Risk management through financial hedging in inventory systems with stochastic price processes

Abstract

We consider the financial hedging problem of a firm whose operational cash flow from its inventory operation is affected by both price and demand uncertainties. We assume that selling prices and demand arrival process are governed by an exogenous continuous stochastic price process which is assumed to be correlated with prices of various products in financial markets. During the selling horizon, the firm dynamically invests in a financial portfolio of these products to manage its exposure to price and demand risks by observing the current inventory and price levels. We explore the problem in a minimum-variance framework where we look for the variance-minimizing financial hedge for a given operational policy and a martingale price process. The framework leads to explicit results for the optimal static and dynamic financial hedges in single-period problems with complicated within-period dynamics. We also obtain characterizations of optimal dynamic hedges for multi-period problems using dynamic programming. We explore the risk reduction effects of minimum-variance financial hedges through numerical examples and show that significant risk reductions may be possible by using the right hedge.