Trading on Private Information: Evidence from Members of Congress

I examine the stock trades of members of Congress and find that over 2004–2010 the buy‐minus‐sell portfolios of powerful Republicans have the highest abnormal returns, exceeding 35% on an annual basis under a one‐week holding period. Among powerful Republicans, the abnormal returns are mostly concentrated in the portfolios of those with less trading experience. I also find that the positive abnormal returns disappear after the Stop Trading on Congressional Knowledge (STOCK) Act was passed in 2012. My results imply that the STOCK Act affected politicians' incentives to trade on private information, which they acquired through their power and party membership.     

Trader Anonymity, Price Formation and Liquidity

Using data from the Frankfurt Stock Exchange we analyze priceformation and liquidity in a non-anonymous environment withsimilarities to the floor of the NYSE. Our main hypothesis isthat the non-anonymity allows the specialist to assess the probabilitythat a trader trades on the basis of private information. Heuses this knowledge to price discriminate. This can be achievedby quoting a large spread and granting price improvement totraders deemed uninformed. Consistent with our hypothesis wefind that price improvement reflects lower adverse selectioncosts but does not lead to a reduction in the specialist's profit.Further, the quote adjustment following transactions at thequoted bid or ask price is more pronounced than the quote adjustmentafter transactions at prices inside the spread. Our resultsindicate that anonymity comes at the cost of higher adverseselection risk. JEL Classification: G10.     

Trader Anonymity, Price Formation and Liquidity

Using data from the Frankfurt Stock Exchange we analyze price formationand liquidity in a non-anonymous environment with similarities to thefloor of the NYSE. Our main hypothesis is that the non-anonymity allows the specialist to assess the probability that atrader trades on the basis of private information. He uses this knowledgeto price discriminate. This can be achieved by quoting a large spread and granting price improvement to traders deemed uninformed.Consistent with our hypothesis we find that price improvement reflects loweradverse selection costs but does not lead to a reduction in the specialist's profit. Further, the quote adjustmentfollowing transactions at the quoted bid or ask price is more pronounced than the quote adjustment aftertransactions at prices inside the spread. Our results indicate that anonymity comes at the cost ofhigher adverse selection risk.     

Preferenced Trading,Quote Competition,and Market Quality: Evidence from Decimalization on the NYSE

We examine the impact of decimalization on preferenced trading in NYSE‐listed stocks and show a significant decline in preferenced trading around decimalization. For the largest NYSE stocks, the total decline is nearly 22%. We also find a negative correlation between the changes in preferenced trading and the changes in quote competition intensity, and a positive correlation between the changes in preferenced trading and the changes in spreads. Consistent with the cream skimming hypothesis, we find that abnormal changes in information asymmetry cost for NYSE trades are positively correlated with the changes in preferenced trading.     

To Trade or Not to Trade: The Effect of Broker Search and Discretionary Trading on Securities Market Performance

In this article we examine the interaction of brokerage search with the Bayesian learning behavior of competitive dealers under asymmetric information. We particularly focus on the effects of price search and discretionary trading on the performance of a dealer market. A search process is incorporated into a model in which brokers determine their reservation price and whether to continue their trades. The model enables us to uncover the interrelationships among search cost, bid‐ask spread, and price volatility. We show that both spread revision and price volatility are dependent upon the optimal search process, inventory fluctuation, and search cost. Furthermore, our model predicts a negative relationship between price volatility and liquidity trading volume.     

证券交易的透明度与信息揭示制度：理论综述

证券交易过程中，交易信息的发布、扩散和传递方式对于各类市场参与者非常重要。目前关于信息揭示制度和交易透明度对市场运行效果的影响尚存在许多争议。本文讨论了交易透明度的含义、研究者和市场机构对于交易透明度的争论、交易透明度与市场绩效的关系，以及不同交易透明性的市场之间的竞争等问题，系统总结了目前与证券交易透明度和交易信息揭示有关的理论观点，以期把握交易信息揭示程度对市场产生的影响，以及由此引起的交易透明度对市场的运行效率产生的影响。     

Insider Trading and Corporate Information Transparency

Our study examines the relation between insider trading and corporate information transparency. We find a negative relation between firms’ information transparency and the economic significance of insider trading, including the amount of insider purchase and sale and the profitability of insider transactions. We also find a negative relation between information transparency and stock price reaction to news of insider trading, which suggests that increases in information transparency preempt insiders’ private information. Our study provides evidence consistent with firms’ transparency-enhancing activities decreasing information asymmetry between insiders and investors by revealing insiders’ private information to investors in a timely manner.     

基于面板数据的我国知情交易与股价信息含量研究

知情交易概率是指知情交易委托单占总交易委托单的比重,用于度量我国知情交易强度.R2代表公司回报率能被市场回报率解释的程度,R2越大,股价信息含量越低.在以往的研究基础上,利用面板数据来考察知情交易概率与股价信息含量的关系,发现知情交易概率越低,R2越高,股价信息含量越低.在控制了流动性与部分公司财务指标后,实证结果依然显示我国股价信息含量与知情交易概率存在正相关关系,说明我国知情交易者进行交易时,更有利于公司特质信息进入股票价格.     

Nasdaq Trading and Trading Costs: 1993–2002

Nasdaq spreads decline from 1993 to 2002, largely independently of tick‐size reductions. Trade size declines, consistent with greater retail investor activity. Using the method of Chordia, Roll, and Subrahmanyam (2001), we find that concurrent market returns strongly affect liquidity and trading activity. Liquidity exhibits distinct day‐of‐the‐week patterns. There is little evidence that macroeconomic announcements or changes in key interest rates affect Nasdaq stocks overall; but in the bear market, we find a relation between some of these variables and effective spreads, which we interpret as consistent with Nasdaq participants' paying greater attention to fundamentals after the market crash.     

Information-Based Trading and Price Improvement

Abstract:  In this study we test the information hypothesis of price improvement. Our results show that price improvement is negatively related to both the probability of information-based trading and the price impact of trades. We interpret these results as evidence that liquidity providers selectively offer price improvements according to the information content of trades. We also show that liquidity providers offer greater (and more frequent) price improvements when they are at the NBBO, and for stocks with wider spreads, fewer trades, or smaller trade sizes relative to the quoted depth. Buyer-initiated trades receive smaller (larger) price improvements than seller-initiated trades on the NYSE (NASDAQ).     

Dispersed Trading and the Prevention of Market Failure: the Case of the Copenhagen Stock Exchange

With augmented demands on power grids resulting in longer and larger blackouts combined with heightened concerns of terrorist attacks, trading institutions and policy makers have widened their search for systems that avoid market failure during these disturbing events. We provide insight into this issue by examining trading behaviour at the Copenhagen Stock Exchange during a major blackout. We find that although market quality declined, markets remained functional and some price discovery occurred during the blackout period suggesting that the NOREX structure of interlinked trading systems combined with widely dispersed trading locations may be a viable means of protection against market failure during massive power disruptions or terrorist attacks.     

The Flash Crash: Trading Aggressiveness,Liquidity Supply,and the Impact of Intermarket Sweep Orders

During the Flash Crash on May 6, 2010, a short period of high stock market volatility, some stock prices declined to $0.01, while others increased to $100,000. Examining Intermarket Sweep Orders (ISOs) before, on, and after May 6, we find that ISO use is substantially higher on May 6. For those stocks whose prices fell the most, over 65% of the sell volume comes from ISOs. During the price recovery period for these stocks, about 53% of the buy volume comes from ISOs. We believe that the unusual behavior of ISOs contributed to the sudden drop and recovery of the market.     

Investor Sentiment,Trading Behavior and Informational Efficiency in Index Futures Markets

This paper shows that traders in index futures markets are positive feedback traders—they buy when prices increase and sell when prices decline. Positive feedback trading appears to be more active in periods of high investor sentiment. This finding is consistent with the notion that feedback trading is driven by expectations of noise traders. Consistent with the noise trading hypothesis, order flow in index futures markets is less informative when investors are optimistic. Transitory volatility measured at high frequencies also appears to decline in periods of bullish sentiment, suggesting that sentiment‐driven trading increases market liquidity.     

Short‐ and Long‐Term Effects of Multimarket Trading

We analyze short‐ and long‐term effects of multimarket trading by examining the entries of multiple markets into transacting three ETFs, DIA, QQQ, and SPY. We find that large‐scale entries improve overall market quality, while small‐scale entries have ambiguous effects. Our results show that the competition effect dominates the fragmentation effect over a long horizon and that market fragmentation leads to a decline in trading costs. Further, we find that the order handling rules help mitigate the fragmentation effect and facilitate the competition effect. We do not find that multimarket trading harms price efficiency or increases price volatility.     

Odd Lot Trades: The Behavior,Characteristics, and Information Content,Over Time

I investigate the role odd lot trades play in equity markets, and how this role changes over four periods: 2005, 2007, 2010, and 2012. In each of these years, I examine the determinants, price contribution, and characteristics of odd lot trading. I find that odd lot proportions are increasing, but the determinants of the proportions remain consistent. I find that odd lot transactions contribute to price formation, this contribution is in excess of the odd lot proportion of volume, and is increasing over time. An intraweek pattern of odd lot trading exists with Monday having the highest proportions.     

Information‐Hedging Disclosures and Insider Trading

I model the effect of disclosure on the tradeoff between information risk, liquidity risk, and price risk for a well‐informed, risk‐averse insider. Revealing some information before trading decreases the variability of the insider's information advantage and thus reduces his information risk. Disclosure also lowers adverse selection costs for market makers, which reduces the insider's liquidity risk by increasing his trading flexibility. However, disclosure increases price risk for the insider because the price fully reflects the revealed information. The reduction in information and liquidity risks outweigh the rise in price risk when the insider is less risk averse because a less risk‐averse insider's information‐based motive for trading is stronger than his hedging motive. The opposite relation holds when the insider is more risk averse. Therefore, a less (more) risk‐averse insider experiences an increase (decrease) in welfare when he discloses some information before trading. Cost of capital and policy implications are identified.     

Empirical Evidence on the Role of Trading Suspensions in Disseminating New Information to the Capital Market

Abstract:  This paper examines the effect of temporarily suspending the trading of exchange-listed individual stocks. We evaluate whether regulatory authorities can successfully use the mechanism of trading suspension in forcing companies to disclose new and material information to the capital market. Previous studies on trading suspensions mainly concentrate on North-American stock markets and find conflicting results. This study utilizes a new data set comprising of firms listed on Euronext Brussels – an important segment of Europe's leading cross-border exchange. Our results show that suspension is indeed an effective means of disseminating new information. Stock prices adjust completely and instantaneously to the new information released during trading suspensions. We also observe a significant increase in trading volume with the reinstatement of trading. On the other hand, we do not find support for the claim that trading suspensions increase the volatility of stock prices. Overall, our results show the efficacy of trading suspensions in disseminating new information.     

Passive Institutional Ownership,R2 Trends,and Price Informativeness

A distinctive trend in the capital markets over the past two decades is the rise in equity ownership of passive financial institutions. We propose that this rise has a negative effect on price informativeness. By not trading around firm‐specific news, passive investors reduce the firm‐specific component of total volatility and increase stock correlations. Consistent with this hypothesis, we find that the growth in passive institutional ownership is robustly associated with the growth in market model R²s of individual stocks since the early 1990s. Additionally, we find a negative relation between passive ownership and earnings predictability, an informativeness proxy.     

Information, Trading Demand, and Futures Price Volatility

We examine the relation between futures price volatility and trading demand by type of trader in the Standard & Poor's (S&P) 500-stock index futures market. We find that volatility covaries negatively with signed speculative demand shocks but is positively related to signed hedging demand shocks. No significant relation between volatility and demand shocks for small traders is found. Our results suggest that changes in positions of large hedgers destabilize the market, whereas changes in positions of large speculators stabilize volatility. Consistent with models with asymmetrically informed traders, we find that large speculators are likely to possess superior forecasting ability, large hedgers behave like positive feedback traders, and small traders are liquidity traders.