خلاصة:
In pricing financial risks, models are built on theoretical assumptions. Financial pricing models such as CAPM and Black-Scholes, usually depend on the assumption that future asset stock price follows the lognormal distribution and returns are normally distributed. Lack of the assumptions would have a serious inappropriate effect on pricing results. Thus, many researchers are trying to find a method of relaxing the underlying assumptions in these models. Further, there are many similarities between financial and insurance risks (e.g. options and stop-loss reinsurance contract). However, actuaries usually cannot use financial models for pricing insurance liabilities, because the loss amounts do not follow the distributions of the financial assets’ prices. Therefore, financial and insurance researchers are looking for a unified suitable frame for pricing all kinds of (financial) assets and (insurance) liabilities, with different types of probability distribution, whether traded or underwritten. In this research, we are going to introduce a new method to achieve this goal. In this approach, we transform the distribution of risk to a new distribution by Wang transformation with a risk parameter. The transformation applies on the distribution function as below; F* (x)=Φ[Φ-1(F(x)+α)] Where F is distribution functions of price and α is the risk parameter. Using this approach, it will be obtained a new technique for relaxing the distributional assumption in financial models. Wang's pricing framework recovers the results of CAPM and Black-Scholes model by necessary assumptions. Additionally, this approach presents a new method of empirical estimation and pricing financial derivatives consistent with real market conditions.
ملخص الجهاز:
Financial pricing models such as CAPM, Black-Scholes, all depend on the assumption of a statistical distribution like Lognormal for future prices and Normal for the rate of return.
Keywords: Financial risks, insurance risks, Wang transformation, risk parameter, option contract, reinsurance, financial derivatives, loss distribution, price distribution Subject classification: G12-G13 - Introduction Pricing of risks and financial assets is one of the most fundamental and important topics of interest for financial institutions and insurance companies.
38 Vbank 39 Iteration Method Using the Wang transformation, the pricing framework of the CAPM model can also be extended to non-normal distributions; such a result is obtained with a value using the transformed correlation coefficient of asset return and market return under the Wang transformation.
٠ر By selecting the risk parameter of the transformation as rf_i^T and applying the transformation to iس the random variable of the future price of the asset, we have; iTced٢س, T(i٢٢س٠ LogNormal POQ)rf ((٠)) *XX i i Using this transformed distribution and calculating the price of the call option payoff function, the price of this contract is obtained as follows; (d٢)ـ rfTK٠ e ٠ ( d١)ـ(٠) X ٔ [ح٠ ;( K ,T )C ]rfT H ٠ Price ٔ e where, St .
28 2) Present value calculation with discount rate: The neutral valuation method for pricing option contracts and assets uses the risk-free rate of return to find the present value of future values.