A one step process for making a dendritic hydrocarbon polymer, e.g., dendritic polyolefin, by metathesis insertion polymerization. The process comprises polymerizing an amount of one or more cyclic olefins and one or more multi-functional (meth)acrylates in the presence of a metathesis catalyst and under conditions sufficient to produce the dendritic hydrocarbon polymer. The one or more multi-functional (meth)acrylates have a functionality of 3 or higher. The dendritic hydrocarbon polymer can be hydrogenated to produce a substantially saturated dendritic hydrocarbon polymer. The hydrogenation can take place in the same reaction vessel as the polymerization, i.e., one pot process.