We prove a version of the Fundamental Theorem of Asset Pricing, which applies to Kabanov's approach to foreign exchange markets under transaction costs. The financial market is modelled by a d x d matrix-valued stochastic process Sigma_t_t=0^T specifying the mutual bid and ask prices between d...

In securities markets, the characterisation of the absence of arbitrage by the existence of state price deflators is generally obtained through the use of the Kreps-Yan theorem. This paper deals with the validity of this theorem in a general framework. We apply this results to the...

This article explains the role of the convenience yield in the relationships linking spot and futures prices in commodity derivatives markets. First, this variable restores the non arbitrage relationship between the prices of the underlying asset and the derivative instrument. Second, it allows...

When the markets are dynamically complete and without imperfections there are three equivalent approaches in order to price a given asset : the arbitrage approach through the existence of a risk-neutral density, the utility approach through a utility maximization program and the equilibrium...

This paper studies foundational issues in securities markets models with fixed costs of trading, i.e. transactions costs that are bounded regardless of the transaction size, such as fixed brokerage fees, investment taxes, operational, and processing costs or opportunity costs. We show that the...