We propose a simplified approach to mean-variance portfolio problems by changingtheir parametrisation from trading strategies to final positions. This allows us to treat,under a very mild no-arbitrage-type assumption, a whole range of quadratic optimisationproblems by simple mathematical tools...

We analyze numerically the superreplication problem and the associatedhedging strategy in an illiquid binomial market. We prove theexistence of an optimal feedback strategy for European and barrier optionsand compute it numerically by means of a dynamic programmingprinciple. We exhibit that the...

The Markowitz problem consists of finding in a financial market a self-financingtrading strategy whose final wealth has maximal mean and minimal variance. Westudy this in continuous time in a general semimartingale model and under coneconstraints: Trading strategies must take values in a...

We solve the problem of mean-variance hedging for general semimartingale modelsvia stochastic control methods. After proving that the value process of theassociated stochastic control problem has a quadratic structure, we characteriseits three coefficient processes as solutions of semimartingale...

We study mean-variance hedging under portfolio constraints in a general semi-martingale model. The constraints are formulated via predictable correspondences,meaning that the trading strategy is restricted to lie in a closed convex set whichmay depend on the state and time in a predictable way....

We provide a representation for the nonmyopic optimal portfolio of an agentconsuming only at the terminal horizon when the single state variable follows ageneral diusion process and the market consists of one risky asset and a risk-freeasset. The key term of our representation is a new object...