The Evolution Model Of Stock Investor Sentiment Based On Symmetric Triangular Fuzzy Set

In the social network environment,stock investors use words such as “the price of the stock will surge” to interact with each other.In the process of interaction,investor sentiment will spread to each other,which will affect their buying and selling decisionmaking behavior,and ultimately lead to stock price fluctuations.Therefore,it is very important to build a stock investor sentiment evolution model under the opinion networks environment to deeply understand asset pricing Price matters.It has been argued that investor sentiment is the expectation of future earnings,which is ultimately reflected in the price of financial assets.This paper also defines investor sentiment from the perspective of stock investor expectation(such as “surge”).Considering that unlike random uncertainty,the uncertainty of stock investors' expectation described by words such as “surge” is a fuzzy uncertainty problem,this paper uses a fuzzy set which can describe the fuzzy uncertainty to express the expectations of stock investors like “surge” and constructs a model.In addition,considering that it is difficult to determine the value of people's opinions in the infinite interval,but in a limited interval.Therefore,the membership function of the fuzzy set is chosen the symmetric triangular function when constructing the model of stock investor's emotion propagation.The main achievements of this dissertation are summrized as follows:(1)A static propagation model of stock investor sentiment based on symmetric triangular fuzzy set is proposed.First of all,several static propagation models are constructed based on symmetric triangular fuzzy sets,including fuzzy stock price expectation center propagation,fuzzy stock price expectation uncertainty propagation,fuzzy stock price expectation center and uncertainty propagation,fuzzy stock price expectation center value's chain propagation—and fuzzy stock price expectation uncertainty chain propagation.Secondly,the rationality of the model is verified by numerical simulation.Finally,taking the investor sentiment communication in the “Guba” community as an example,the effectiveness of the model is proved.(2)Furthermore,A dynamic propagation model of stock investor sentiment based on symmetric triangular fuzzy set is proposed.First of all,several dynamic propagation models are constructed based on symmetric triangular fuzzy sets—including self feedback propagation,fuzzy opinion center value time-varying and fixed propagation,fuzzy opinion center value time-varying propagation,fuzzy opinion center value timevarying and uncertainty decreasing propagation.Secondly,we built a dynamic propagation model based on limited trust model.Finally,we simulate the model under the uncertainty input of local recommendation and global recommendation,respectively.(3)A price dynamic application of the stock investor sentiment propagation model is given.Firstly,the price dynamics model of stock fund is constructed.Secondly,we use the weighted recursive least square method to simplify the identification of model parameters,and verify the validity of the model by using the daily unit net value data of the stock fund.Finally,we construct the trading strategy rule of stock fund based on the simulation results.