Short sellers and insider trading profitability: A natural experiment

We examine the impact of short sellers on insider trading profitability using a natural experiment of a pilot program which relaxed short-selling constraints for randomly selected pilot stocks. We find that pilot firms experienced a significant decrease in insider trading profitability during the pilot program. The results are more pronounced for the pilot firms with poor information quality, and for the pilot firms without corporate restrictions on insider trading. Our evidence suggests that short sellers serve an important market disciplinary role by reducing insider trading profitability.     

中国地区金融发展水平的评价与实证分析

从金融发展和经济基础两方面选择了FIR等指标,构建了评价中国地区金融发展水平的评价指标体系,以层次分析法确定指标权重,以阀值法进行无量纲处理,利用所构建的指标体系,对2004年中国31个省市的金融发展水平进行检验。认为,东中西部地区金融发展水平差异明显,金融发展形如一右端被拉长的"橄榄球";东部地区金融发展水平成"圆柱体"形分布;影响西部地区金融发展水平的是"经济短板";制约各省份金融发展的"短板"各不相同。     

Stabilizing the market with short sale constraint? New evidence from price jump activities

We re-examine the impact of short-sale constraints (SSC) on market stabilization via realized jump activities during 2002–2009 to circumvent the reverse causality in identifying the policy effects of SSC. We observed that the abnormal downturns under tighter short sale constraints are significantly larger whereas there is no difference for abnormal upturns. Our empirical results survive across a sequence of robustness examinations controlled for market illiquidity. The findings do not support the claims by regulators that restraining short-sales can stabilize prices; instead, SSC has led to a less efficient market with stronger extreme downward returns.     

Impact of short selling activity on market dynamics: Evidence from an emerging market

With unique daily short sale data of Borsa Istanbul (stock exchange of Turkey), we investigate the dynamic relationship between short selling activity and volatility, liquidity and market return from January 2005 to December 2012 using a VAR(p)-cDCC-FIEGARCH(1,d,1) approach. Our findings suggest that short sellers are contrarian traders and contribute to efficient stock market in Turkey. We also show that increased short selling activity is associated with higher liquidity and decreased volatility. However this relation weakens during the financial turmoil of 2008. Our results indicate that any ban on short sales may be detrimental for financial stability and market quality in Turkey.     

Short interest and stock price crash risk

Using a large sample of U.S. public firms, we find robust evidence that short interest is positively related to one-year ahead stock price crash risk. The evidence is consistent with the view that short sellers are able to detect bad news hoarding by managers. Additional findings show that the positive relation between short interest and future crash risk is more salient for firms with weak governance mechanisms, excessive risk-taking behavior, and high information asymmetry between managers and shareholders. Empirical support is provided showing that the relation between short interest and crash risk is driven by bad news hoarding.     

Which financial stocks did short sellers target in the subprime crisis?

Tracing the SEC ban on the short selling of financial stocks in September 2008, this paper investigates whether such selling activity before the 2008 short ban reflected financial companies’ risk exposure in the subprime crisis. Evidence suggests that short sellers sold short stocks that had the greatest asset and insolvency risk exposures, and that the short selling of financial firms’ stocks was not significantly greater than that of non-financial firms after we match them on firm size and insolvency risk. When the short ban was in effect, the market quality of financial stocks without subprime assets exposure had deteriorated to a larger degree than that of financial companies with subprime assets exposure. The findings imply that such a regulation may mute the market disciplining effects of investors and may also be seen as a counterweight to any perceived macro or systemic risk reduction benefits resulting from such a ban.     

卖空限制与收益可预测性——A股融资融券制度的证据

基于A股市场融资和融券余额的巨大差距,本文拓展了Hong et al.(2016)的理论模型,在融券端和融资端分别找到了影响股票收益率的变量:融券比率(融券余额/流通市值)和融资回补天数(融资比率/日均换手率)。进一步,本文利用组合价差法和Fama-MacBeth横截面回归法,实证检验了A股市场中融券比率与融资回补天数解释和预测股票收益率的能力。实证结果表明,在存在融券限制条件下,融券比率相比融券回补天数(融券比率/日均换手率)能更好地代表套利者对股票价格高估程度的看法,根据融券比率构建的等权重多空组合能带来月均1.58%的显著收益;而由于融资约束相对较少,融资回补天数相比融资比率(融资余额/流通市值)能更好地代表套利者对股票价格低估程度的看法,根据融资回补天数构建的等权重多空组合能带来月均1.28%的显著收益。实证结果与本文存在融券数量限制下的理论模型相符,且该收益率不能被多因子模型和常规股票特征所解释。     

Equilibrium in a reinsurance market with short sale constraints

Summary. This paper deals with the existence of equilibrium in a dynamic reinsurance market with short sale constraints, driven by a marked point process, as studied in Bernis and Jouini (2001). We use the set of reinsurance treaties as consumption set, which is the positive orthant of some Banach lattice that can be identified to a space of martingales, . The properness of preferences is a key assumption for us to prove the existence of an equilibrium. We provide a sufficient condition for the preferences to be proper in term of loading factor of the reinsurance premium. Received: June 15, 2000; revised version: May 17, 2001     

一种利用短时DFT分析实现全数字2DPSK接收机解调的新算法

本文提出了一种简单而实用的利用短时DFT（ST-DFT）分析实现全数字2DPSK接收机的解调算法。该算法对由多谱勒效应引起的时变频率漂移具有鲁棒性。由于该算法是通过检测在载频处的瞬时能量谱的跳变来实现2DPSK信号的解调，所以该算法不需要进行专门的载波相位恢复、符号定时，且具有较好的抗噪性能，实现起来简单。     

An Empirical Investigation of Trade Credit Demand

This paper investigates the motivations for a firm's demand for trade credit. Demand for credit is modelled as a function of transaction costs motivations, financing motivations, operational considerations, seller compliance issues and supplier marketing, whilst controlling for the firm's business environment and for firm characteristics such as size and industry. This paper builds on previous studies by considering a wider range of factors that can affect trade credit demand holistically on a single sample. It appears that the use of trade credit is widespread, and that it is generally perceived as an important short term financing option, although the availability of trade credit is not a major influence on supplier choice. The level of a firm's trade credit demand is found to be significantly influenced by transaction costs, financing, operational issues, marketing activities by suppliers, the firm's investment in trade debtors and firm size.