“…Text mining techniques, such as a sentiment analysis [10][11][12][13], part of speech tagging (POS) [14,15], text representation, such as transformer-based word embedding [16][17][18][19][20][21][22], and machine learning techniques [23][24][25][26][27][28][29][30][31], have been used in this area after 2006. Recently, researchers have focused on using deep learning-based natural language processing (NLP), such as Bidirectional Encoder Representations from Transformer (BERT) [18,21,[32][33][34] or seq2seq architecture with an attention mechanism [20,[35][36][37][38], to structure textual web data. BERT-contextualized word embedding, announced by Google in 2018, is used as a word sense disambiguation technique for summarizing and selecting important news for investors' behavior analysis [21,25].…”