to  estimate  the  model.  Further,  AR  model  and  its 
variant versions have been extensively used in field of 
economics and finance (Ye 2017, Santosa 2022, Tash 
2011).  For  example, Ye  proposed  an  ARIMA-SVR 
stock  prediction  model  based  on  wavelet  analysis, 
which improved the forecasting accuracy but did not 
overcome  the  influence  of  singularities  in  the  time 
series  (Ye  2017).  ARIMA  model  was  employed  to 
predict  the  prices  of  45  stocks  with  different 
characteristics, and the stock sequence suitable for the 
model was procured by classification (Santosa 2022). 
Tash and Modarres applied the AR/GARCH model to 
Tehran stocks, and the prediction results show ed that 
their method  could improve the prediction accuracy 
(Tash 2011). 
However,  the  method  based  on  autoregressive 
model  still  has  two  deficiencies,  which  may  lead  to 
prediction bias in the model. 
(1) The  mean  square  error  criterion  used  in  the 
autoregressive model will lead to errors in prediction. 
Specifically, if some data points of random variables 
are far away from each other in the coordinate system 
of the same name, the error will expand in the form of 
square,  which  makes  a  huge  gap  between  the  two 
random variables. 
(2) The autoregressive model uses the same order 
to  predict  different  fluctuations,  which  will  lead  to 
prediction  errors.  Specifically,  because  of  the 
complexity  of  the  stock  price  curve,  a  regression 
model is used to predict the change of the price curve 
of all stocks, resulting in low prediction accuracy. 
In order to accurately predict the stock price trend, 
this paper proposes a stock price trend prediction 
method  based  on  the  maximum  correlation  entropy 
autoregressive  model.  Specifically,  firstly,  the  stock 
price curve is segmented and correlational entropy is 
used  as  the  similarity  measure  to  cluster  the  price 
curve segments. Then, for each class of clustered data, 
a regression model is constructed using the maximum 
corentropy criterion as the constraint function, which 
is used to predict the change trend of the stock price 
curve.  In  summary,  this  paper  mainly  does  the 
following  four  aspects  :(1)  based  on  the  maximum 
correlationentropy  criterion,  a  new  regression 
prediction  model  is  constructed.  Traditional 
autoregressive  models  are  sensitive  to  singularities 
because of the minimum mean square error criterion. 
In  this  paper,  the  maximum  corentropy  criterion  is 
used  as  the  constraint  function,  and  the  Gaussian 
corentropy  is used to  limit  the  infinite  expansion  of 
the error, which effectively weakens the influence of 
the singularity on the curve similarity measurement. 
(2) Based on  the  clustering  strategy,  a  well-targeted 
regression  prediction  model  is  constructed  for  each 
type  of  price  curve.  The  prediction  accuracy  of 
regression model is greatly affected by model order. 
Because of  the  complexity of using  the stock  price 
curve,  using  one  regression  model  to  predict  the 
change of the price curve of all stocks leads to low 
prediction accuracy. Using the clustering strategy, the 
price curves with similar change trends are grouped 
into a group, and a regression model is constructed 
for price  prediction, which can  effectively improve 
the accuracy of prediction. (3) Based on correlational 
entropy, a new  similarity  measure of price curve  is 
proposed.  The  existing  clustering  methods  are 
generally  based  on  Euclidean  distance  and  the 
clustering  results  are  particularly  sensitive  to  the 
singularity  of  the  stock  price  curve.  Correlational 
entropy is used to measure the similarity of any two 
curves. Essentially, two curves are taken as random 
variables  to  measure  the  similarity  based  on  the 
difference of their probability distribution, which can 
better  overcome  the  influence  of  singularities.  (4) 
Based on the open set identification, the singularity 
problem in the clustering process is optimized. In this 
paper, the open set recognition strategy is adopted to 
add  boundary  constraints  to  the  clustering  results, 
which makes the clustering results more accurate and 
can  better  deal  with  the  problem  of  singular  point 
classification  in  the  clustering  process.  In  order  to 
visually  illustrate  the  advantages  of  open  set 
recognition, this paper clustering the data containing 
singularities.  As  shown  in  Figure  1,  Figure  1  (b) 
represents  the  original  data,  where  sample  points 
①~④ represent the data to be classified. Figure 1 
(a)  shows  the  result  obtained  by  using  closed  sets, 
and  symbols  "⊕"  and  "
○
,— "  represent  different 
categories. It is obvious that singularities ② and ④ 
do not fit into any category. If open set identification 
is adopted, the result is shown in FIG. 1 (c). It can be 
seen  that  singularities  ②  and  ④  are  outside  the 
boundary constraints and can eliminate this problem. 
2  RELATED METHODS 
This section mainly introduces the methods related to 
this  paper,  including  similarity  measures  and 
autoregressive  models.  This  paper  uses  uppercase 
letters  (e.g. X,Y )  to  represent  time  series  data, 
lowercase  letters  with  subscripts  (e.g. x
,y
 )  to 
represent  individual  data,  uppercase  bold  letters 
(e.g.𝑿,𝒀)to represent matrices, and superscript letter 
d to represent distances (e.g.d
, Euclidean distances).