Stock market prediction is vital in the field of economics and in the business world. However, it is a challenging task since it is greatly affected by several factors. Relatively, this study aimed to forecast the behavior of stock market using the historical data from Philippine Stock Exchange Index from January 2022 to July 2023. In addition, the study also used the data from a previous study to further prove the method’s reliability. In this paper, the Markov Chain model, a mathematical model under Linear Algebra, was used to analyze and forecast the stock market behavior considering three different states of the stock market: “up” – when the stock price increases, “down” – when the stock price decreases, and “stagnant” – when the stock price remains unchanged. Furthermore, a user-friendly application, Matrix Calculator, was also utilized to show an easier way of solving for the forecasted behavior of the stock market. The results of the study showed that on the 366th day, the probability that the stock market will go up, down, and remain stagnant are 0.3602 or 36.02%, 0.4036 or 40.36%, and 0.2389 or 23.89%, respectively. Moreover, the chances that the stock market will go up, down, and stagnant on the 367th day are 0.3612 or 36.12%, 0.4047 or 40.47%, and 0.2396 or 23.96%, respectively.