Table 6. Performance comparison.

Models	S&P500		DAX		DJI		SSE
	RMSE	MAE	RMSE	MAE	RMSE	MAE	RMSE	MAE
CEEMD-CNN-LSTM (Rezaei, Faaljou & Mansourfar, 2021)	13.76	10.58	84.88	65.03	155.52	118.02	–	–
CEEMDAN-LSTM (Cao, Li & Li, 2019)	4.83	3.92	33.35	24.85	–	–	8.74	6.86
CAL (Lv et al., 2022)	26.14	17.14	101.83	72.33	–	–	19.92	14.03
GRU based on CEEMDAN-Wavelet (Qi, Ren & Su, 2023)	22.27	17.39	–	–	–	–	–	–
2LE-CEEMDAN-LSTM-SVR	5.25	4.11	11.77	10.42	23.50	19.81	7.30	6.18