融券约束和市场定价效率*——基于我国股票市场转融通的准自然实验证据

本文从融券约束的视角出发，研究我国股票市场融券机制对标的股票价格发现效率的影响。相比于融券交易量，融券约束可以更好地识别融券机制的作用。因为它可以从交易渠道、信息渠道、外部监管渠道对股价产生影响。笔者利用转融通的实施作为准自然实验，识别出了融券约束放松后标的股票价格发现效率的变化。实证结果显示融券约束放松后：（1）在市场下跌的情况下股价的共同趋势增强，意味着此时股价中包含的个股特质性信息含量降低，而市场上涨时则不存在这种效应；（2）股价对市场信息的反应速度增快；（3）股价更加接近随机游走，即股价的可预测性降低。本文的政策启示是，适当降低融券约束、扩大机构投资者比例、保持较高的融券交易准入门槛以及加强投资者教育可以促进融券机制发挥积极作用。     

Stock return autocorrelations and predictability in the Chinese stock market—Evidence from threshold quantile autoregressive models

This paper applies the threshold quantile autoregressive model to study stock return autocorrelations and predictability in the Chinese stock market from 2005 to 2014. The results show that the Shanghai A-share stock index has significant negative autocorrelations in the lower regime and has significant positive autocorrelations in the higher regime. It attributes that Chinese investors overreact and underreact in two different states. These results are similar when we employ individual stocks. Besides, we investigate stock return autocorrelations by different stock characteristics, including liquidity, volatility, market to book ratio and investor sentiment. The results show autocorrelations are significantly large in the middle and higher regimes of market to book ratio and volatility. Psychological biases can result into return autocorrelations by using investor sentiment proxy since autocorrelations are significantly larger in the middle and higher regime of investor sentiment. The empirical results show that predictability exists in the Chinese stock market.     

卖空机制、股价信息含量与暴跌风险--基于融资融券交易的经验证据

文章利用我国逐步推出融资融券交易的自然实验机会,运用双重差分的研究设计,考察了卖空机制对股价反映负面消息效率的影响。文章以2007-2012年的数据为样本研究发现：相对于非标的股票,融资融券标的股票在成为标的之后,其股价对市场的向下波动及时做出了调整,使得股价对市场正负向波动反应之间的不对称性显著降低,表明标的股票更加及时和充分地吸收了有关公司价值的负面信息;同时,相对于非标的股票,融资融券标的标的股票在成为标的之后,其股价暴跌风险显著降低。文章结果表明,我国股市推出融资融券交易后,卖空机制提高了市场对标的股票负面消息的定价效率。     

Return patterns of South Korean stocks following large price shocks

This study tests the market efficiency of the South Korean stock market by examining returns on stocks of the constituents of the KOSPI 50 from 2000 to 2014 following large 1-month price decreases and increases. An exponential GARCH (EGARCH) event study framework is used to analyse the stock returns. The results show that large price shocks, positive and negative, are likely to be followed by positive market returns. Moreover, the results show an increase in the beta of stocks in the years following a large price shock. The overall results therefore support the Uncertain Information Hypothesis. However, beginning in 2008, return patterns more closely reflect those hypothesised by the Efficient Market Hypothesis, possibly due to increased participation by international investors. The observed returns following large price increases and decreases can be partially explained by changes in the Korean won to US dollar exchange rate and the trading behaviour of foreign investors.     

Oil price and automobile stock return co-movement: A wavelet coherence analysis

This paper explores possible co-movement between oil price and automobile stock return in a joint time-frequency domain. Daily price series from August 01, 1996 to June 20, 2017 is used in this analysis. The results indicate that the co-movement between oil price and automobile stock return is strong during November, 2000–December, 2002 and March, 2006–December, 2009. The co-movement is found to be more pronounced in the long-term and stock return is sensitive to the higher oil price emanating from the demand shock. This contravenes the conventional wisdom that crude oil is always counter-cyclical to the automobile stocks. For investor, this weakens the probable gain from including oil asset in a portfolio of automobile stocks as crude oil does not offer cushion against bearish automobile stock markets during the crisis period.     

融资融券与企业产品市场竞争

本文探究融资融券对上市公司产品市场竞争行为的影响。通过理论分析与实证检验,本文发现融资融券政策的实施促进了标的企业产品市场竞争行为,但是由此带来的潜在的过度竞争问题可能导致企业整体绩效有所下降。本文还发现融资融券的政策效果主要集中于融资交易强度较高、或股价信息敏感度较低的公司。本文的研究结果表明,我国融资和融券交易发展的不对称性放大了资本市场对公司正面信息的奖励效应,可能促使公司在产品市场过度竞争,降低了整体绩效,而个股股价信息敏感度的提高有助于缓解上述问题。     

反转效应、负反馈交易与股价波动——基于面板数据的开放式基金投资策略研究

本文利用2002年至2007年基金交易数据,从不同的市场状态、公司规模、买卖股票的基金数量和行业特征等层面深入分析了我国开放式基金的交易策略、影响基金交易策略的因素以及基金交易对于股市波动的影响。实证结果表明：我国开放式基金所投资的股票在中期内并不存在动量效应,相反存在显著的反转效应,基金的投资行为也表现出明显的负反馈交易策略;与前期股票的买入比率相比,股票的收益率以及收益率的波动对基金投资策略的影响更为明显;开放式基金前期的股票交易会加剧当期的股价波动。     

The Availability Heuristic and Reversals Following Large Stock Price Changes

The author explores the effect of the availability heuristic on large daily stock price changes and on subsequent stock returns. He hypothesizes that if a major positive (negative) stock price move takes place on a day when the stock market index rises (falls), then its magnitude may be amplified by the availability of positive (negative) investment outcomes. In both cases, the availability heuristic may cause price overreaction to the initial company-specific shock, resulting in subsequent price reversal. In line with the hypothesis, the author documents that both positive and negative large price moves accompanied by the same-sign contemporaneous daily market returns are followed by significant reversals on the next 2 trading days and over 5- and 20-day intervals following the event, the magnitude of the reversals increasing over longer postevent windows, while large stock price changes taking place on the days when the market index moves in the opposite direction are followed by nonsignificant price drifts. The results remain robust after accounting for additional company (size, beta, historical volatility) and event-specific (stock's return and trading volume on the event day) factors, and are stronger for small and volatile stocks.     

Daily happiness and stock returns: The case of Chinese company listed in the United States

Existing literature exclusively focuses on the association between local investor sentiment and local stock market performance. In this paper, we investigate the contemporaneous and the lead-lag relationship between local daily happiness sentiment extracted from Twitter and stock returns of cross-listed companies, i.e., the Chinese companies listed in the United States. The empirical results show that: 1) by respectively controlling for the firm capitalization, liquidity and volatility, there exists the largest skewness on the Most-happiness subgroup. (2) There exist bi-directional relationships between daily happiness sentiment and market variables, i.e., the stock return, range-based volatility and excess trading volume. (3) There are significantly positive stock returns, higher excess trading volume and higher range-based volatility around the daily happiness sentiment spike days. These findings not only suggest that there exists significant interdependence between online activities and stock market dynamics, but also provide evidence for the existence of “home bias”.     

中国股票市场交易型的价格操纵研究

本文研究中国股票市场的交易型价格操纵问题。我们推广了Mei、Wu和Zhou(2005)的模型,研究在市场不允许卖空的条件下,交易型价格操纵发生的条件。我们的主要结果有:(1)非充分理性投资者的存在和有限套利的制约是交易型价格操纵获利的重要原因,投机者套利能力越弱,操纵者的价格操纵越容易获利;(2)当市场中投机者的总禀赋大于0时,即使不允许卖空,价格操纵者依然可以操纵价格来获得利润;(3)如果市场监管者无法杜绝操纵者通过对敲等手段来拉抬股价,则在市场中引入卖空机制反而可以减小股价对基本面的偏离程度,从而在某种程度上限制操纵者操纵股价的空间;(4)在股价被操纵的过程中,存在一个建仓期和抛盘期;操纵期内换手率更高、股价波动更大;在建仓期,回报率与换手率,换手率与回报波动率之间存在正相关关系;(5)我们利用中国股市的数据检验了我们的结论,发现理论结果和实证数据非常吻合。     

高送转与股价崩盘风险:抑制还是加重

本文以我国2003—2015年A股公司为样本,考察了公司“高送转”与股价崩盘风险之间的关系。研究发现,公司“高送转”能够有效抑制股价崩盘风险,相对于创业板,主板公司“高送转”抑制股价崩盘风险的作用更为显著。而且,“高送转”对于股价崩盘风险的抑制作用并不受公司财务状况和减持情况的影响,该抑制作用的期限超过了我国投资者平均持股时间。本文有助于加深人们对于“高送转”经济后果的认识。     

融券制度与内部人寻租——来自准自然实验的经验证据

内部人寻租一直以来是理论与实务界关心的重点,如何有效抑制内部人寻租行为是资本市场的重大课题。本文以内部人交易度量内部人寻租,分析了融券制度对内部人寻租的影响。研究发现:(1)融券制度对内部人寻租有显著抑制作用,并且融券规模越大,内部人寻租越少。(2)相比于国有企业,非国有企业当中融券制度对内部人寻租的抑制作用更加明显。本文还将内部人交易分方向进行回归,结果显示融券制度对内部人寻租的抑制作用主要体现在卖出方向上。本文进一步分析了融券制度影响内部人寻租的路径,发现“竞争效应”和“信息效应”是融券制度影响内部人寻租的两条重要路径。本文考虑了竞争性解释——分析师关注的作用,发现分析师关注并不能影响本文结论的正确性;本文还利用反面事实推断、倾向得分匹配、反向因果检验等方法,确保实证结论的稳健性。本文的研究结果,丰富了内部人寻租的特征及影响因素研究,有利于市场监管部门加强对内部人寻租行为的控制;扩充了有关融券制度的文献,为卖空制度的推行及完善提供理论依据。     

Individual investor’s limited attention and IPO performance

The paper models and verifies the spread and decay of investor’s attention before listing on the stock market by using the Baidu Index as a proxy for investor attention of the frequency of searches. We find that individual investor’s attention has a significant influence on the first-day IPO return. We empirically study the allocation of investor attention among several stocks and discover that the more stocks going public on the same day, the milder and more similar their performance tends to be. This paper is the first to research IPO performance and individual attention.     

投资者“热手效应”与“赌徒谬误”的心理实验研究

本文运用心理学实验研究发现,无论股价连续上涨还是下跌,在中国资本市场上具有较高教育程度的个人投资者或潜在个人投资者中,“赌徒谬误”效应对股价序列变化的作用均要强于“热手效应”,占据主导地位。在股价连续上涨的情况下,随着上涨时间加长,他们认为下一期股价下跌的可能性越来越大,从而卖出的倾向增大,而买进的倾向变小;股价连续下跌时,随着下跌的时间加长,投资者认为下一期股价上涨的可能性越来越大,从而买进的倾向增大,卖出的倾向减小。这一结果表明,在中国股票市场处于中长期“熊市”中时,至少较高知识水平的个体投资者存在期望市场回升的基本心理动力。实验也发现了这些投资者存在着明显的“处置效应”,即股价上涨时倾向于卖出,股价下跌时则倾向于继续持有,该效应在女性及专业投资知识与经验程度较低的投资者身上更加明显。     

IPO重启首日超额收益实证研究

重启之后的中国证券市场,是否能有效地消除各种弊端,抑制首日超额收益过高等异常现象?文章选取我国IPO重启以后发行的新股作为样本,从信息的不对称、承销商的声誉、我国特殊的新股发行制度以及我国投资者的情绪四个角度对我国IPO重启首日超额收益现象进行实证分析,并力图从一级市场发行价格确定和二级市场交易价格形成两个环节来解释我国的IPO首日超额收益,提出一些建设性的参考意见,促进我国的上市公司对IPO进行合理定价,优化资本市场资源的配置。     

New Evidence of Psychological Barrier from the Oil Market

The authors examine how stock returns were affected when the oil price reached the psychological barrier of US$100 per barrel for the first time in history. Using an event study approach, 4 key results emerge. First, the authors show that a psychological barrier event in the oil market does affect stock returns. Second, they show that a psychological barrier event in the oil market is a source of return drift—a phenomenon well explained and understood with respect to nonoil news events. Third, the psychological barrier affects small/medium-sized stocks and not large stocks. Last, the authors show that successful trading strategies can be devised based on the information that the oil price psychological barrier significantly impacts the market and that it contributes to return drift.     

股票转让方式与极端收益风险——兼论新三板市场引入做市转让制度的经济后果

在极端收益风险形成机理的现有研究中,交易环节是其逻辑链条中缺失的一环;对于做市转让制度的实施效果,现有实证研究也普遍忽视了其对极端收益风险的影响.文章从交易环节入手,提出了一个解释极端收益风险形成机理的新假说,并以新三板市场引入做市转让制度为契机,实证考察了股票转让方式和极端收益风险之间的关系.研究发现:(1)与实施协议转让的股票相比,实施做市转让的股票极端收益风险显著较低,但更多的做市商并未带来显著更低的极端收益风险;(2)做市转让方式对股价暴涨风险的抑制作用在熊市中较强,对股价暴跌风险的抑制作用则在牛市中较强;(3)股票转让方式对极端收益风险的影响主要通过股票流动性路径起作用,而信息有效性路径会起作用主要是因为信息有效性和股票流动性之间的高相关性.使用处理效应模型来控制自选择偏差的影响,使用不同的极端收益风险度量指标,延长极端收益风险的计算窗口,均不改变上述实证结果.这表明,交易环节是影响极端收益风险的重要因素,做市转让方式的引入有助于降低新三板挂牌公司的极端收益风险.文章对于深入理解极端收益风险形成机理、改善新三板市场交易机制具有重要的意义.     

Investor sentiment,trading behavior and stock returns

This article examines how investor sentiment and trading behaviour affect asset returns. By analysing the unique stock trading dataset of the Korean market, we find that high investor sentiment induces higher stock market returns. We also find that institutional (individual) trades are positively (negatively) associated with stock returns, suggesting the information superiority (inferiority) of institutional (individual) investors. Investor sentiment generally plays a more important role in explaining stock market returns than investor trading behaviour.     

关于我国股市知情交易水平及其性质的实证研究

基于Easley、Hvidkjaer和O'Hara的序贯交易模型与PIN (Probability of Information-based Trading,基于信息的交易比率)指标对我国股市知情交易情况进行的实证分析研究结果表明:(1)我国股市信息不对称程度较高;(2)由于知情交易者利用坏消息的能力有限且流动性交易水平较高,我国股市知情交易比率并不太高;(3)知情交易比率与后续期间股票收益率的负相关性,表明我国股市中市场操控型知情交易比较严重.因此,我们认为应进一步完善上市公司的信息披露制度,降低投资者之间的信息不对称程度,同时确保流动性投资者参与股市的积极性;在引入做空机制时应慎重考虑和综合权衡,避免不适当地增加流动性投资者所承担的逆向选择风险水平,降低股市的流动性供给和风险分散功能;证券市场监管部门应进一步加强对异常交易活动的监控,加大对市场操纵行为的打击力度,以确保我国证券市场的健康发展.     

限售股流通与股价效应关系的实证研究

本文运用事件研究法对限售股上市流通的股价效应进行了实证研究。研究结果袁明：限售股的上市流通带来负的股价效应;样本公司的特征及股票的交易特性显著影响股价效应;在累积超额收益率为正的样本中,累积超额收益率与净资产收益率负相关,与区间日均股票换手率、股票每股收益正相关;在累积超额收益率为负的样本中,累积超额收益率与IPO到限售流通股上市流通的时间、账面市值比、区间日均成交量负相关。