A theory of the interday variations in volume, variance, and trading costs in securities markets

In an adverse selection model of a securities market with oneinformed trader and several liquidity traders, we study theimplications of the assumption that the informed trader hasmore information on Monday than on other days. We examine theinterday variations in volume, variance, and adverse selectioncosts, and find that on monday the trading costs and the varianceof price changes are highest, and the volume is lower than onTuesday. These effects are stronger for firms with better publicreporting and for firms with more discretionary liquidity trading.     

The effect of public information and competition on trading volume and price volatility

In a one-period model of market making with many exogenouslyinformed traders, we first show that the variance of pricesand expected trading volume depend on the public informationreleased at the start of trading. This is accomplished by representingbeliefs with elliptically contoured distributions, for whichthe form of optimal decision rules does not depend on the specificdistribution used. Second, if the model is altered so that thedecision to become informed is made endogenous, then the decisionrules of the market-maker and informed traders depend on thepublic information. Third, in a multiperiod model with manyinformed traders and long-lived private information, recursionformulas similar to those of Kyle (1985) hold for all ellipticallycontoured distributions, trading volume is autocorrelated and,unless per period liquidity trading is bounded away from zeroas new trading periods are added, informed traders' profitsvanish.