Individuals are affected by different biases and heuristics in different ways. This dissertation explores the two of these (underdog bias and self-rated performance) and their relationship with personal risk propensity in the South African investment professional community. To measure risk propensity in investment professionals, a new instrument was developed. This was tested against a risk measurement scale based on the original work in prospect theory. Both risk propensity measures found similar and comparable results in the investment professionals, and similar results when compared to other studies that studied risk propensity in a more general population and risk tolerance in investment professionals in Europe. Similarly, self-rated performance had comparable results to other studies on overconfidence bias and the better than average effect. Investment professionals, on average, think that they are better than their average peer. Underdog bias, or the headwinds/tailwinds asymmetry, had an unexpected result where the investment professionals felt they did not suffer from stronger headwinds and barriers compared to their peers. This was an unexpected result and may show that the South African investment industry feel more grateful than others to be where they are or, the sample may have triggered the boundary condition of underdog bias where individuals feel their personalised benefits more than their shared headwinds. Further testing is required in the same population as well as similar populations to confirm the boundary condition. The three constructs were tested to understand the relationship between them. In each of the three cases, there was no significant relationship between any of the constructs. The results were different to what was expected and, subject to further testing, may have found a blind spot in investment professionals where they believe that what when they are doing something they consider to be right, they do not perceive the increased risks associated with the action. These blind spots have an impact on how risk is managed investment firms and needs to be monitored to protect the overall firm. / Mini Dissertation (MBA)--University of Pretoria, 2018. / Gordon Institute of Business Science (GIBS) / MBA / Unrestricted