Chief executive officers (CEO), as the central pillar directing companies at the capital market level, plays a critical role in making investment decisions to de-crease agency costs and maximize shareholders’ wealth; however, their psycho-logical attitudes and perceptions lead to different investment functions of these companies in a competitive market. Accordingly, this study aimed to detect the propositional arrays of the investment functions using Q analysis in order to identify the CEOs’ mental typology in distinguishing investment functions. The present study was carried out with the participation of 13 CEOs from Tehran Stock Exchange companies during a one-year period (2018-2019). The study encompassed two different phases. In the first phase, content analysis was used to identify the phrase Q of the CEOs’ investment functions. In the second phase, Q analysis was adopted to typify the CEOs’ investment functions, which was based on the subjective cognition of the target population and contributed to the development of the approaches in line with the research objectives. The results confirmed the existence of three mental patterns in the CEOs regarding the in-vestment functions in the capital market. These mental patterns were ‘investment function in stock market indices’ as the first mental pattern, ‘investment function in risk control’ as the second mental pattern, ‘strategic investment function’ as the third mental pat-tern. The study results revealed different types of investment functions among the CEOs’ of stock exchange companies and thus contributed to the development of financial theories from the perspective of CEOs’ cognition.
