全球股票市场卖空交易机制的演进与发展分析

双向交易是资本市场的基本制度,目前全球主要市场均已建立卖空机制,双向交易成为资本市场普遍选择。文章从股票市场卖空交易机制的建立伊始,回顾了双向交易机制从建立到初步发展——被质疑——逐步完善并被广泛认可的演进过程。文章详细介绍了1929年全球股灾后股票卖空市场发生的巨大变革,包括完善交易制度、纳入法律监管范畴等,追踪了2008年金融海啸中海外市场禁止股票卖空的事件,深入分析了"禁空令"对市场的影响。2011年欧债危机中欧洲六国重拾限空令,但美英德没有跟进,表现出这些监管机构相较2008年,对股票卖空的态度发生了明显的转变。文章认为,双向交易历史悠久,是资本市场不可或缺的基础交易制度和有机组成部分,是资本市场的客观需求产物和内在稳定机制,是我国资本市场健康发展的基础。然而,发展双向交易的同时,必须严格监管,禁止裸卖空,重点打击利用双向交易进行市场操纵的企图。     

卖空行为市场效应研究

证券卖空是发达证券市场普遍实施的一项交易制度。随着我国资本市场规模的不断扩大,规范化建设取得重大进展,证券卖空的限制对我国证券市场发展的制约作用愈加明显。虽然卖空的引入最初是出于保险目的,但同时也带来了巨大的风险,允许证券卖空究竟会对市场产生什么影响,存在哪些风险。对于这些问题,学术界仍存在激烈讨论,这也是引入卖空制度前后政府、学术和实务各界非常关注的问题。卖空领域产生了众多的理论研究结论与实证证据。本文是这些研究的文献综述,对相关领域的研究进行了归纳整合,系统展现卖空的研究成果。     

卖空行为市场效应研究

证券卖空是发达证券市场普遍实施的一项交易制度.随着我国资本市场规模的不断扩大,规范化建设取得重大进展,证券卖空的限制对我国证券市场发展的制约作用愈加明显.虽然卖空的引入最初是出于保险目的,但同时也带来了巨大的风险,允许证券卖空究竟会对市场产生什么影响,存在哪些风险.对于这些问题,学术界仍存在激烈讨论,这也是引入卖空制度前后政府、学术和实务各界非常关注的问题.卖空领域产生了众多的理论研究结论与实证证据.本文是这些研究的文献综述,对相关领域的研究进行了归纳整合,系统展现卖空的研究成果.     

卖空机制对股票市场影响的研究初探

2010年3月31日,我国股票市场正式启动了融资融券业务,融资融券业务的推出标志着我国证券市场正式告别"单边市"时代,我国证券市场也具有了卖空机制,本文以卖空交易为研究对象,研究卖空交易对股票市场的相关影响,笔者认为我国融资融券业务的推出将极大增强我国股票市场的有效性,有利于我国股票市场稳步健康发展。     

证券卖空机制的风险及其控制

卖空机制对证券市场既能提供不可或缺的功能,也会带来潜在的风险,我们可以采取芬兰模式在规避法律限制的同时,对卖空机制中证券借贷关系的进行控制,借鉴美国模式对卖空交易基本要素进行控制,用逐步推进的方式建立卖空机制,确立相应的法律监管框架,减少市场制度层面的不确定性,从而实现卖空机制的风险控制。     

推出卖空机制对证券市场波动率的影响

一直以来,理论界和实务界对于证券市场上是否允许卖空存在很大争议,争议的焦点之一就在于引入卖空机制是否会加大市场的波动性甚至引发市场危机.本文运用非对称GARCH模型探讨了香港市场推出卖空机制前后市场波动率的变动情况,发现推出卖空机制不仅不会加大证券市场的波动,反而使权证券市场的波动率有所降低.     

证券市场中卖空交易机制基本功能研究

本文通过利用境外实证研究结果和境外市场的数据进行实证这两种方式对国外证券市场中卖空交易机制的基本功能进行深入的研究.研究结果表明,证券市场中的卖空交易机制能发挥稳定市场、价格发现和提供流动性的功能,但卖空机制的宏观调控功能的实际效果并不理想.     

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。     

股市卖空的理论与实践

背景介绍卖空是股市交易的一种基本模式。虽然卖空的产生几乎与股市的产生一样早(形成于17世纪初的阿姆斯特丹股票市场被认为是最早的现代股市),卖空却往往被股市的监管机构禁止。被禁止的原因最初是在道德方面,卖空者的获利是基于其他人的损失,即股票价格下跌,后来是由于担心卖空会增加股市的恐慌,当有负面消息时,卖空加剧了股价的下跌。其它的原因包括允许卖空使雄厚资本对股市的操纵变得更加容易。但是学者不断地提出上述对卖空的指责都是一厢情愿,卖空并不具备     

卖空机制的审计收费效应研究

卖空机制作为一种金融创新,如何在提高证券市场定价效率的同时,有效发挥外 部治理功能、改善公司治理、间接推动国内资本市场健康发展成为理论和实践中的一项重要 课题。运用多元回归模型对国内卖空机制改变审计风险、进而影响审计收费行为的实证检验表 明,随着股票卖空比率的上升,公司审计收费也相应增加。而股票卖空比率与公司审计费用受 制度环境影响显著,在市场化水平较高的地区,公司审计面临来自投资者更大的压力。此外, 公司审计收费与股票卖空比率的正相关关系会因卖空机制的存在变得更加显著。     

Sovereign CDS Spreads,Volatility, and Liquidity: Evidence from 2010 German Short Sale Ban

The paper examines global impact of 2010 German short sale ban on sovereign credit default swap (CDS) spreads, volatility, and liquidity across 54 countries. We find that CDS spreads continue rising after the ban in the debt crisis region, which suggests that the short selling ban is incapable of suppressing soaring borrowing costs in these countries. However, we find that the ban helps stabilize the CDS market by reducing CDS volatility. The reduction in CDS volatility is greater in the eurozone than that in the non‐eurozone. Furthermore, we find that the CDS market liquidity has been impaired during the ban for the PIIGS (Portugal, Ireland, Italy, Greece, and Spain) countries. In contrast, there are no dramatic changes in the market liquidity for non‐PIIGS eurozone and non‐eurozone samples. The findings suggest that the short sale ban is ineffective to reduce sovereign borrowing costs in the debt crisis region if the underlying economy has not been significantly improved.     

Short trading and short investing

Short selling is measured in the literature as both constraint (e.g., lending fees) and activity (e.g., trades). We show that these two measures capture separate effects, which we characterize into two different strategies. The first strategy, “short trading,” has minimal constraints, weekly scale return predictability and average risk. The second strategy, “short investing,” has high constraints, multi-month return predictability and higher risk. Moreover, each strategy incorporates different types of information. Short trading includes short-lived information while short investing includes more long-lived, fundamental information. This diversity in short sellers has implications for both theoretical and empirical research.     

The Short Sale Stigma

Despite a recent upturn, housing prices remain in flux in most cities nationwide. Lenders are still left dealing with a glut of distressed properties. They can choose to foreclose on the property or allow the owner/mortgagor to attempt to sell the property for less than the outstanding balance of the mortgage in a short sale agreement. The best way to clear the market of distressed properties is an important policy question. This is the first study to examine not only the price and time on market effect of being a short sale but also whether the short sale process itself creates a market stigma.     

Does economic policy uncertainty drive CDS spreads?

This study analyzes the dynamic interactions between changes in economic policy uncertainty and the fluctuations in the cost of credit protection. We find that the differenced iTraxx and CDX indices are Granger-caused by variations in the political environment. Within a vector autoregressive framework, impulse response functions show a significant reaction of the CDS spreads to shocks in the policy risk. Implied in these findings is the possibility that country-level risk can permeate to the corporations. Furthermore, financial institutions and traders should closely monitor political developments in order to better predict the CDS premia.     

Short interest in exchange-traded funds

Short selling exchange-traded funds (ETFs) has become a common means of speculating or hedging in response to pessimistic expectations about a specific market or sector, as the short interest of ETFs is more than 10 times that of individual stocks, on average. We determine that sector-based ETFs have an abnormally large short interest level, whereas international ETFs have an unusually small short interest level. The level of short interest is larger for ETFs that have a higher trading volume and a lower market capitalization, regardless of the type of ETF assessed. The level of short interest is lower for ETFs representing indexes that have tradable derivatives, but higher for international ETFs representing indexes that have tradable derivatives. We also determine that the level of short interest in an ETF serves as an effective signal of bearish sentiment when considering all ETFs, but is not an effective signal when isolating any particular type of ETF.

Bank credit risk and macro-prudential policies: Role of counter-cyclical capital buffer

This paper investigates the impact of macro-prudential policy (proxied by the counter-cyclical capital buffer (CCyB)) on bank credit risk during uncertain times, as banking sector stability is crucial in promoting financial intermediation. Using a unique daily data set consisting of 4939 credit default swaps (CDS) of 70 banks from 25 countries over the period 2010–2019, we find that CCyB tightening decreases bank-level CDS spreads, while CCyB loosening increases CDS spreads. This heterogeneous effect of CCyB arises due to its asymmetric effect on the capital ratio (i.e., the equity-to-total assets ratio) of banks. Tightening CCyB significantly increases capital, whereas loosening CCyB does not impact capital. Thus, the risks that emanate from the banking sector during periods of heightened uncertainty and financial distress can be significantly dampened when CCyB regulation is enabled. Consequently, macro-prudential policies for banks to hold higher levels of capital during good times are justified to contain financial market risks during downturns.     

Short selling and stock returns: Evidence from the UK

The practice of shorting stocks was put forward as one of the causes of the recent financial crisis whereas Shiller (2003), for example, considers shorting an essential element of an efficient market. Shorting involves selling borrowed stocks and subsequently closing the position by purchasing and returning the stock to the lender. A profit will be realised if the stock's price decreases. Shorting enables investors who do not own a perceived overvalued stock to sell. Using a high-frequency UK dataset for the period between September 2003 and April 2010, our findings suggest shorting indicates evidence of overvalued stocks as significantly negative abnormal stock returns appear to follow an increase in shorting. These results do not hold, however, for shorting which occurs around the ex-dividend date. We further find that these results hold during the recent financial crisis.     

Assessing the information content of short-selling metrics using daily disclosures

As a consequence of the 2008 financial crisis, the Australian regulator mandated daily reporting and disclosure of both short flow and short interest at an individual stock level. This provides a unique opportunity to study the nature and source of information embedded in each metric. Our empirical findings are consistent with short sellers being heterogeneous with respect to their information. Short flow is strongly related to recent returns and buy-order imbalance, and both anticipates and reacts to price-relevant announcements. In contrast, short interest is related to the mispricing of firm fundamentals. The distinct differences in the nature of information embedded in the two metrics provide an economic rationale for both the unique ability of each metric to predict returns and the future horizons over which the information is relevant.     

CDS as insurance: Leaky lifeboats in stormy seas

What market features of financial risk transfer exacerbate counterparty risk? To analyze this, we formulate a model which elucidates important differences between financial risk transfer and traditional insurance, using the example of Credit Default Swaps (CDS). We allow for (heterogeneous) insurer insolvency, which captures the possibility that relatively risky counterparties may exist in the market. Further, we find that stable insurers become less stable as the price of the contract decreases. The analysis includes insured parties that have heterogeneous motivations for purchasing CDS. For example, some may own the underlying asset and purchase CDS for risk management, while others buy these contracts purely for trading purposes. We show that traders will choose to contract with less stable insurers, resulting in higher counterparty risk in this market relative to that of traditional insurance; however, a regulatory policy that removes traders can, perversely, cause stable counterparties to become less stable. We conclude with two extensions of the model that consider a Central Counterparty (CCP) arrangement and the consequences of asymmetric information over insurer type.