The current concept of open innovation corresponds to the R&D products transfer model -"role changes". One of the fundamental provisions of the model is that R&D products are considered for commercialization not only at the final stage of technological readiness, but at any of them. In today's changing market environment, special attention is paid to the transfer and commercialization of R&D products at the early stages of readiness, but this process is characterized by significant problems from the point of view of technological forecasting. To solve the problems, the article substantiates the method of technological forecasting of market behaviour of R&D products at the early stages of technological readiness, which is based on taking into account the strengths and weaknesses, development factors and limiting factors of R&D product. The method allows you to predict indicators of product behaviour relative to the market where its commercialization is planned. As a component of the above method and in order to increase the level of reliability of calculations and validity of results, a method for determining the correction factor of indicators of market behaviour of R&D product has been developed. The method was developed on the basis of fuzzy set theory algorithms using the fuzzy logic toolbox (MATLAB), which made it possible to integrate a set of different types of forecast data on the market behaviour of an R&D product, taking into account the relationships and interdependencies between them, into one correction factor. This coefficient contains the characteristics of signs of the impact of R&D product on the market (in particular, market effects, types of market changes) and the impact of market effects on R&D product (effects generated by R&D products, organizational and technological changes in R&D products). To justify the correction factor, a knowledge base of responses from subject area experts has been formed. In order to further select a commercialization strategy for R&D product, a system with normative indicators has been developed that interpret the following types of strategies: zero-level commercialization of R&D product; first-level commercialization of R&D product; commercialization of the second level of R&D product. The author's method of technological forecasting of market behaviour of R&D products and choosing a commercialization strategy for a product is universal, can be applied to R&D product of any type of economic activity, transfer method, etc. Testing of the method on the example of a number of R&D products presented by the developers of the Lviv Polytechnic National University (Lviv, Ukraine) showed the validity of the author's method and its relevance in modern conditions of market singularity.