Title: Stock Price Modelling of PT United Tractors Tbk (UNTR) Using Fourier Series Estimator
Authors: Ghisella Asy Sifa, Sediono, M. Fariz Fadillah Mardianto, Elly Pusporani
Volume: 9
Issue: 1
Pages: 93-99
Publication Date: 2025/01/28
Abstract:
This research analyzes the stock price movement of PT United Tractors Tbk (UNTR) using the Fourier Series Estimator approach to identify dynamic patterns of complex stock data. By utilizing trigonometric functions such as sine and cosine, the Fourier series is able to detect seasonal trends and market cycles. Weekly data from May 2022 to December 2024 is used to model the relationship between predictor and response variables. Optimal results were achieved with a smoothing parameter (?) of 18, resulting in a model with high accuracy values: MAPE 0.25%, RMSE 18.69, and Rē 99.998%. The model is effective in projecting UNTR stock movements and can serve as a strategic basis for investment decision-making. The findings show that Fourier series is a reliable method to separate the frequency components of stock data, providing important insights for investors and companies to manage risks and maximize profits.