Entering the post-industrial age, knowledge has become an important asset for sustained competitive advantage. In recent years, a new type of patent acquirers has emerged. These companies do not produce goods and therefore, do not need patents in their historical meaning. However, they acquire patents and aggregate patent portfolios and little is known about them. Frauke Rüther defines patent aggregating companies and explores their strategies, activities, and their evolution over time, as well as how producing companies can utilize them to leverage their patent portfolios.