Herd mentality in the stock market: On the role of idiosyncratic participants with heterogeneous information

This paper examines herd behaviour using aggregate market data for stocks, with a focus on the role of idiosyncratic participants with heterogeneous information. We look at herding asymmetry between up and down markets, taking into consideration the daily price limits and the impact of the recent financial crisis. We also improve upon existing tests for fundamental and non-fundamental herding, as well as proposing a method for investigating herd behaviour of different groups of investors. Empirical evidence based on the Ho Chi Minh Stock Exchange in Vietnam reveals a greater level of herding on up compared to down market days, and a significant reduction in the magnitude of herding following the crisis. We document robust intentional herding even when unintentional (fundamental) herding is factored out. Our empirical results also uncover potential within-group herding and between-group interactions among arbitrageurs and noise traders in the market.     

Gender and herding

This study uses a unique dataset from a large anonymous brokerage firm to examine the herding behavior of Chinese individual investors. The empirical evidence reveals that females are more inclined to follow the behavior of ‘same-sex’ investors. Market conditions and stock characteristics affect females and males similarly in that individual investors herd more intensively in the bull market, on stocks with better liquidity and larger market capitalization. We find female investors generally yield lower returns than males when they herd intensively, and this finding is more pronounced during a bull-market period. Outcomes from individual-level herding measurements suggest that portfolio turnover drives the difference in herding between genders.     

Individual and institutional herding and the impact on stock returns: Evidence from Taiwan stock market

Using high frequency intraday data, this paper investigates the herding behavior of institutional and individual investors in the Taiwan stock market. The study finds evidence of herding by both investors but a stronger herding tendency among institutional than among individual investors. Institutional investors herd more on firms with small capitalizations and lower turnovers and they follow positive feedback strategies. The portfolios that institutional investors herd buy outperform those they sell by an average of 1.009% during the 20 days after intense trading episodes. By contrast, individual investors herd more on firms with small sizes and higher turnovers, and they crowd to buy (sell) stocks with negative (positive) past returns. The portfolios that individual investors herd buy underperform those they sell by an average of − 0.829% during the following 20 days. Moreover, these return differences of both investors are more pronounced under a market with higher pressure and among small stocks. These findings suggest that the herding of institutional investors speeds up the price-adjustment process and is more likely to be driven by correlated private information, while individual herding is most likely to be driven by behavior and emotions.     

Do Qualified Foreign Institutional Investors Herd in Taiwan's Securities Market?

This paper investigates whether and why qualified foreign institutional investors (QFIIs) in Taiwan herd when picking stocks. The evidence shows that QFIIs herd in Taiwan's securities market: They follow each other into and out of the same securities. We identify how the herding behavior forms and how it changes over time. The results suggest that there is an industry effect when QFIIs pick up stocks. They herd on securities classified in specific industries and also prefer stocks with high past returns as well as large firm size, supporting the argument that QFIIs are momentum traders. Characteristic herding and investigative herding explain QFIIs' trading behavior in Taiwan.     

An Empirical Investigation of Herding Behavior in the U.S. REIT Market

Our study investigates the market-wide herding behavior in the U.S. equity REIT market. Utilizing the quantile regression method, we find that herding is more likely to be present in the high quantiles of the REIT return dispersion. This implies that REIT investors tend to herd under turbulent market conditions. Our results also support the asymmetry of herding behaviors, that is, herding is more likely to occur and becomes stronger in declining markets than in rising markets. In addition, our findings show that the current financial crisis has caused a change in the circumstances under which herding can occur, as we find that during the current crisis REIT investors may not start to herd until the market becomes extremely turbulent whereas during the relatively normal period before the crisis, investors tend to herd when the market is moderately turbulent. Finally, we find that compared with the case of the ‘pre-modern’ era, REIT investors are more likely to herd in the ‘modern’ era, during which herding usually occurs when the market becomes tumultuous. This implies that the switch of REITs from passive externally managed entities into active self-managed ones has made the investors more responsive to market sentiment.     

Institutional herding in international markets

This paper studies herding behavior of institutional investors in international markets. First, we document the existence of wide-spread herding in 41 countries (referred to as “target countries” hereafter) in the sample. We then examine the relation between contemporaneous institutional demand and future returns and find that institutional herding stabilizes prices. Next, we examine the relation between institutional investors’ herding behavior and the level of information asymmetry in the target countries. We measure the degree of information asymmetry in each target country along five dimensions: (1) stock market development, (2) ease of access to information, (3) corporate transparency, (4) investor rights, and (5) macroeconomic factors that relate to the information environment. We find evidence that institutional investors herd more in markets characterized by low levels of information asymmetry (high level of information transparency). This result suggests that institutional investors’ herding behavior is likely driven by correlated signals from fundamental information. Lastly, we show that price adjustment is faster in informationally transparent markets.     

Firm specific and macro herding by professional and amateur investors and their effects on market volatility

We find a herding tendency among both amateur and professional investors and conclude that the propensity to herd is lower in the professionals. These results are obtained both when we consider herding into individual stocks and herding into stocks in general. Herding depends on the firm’s systematic risk and size, and the professionals are less sensitive to these variables. The differences between the amateurs and the professionals may be attributable to the latter’s superior financial training. Most of the results are consistent with the theory that herding is information-based. We also find that the herding behavior of the two groups is a persistent phenomenon, and that it is positively and significantly correlated with stock market returns’ volatility. Finally, herding, mainly by amateurs, causes market volatility in the Granger causality sense.     

THE BROKERAGE FIRM EFFECT IN HERDING: EVIDENCE FROM INDONESIA

We examine herding behavior of domestic and foreign investors in the Indonesian stock market. We document that both domestic and foreign investors from a particular brokerage firm tend to herd. The foreign investors exhibit a greater propensity to herd than domestic investors. However, when examining investor trading across brokerage firms, we find only weak evidence of herding by domestic investors and no herding by foreign investors. Our overall findings suggest a strong brokerage firm effect on herding but a weak marketwide effect. Moreover, we find evidence that the strong brokerage effect on herding is likely driven by acting on common information.     

The effects of firms’ information environment on analysts’ herding behavior

We find financial analysts herd to a greater degree in firms with more opaque information environments as measured by the incidence of short-term institutional investors present. The S-statistic, a measure of forecast bias, and forecast timing and quality metrics are used to measure analyst herding behavior. The results are consistent with the notion that opaque information environments are more conducive to analysts engaging in reputational herding behavior where more capable analysts act first and less capable analysts follow. Additionally, analysts are more likely to issue forecast revisions subsequent to management earnings guidance in less opaque environments. Robustness tests indicate our operational measure of opacity is not subsumed by other measures of the information environment, namely information asymmetry.     

Dynamic herding analysis in a frontier market

We use constant coefficient and time-varying parameter approaches to examine herding in the context of a frontier market. Our sample comprises of all companies listed on the Trinidad and Tobago Stock Exchange from January 2001 to December 2014. We find significant evidence of herding across the market, which is more prominent for smaller stocks. Microstructures, including liquidity and volatility, intensify herd behavior, except for larger firms. Additional analyses show that herding is present in both up and down markets, but is stronger during rising markets. The time-varying analysis, based on a state-space Kalman filter, further establishes that herding, though quite prevalent, is not a static feature of the market but evolves throughout the sample period. Specifically, it oscillates between greater herding to anti-herd behavior, as investors identify themselves with crises and better information access respectively.     

Herd Behaviour and Cascading in Capital Markets: a Review and Synthesis

We review theory and evidence relating to herd behaviour, payoff and reputational interactions, social learning, and informational cascades in capital markets. We offer a simple taxonomy of effects, and evaluate how alternative theories may help explain evidence on the behaviour of investors, firms, and analysts. We consider both incentives for parties to engage in herding or cascading, and the incentives for parties to protect against or take advantage of herding or cascading by others.     

Mutual Fund Herding and the Impact on Stock Prices

We analyze the trading activity of the mutual fund industry from 1975 through 1994 to determine whether funds "herd" when they trade stocks and to investigate the impact of herding on stock prices. Although we find little herding by mutual funds in the average stock, we find much higher levels in trades of small stocks and in trading by growth-oriented funds. Stocks that herds buy outperform stocks that they sell by 4 percent during the following six months; this return difference is much more pronounced among small stocks. Our results are consistent with mutual fund herding speeding the price-adjustment process.     

Herding behavior in the Pakistan stock exchange: Some new insights

This study attempts to examine the presence of herding behavior in the Pakistan Stock Exchange (PSX). The novel contribution of this paper is that it investigates the herding phenomenon from a large number of facets such as herding of firms towards market, herding of firms towards industry portfolios, herding of industry portfolios towards market, herding in mostly traded stocks and in large and small stocks, and herding in the crisis period. For this purpose, we use the herding behavior model of Christie and Huang (1995) on the daily closing prices data of 609 firms listed on the PSX from January 2004 to December 2013. Results show that individual firms do not herd towards market index, except when the market experiences a negative return of 5%. However, when we sort firms into small and large groups based on median market capitalization, results indicate that large firms show herding behavior in extreme market movements. Further, we find that firms in several industries herd towards their industry portfolios. However, we find weak evidence of industry portfolios herding towards the market. We also segregate the impact of financial crisis of 2008 from normal times. These findings support results of our baseline estimation.     

Herding and market volatility

In this paper, we explore the impact of investor herding behavior on stock market volatility. We adopt a direct herding measure based on the variation of cross-sectional stock betas. The measure can be readily separated into positive and adverse components, whereby investors herd towards and away from the market portfolio, respectively. Using A-shares listed in the Chinese equity market from August 2005 to March 2021, we show that the market volatility is Granger caused by the measure, and that there exists an asymmetric effect between positive and adverse herding on volatility. Furthermore, we provide robust evidence that the information contained in the herding measure helps generate significantly improved volatility forecasts and add economic value to investors. Our paper not only contributes to the volatility forecasting literature but also advances our understanding of herding in the equity market.     

短期羊群行为的影响因素与价格效应——基于高频数据的实证检验

通过创新性地使用日内高频交易数据对A股市场中的羊群行为进行研究,本文发现:(1)羊群行为具有短期脆弱性特征,随着度量频率的提高,羊群行为的程度严格递增。(2)信息不对称程度、机构投资者比例、股票规模等因素,会显著影响短期羊群行为程度。(3)短期羊群行为会伴随着明显的价格反转:短期买入(卖出)羊群行为后,股票的超额收益显著为负(正),并且短期羊群行为越显著,价格反转的程度越大。(4)价格反转效应存在不对称性:规模越大、交易越活跃的股票,短期买入羊群行为的价格反转越明显,而短期卖出羊群行为的价格反转越不明显。     

Herd behavior and equity market liquidity: Evidence from major markets

This paper provides new evidence on the relation between herd behavior and equity market liquidity, an issue that has been neglected when it comes to studying herd behavior towards the consensus. We use equity price data for the G5 markets, and initially find no evidence of herding. When, however, we condition on the liquidity of stocks we find significant evidence of herd behavior for high liquidity stocks, for most countries, a result robust to different definitions of the crisis period and different measures of liquidity. The only exception is Germany for which there is weaker evidence of herding in high liquidity stocks. Variance decomposition tests indicate that the variance of the average equity market liquidity is affected by return clustering, especially during the crisis and post-crisis period an effect that is more pronounced for the US market.     

Herding and Feedback Trading by Institutional and Individual Investors

We document strong positive correlation between changes in institutional ownership and returns measured over the same period. The result suggests that either institutional investors positive-feedback trade more than individual investors or institutional herding impacts prices more than herding by individual investors. We find evidence that both factors play a role in explaining the relation. We find no evidence, however, of return mean-reversion in the year following large changes in institutional ownership—stocks institutional investors purchase subsequently outperform those they sell. Moreover, institutional herding is positively correlated with lag returns and appears to be related to stock return momentum.     

信息不对称、过度自信与股价变动

信息传导的非同步和投资者情绪变化是股票市场的两个典型特征,前者会引发投资者之间出现信息不对称问题,后者主要体现为投资者过度自信,两者共同作用影响股票价格变动。本文将信息不对称和投资者过度自信情绪置于同一个分析框架,建立两阶段动态序贯定价理论模型研究现实市场上信息传导过程中股价变动的内在机制。结果表明:(1)面临新信息的进入,投资者对股票收益预期的调整与均衡价格之间具有正相关关系;(2)面临有利消息时,过度自信投资者比例越大,股票的均衡价格越高,投资收益将越低;面临不利消息时则相反;(3)随着过度自信投资者比例以及过度自信程度升高,市场风险溢价将下降;(4)投资者群体在信息传导过程中出现分化,对股价变动形成异质信念,未获取信息和获取信息但未出现过度自信的投资者认为股价被高估,获取信息且出现过度自信的投资者认为价格被低估,促使更多的交易,引发市场成交量和股价变动;(5)过度自信投资者比例与过度自信程度提高均会对市场效率产生正向影响,而对市场深度具有负向效应。最后,基于理论结果对非对称性和持续性等典型的市场波动性特征进行解释。     

Momentum in the Chinese Stock Market: Evidence from Stochastic Oscillator Indicators

ABSTRACT

We explore whether investors earn profits through the use of stochastic oscillator indicators (SOI) for trading stocks. The results reveal that investors might use momentum strategies when trading constituent stocks of SSE 50 as the overbought trading signals emitted by SOI. We infer that the results might be caused by herding behaviors of Chinese investors since overoptimistic moods are likely to exist as evidenced by the 80 percent trading volume traded by individual investors in the Chinese stock market.     

The Response of Dynamic Herd Behavior to Domestic and U.S. Market Factors: Evidence from the Greater China Stock Markets

ABSTRACT

We investigate the dynamic reaction of stock market herding in China, Hong Kong, and Taiwan to unexpected shocks from domestic and U.S. market factors. In China and Taiwan, herding is more pronounced, and the investors tend to herd with the rising stock market returns. Overconfident investors will herd on the subsequent trading days under market stress. Compared with the response to the domestic market factors, the responses of herding in the Greater China stock market to the U.S. market factors are weaker. After the 2007–8 financial crisis, the U.S. market factors highly explain the forecast error variance of herding in the Shanghai A-share and Taiwan markets.