiosyncratic return skewness. CEO purchases are followed by an increase and CEO sales by a decrease in idiosyncratic skewness. The evidence suggests that this effect is driven by personal preferences rather than behavioral biases such as overconfidence. Our findings are consistent with the interpretation that CEOs, who are generally considered to be underdiversified, optimize their holdings by taking their preference for positive return skewness into account. We observe particularly robust results for CEO sales, which substantiates the less common notion that insider sales can be informative for investors.     

Poison Pill Securities: Shareholder Wealth and Insider Trading

Existing empirical studies on poison pill securities have examined their overall effect on shareholder wealth. This paper segregates the wealth-increasing poison pills from the value-reducing ones by examining the pattern of insider trading activity prior to the pill adoption announcement. Our results show that pill adoptions that are preceded by net insider purchases are associated with significant stock price increases. This finding is consistent with the proposition that corporate insiders buy their own securities because they do not view the adoption of poison pills as an antitakeover strategy, but rather one that enables the board of directors to extract a greater share of the economic gains from the bidder. Our findings also indicate that firms with net insider sales prior to pill adoption announcement experience generally negative but insignificant changes in value. Finally, firms with no insider trading or with an equal number of insider purchases and sales register marginally significant negative returns.     

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.     

Family control and idiosyncratic volatility: Evidence from listed firms in Hong Kong

Family control of listed firms in Hong Kong is substantively different and materially higher than in the US which could offer different insights into the effects of family ownership on corporate transparency. Using a sample of listed Hong Kong firms and idiosyncratic volatility as a proxy for firm-specific stock price informativeness, we find that family firms exhibit higher idiosyncratic volatility of stock prices than similar non-family firms. Further, the relation between family ownership and idiosyncratic volatility is weaker for firms with higher leverage but stronger in periods before equity issues. Additionally, we find that family firms disclose more information, particularly related to operations, than nonfamily firms in annual reports. These results are consistent with the argument that family firms disclose more information than their nonfamily peers to reassure skeptical outside investors that they are not expropriating their investment.     

An Empirical Analysis of Illegal Insider Trading

Whether insider trading affects stock prices is central to both the current debate over whether insider trading is harmful or pervasive, and to the broader public policy issue of how best to regulate securities markets. Using previously unexplored data on illegal insider trading from the Securities and Exchange Commission, this paper finds that the stock market detects the possibility of informed trading and impounds this information into the stock price. Specifically, the abnormal return on an insider trading day averages 3%, and almost half of the pre-announcement stock price run-up observed before takeovers occurs on insider trading days. Both the amount traded by the insider and additional trade-specific characteristics lead to the market's recognition of the informed trading.     

One-Period Model of Individual Consumption, Life Insurance, and Investment Decisions

This article studies individuals' optimal decisions on consumption, life insurance, and stock purchases in a one‐period framework. With exponential utility functions, individuals' life insurance and stock purchases are independent of each other; life insurance purchases are affected only by individuals' future income, bequest intensity, risk attitude, survival probability, and the insurance risk premium; stock purchases are affected only by individuals' risk attitude, the risk‐free rate of return, the stock return, and stock volatility. With power utility functions, life insurance and stock purchases are positively related with each other and are affected by all the factors.