Abstract <p>Following the theories that study the causes and factors of company growth, the article focuses on identifying growing companies as an important element in the development of high-tech business. The article develops a methodology that makes it possible to identify key categories of companies for the regional market that influence their dynamics. The regional market is understood here as a set of companies located in a given region. Companies are categorized through grouping by size (four levels) and age (four levels), so that companies in each region are grouped into 16 size−age groups. This methodology is tested with a case study of development of high-tech business in Russia’s eastern regions. It is shown that although the revenue structure of high-tech businesses varies by region, large mature companies are dominant in all of them. Assessment of the contribution of various age and size groups to the dynamics of total regional revenue made it possible to identify groups that are the growth drivers in each region. It seems that government support for these groups of companies could have a greater impact on the development of a region’s economy. The methodology can be used to analyze the development dynamics of other sectors and regions.</p>