Kalman Filter Estimation for Cox-Ingersoll-Ross Term Structure Model [PDF] [Github]
The Cox-Ingersoll-Ross (CIR) model is a mathematical model that assumes interest rates will go back to a long-term average, which helps explain why interest rates usually stay positive in the real world. This makes the CIR model useful for understanding how interest rates change in financial markets. However, real-world data is often noisy and not always perfect. This is where the Kalman filter comes in. It is an algorithm that helps estimate the true values of a system by predicting, updating, and correcting guesses as new data is added. When used with the CIR model, the Kalman filter helps improve the accuracy of interest rate predictions by removing unnecessary noise and focusing on the important information.