融资融券交易的市场冲击效应研究——基于中国台湾证券市场的经验与启示

融资融券交易是证券市场的重要组成部分,它的推出会对整个市场产生何种影响是非常值得研究的问题.文章利用中国台湾证券市场的融资融券交易数据,从市场流动性与波动性角度研究融资融券交易对整个市场的冲击效应.研究结果表明,融资买空交易有助于提升整个市场的流动性水平,在一定程度上可以改善市场流动性水平相对不足的状况,但融券卖空交易对市场流动性水平没有显著影响;融资买空与融券卖空交易并未显著影响整个市场的波动性水平.文章建议证券监管部门可以将融资融券交易保证金率作为市场调控工具,通过适时调整保证金率调控整个市场,避免市场出现大幅震荡.     

Impact of government policy responses of COVID-19 pandemic on stock market liquidity for Australian companies

This study investigates the impact of government policy responses of COVID-19 pandemic on stock market liquidity for listed Australian companies and for 11 different industries separately. A quantitative deductive approach is used for a sample of 1,452 companies with a total of 292,164 firm-day observations over a period from January 25, 2020 to December 31, 2020 during the outbreak of COVID-19. Univariate and multivariate (two-way cluster-robust panel regression) analysis were conducted. Data were collected from the Oxford COVID-19 Government Response Tracker, Worldmeter, Refinitiv Workspace and Datastream. Our findings indicate that the influences of the six out of seven stringency policy responses reduced Australian equity market liquidity. However, public information campaigns enhanced market liquidity and hence trading activity. Among the 11 industries, our analysis shows that the non-pharmaceutical interventions by the Australian government have significant and positive effects on four industries: Consumer non-cyclicals, healthcare, financial and technology. However, the worse effects were depicted in the industrial (transportation) and energy industries. This study is important for investors, policymakers and regulators to understand the diverse effects of government policy responses of COVID-19 on stock market liquidity to enhance financial stability. Moreover, understanding this effect is particularly important to decision-makers such as portfolio and fund managers to manage their portfolios and trading activities during extreme turbulence times, such as COVID-19. Unlike previous studies that focus on country analysis, this study examines on firm basis the impact of government interventions on stock market liquidity in a well developed Australian stock market.     

Rolling settlement and market liquidity

This paper investigates the impact on UK stock and option markets of the change from an account based settlement system to a rolling settlement procedure. Such a change increases the transaction costs of short-term margin traders, and is likely to impact on the liquidity of the underlying market, as well as trading in the options market. Evidence is presented that the settlement procedure does impact on the liquidity of the market. Further, we find that rolling settlement increased market liquidity, consistent with the exit of margin traders as a result of the increase in short selling costs. Associated with this increase in liquidity is a significant reduction in nonoptionable stock trading volume, implying that margin trading may have been more prevalent in stocks without options. Finally, it is shown that while trading in stock options increased, the volatilities implied from call and put option prices indicate that put options have become relatively more expensive. This reflects the change in demand induced by the new settlement procedure, especially in terms of the increase in short selling costs.     

Cash-flow news,market liquidity and liquidity risk

This article adopts Campbell's (1991) return decomposition model to decompose the unexpected stock return and unexpected excess stock return in the US stock market. The study also investigates the factors that cause the shock to stock return and excess stock return. We further examine the responses of stock market to cash-flow news, expected stock return news, expected excess stock return news and interest rate news. Last, we examine the reaction of market liquidity, liquidity risk and abnormal trading volume to cash-flow news, expected stock return news, expected excess stock return news and interest rate news. Our main findings are summarized as follows: first, cash-flow news is the main driver of stock return and excess stock return in stock market. Second, the dividend payout ratio is able to predict stock return and excess stock return. Third, under the model of stock return variance, unexpected market liquidity and unexpected liquidity risk are negatively related to expected stock return news, but not related to cash-flow news. Fourth, under the model of excess stock return variance, unexpected market liquidity and unexpected liquidity risk are negatively related to cash-flow news, expected excess stock return news, and interest rate news.     

连续竞价市场的股权结构、非对称信息与流动性

本文采用分笔交易的高频数据研究了股权结构对指令驱动的连续竞价市场中流动性和非对称信息的影响。研究表明,机构投资者对股票流动性有正的影响,且机构投资者能够显著减少交易过程的信息不对称程度,从而降低流动性成本。以国有股权和法人股权为代表的公司内部人对股票流动性没有显著影响,但能够降低交易过程的信息不对称程度,对减少流动性成本有积极作用。上市公司持股比例越分散,信息不对称程度越低,流动性成本越低。     

Information asymmetry,cluster trading,and market efficiency: Evidence from the Chinese stock market

This study investigates the effect of asymmetry information and illiquidity related to cluster trading on information integration efficiency in the Chinese stock market. The results show that information asymmetry and illiquidity related to cluster trading both negatively affect market efficiency in the Chinese stock market. While the effect of information asymmetry on market efficiency dominates in the informational period, the effect of illiquidity related to cluster trading dominates in other periods, when trading is less concentrated. Noise trading has a positive effect on market efficiency by greatly reducing the illiquidity related to cluster trading; however, its effect on information asymmetry is not significant. Our results provide insight into investors’ trading strategies.     

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.     

我国货币政策对股票市场流动性风险的影响——基于流动性波动性的风险测度方法

本文以流动性的波动性度量流动性风险,从货币供应量和利率两个方面,应用VAR模型首次研究了我国货币政策对股票市场流动性风险的影响。研究发现,货币供应量变化与流动性风险负相关,其中,M2变化对流动性风险影响最大,M1变化的影响次之,M0变化的影响最小;利率对流动性风险有正向影响,但影响力度小于货币供应量变化的影响。研究还发现,牛市状态下,货币供应量变化和利率对流动性风险的影响周期长于熊市状态,利率对流动性风险的影响力度明显大于熊市状态;但熊市状态下,货币供应量变化对流动性风险的影响力度相对较大,其中,M0变化对流动性风险的影响明显大于牛市状态。     

Front-running dynamics

We integrate a monopolist dual trader into a dynamic model of speculation. In static settings, [J.-C. Rochet, J.-L. Vila, Insider trading without normality, Rev. Econ. Stud. 61 (1994), 131-152] establish an irrelevance result—expected equilibrium outcomes are the same whether the monopolist speculator sees liquidity trade or not; and Roell [Dual-capacity trading and market quality, J. Finan. Intermediation (1990), 105-124] shows that with multiple speculators, dual trading benefits liquidity traders. In dynamic settings, these results are reversed: a front-running speculator exploits knowledge of future liquidity trade, extracting greater profits by smoothing profit extraction intertemporally. Front running introduces positive serial correlation to order flow. Accordingly, market makers discount past order flow in prices, but prices retain the martingale property.     

股票流动性与企业创新：促进还是抑制——企业异质性视角

基于2010—2017年我国沪深A股1281家上市公司数据,从企业异质性视角分析股票流动性对企业创新的影响。结果发现：总体来看,股票流动性会抑制企业创新,而且对后期抑制作用更大;企业规模和行业特征是影响“股票流动性-企业创新”关系的重要因素,即股票流动性对大型企业和传统行业企业创新具有促进作用,而对中小型企业和高科技行业企业具有抑制作用。进一步机制研究显示,稳定型机构投资者和交易型机构投资者在股票流动性与企业创新间起双中介作用,虽然股票流动性对二者的作用方向相反,但最终都会导致企业创新水平下降。     

内幕交易监管、投资者交易策略与市场利益分配

当证券市场实施内幕交易监管后,投资者的交易策略可能会发生改变,市场利益的分配也会发生相应的改变。文章在一个实施内幕交易监管的框架下,对内部人的利益分配进行了研究,发现内部人的利益不仅与内幕交易监管力度和执行能力有关,还与市场流动性、交易者类型、信息准确度和市场波动性等因素密切相关。同时,由于监管有效性幻觉和内部人分层现象的存在,内部人利益在一定时期内还可能出现反常变动。     

股票流动性与企业创新：促进还是抑制——企业异质性视角

基于2010—2017年我国沪深A股1281家上市公司数据，从企业异质性视角分析股票流动性对企业创新的影响。结果发现：总体来看，股票流动性会抑制企业创新，而且对后期抑制作用更大；企业规模和行业特征是影响“股票流动性-企业创新”关系的重要因素，即股票流动性对大型企业和传统行业企业创新具有促进作用，而对中小型企业和高科技行业企业具有抑制作用。进一步机制研究显示，稳定型机构投资者和交易型机构投资者在股票流动性与企业创新间起双中介作用，虽然股票流动性对二者的作用方向相反，但最终都会导致企业创新水平下降。     

Informed trade,uninformed trade and stock price delay

The probability of informed trading (PIN), a measure of information-based trading risk, has been broadly applied to empirical studies on asset pricing. However, it is still controversial whether PIN measures exclusively the risk of firm-specific private information or it also captures the private interpretation of market wide public information. This article examines the relevance of PIN to the delayed response of stock prices to market-wide information. We find that PIN significantly explains individual stock price delay even controlling for size, liquidity and risk, and low-PIN stock prices adjust to market information more rapidly not only because of a notably high level of informed trading but also an even much higher level of uninformed trading. Our findings support the notion that PIN also captures the private skilled interpretation of public common factor information by sophisticated investors, and provide new empirical evidence on how information-based trading affects the speed at which stock prices adjust to information.     

Short sale constraints and the information content of trading

We examine changes in the information content of trading when short sale constraints between prohibition and restriction exist on a stock exchange. This is made possible by a unique institutional arrangement at the Stock Exchange of Hong Kong. It maintains a list of stocks which can be sold short under regulations. Stocks not on the list are prohibited from short selling. The list is revised on a quarterly basis based on predetermined criteria. We find that the probability of information-based trading (PIN) significantly increases when a stock is added to the list. Further analysis shows that this is mainly because uninformed traders are driven out of the market. Elimination of uninformed traders also causes the aggregate trading volume to decrease rather than increase. In comparison, the PIN does not change when a stock is dropped from the list. We also find that market liquidity, measured by volatility and bid–ask spreads, slightly decreases when a stock is added to the list and significantly increases when a stock is dropped from the list. Possible explanations are discussed.     

Price discovery and the effects of fragmentation on market quality: evidence from Cypriot cross-listed stocks

Using a novel high-frequency data set, we examine the contribution of Greek trading to the price discovery process of a pair of Cypriot blue-chip, cross-listed stocks during overlapping trading hours. Additionally, we investigate the effects of market fragmentation on the home market’s quality, as measured by microstructure-based liquidity measures. Contrary to earlier studies from other markets, our findings show that foreign stock exchanges can act as the leading contributors to price discovery and can concentrate the majority of trading activity and produce the lowest transaction costs. Our results also show that market fragmentation can lead to negative effects on market liquidity.     

Do Market‐based Indicators Anticipate Rating Agencies? Evidence for International Banks

This paper analyses the ability of credit default swap (CDS) spreads, bond spreads and stock prices to anticipate the decisions of the main rating agencies, regarding the largest international banks. Conditional on negative rating events, all the three indicators show significant abnormal changes before both announcements of review and actual credit rating changes, but rating actions still seem to convey new information to the market. Results for positive rating events are less clear‐cut with the market indicators generally showing abnormal behaviours only in conjunction with the events. As for the predictive power of the financial indicators examined, the CDS market is particularly useful for negative events and stock prices for positive events. However, all indicators also send many false signals and are to be interpreted with care.     

我国公司红利政策与股市波动

本文从实证的角度分析了中国上市公司的年度红利公告对股价及交易量的影响。我们发现 ,不论是首次分红还是一般的年度分红 ,现金股利所引起的股价异常收益显著小于股票股利和混合股利 (即现金和红股 )。此外 ,现金股利作为首次分红支付方式不受市场欢迎 ,其异常收益显著为负值。为了保证实证结果的纯净性 ,本文还进行了干扰排斥性检验 ,排除了除息除权日的溢出效应、大宗交易所引起的股价偏差及红利公告期间风险要素增加的影响。此研究回答了我国证券市场建立以来公司红利政策与市场价格及交易额的相关关系问题。     

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。     

Insider trading and information revelation with the introduction of futures markets

We establish a theoretical model with informed trading in which both of individual stock futures and its underlying stock are traded in the market. With the introduction of the futures, the paper shows that an informed trader's position of futures usually motivates him or her to trade more aggressively in the stock market at the expiration day. This also worsens the adverse selection problem and makes the stock market become less liquid. Moreover, the increase of the informed trading accelerates the information revelation and improves market efficiency on the expiration date. Finally, our results suggest that price manipulation could be one factor that affects the market liquidity and market efficiency when the futures are introduced into the market.     

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.