The qualifying aspect of the ongoing changes in firm growth processes seems to be the increased heterogeneity of size and a trend towards a broader fluctuation in average size. Exogenous factors (market size, demand trends, technological innovations, higher competition) determine a different impact on firms will to increase their own size, while endogenous variables play a greater role than in the past. The outcome is represented by a growth pattern that characterises some firms, but not all of them. Growth appear to be an asymmetric phenomenon, involving selectively but not casually a subgroup of firms. In the present paper it is hypothesized that growth stems from the asymmetric distribution of internalized resources (both material and immaterial), allowing some firms (regardless of the original size) to enter evolutionary paths that others don’t want or simply can’t enter.