Optimal hedging under departures from the cost of carry valuation: evidence from the spanish stock index futures market

Abstract

This paper provides an a~alytical discussion of the optimal hedge ratio when discrepancies between the futures trading price and its theoretical valuation according to the cost-of-carry model occurs. Under the assumption of a geometric Brownian motion for spot prices we model the mispricing by a new specific noise in the theoretical dynamic of futures market. Empirical evidence above the model is provided for the Spanish stock index futures. Ex-post simulations reveal that hedging effectiveness applying the estimated ratio is similar to the achieved with a systematic unitary hedge ratio, the optimal one when a mispricing does not appear. However, a small number of futures contracts is needed.