  The proposed model modifies option pricing formulas for the basic case of
log-normal probability distribution providing correspondence to formulated
criteria of efficiency and completeness. The model is self-calibrating by
historic volatility data; it maintains the constant expected value at maturity
of the hedged instantaneously self-financing portfolio. The payoff variance
dependent on random stock price at maturity obtained under an equivalent
martingale measure is taken as a condition for introduced "mirror-time"
derivative diffusion discount process. Introduced ksi-return distribution,
correspondent to the found general solution of backward drift-diffusion
equation and normalized by theoretical diffusion coefficient, does not contain
so-called "long tails" and unbiased for considered 2004-2007 S&P 100 index
data. The model theoretically yields skews correspondent to practical term
structure for interest rate derivatives. The method allows increasing the
number of asset price probability distribution parameters.
