Page 36 - 34-1
P. 36

Valuation of Spread and Basket Options




               is assumed to be 1.5%. The weight of each company makes the underlying general basket
               belong to the basket options if all weights are positive, including GB1, GB2, and GB4, and
               belong to the spread options if some weights are negative, including GB3, GB5, and GB6.
               All parameters are summarized in Table 9.

                    Table 10 presents the pricing results of various GB computed by three different
               pricing methods: USD represents the pricing model based on the unbounded system of the
               Johnson distribution family, SLN represents the pricing model developed by Borovkova

               et al. (2007), and MC denotes the Monte Carlo simulation method based on 100,000
               simulation paths with the variance reduction technique named the antithetic variates
               method. The standard error of the Monte Carlo simulation method is denoted by “se”. All
               pricing results show that our pricing model can accurately price both the basket and spread
               options based on the market data.



               4.3. Sensitivity Analysis
                    Since basket and spread options do not have close-form pricing models, their

               pricing models in the early literature are developed independently under various model
               assumptions. This may lead to inconsistency, and cause pricing and hedging errors between
               basket and spread options. However, our pricing model can price both basket and spread
               options, and thus, it can eliminate the pricing errors. In addition, the Greeks of basket and
               spread options are derived from the same pricing formulas; in consequence their Greek

               risks can be integrated to help traders manage and hedge their option portfolios.
                    As indicated by Figures 4, 5, and 6, the correlation coefficient ρ substantially affects
               the Greeks of both basket and spread options. The humped-shape figure of the correlation

               vega shows that ρ positively affects the basket-option value, which decreases with increasing
               ρ. On the contrary, ρ negatively affects the spread-option value, which increases with
               decreasing ρ. The behavior of vega (υ) and delta (Δ) of an asset is affected by ρ, moneyness,
               and the (long or short) position of the asset. These Greeks can help financial institutions
               construct hedging strategies to manage the risks of issuing basket/spread options.

                    Next, we present some numerical examples to demonstrate the sensitivity analysis
               of basket and spread options based on the Greek formulas provided in Definition 2. To
               save space, we only show the delta (Δ), vega (υ), and correlation vega of both options in

               Figures 4, 5, and 6. Other Greeks can also be easily examined by using Definition 2. For


                                                      28
   31   32   33   34   35   36   37   38   39   40   41