Institutional owners such as mutual funds are often claimed to be impatient and narrowly focused on next quarter’s performance. The purpose of this research project is to analyze whether owner impatience translates into corporate behavior. We (1) start with an investigation of the length and determinants of investment horizons of the owners of Finnish listed firms. We then (2) investigate whether owner impatience affects a firm’s operating decisions (long-term investments, employment and acquisition decisions, and focus) and its overall performance (risk and return). Finally (3) we study the interactions between owner impatience and governance by examining whether owner impatience can lead to earnings manipulation, dividend avoidance, higher CEO turnover, and suboptimal management compensation policies. In this context, we also investigate to what extent and by which means a firm can influence its ownership structure, i.e. to attract more patient owners.