The main purpose of this study is to develop an understanding of the impact of neoliberal financialisation on income inequality. The distributional patterns and their relations to financialisation in four countries (USA, South Korea, Argentina, and Sweden) between circa 1980 and 2010 are analysed and compared. This research involves addressing the question as to whether financialisation facilitates uneven capital accumulation and generates conditions that increase income inequality. Critical realism's approach to ontology is employed to situate the empirical trajectories of economic disparity in the context of finance capitalism. Drawing on comparative political economy, the analytical framework of a financialisation-induced income inequality hypothesis was developed. This framework is based on the assumption that finance within the neoliberal mode of production facilitates upward income distribution. The investigation included developing three explanatory causal-processual analytical constructs derived from different heterodox schools of thought. It is contended, that in order to comprehend the nature of social reality in the financialisation-income inequality nexus, the non-orthodox methods of an open system, as advocated by critical realists, are required. The results of this study indicate that there are causal relations between upward income distribution and financialisation of national economies that developed after neoliberal restructuring. In particular, new institutions of neoliberal financialisation regressively affect the functional distribution of income. Specifically, with financial liberalisation, profits and rents in financial sector increase, whilst labour's share decreases, thereby exacerbating the level of private/public debt. In USA, South Korea, and Argentina the hypothesis was confirmed, while in Sweden neoliberal restructuring was not achieved and the national model was not transformed to affect income distribution regressively. This research has led to the identification of components of upward distribution in finance capitalism and causal links in the financialisation-induced income inequality nexus. An institutionalised generative mechanism of regressive income redistribution is an effect of finance capitalism, which transforms national distributional trajectories.