G13 - Contingent Pricing; Futures Pricing; option pricingReturn

The study attempts to assess the effects of lifting short sale restrictions on the Warsaw Stock Exchange in terms of futures pricing efficiency. The approach implemented in the article involves evaluation and comparison of the mispricing series of the WIG20 index futures listed on the WSE, in a one-year time span before and after the regulatory change introduced in 2010. The results show that lifting short sale constraints has increased the efficiency of the Polish futures market. There was a decline both in the number of mispricing occurrences, and in the mean level and dispersion of deviations from the fair values, especially with regard to underpriced contracts series. The study reveals that, in contrast to the pre-event period, after the regulatory change the arbitrage opportunities were virtually absent for investors bearing the highest transaction costs.

We investigate valuation of derivatives with payoff deined as a nonlinear though close to linear function of tradable underlying assets. Interest rate derivatives involving Libor or swap rates in arrears, i.e. rates paid at wrong time, are a typical example. It is generally tempting to replace the future unknown interest rates with the forward rates. We show rigorously that indeed this is not possible in the case of Libor or swap rates in arrears. We introduce formally the notion of linear plain vanilla derivatives as those that can be replicated by a inite set of elementary operations and show that derivatives involving the rates in arrears are not (linear) plain vanilla. We also study the issue of valuation of such derivatives. Beside the popular convexity adjustment formula, we develop an improved two or more variable adjustment formula applicable in particular on swap rates in arrears. Finally, we get a precise fully analytical formula based on the usual assumption of log-normality of the relevant tradable underlying assets applicable to a wide class of convexity related derivatives. We illustrate the techniques and different results on a case study of a real life controversial exotic swap.