The no-arbitrage condition and financial markets with transaction costs and heterogeneous information: The bid-ask spread

Abstract

This paper investigates the implications of the no-arbitrage (NA) condition in markets with transaction costs and heterogeneous information. Dermody and Prisman (1993) showed that, in financial markets with increasing marginal transaction costs, the NA condition is equivalent to the existence of a valuation operator. They explore the exact dependence of this operator on the structure of transaction costs. They show that equilibrium prices in the “corresponding” perfect markets plus a certain factor determine the valuation operator in markets with increasing marginal transaction costs. This paper emphasizes that their result is applicable to financial markets with decreasing marginal transaction costs. Furthermore, this paper shows that, in financial markets with transaction costs and heterogeneous information, the NA condition imposes a constraint on the bid-ask spread.