中国股市的惯性与反转效应研究

由于中国股市具有政策市的特征,本文在Hong和Stein(1999)模型的基础上,研究政策市背景下的中国股市的惯性与反转效应。我们的主要结果有:中国股市的反转效应相对于惯性效应要更明显一些,并且除了中期惯性与长期反转外,还存在一个超短期的惯性与短期的反转;同时,小公司股票相对大公司股票,惯性运动的趋势较弱,更容易发生反转,成交量大的股票相对于成交量小的股票,惯性运动的趋势较弱,更容易发生反转。最后通过实证分析,在中国股票市场对上述结果进行了检验,实证结果支持了我们的结论。     

Industry Herding and the Profitability of Momentum Strategies During Market Crises

The degree of industry herding is significantly related to the subsequent performance of winner and loser industries. While the herding effect on losers is not inconsistent with investors’ tendency to herd on negative information, the herding effect on winners reflects institutional demand for overpriced securities. An alternative momentum strategy based on the degree of herding within an industry significantly outperforms the conventional industry momentum strategy over the subsequent 1, 3, 6, and 12 months. The findings suggest that behavioral patterns could be utilized to generate enhanced momentum profits, even during market stress periods when the conventional momentum strategy performs poorly.     

Momentum and betting market perceptions of momentum in college football

Past research has demonstrated that bettors believe positive momentum carries over from contest to contest. This article examines whether there is any empirical support for this belief by testing for the presence of across-contest momentum effects in college football. We characterize momentum in multiple fashions and after controlling for between-team heterogeneity find no evidence that systematic relationships exist between the degree of momentum a team enters a contest with and the outcome of that contest. From a wagering market perspective, this indicates that there is no statistically significant advantage to betting on teams perceived to possess positive momentum. Our results also suggest that the combination of the opening betting line set by odds makers and the subsequent market movement of that line does not systematically overreact to teams on streaks.     

Overreaction to extreme market events and investor sentiment

This article investigates the role of investor psychology, captured here by investor sentiment index, in driving individual stock price reactions to extreme movements in the broader market. In addition to confirming prior evidence of overreaction, we find much stronger overreaction when investor sentiment is low rather than high. This is consistent with the role of the contrast dimension of an uncommon event, suggested in the psychology literature, over and above the emotion of surprise it brings about. In a low sentiment environment, the contrast is sharper and hence leads to stronger overreaction.     

Market states and disposition effect: evidence from Taiwan mutual fund investors

We study the disposition effect across market states in the context of mutual fund investors in Taiwan. Using mutual fund data at the fund and individual levels during July 2001 to October 2008, we find that the disposition effect varies across market states. Our results suggest that investors redeem their mutual fund units more under a bear market than a bull market when they have extreme capital losses. When investors have moderate capital gains, they are less active in redeeming their mutual fund units under a bull market relative to a bear market. Under a neutral market, investors actively redeem mutual fund units in both winner and loser mutual funds except when they have extreme capital losses. Thus, disposition effect is not uniform; it varies by market condition. In addition, the disposition effect phenomenon also exists for Taiwan mutual fund investors as well. Our findings are robust to aggregate and individual investor levels.     

Emotions Matter: Sentiment and Momentum in Foreign Exchange

The author introduces news sentiment as a variable that can explain and predict subsequent changes in the USD/EUR exchange rate and therefore close a gap in the foreign exchange literature. By applying the concept of frequency filtering from the domain of electrical engineering, the author shows an innovative way of filtering for noise not only in news sentiment, but also in price momentum. The author finds that news sentiment is not correlated to price momentum, and that trading strategies based on news sentiment achieve around twice as high information ratios (up to 0.9) than with trading strategies based on price momentum.     

Cross-sectional and time-series momentum returns and market dynamics: evidence from Japan

We test the behavioural theories of overconfidence and underreaction on cross-sectional (CS) and time-series (TS) momentum returns in the Japanese stock markets. Both CS and TS momentum returns are large and significant when the market continues in the same state and turns into losses when the market transitions to another state, consistent with the overconfidence but not the underreaction model. We find that TS conditional momentum returns exceed conditional CS momentum returns because of its active position since TS takes a net long (short) position following UP (DN) markets while CS is a zero-cost strategy irrespective of the market state. Finally, we find no relation between idiosyncratic volatility (IV) and momentum returns which is not supportive of either the overconfidence or underreaction model but implies that IV is not a significant limit to arbitrage in Japan.     

Stochastic investor sentiment,crowdedness and deviation of asset prices from fundamentals

This study constructs a theoretical model to address how stochastic investor sentiment affects investor's crowdedness, and how stochastic investor sentiment and crowdedness affect asset prices. An asset pricing model incorporating stochastic investor sentiment and crowdedness is developed, which can provide efficient explanations for the deviations of asset prices from fundamentals and the maverick risk of investors. This model indicates that the optimistic (pessimistic) investor sentiment and the long (short) crowdedness caused by optimistic (pessimistic) sentimental investors can push asset price above (below) fundamental value. Also, the sentimental investors who are wrong and alone would take the maverick risk. Our results are consistent with the idea that investor sentiment and investor behavior matter for the asset prices and the deviations of asset prices from fundamentals.     

Price clustering and natural resistance points in the Dutch stock market: A natural experiment

This paper focuses on the tendency of stock prices to cluster at round numbers (like 10, 20, 30, etc. and to a lesser extent 5, 15, 25, etc.) and the related effect of round number price barriers (prices pass round numbers less frequently than other numbers). Two competing hypotheses are tested, using data from the Dutch stock market of the period 1990–2001. After 1 January 1999 stock prices were listed in euros, while guilders were still the currency of daily life until 2002. The aspiration level hypothesis predicts that round number effects in guilders will only slowly disappear. The odd price hypothesis predicts an abrupt change in round number effects after 1 January 1999. Generally, the results are consistent with the odd price hypothesis.     

股票市场量价关系分析——模型与实证

文章将行为金融学的分析方法引入到股票市场量价关系的研究中,在考虑市场参与者非理性行为———＂急于实现盈利＂同时＂不愿结算浮亏＂的前提下,首先通过供求分析,给出股票市场中的需求曲线与供给曲线,然后设定初始均衡,采用经济学中的比较静态分析方法,研究新信息到来时对初始均衡的影响,进而分析新信息的到来对成交量和价格的影响。模型的结论是＂成交量和成交价格的变动正相关＂、＂成交量和成交价格变动的绝对值正相关＂。使用计量经济学方法,基于中国A股市场的历史数据进行了实证检验,实证结果支持了模型的结论。通过进一步分析,文章最后还得出＂投资散户是股票市场的自动稳定器＂的结论。     

Momentum crash,credit risk and optionality effects in bear markets and crisis periods: evidence from the US stock market

This study explores whether the credit risk anomaly exhibits option-like behaviour similar to the momentum anomaly. It finds that the inverted credit risk spread indeed displays option-like behaviour in bear market states. Unlike a momentum portfolio, which is effectively a short call option on the market, an inverted credit risk portfolio appears to be a long call option on the market.     

The New York Times and Wall Street Journal: Does Their Coverage of Earnings Announcements Cause “Stale” News to Become “New” News?

Recent research suggests that the stock market reacts to stale information if it is reported in the media because it is gives the impression of being “new” news. The objective of this study is to provide a unique test of this hypothesis using the time-series properties of quarterly earnings. It is well documented that seasonally differenced quarterly earnings for adjacent quarters are positively correlated. Therefore a component of current quarter earnings when reported is news that was known or predictable at the end of the prior quarter and thus is old news. We find for those firms that receive media coverage in the Wall Street Journal and The New York Times that the price reaction at the time of the announcement of current earnings to past quarter's seasonally differenced quarterly earnings is greater than those firms that do not receive media coverage. The result is consistent with stale earnings information being given the appearance of new information resulting in a further price reaction. This suggests that the stale information hypothesis and media coverage could be a partial explanation for post-earnings announcement drift.     

Pure numbers effects, market power, and tacit collusion in posted offer markets

This paper studies the effects of seller concentration and static market power on tacit collusion in extensively repeated laboratory posted-offer markets. Contrary to the implications of some earlier research, we find that tacit collusion does not become pervasive with extensive repetition. In a ‘strong no-power’ design persistently competitive outcomes are observed in markets with three or four sellers. Even duopolies are frequently competitive in this design. Unilateral market power raises prices, as predicted. However, static Nash predictions fail to organize outcomes across power treatments, because tacit collusion moves inversely with concentration. Excess capacity appears to explain observed tacit collusion levels.     

沪市“风格惯性”与“价格惯性”比较之实证研究

本文以1997～2003年沪市261支A股为样本．实证对比了＂风格惯性策略”和“价格惯性策略”的盈利性。结果表明．在我国股市上运用传统的价格惯性策略不能获利，而运用“风格惯性策略”，特别是买入过去6、9、12个月内收益最高的赢家组合．则能够获利。本文从行为金融学角度对这一现象作了理论分析。     

中国证券市场机构投资者的羊群行为研究

“羊群行为”是金融市场上一个令人困惑的现象,长期以来,投资者的羊群行为一直被认为是导致股票市场剧烈波动和引发市场系统风险的一个重要原因。以往对美国金融市场的研究表明,机构投资者在进行投资时存在典型的羊群效应,而研究表明我国证券市场中机构投资者的羊群行为更加典型。对这个问题作一个文献综述,并在此基础上进一步作理论研究和政策分析。     

Limited attention,salience of information and stock market activity

It is now widely recognized in the literature that individuals have limited attention and that salient information plays a key role in individuals choices. We analyze the salience of two sources of information for investors: firm-specific and market. Salient information on firm and market levels is captured by 52-week highs and low indicators while investor attention is filtered by Google web searches. Results show that web searches is a predictor of volume, volatility and returns, and the effects are stronger when using market information. Our findings help to better understand the sources of information that lead individuals in making investment decisions.     

上海股票市场动量效应研究——基于1995—2009年周收益率数据

利用1995年1月至2009年12月期间上海证券交易所所有A股股票的日收益率数据,以本周四到下周三为一个周期计算周收益率,采用重叠抽样方法,对上海股票市场的动量效应进行实证研究。结果表明:上海股票市场存在动量效应现象,但动量效应持续的期限要短于西方发达国家的股票市场;当形成期为1周、持有期为1~3周时,投资策略组合表现出显著的动量效应;当形成期大于1周、持有期超过3周时,投资策略组合开始出现收益反转现象;当持有期和形成期增大到12~26周时,投资策略组合又表现出不显著的动量效应。     

An experimental study of adaptive behavior in an oligopolistic market game

We consider an oligopolistic market game, in which the players are competing firms in the same market of a homogeneous consumption good. The consumer side is represented by a fixed demand function. The firms decide how much to produce of a perishable consumption good, and they decide upon a number of information signals to be sent into the population in order to attract customers. Due to the minimal information provided, the players do not have a well-specified model of their environment. Our main objective is to characterize the adaptive behavior of the players in such a situation.     

Threshold effect in the relationship between investor sentiment and stock market returns: a PSTR specification

This article verifies whether the hypothesis of heterogeneous agent modelling and the behavioural heterogeneity framework can reproduce recent stylized facts regarding stock markets (e.g. the 1987 crash, internet bubble, and subprime crisis). To this end, we investigate the relationship between investor sentiment and stock market returns for the G7 countries from June 1987 to February 2014. We propose an empirical non-linear panel data specification based on the panel switching transition model to capture the investor sentiment-stock return relationship, while enabling investor sentiment to act asymmetrically, non-linearly, and time varyingly according to the market state and investor attitude towards risk. Our findings are twofold. First, we show that the hypotheses of efficiency, rationality, and representative agent do not hold in reproducing stock market dynamics. Second, investor sentiment affects stock returns significantly and non-linearly, but its effects vary with the market conditions. Indeed, the market appears predominated by fundamental investors in the first regime. In the second regime, investor sentiment effect is positively activated, increasing stock returns; however, when their overconfidence sentiment exceeds some threshold, this effect becomes inverse in the third regime for a high threshold level of market confidence and investor over-optimism.     

The Information Environment,Informed Trading,and Volatility

The relation between informed trading and volatility is analyzed using the change in the proportion of informed transactions calculated through the probability of informed trading variable. The analysis relates to the Spanish market during 1997–2010, given that the Spanish market covers a very diverse range of listed companies. Some companies are comparable to companies listed on U.S. markets while others are smaller in size and have a lower trading volume and inferior quality of information. The methodology is based on a modification of the model proposed by Avramov, Chordia, and Goyal [2006 Avramov, D., T. Chordia, and A. Goyal. “The Impact of Trades on Daily Volatility.” Review of Financial Studies, 19, (2006), pp. 1241–1277.[Crossref], [Web of Science ®] , [Google Scholar]]. The authors’ proposal incorporates the change in the proportion of informed transactions, calculated with intraday data, into the volatility model. The results are also presented using a conditional volatility model in which the change in the proportion of informed transactions is incorporated. These results attest to the influence of informed trading as a price-stabilizing factor in heavily traded and highly capitalized stocks (familiar stocks). Informed trading leads to a marked decrease in volatility for these particular stocks both in periods of calm and crisis.