交易所大宗交易流动性折价研究——来自沪深交易所的经验证据

随着证券市场规模的扩大及机构投资者规模的壮大，机构投资者对市场流动性的需求日益剧增，大宗交易制度是满足投资者流动性需求的制度性创新。由于大宗交易的数量较大，其交易价格有别于正常交易规模的价格。本文利用沪深交易所的大宗交易数据实证探讨大宗交易价格及其影响因素。研究结果表明，大部分大宗交易价格低于当日收盘价格，呈现流动性折价现象，折价率达到1．27％：研究还发现，折价水平还受交易数量、正常交易时间段股票流动性水平、市场流动性水平及股价波幅等因素影响。     

Market-wide impact of the disposition effect: evidence from IPO trading volume

I study empirically the market-wide importance of investors’ reluctance to realize losses by investigating IPO trading volume. In IPOs all initial investors have a common purchase price, and the disposition effect should thus be at its strongest. Turnover is significantly lower for negative initial return IPOs when the stock trades below the offer price, and increases significantly on the day the price surpasses the offer price for the first time. The increase in volume lasts for two weeks. On a daily level, attaining new maximum and minimum stock prices also produces strong increase in volume. These results suggest that reference price effects play a role in aggregate stock market activity.     

信息不确定、坏消息与投资者交易行为

本文以2000年至2010年的A股上市公司违法违规事件为样本,分析该类事件中信息不确定性的影响,以及市场反应中的投资者交易行为。研究发现:上市公司市场价值在事件日呈显著下跌;然而,与直觉有些相悖的是,信息不确定程度与超额累积收益呈显著正相关,这意味着在坏消息到来时,不确定性反而提高了股票的市场价值;最后,通过对各类投资者在此类事件中的净买入情况分析,我们发现不同投资者的交易行为有明显差异。机构投资者在坏消息中采用了反向交易策略,并且知情交易促进机构投资者的买入。     

Striking oil: Another puzzle?

Changes in oil prices predict stock market returns worldwide. We find significant predictability in both developed and emerging markets. These results cannot be explained by time-varying risk premia as oil price changes also significantly predict negative excess returns. Investors seem to underreact to information in the price of oil. A rise in oil prices drastically lowers future stock returns. Consistent with the hypothesis of a delayed reaction by investors, the relation between monthly stock returns and lagged monthly oil price changes strengthens once we introduce lags of several trading days between monthly stock returns and lagged monthly oil price changes.     

An intertemporal capital asset pricing model with heterogeneous expectations

This paper extends the intertemporal capital asset pricing model (ICAPM) to integrate the heterogeneous trading behavior of three groups of investors; rational utility maximizers, positive feedback, or momentum, traders, and fundamental traders. Using several contemporary fundamental factors to proxy for the latter of these investors’ trading patterns, the interaction of these three groups of investors is explored in the G-7 markets using monthly stock market prices. There is no evidence that positive feedback traders are present in the sample data. Fundamental traders are however observable. This finding suggests that although positive feedback traders may drive stock prices in the short-run, as is typically observed in higher frequency data, fundamental traders likely play a role in pushing prices back to their fundamental value in the longer-run.     

On the Magnet Effect of Price Limits

The ‘magnet’ or ‘gravitational’ effect hypothesis asserts that, when trading halts are rule‐based, investors concerned with a likely impediment to trade advance trades in time. This behaviour actually pushes prices further towards the limit. Empirical studies about the magnet effect are scarce, most likely because of the unavailability of data on rule‐based halts. In this paper, we use a large database from the Spanish Stock Exchange (SSE), which combines intraday stock specific price limits and short‐lived rule‐based call auctions to stabilise prices, to test this hypothesis. The SSE is particularly well suited to test the magnet effect hypothesis since trading halts are price‐triggered and, therefore, predictable to some extent. Still, the SSE microstructure presents two particularities: (i) a limit‐hit triggers an automatic switch to an alternative trading mechanism, a call auction, rather than a pure halt; (ii) the trading halt only lasts 5 minutes. We find that, even when prices are within a very short distance to the price limits, the probability of observing a limit‐hit is unexpectedly low. Additionally, prices either initiate reversion (non limit‐hit days) or slow down gradually (limit‐hit days) as they come near the intraday limits. Finally, the most aggressive traders progressively become more patient as prices approach the limits. Therefore, both the price patterns and the trading behaviour reported near the limits do not agree with the price limits acting as magnetic fields. Consequently, we conclude that the switching mechanism implemented in the SSE does not induce traders to advance their trading programs in time.     

The Media and the Diffusion of Information in Financial Markets: Evidence from Newspaper Strikes

The media are increasingly recognized as key players in financial markets. I investigate their causal impact on trading and price formation by examining national newspaper strikes in several countries. Trading volume falls 12% on strike days. The dispersion of stock returns and their intraday volatility are reduced by 7%, while aggregate returns are unaffected. Moreover, analysis of return predictability indicates that newspapers propagate news from the previous day. These findings demonstrate that the media contribute to the efficiency of the stock market by improving the dissemination of information among investors and its incorporation into stock prices.     

Futures trading volume as a determinant of prices in different momentum phases

Recent studies contend that trading volume has predictive power for ex ante stock prices, particularly small stocks that do not react quickly to macroeconomic information. This study postulates that a significant amount of macro-information that flows on to stock markets is derived from derivative markets. We examine the impact of short-term futures trading volume and prices on cash stock prices using a case study of 15-min data from the Australian stock index futures market which reports actual trading volume. After applying vector error correction modelling (VECM), variance decomposition and impulse functions, we conclude that futures prices provide a short-term information lead to stock prices that dominates trading volume effects. We also observe asymmetric changes in the impact of trading volume between bull and bear price momentum phases and after large trading volume shocks. These results suggest that, in future, studies on trading volume should control for the cross-correlation impact from derivative prices and the differential impact of trading phases.     

Portfolio pumping: An examination of investment manager quarter-end trading and impact on performance

Utilizing a database of daily institutional fund manager trades, we examine the contribution of strategic trading at quarter-end associated with potential ‘portfolio pumping’ or ‘ramping up’ of reported stock prices around quarter-ends. We provide the first direct evidence that active fund managers tend to purchase illiquid stocks on the last day of the quarter, in stocks in which they already hold overweight portfolio positions. Consistent with the way fund managers are evaluated, we found that the poor-performing managers display greater evidence of portfolio pumping. Both increased regulatory scrutiny and improvements to market microstructure design reduce the severity of stock price changes at quarter-ends.     

Gone fishin’: Seasonality in trading activity and asset prices

We use seasonality in stock trading activity associated with summer vacation as a source of exogenous variation to study the relationship between trading volume and expected return. Using data from 51 stock markets, we first confirm a widely held belief that stock turnover is significantly lower during the summer because market participants are on vacation. Interestingly, we find that mean stock return is also lower during the summer for countries with significant declines in trading activity. This relationship is not due to time-varying volatility. Moreover, both large and small investors trade less and the price of trading (bid-ask spread) is higher during the summer. These findings suggest that heterogeneous agent models are essential for a complete understanding of asset prices.     

Informed Trading in Stock and Option Markets

We investigate the contribution of option markets to price discovery, using a modification of Hasbrouck's (1995) "information share" approach. Based on five years of stock and options data for 60 firms, we estimate the option market's contribution to price discovery to be about 17% on average. Option market price discovery is related to trading volume and spreads in both markets, and stock volatility. Price discovery across option strike prices is related to leverage, trading volume, and spreads. Our results are consistent with theoretical arguments that informed investors trade in both stock and option markets, suggesting an important informational role for options.     

Feedback and the success of irrational investors

We provide a model in which irrational investors trade based upon considerations that have no inherent connection to fundamentals. However, trading activity affects market prices, and because of feedback from security prices to cash flows, the irrational trades influence underlying cash flows. As a result, irrational investors can, in some situations, earn abnormal (i.e., risk-adjusted) profits that can exceed the abnormal profits of rational informed investors. Although the trading of irrational investors cause prices to deviate from fundamental values, stock prices follow a random walk.     

Does investor sentiment really matter?

We examine the role sentiment plays and its manifestation in the trading behavior of investors in the U.S. stock market. Our findings support the notion that sentiment-induced buying and selling is an important determinant of stock price variation. While ‘classical’ asset pricing categorizes investors who trade in ways not consistent with mean-variance optimization as ‘irrational,’ we show that this traditional view should not hastily be evoked to characterize sentiment-driven investing. We instead show that sentiment-driven investors can trade against the herd and sell when prices are overinflated as a result of over-bullishness and vice versa. The asset pricing implications of this paper are that sentiment is linked to shifts in risk tolerance and this triggers contrarian-type behavior. In sum, we uncover the following regarding the behavior of sentiment-driven investors; firstly, they are more apt to trade on survey-based indicators rather than market-based indicators. Secondly, they trade on the basis of information extracted from individual, rather than institutional, investor surveys. Thirdly, they respond asymmetrically to shifts in sentiment and trade more aggressively during periods of declining sentiment. Finally, there is asymmetry in the role of sentiment with respect to business conditions whereby such buying and selling is more pronounced during bear markets.     

EARNINGS ANNOUNCEMENTS,QUALITY AND QUANTITY OF INFORMATION,AND STOCK PRICE CHANGES

We analyze the informational effect of earnings announcements on stock price changes. Although prior studies postulate that the direction and magnitude of earnings surprises contribute to abnormal stock price changes, we attribute earnings surprises and subsequent stock price changes to the quality and quantity of available information. If a stock is followed by many financial analysts, the amount of information available to investors contributes to higher quality information, which in turn is reflected by a small earnings surprise. Furthermore, we demonstrate that as the quality and quantity of information increase, stock prices adjust more quickly, which sheds additional light on the post-earnings-announcement drift issue. Finally, cross-sectional analysis reveals that the flow of information, as measured by the rate of trading volume changes, and the stock of information, as measured by the number of financial analysts, contributes significantly to the variations in excess returns and return volatility. Traditional variables, such as earnings surprises, earnings reporting lag, and firm size, do not perform well.     

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。     

Intraday stock price effects of ad hoc disclosures: the German case

This paper examines intraday stock price and trading volume effects caused by ad hoc disclosures in Germany. The evidence suggests that the stock prices react within 30 min after the ad hoc disclosures. The adjustment of the trading volume needs even more time. We find no evidence for abnormal high price nor trading volume reactions in the five transactions before ad hoc disclosures. The bigger the company, which announces an ad hoc disclosure, the less severe the abnormal price effect, following the announcement, is. The higher the trading volume at the last trading day before the announcement, the higher the price and trading volume effects, after the ad hoc disclosures, are.     

Which trades move prices in emerging markets?: Evidence from China's stock market

This paper extends Barclay and Warner's [Barclay, M.J. and J.B. Warner (1993), ‘Stealth trading and volatility: which trades move prices?’, Journal of Financial Economics, vol. 34, pp. 281–306.] original work on stealth trading by analysing which trades move price for the emerging Chinese stock market. A large block trade/manipulation hypothesis is proposed in addition to the stealth and public information hypotheses examined by Barclay and Warner. Using high-frequency data the results show that while medium and large-size trades are associated with disproportionately large, overall, cumulative stock price changes, it is the large-size trades (in terms of the number of transactions) which have the largest effect on cumulative price increases. Thus, while there is some support for stealth trading in the Chinese market, there are other effects in operation such as large block trades/price manipulation.     

Dividend Policies and Price-Volume Reactions to Cash Dividends on the Stock Market: Evidence from the Istanbul Stock Exchange

This study examines the effects of cash dividend payments on stock returns and trading volumes in the stock market. It also investigates whether there is any difference in the investment behavior of investors with respect to the dividend pay out ratio and size in the Istanbul Stock Exchange (ISE)from 1995 to 2003. Prices start to rise a few sessions before cash dividend payments, and on the ex-dividend day, they fall less than do dividend payments, finally decreasing in the sessions following the payment. Trading volume shows a considerable upward shift before the payment date and, interestingly, is stable after Thus, cash dividends influence prices and trading volumes in different ways before, at, and after payment, providing some profitable active trading strategy opportunities around the ex-dividend day. The findings support price-volume reaction discussions on the divident payment date and the significant effect of cash dividends on the stock market.     

The trading behavior of foreign,domestic institutional,and domestic individual investors: Evidence from the Taiwan stock market

In this paper, we apply the threshold cointegration model of Hansen and Seo (2002), incorporating differences in the nonlinear behavior of investors across regimes. An examination of the trading behavior of foreign, domestic institutional, and domestic individual investors in Taiwan revealed no predominance among the three types of investors. When the market was near equilibrium, the purchases of domestic individual investors positively impacted stock prices. This finding, which is consistent with Choe et al. (2005), suggests that domestic individual investors have an edge in investment performance over other types of investors. However, when the market departed substantially from equilibrium, the purchases of foreign and domestic institutional investors predicted a rise in stock prices. On the other hand, domestic individuals traded at worse stock prices; these prices tended to fall (rise) after the purchase (sale).     

Effects of investor tax heterogeneity on stock prices and trading behaviour around the ex-dividend day: the case of Australia

Using a sample of Australian stocks during the 1996–2014 period, this study examines how tax heterogeneity between domestic and foreign investors affects trading behaviour and stock prices around the ex-dividend day. Domestic investors prefer dividends and tend to buy stocks cum-dividend and sell them ex-dividend whereas foreign investors tend to trade in the opposite direction. Abnormal trading turnover increases with tax heterogeneity. Moreover, stocks with a larger domestic investor base are associated with a higher price drop-off ratio on the ex-dividend day and higher market value of franking credits. Overall, our findings support the dynamic dividend clientele hypothesis.