卖空机制与股指期货关系研究

卖空机制和股指期货是中国即将推出的两个金融衍生品。面对美国次贷而引发的全球危机的情况下,中国对于两者推出时间的先后及在推出的时机有不同的观点。观点认为,股票卖空交易是推出股指期货的必要前提条件,必须先建立卖空交易才能推出股指期货,否则将显著影响股指期货定价效率;另有观点认为,在尚未建立股票卖空交易的情况下推出股指期货,不会对股指期货市场的正常运作造成根本性障碍,可以考虑先推股指期货再推出融资融券业务。本文针对于此进行理论和实证分析,为今后的稳定发展提供一些建议。     

卖空机制对股票定价效率影响的实证研究——基于创业板股票融资融券和股指期货交易

本文选取了2014年9月第四次融资融券扩容的23只创业板股票,结合2015年4月中证500股指期货的推出,实证研究了不同市场状态下,卖空机制对股票定价效率的影响,研究发现:无论牛市或熊市,引入卖空机制都能够显著改善股票的定价效率,样本加入融券卖空名单后再次引入股指期货这一卖空机制时,定价效率得到了进一步的提升;相较于熊市,牛市中卖空机制反而导致了定价效率的降低.     

浅析我国股指期货业务风险以及防范措施

在国外发达的证券市场,股票股指期货是一种非常重要的衍生产品.而股指期货的推出,将对我国证券市场产生重大影响.股指期货不但具有对冲风险、提高市场流动性,促进金融创新的作用,在我国证券市场,它也将成为系统性的卖空机制.股指期货现已成为国际金融市场体系中的重要组成部分,但同时也伴随着诸多的风险,本文首先介绍了股指期推出的背景、发展概况,随后探讨了我国股指期货市场可能存在的风险,以及相应的防范和控制措施.     

中国股指期货的特有风险及控制

国外经验表明,为了使股指期货发挥出其应有的功能,在其正式推出之前有必要充分认识其风险并做好相应的控制准备。本文深入地分析了股指期货在我国市场上可能具有的特有风险,并针对风险的根源提出了风险控制措施,即要减少政策干预,加强投资者教育,建立卖空机制,发展QDII以及培养市场信用机制。     

股指期货推出对A股市场的影响

随着股指期货的即将推出,社会对股指期货推出可能对股票现货市场产生的影响高度关注。本文通过对己推出股指期货国家和地区(美国、日本、韩国、香港等)股指期货上市时市场情况的实证考察,对股指期货推出将对我国股票现货市场产生的影响进行分析和预测。     

基于股指期货期现套保原理的股票套期保值分析

股票市场和期货市场是既区别又联系的。商品期货的价格变动对相关上市公司的业绩和公司股票价格产生直接或间接的影响。目前我国刚刚推出股指期货、融资融券的情况下,因入市门槛比较高,对于广大的中小投资者,股票市场的系统性风险得不到有效的规避。本文分析了股票市场与期货市场的关系及股指期货套期保值原理及方法。根据股指期货套利原理,挑选一个股票组合,要求这个股票组合与期货合约标的物有显著的协整关系,从而可以通过期货市场的买空、卖空功能来降低这个投资组合的系统性风险。从而使得那些达不到股指期货交易标准的中小投资者能够有效的规避系统性风险。     

沪深300股指期货的推出对股票市场的影响

股指期货具有价格发现、套期保值等功能,是现货市场发展到一定阶段的产物。我国股权分置股改革已基本完成,股市机制不断健全,机构投资者日益壮大,股票市场健康快速发展。我国推出股指期货的条件已经成熟。本文在介绍股指期货基本功能和意义的基础上,深入分析了沪深300股指期货对我国股票现货市场的影响及稳步推出股指期货的保证措施。     

股指期货对股指波动性影响的方法研究

我国的股票市场长期以来只准买涨不准买跌,股票换手率高且价格波动较大,研究股指期货推出对股指波动率的变化情况关系到股指期货机制设立的初衷和我国的资本市场能否长期健康的发展。由于股票价格波动的非对称性存在,股指期货的推出能否减弱或是增强这种非对称性也是值得关注的另一个方面。     

股指期货对现货市场影响——理论与实证分析

论文分析了股指期货对股票现货市场的影响,并通过对世界各国股指期货推出前后股票市场的走势,得出股指期货对现货市场的影响,并简要分析了上证300指数期货推出对A股指数的影响,论文最后就进一步发展和完善股指期货提出政策建议。     

使用高频数据分析股指期货的推出对我国现货市场波动性与信息定价效率的影响

随着我国股指期货的推出,社会对股指期货的推出对股票现货市场产生的影响高度关注。本文基于EGARCH模型利用2010年4月16日我国股指期货推出以来的五分钟交易高频数据进行股指期货对股票现货市场波动性的影响进行实证分析,并借鉴了海外学者对就股指期货上市对对股票市场波动性影响的基本结论。结果表明,我国股指期货推出后加大了现货市场的波动水平,这样的影响结果是根源于股指期货本身的影响还是由于我国股指期货的制度不完善造成的需要进一步讨论。本文的研究,对监管层制定跨市场监管制度和对投资者深刻理解股票市场并进行有效投资都有很好的理论和实践意义。     

Short Selling: The Impact of SEC Rule 201 of 2010

Despite its sizeable compliance costs, we are unable to document any clear benefits of SEC Rule 201 in ensuring fair valuations and price stability, promoting higher liquidity and execution quality, or preventing a sudden flash crash or prolonged market crises. Our daily and intraday analysis of data both before and after Rule 201 finds that short sellers are naturally more active before the occurrence of negative returns, not after significant price declines. Our simulation results show that Rule 201 further curtails short selling during normal periods, but is not binding on short sellers during the volatile period of the 2008 financial crisis.     

Whose opinion matters when insiders disagree with short sellers?

This study investigates the credibility of conflicting trading signals from two well-informed and sophisticated parties: corporate insiders and short sellers. Our results suggest that insiders’ information is dominant when short sellers trade in the opposite direction. We attribute the positive price reaction following a disagreement to insiders’ superior information that is not available to short sellers. Our results do not support the managerial short-termism argument. Two additional tests show that insider buying credibility enhances when information asymmetry is high and that short sellers reverse their shorting position after the disclosure of insider buying. Both findings support the idea that short sellers may experience a previously unacknowledged barrier in accessing private information.     

关于建立融券卖空机制对股市影响的分析

通过对股价涨跌、波动幅度和成交量的对比分析,可以发现融券卖空机制的引入有利于完善证券市场的价格发现机制,增强证券公司的盈利能力,丰富投资者的投资选择。在进一步增强证券的可融性,降低中国股市的系统性风险和控制监管漏洞与异常交易的基础上,中国股市建立融券卖空机制的现实条件已基本具备。     

卖空威胁、公司融资扩张战略与违规行为

利用中国推出融资融券业务的准自然实验机会,本文以2010—2016年中国A股上市公司为样本,使用双重差分模型研究放松卖空限制对企业违规行为的影响。研究发现,融券业务允许市场中的知情投资者挖掘企业负面信息进行卖空,形成有效的卖空威胁,从而震慑企业,显著降低其发生违规行为的概率。具体而言,卖空交易行为跟企业违规行为的严重程度正相关;卖空交易行为能显著降低企业的超额收益率;当企业有进一步融资需求或并购扩张战略需求时,卖空威胁对企业的震慑作用更为显著。研究表明,融券业务带来的卖空威胁是企业外部监管的重要机制。     

Options trades,short sales and real earnings management

We study the link between measures of stock options’ volatility and firms’ real earnings management (RM). We hypothesise that RM causes uncertainty in the value of a firm’s common stock and, as a result, increases the volatility spread and skew of the firm’s options. Spread and skew proxy for investors’ uncertainty in the value of the options underlying a stock. Consistent with our hypothesis, we find an association between a firm’s use of RM, and the volatility spread and skew in the firm’s options, more precisely in its put options. We also study the link between short selling and the extent of RM but do not find a consistent relationship between the two.     

Earnings quality and short selling: Evidence from real earnings management in the United States

Prior research provides evidence consistent with managers using real earnings management (REM) to increase earnings. This study examines whether short sellers exploit the overvaluation of firms employing REM. I find that firms with more REM have higher subsequent short interest. The positive relation between REM and short interest is more pronounced in settings where the costs associated with accrual‐based earnings management are high, such as when a firm has low accounting flexibility or faces greater scrutiny from a high quality auditor. I also find some evidence that short sellers respond to REM more than to other fundamental signals of firm overvaluation. My inferences are robust to the use of propensity score matching. Collectively, my evidence suggests that short sellers not only trade on REM information, but they also trade as if they understand the substitutive nature of alternative earnings management methods. This study provides additional insight into the important role that short sellers play in monitoring managerial operating decisions and overall earnings quality.     

Does short sales deregulation affect qualitative information disclosure?

We examine the impact of short sales deregulation on firms' disclosure of non-financial qualitative information. Our simple analytical model predicts that, after short sales deregulation and when the cost of disclosing proprietary qualitative information to the firm and its executives is sufficiently high, shortable firms respond by disclosing less proprietary and more non-proprietary qualitative information than non-shortable firms. Using a textual analysis of qualitative information about the supply chain, available in the management disclosure and analysis sections of the annual reports of a sample of Chinese firms, and applying a staggered difference-in-differences research design, we find evidence consistent with the model's prediction.     

Are Short Sellers Informed? Evidence from REITs

This paper uses intraday short sale data to examine whether short sellers of Real Estate Investment Trusts (REITs) are informed. We find strong evidence that short selling predicts future returns of REITs. Heavily shorted REITs significantly underperform lightly shorted REITs by approximately 1% over the following 20 trading days. This predictive relation holds for both small and large trades, but is stronger for large short trades. We also document a positive relation between shorting activity and volatility. Our results are consistent with the view that short sellers of REITs are informed and contribute to market efficiency by impounding information into prices.     

Does short selling improve stock price efficiency and liquidity? Evidence from a natural experiment in China

China introduced short selling for designated stocks in March 2010. Using this important policy change as a natural experiment, we examine the effect of short selling on stock price efficiency and liquidity. We show that the introduction of short selling significantly improves price efficiency, as measured by the differences in individual stock responses to market returns and the delay in price adjustments. Short selling also enhances stock liquidity, as measured by bid-ask spread and Amihud [2002. ‘Illiquidity and Stock Returns: Cross-section and Time-series Effects.’ Journal of Financial Markets 5: 31–56] illiquidity measure; and reduces stock volatility. Overall, our results suggest that short selling helps to stabilize asset prices, provides additional liquidity and improves market quality, even in an emerging economy with a less developed stock market than that in the US and Europe.     

Short selling and the independence of business-related analysts: Evidence from an emerging market

This paper investigates whether short-sale deregulation improves analysts' independence in an emerging market where conventional mechanisms mitigating conflicts of interest are either ineffective or absent. Short selling reduces the effectiveness of analysts' favourable opinions in creating or sustaining overvalued stock prices, thus decreasing the incentives of institutional clients of brokerages to exert pressure on related analysts to initiate coverage and issue biased opinions. Using a difference-in-difference approach, we find strong evidence that stocks that are eligible for short sales experience a greater reduction in coverage by related analysts than stocks that are ineligible for short sales. When covered firms become eligible for short sales, the quality of forecasts and recommendations issued by related analysts improves considerably. Further analyses show that shortable firms with a significant reduction in related analysts' coverage are more likely to underperform and to experience stock price crashes in the future. Altogether, our results are consistent with short selling effectively restoring related analysts' independence in emerging markets.