The book "Fundamental Models in Financial Theory" offers a comprehensive approach to understanding complex financial models by integrating various topics into a cohesive whole. It combines financial models with high-level mathematics, starting with basic assumptions and progressing to more advanced models. The book addresses the limitations of traditional investment portfolio models like Markowitz's mean-variance model and CAPM, introducing the Black-Litterman model for optimal portfolio construction. It also explores the Modigliani-Miller model and CCAPM. Practical Excel templates are provided for applying these models, making them useful for real-life financial scenarios. The book includes problems at the end of each chapter for immediate application of the models.