Stock prices are dynamic and changing frequently whenever the financial markets are opened. Many people aspire to know where prices are likely to be at future times. One of the basic problems, connected with stock valuation is to create an appropriate model of stock prices dynamics. This paper deals with the stock valuation models, such as binomial, additive, multiplicative, Brownian motion and etc. These models appeals to hypothesis, declaring that returns of stock follows by normal distribution and stock prices by lognormal one. The aim of this work is to test these hypothesis. The research of this paper discloses the basic tendency, announcing that stock is not applicable for a real adaptability of methods in Lithuanian companies because the returns of stock do not follow by the normal distribution. Disputed situation is opposite in companies of the USA. The returns of stocks are calculated by the following ways. They are numbered in the area of MS Excel. In order to review the conditions of normality, the SAS software was chosen. Finally, Delphi 10 programming language was selected for realization of the binomial tree.