“…Traditional statistical methods provide great prediction results under the linear assumption. For example, linear regression model [1], autoregressive integrated moving average model (ARIMA) [2], autoregressive conditional heteroskedasticity (ARCH) [3], generalized autoregressive conditional heteroskedasticity (GARCH) [4], and vector autoregressive regression (VAR) [5]. Because the financial time series is complicated, dynamic, and non-linear, various approaches which belong to the machine learning field have been employed to build the prediction model.…”