The growth of users and mutual fund portals in Indonesia has experienced a significant increase, although the increases still below the average numbers in other Southeast Asian countries. This research was carried out to identify the factors influencing the use of online mutual fund portals in Indonesia based on the user risk profiles namely conservative and aggressive users. There were 502 respondents participated in the survey. Data from the survey were processed using the SEM-PLS method with SmartPLS 3.2.9. The results show that behavioural intention directly influences the use of online mutual fund portals. Then, behavioural intention itself is influenced by subjective norm and perceived behavioural control in conservative users, whereas aggressive users are only influenced by perceived behavioural control. Subjective norms are influenced by injunctive norms and descriptive norms, while perceived behavioural control is influenced by trust. Almost all factors tested affect the use of online mutual portals directly or indirectly in the group of aggressive and conservative respondents.