Due to the relative uncertainty involved with the variables which affect financial market behavior,
forecasting future variations in a time series of the Brazilian stock market Index (Ibovespa) can be
considered a difficult task. This article aims to evaluate the performance of the model ARIMA for
time series forecasting of Ibovespa. The research method utilized was mathematical modeling and
followed the Box-Jenkins method. In order to compare results with other smoothing models, the
parameter of evaluation MAPE (Mean Absolute Percentage Error) was used. The results showed
that the model utilized obtained lower MAPE values, thus indicating greater suitability. This
therefore demonstrates that the ARIMA model can be used for time-series indices related to stock
market index forecasting.