These  events  have  disrupted  and  significantly 
shattered  production  activities  and  affected  the 
regular operation of numerous industries, underlining 
the gravity of the situation. Therefore, the researchers 
adopted a new calibration process "Short-Term Bias 
Compensation"  (STBC),  aiming  to  further  calibrate 
LSTM  model  predictions.  This  method  could 
minimize the volatility influence impact of sudden or 
extreme  events  on  forecasting  accuracy. 
Additionally,  fuzzy  rules  evolved  via  genetic 
algorithms (GA) are employed for optimizing trading 
strategies. 
The dataset covered ETF trading data from 2003 
to  2020,  and  black  swan  events  are  deliberately 
included  to  assess  model  precision.  By  calculating 
daily  forecast  errors  and  comparing  the  daily 
anticipated  amounts  with  the  actual  data,  the 
prediction's  short-term  bias  (STB)  was  first 
estimated. The anticipated price for the following day 
will be automatically adjusted if the STB rises above 
a  predetermined  level.  The  STBC  parameters  are 
further optimized by using genetic algorithms (GAs). 
Simultaneously, trading strategies and stock buying 
and selling signals were determined by genetic fuzzy 
systems (GFS). According to the findings, STBC can 
cut the prediction error by over 90%. 
Shih et al. focused on exploring how to combine 
traditional financial models (such as the Fama-French 
three-factor  model,  the  capital  asset  pricing  model 
(CAPM)) and artificial neural network architectures 
applicable to handling time series, including LSTM, 
ANN, GRU, CNN and their variants, to obtain better 
results  in  ETF  daily  return  prediction  (Shih  et  al., 
2024). The multi-factor market model and the Taiwan 
Economic  Journal  (TEJ)  provided  the  data  for  this 
Python-based analysis. Daily returns of six ETFs 
listed in Taiwan: Yuanta Taiwan 50 (0050), Yuanta 
Mid-Cap  100  (0051),  Yuanta  Electronics  (0053), 
Yuanta S&P Custom China 50 (0054), Yuanta MSCI 
Taiwan  Financial  (0055),  and  Yuanta  Taiwan 
Dividend Plus (0056) were chosen as the dependent 
variables. The time range spans from 2010 to 2020. 
The  study  is  divided  into  three  parts.  First,  the 
Fama-French  three-factor  model  and  the  deep 
learning algorithm's daily return prediction effects are 
compared. The contrast of the linear traditional model 
and the nonlinear artificial neural network is one of 
the distinctive study features.  
The  findings  demonstrated  that  the  nonlinear 
ANN combined with the CAPM, the Fama-French 
three-factor model and the Fama-French five-factor 
model yielded significantly stronger predictive power 
than  regression-based  approaches.  First  and  second 
place went to the ANN combination with the Fama-
French  three-factor  and  Fama-French  five-factor 
models, respectively. Other commonly used artificial 
neural  networks,  LSTM  and  GRUs,  were  further 
studied. The prediction effects of these two models 
were  compared  with  the  CAPM,  the  Fama-French 
three-factor model and the Fama-French five-factor 
model. The study demonstrated that the Fama-French 
three-factor  model  in  association  alongside  any 
artificial  neural  network  performed  better  than  the 
Fama-French  five-factor  model  and  the  CAPM  in 
conjunction  with  other  models.  Out  of  all  the 
combinations that contained the Fama-French three-
factor model, the combination of LSTM and it yielded 
the lowest mean absolute error (MAE) value. 
Furthermore,  the  Fama-French  three-factor 
model's MAE values were all lower than ANN's when 
combined with LSTM and GRU. Moreover, the study 
began  to  add  other  variables  to  explore  better 
prediction  results.  The  added  factors  include 
Momentum  Factor,  Investment  Factor,  Profitability 
Factor, Dividend Yield Factor, Long-Term Reversal, 
and Short-Term Reversal. The results showed that the 
combination of the Fama-French three-factor model 
performs well regardless of whether the Short-Term 
Reversal factor is added. The researchers also added 
CNN  but  found  that  the  prediction  error  increased 
after  adding  CNN  except  in  2016  and  2019. 
Therefore,  the  model  using  hybrid  or  stacked 
networks has not effectively improved the ability to 
explain daily prices. The study pointed out  that the 
combination of the Fama-French three-factor model 
and LSTM was the most effective way to predict daily 
returns, providing excellent prediction accuracy.  
Using the historical return data of its constituent 
equities, this study (Piovezan, de Andrade Junior, & 
Ávila,  2024)  suggested  a  machine  learning-based 
prediction strategy for the direction of ETF returns. 
The  study  used  information  from  five  reference 
markets to compare the outcomes with buy-and-hold 
and  naive  prediction  strategies.  Regression  models 
(linear regression, ridge regression, extreme gradient 
boosting  (XGBoost),  lightweight  gradient  boosting 
(LightGBM),  and  classification  models  (logistic 
regression,  support  vector  machine  (SVM),  naive 
Bayes  (GaussianNB),  K-nearest  neighbour  (KNN), 
and random forest) were among the machine learning 
models that were employed. Each model was studied 
and  applied  to  five  underlying  indexes.  BOVA11, 
SPY, DAXEXx, MAXIS, and ISF ETFs reflect the 
Ibovespa,  S&P500,  DAX,  NIKKEI,  and  FTSE 
indexes. The 12 largest constituent stocks that make 
up  each  index  were  selected,  including  their  daily 
closing prices from January 1,  2012 to January 25, 
2022,  and  the  entire  data  set  contains  about  2,500