44 GenAI in Banking & Finance : Unsupervised Learning in FinTech
Unsupervised Learning in FinTech Mathematical Foundations with Conceptual Interpretation 1. Introduction In previous discussions on supervised learning, we considered problems where a target variable Y Y is known. The objective was to learn a mapping: f : X → Y f: X \rightarrow Y where X represents input variables and Y represents known outcomes such as loan default, fraud occurrence, or asset returns. However, many real-world financial datasets do not come with labeled outcomes. A bank may possess millions of customer records containing income, spending behavior, and transaction history—but no explicit label indicating customer category. Similarly, a trading firm may observe stock returns but may not have predefined “market regime” labels. In such cases, prediction is not the immediate objective. Instead, the goal is structure discovery . This is the domain of Unsupervised Learning . 2. Definition of Unsupervised Learning Mathematical Representation Given a datas...