Economics, as a scientific discipline, has an extremely variable and flexible structure, and it is an undeniable fact that finance, one of its sub-disciplines, is not only variable and flexible but also much more dynamic. Similarly, it is an undeniable fact that the diversity of products and services in financial markets has reached a dizzying pace, especially over the past twenty years. The book titled Theoretical and Applied Research in Finance, published by Özgür Publishing House in October 2025, consists of the following studies: The Impact of Working Capital Management on Firm Profitability: An Application Using the Bhattacharya Index on Companies Listed on the BIST, Effect of Labor Productivity on Firm Performance: The Case of Borsa Istanbul, Comparative Analysis of the Financial and Structural Indicators of Islamic Banks by Country, THE IMPACT OF THE COVID-19 PANDEMIC ON CASH HOLDING STRATEGIES AND FIRMS' FINANCIAL PERFORMANCE: EXAMPLE OF CHINA, INDIA AND SOUTH AFRICA, Investigation of the Relationship Between BIST Food and Beverage Index (XGIDA) and Food Inflation in Turkey, Examining the Factors Affecting the Housing Price Index in Turkey, Money Production Process of Banks: An Animation Study on The Fractional Reserve System. This book is a remarkable work that provides a wealth of information on the most recent and interesting topics in the financial world. We would like to express our gratitude to Dr. Kürşad Özkaynar for his endless efforts in preparing this book for publication and for his support to the authors.