Insider trading with public and shared information

We study the impact of public information and shared information on traders' trading behavior in the context of Kyle's (1985) speculative market. We suppose that there are four types of traders in our model: one insider, M outsiders, liquidity traders, and market makers. We explicitly describe the unique linear Nash equilibrium and find that public information harms the insider but benefits the outsiders and noise traders. Also, the market is more efficient because of the existence of public information.     

Strategic noise traders and liquidity pressure with a physically deliverable futures contract

Do physically deliverable futures contracts induce liquidity pressure in the underlying spot market? The answer is believed to be no since the asset is delivered sometimes after the expiration of the contract so that the futures trader's payoff does not clearly depend on the price of the underlying stock at expiration. We construct a rational expectations equilibrium model in which a strategic uninformed trader induces liquidity pressure in the underlying spot market at the expiration of a physically deliverable futures contract. Liquidity pressure is the result of a pure informational advantage: if it is known that futures traders hedge their position in the spot market then a strategic trader with no information about the fundamental value of the underlying has an incentive to create noise in the futures market in order to gain information on the composition of the spot order flow at future auctions. We show that informed traders benefit from this form of strategic noise and that the efficiency of the prices remains unaffected.     

Information aggregation in financial markets with career concerns

What are the equilibrium features of a dynamic financial market in which traders care about their reputation for ability? We modify a standard sequential trading model to include traders with career concerns. We show that this market cannot be informationally efficient: there is no equilibrium in which prices converge to the true value, even after an infinite sequence of trades. We characterize the most revealing equilibrium of this game and show that an increase in the strength of the traders' reputational concerns has a negative effect on the extent of information that can be revealed in equilibrium but a positive effect on market liquidity.     

Liquid markets and competition

A market is liquid if no individual's actions have a big effect on the prices of goods traded in that market. Perfectly competitive markets are therefore perfectly liquid. It is well known that market liquidity can be achieved by increasing the number of traders so that individual trades are small compared to total trades. We show that even when there are only few traders, market liquidity can be achieved through large short sales in which net trades are small relative to gross trades. In particular, for a natural variant of the market game which permits unlimited short sales, we show that there is always a Nash equilibrium allocation arbitrarily close to a competitive equilibrium allocation. Of course, not all NE are near competitive. Only the large-short-sales NE are nearly liquid and hence close to CE.     

Price Limits, Information Acquisition, and Bid–ask Spreads: Theory and Evidence

A number of futures markets use price limits which, in effect, preclude trade from occurring at prices outside certain exogenous bounds. Noting that such markets are characterized by heterogeneously informed traders, whereas previous work on price limits assumes symmetrically informed traders, we examine the effects of price limits in a setting where market participants are asymmetrically informed. We find that imposing price limits generally lowers the quality of information acquired in equilibrium, but lowers bid–ask spreads as well. Thus, depending on the relative weights placed by society on liquidity versus price efficiency, there may exist a set of price limits that are most efficient in achieving a trade-off between liquidity and informational efficiency. We perform empirical tests of some implications of the model using cross-sectional data on price limits. We find that price limits are strongly negatively related to both price volatility and trading volume. Though other explanations for our empirical findings cannot be ruled out, these results are not inconsistent with the model's implication that price limits should be tighter for contracts which offer greater profit potential for informed traders.     

Effects of Securities Transaction Taxes on Depth and Bid-Ask Spread

This note investigates the effects of introducing a transaction tax on depth and bid-ask spread using a static model where a competitive market maker faces informed and liquidity traders. When the degree of information asymmetry is low, an increase in the transaction tax can result into a smaller rise in the selling price and the depth may even increase in some cases. When information asymmetry is high, the dealer could increase the selling price more than the tax and sometimes lowers the depth. This can result in a market shutdown if the liquidity trader is driven out of the market. We thank Vincent Reinhart and Walter Fisher for helpful discussions. Special thanks are also due to an anonymous referee and the editor C.D. Aliprantis for insightful comments and suggestions which have helped us to improve the paper substantially. The usual disclaimer applies.     

Model uncertainty and liquidity

Extreme market outcomes are often followed by a lack of liquidity and a lack of trade. This market collapse seems particularly acute for markets where traders rely heavily on a specific empirical model such as in derivative markets like the market for mortgage backed securities or credit derivatives. Moreover, the observed behavior of traders and institutions that places a large emphasis on “worst-case scenarios” through the use of “stress testing” and “Value-at-Risk” seems different than Savage expected utility would suggest. In this paper, we capture model-uncertainty using an Epstein and Wang [Epstein, L.G., Wang, T., 1994. Intertemporal asset pricing under Knightian uncertainty. Econometrica 62, 283–322] uncertainty-averse utility function with an ambiguous underlying asset-returns distribution. To explore the connection of uncertainty with liquidity, we specify a simple market where a monopolist financial intermediary makes a market for a propriety derivative security. The market-maker chooses bid and ask prices for the derivative, then, conditional on trade in this market, chooses an optimal portfolio and consumption. We explore how uncertainty can increase the bid–ask spread and, hence, reduces liquidity. Our infinite-horizon example produces short, dramatic decreases in liquidity even though the underlying environment is stationary. We show how these liquidity crises are closely linked to the uncertainty aversion effect on the optimal portfolio. Effectively, the uncertainty aversion can, at times, limit the ability of the market-maker to hedge a position and thus reduces the desirability of trade, and hence, liquidity.     

Pricing accuracy,liquidity and trader behavior with closing price manipulation

We study the effects of closing price manipulation in an experimental market to evaluate the social harm caused by manipulation. We find that manipulators, given incentives similar to many actual manipulation cases, decrease price accuracy and liquidity. The mere possibility of manipulation alters market participants’ behavior, leading to reduced liquidity. We find evidence that ordinary traders attempt to profitably counteract manipulation. This study provides examples of the strategies employed by manipulators, illustrates how these strategies change in the presence of detection penalties and assesses the ability of market participants to identify manipulation.     

Who trades quickly?

We examine differences among US equity market participants according to how quickly, on average, they execute their orders. When traders who execute faster buy (sell), market prices tend to rise (decline). Those who trade more quickly take liquidity more, use smaller trade sizes, transact more frequently, and spread their trading across more venues. Although faster traders are net liquidity demanders, they pay a lower cost to trade. Our results indicate that systematic differences exist across market participants according to how fast they transact, and those with a shorter time to execution exhibit traits that are consistent with information-based trading.     

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.     

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 efficiency and trading behavior in limit order markets with competing insiders

We study price efficiency and trading behavior in laboratory limit order markets with asymmetrically informed traders. Markets differ in the number of insiders present and in the subset of traders who receive information about the number of insiders present. We observe that price efficiency (i) is the higher the higher the number of insiders in the market but (ii) is unaffected by changes in the subset of traders who know about the number of insiders present. (iii) Independent of the number of insiders, price efficiency increases gradually over time. (iv) The insiders’ information is reflected in prices via limit (market) orders if the asset’s value is inside (outside) the bid-ask spread. (v) In situations where limit and market orders yield positive profits, insiders clearly prefer market orders, indicating a strong desire for immediate transactions.     

Financial Bubbles: Excess Cash,Momentum, and Incomplete Information

We report on a large number of laboratory market experiments demonstrating that a market bubble can be reduced under the following conditions: 1) a low initial liquidity level, i.e., less total cash than value of total shares, 2) deferred dividends, and 3) a bid-ask book that is open to traders. Conversely, a large bubble arises when the opposite conditions exist. The first part of the article is comprised of twenty-five experiments with varying levels of total cash endowment per share (liquidity level), payment or deferral of dividends and an open or closed bid-ask book. We find that the liquidity level has a very strong influence on the mean and maximum prices during an experiment (P < 1/10,000). These results suggest that within the framework of the classical bubble experiments (dividends distributed after each period and closed book), each dollar per share of additional cash results in a maximum price that is $1 per share higher. There is also limited statistical support for the theory that deferred dividends (which also lower the cash per share during much of the experiment) and an open book lead to a reduced bubble. The three factors taken together show a striking difference in the median magnitude of the bubble ($7.30 versus $0.22 for the maximum deviation from fundamental value). Another set of twelve experiments features a single dividend at the end of fifteen trading periods and establishes a 0.8 correlation between price and liquidity during the early periods of the experiments. As a result, calibration of prices and evolution toward equilibrium price as a function of liquidity are possible.     

Dynamic price formation in a futures market via double auctions

Summary We report an exploratory study of the process of price formation in a speculative market in the absence of liquidity traders. Traders exchange a futures contract because they interpret information differently. We formulate trading as a sequence of anonymous double auctions and introduce a notion of bounded rationality in which traders use approximate models of market response in forming their bids. We prove existence of a perfect equilibrium in the sequential anonymous auctions game, and show that the equilibrium has a no-regret property. After learning the market price, a trader regrets neither the bid that he made nor the position that he holds. We show that trading volume is related to changes in the distribution of information in the economy. We also show that volume and expected change in price are related to two different attributes of the pattern of private information flow. Fundamentally, no particular relationship between the time series of these variables is always valid for all futures contracts. This point is emphasized by an example.I am thankful for useful comments made by Avraham Beja, James Gammil, Chi-fu Huang, David Scharfstein and three anonymous referees. Financial support from Stanford Graduate School Faculty Fellowship is gratefully acknowledged.     

A theoretical analysis of institutional investors' trading costs in auction and dealer markets

This paper compares trading costs for institutional investors subject to liquidity shocks, in auction and dealer markets. The batch auction restricts the institutions' ability to exploit informational advantages because of competition between institutions when they simultaneously submit orders. This competition lowers aggregate trading costs. In the dealership market, competition between traders is absent but private information is revealed by observing the flow of successive orders and so reduces aggregate trading costs. We analyse the relative effects on trading costs of competition and information revelation in the two systems and derive a parameter inequality which determines which system has lower costs.     

Double Bubbles in Assets Markets With Multiple Generations

We construct an asset market in a finite horizon overlapping-generations environment. Subjects are tested for comprehension of their fundamental value exchange environment and then reminded during each of 25 periods of the environment's declining new value. We observe price bubbles forming when new generations enter the market with additional liquidity and bursting as old generations exit the market and withdrawing cash. The entry and exit of traders in the market creates an M shaped double bubble price path over the life of the traded asset. This finding is significant in documenting that bubbles can reoccur within one extended trading horizon and, consistent with previous cross-subject comparisons, shows how fluctuations in market liquidity influence price paths. We also find that trading experience leads to price expectations that incorporate fundamental value.     

A search model of centralized and decentralized trade

This paper presents a search model of centralized and decentralized trade. In a centralized market, trades are intermediated by market makers at publicly posted bid–ask prices. In a decentralized market, traders search counterparties. Prices are negotiated and transactions are conducted in private meetings among traders. Traders can choose which market to enter. The determinants of bid–ask spreads and liquidity are analyzed. The welfare consequence of the market fragmentation is also analyzed. It is shown that compared to the competitive market-making, monopolistic market-making may improve social welfare.     

Informed manipulation

In asymmetric information models of financial markets, prices imperfectly reveal the private information held by traders. Informed insiders thus have an incentive not only to trade less aggressively but also to manipulate the market by trading in the wrong direction and undertaking short-term losses, thereby increasing the noise in the trading process. In this paper we show that when the market faces uncertainty about the existence of the insider in the market and when there is a large number of trading periods before all private information is revealed, long-lived informed traders will manipulate in every equilibrium.     

Compensation schemes,liquidity provision,and asset prices: an experimental analysis

In an experimental setting in which investors can entrust their money to traders, we investigate how compensation schemes affect liquidity provision and asset prices, two outcomes that are important for financial stability. Compensation schemes can drive a wedge between how investors and traders value the asset. Limited liability makes traders value the asset more than investors. To limit losses, investors should thus restrict liquidity provision to force traders to trade at a lower price. By contrast, bonus caps make traders value the asset less than investors. This should encourage liquidity provision and increase prices. In contrast to these predictions, we find that under limited liability investors increase liquidity provision and asset price bubbles are larger. Bonus caps have no clear effect on liquidity provision and they fail to tame bubbles. Overall, giving traders skin in the game fosters financial stability.     

Information disclosure with leakages

We present a trading game with one insider, many outsiders, liquidity traders and a competitive market maker trading an asset with two value components, a private and a shared one, in a market operating as in Kyle (1985). The insider knows both value components and outsiders only know the shared component. The market maker receives a private signal in the form of a noisy transformation of the shared component, which we refer to as leakages. Before trade begins, the insider can disclose the value of the shared component to the entire market, thus removing the outsiders from the game. When the market maker's signal is sufficiently precise, the insider's benefit from knowing the shared component does not exceed the cost of concurrently trading with the outsiders, thus motivating the insider to reveal the shared component to the entire market. This result provides an explanation as to why some firm managers may naturally prefer to publicly disclose information rather than leaving it in the hands of select investors.