隨著網路資訊普及，投資人能夠即時獲取財經新聞，並能對所獲取的資訊有即時反應，因此，本研究以 2014 年 4 月至 2015 年 12 月，台灣加權指數為樣本，透過文字探勘之方式，量化新聞詞語，計算並結構化新聞情緒，將新聞情緒分為正向、負向新聞情緒，探討新聞情緒對投資人進行交易決策之影響。實證結果顯示，日平均新聞情緒之遞延效果兩日後無顯著與報酬有關，負面新聞情緒較原始新聞情緒對報酬率影響程度較大，而隔夜的新聞情緒會因投資人的過度反應而與報酬產生負向關係，將結構化後新聞情緒分數轉為交易指標濾網後，能有效提升程式之績效，其中空方績效提升較多方大。

The prevalence of information online enables investors to browse real-time financial news and react immediately to the obtained information. This study samples the Taiwan Weighted Stock Index between April 2014 and December 2015 by using text mining to quantify words and phrases in news articles. Sentiments reflected by each article are calculated and structured to divide them into positive and negative sentiments. The goal is to explore the effect of news sentiments on trade decisions made by investors. Empirical results reveal that daily average news sentiments exert a delayed effect on the return on investment; however, this effect becomes nonsignificant after 2 days. Negative news sentiments exert a greater effect on the return rate than do original news sentiments. Overnight news sentiments are negatively correlated with the return because of overreaction in investors. After structured news sentiment scores are converted to trade indicator filters, program performance can be improved effectively, and the level of improvement to short position performance is higher than that of long position performance.

Antweiler, W., & Frank, M. (2002). Internet stock message boards and stock returns. University of British Columbia Working Paper, 1-7.
Alostad, H., & Davulcu, H. (2015, December). Directional prediction of stock prices using breaking news on twitter. In 2015 IEEE/WIC/ACM International Conference on Web Intelligence and Intelligent Agent Technology (WI-IAT) (Vol. 1, pp. 523-530). IEEE.
Barber, B. M., & Odean, T. (2000). Trading is hazardous to your wealth: The common stock investment performance of individual investors. The journal of Finance, 55(2), 773-806.
Barber, B. M., & Odean, T. (2008). All that glitters: The effect of attention and news on the buying behavior of individual and institutional investors. The Review of Financial Studies, 21(2), 785-818.
Chan, L. K., Jegadeesh, N., & Lakonishok, J. (1996). Momentum strategies. The Journal of Finance, 51(5), 1681-1713.
Chan, K., Hameed, A., & Tong, W. (2000). Profitability of momentum strategies in the international equity markets. Journal of financial and quantitative analysis, 35(2), 153-172.
Chen, C. C., Huang, H. H., & Chen, H. H. (2018, May). NTUSD-Fin: a market sentiment dictionary for financial social media data applications. In Proceedings of the 1st Financial Narrative Processing Workshop (FNP 2018).
Dougal, C., Engelberg, J., Garcia, D., & Parsons, C. A. (2012). Journalists and the stock market. The Review of Financial Studies, 25(3), 639-679.
Engelberg, J. E., & Parsons, C. A. (2011). The causal impact of media in financial markets. The Journal of Finance, 66(1), 67-97.
Engelberg, J. E., Reed, A. V., & Ringgenberg, M. C. (2012). How are shorts informed?: Short sellers, news, and information processing. Journal of Financial Economics, 105(2), 260-278.
Garcia, D. (2013). Sentiment during recessions. The Journal of Finance, 68(3), 1267-1300.
Gidófalvi, G., & Elkan, C. (2001). Using news articles to predict stock price movements. Department of Computer Science and Engineering, University of California, San Diego.
Heston, S. L., & Sinha, N. R. (2017). News vs. sentiment: Predicting stock returns from news stories. Financial Analysts Journal, 73(3), 67-83.
Hung, P. H. (2016). Investor sentiment, order submission, and investment performance on the Taiwan Stock Exchange. Pacific-Basin Finance Journal, 39, 124-140.
Lillo, F., Miccichè, S., Tumminello, M., Piilo, J., & Mantegna, R. N. (2015). How news affects the trading behaviour of different categories of investors in a financial market. Quantitative Finance, 15(2), 213-229.
Moshirian, F., Nguyen, H. G. L., & Pham, P. K. (2012). Overnight public information, order placement, and price discovery during the pre-opening period. Journal of Banking & Finance, 36(10), 2837-2851.
Odean, T. (1998). Volume, volatility, price, and profit when all traders are above average. The Journal of Finance, 53(6), 1887-1934.
Ranaldo, A. (2004). Order aggressiveness in limit order book markets. Journal of Financial Markets, 7(1), 53-74.
Sankaraguruswamy, S., Shen, J., & Yamada, T. (2013). The relationship between the frequency of news release and the information asymmetry: The role of uninformed trading. Journal of Banking & Finance, 37(11), 4134-4143.
Shiller, R. J. (2000). Irrational Exuberance, Princeton Univ.
Smales, L. A. (2015). Time-variation in the impact of news sentiment. International Review of Financial Analysis, 37, 40-50.
Solomon, D. H., Soltes, E., & Sosyura, D. (2014). Winners in the spotlight: Media coverage of fund holdings as a driver of flows. Journal of Financial Economics, 113(1), 53-72.
Tetlock, P. C. (2007). Giving content to investor sentiment: The role of media in the stock market. The Journal of Finance, 62(3), 1139-1168.
Tetlock, P. C., Saar‐Tsechansky, M., & Macskassy, S. (2008). More than words: Quantifying language to measure firms' fundamentals. The Journal of Finance, 63(3), 1437-1467.
Wu, C. H., & Lin, C. J. (2017). The impact of media coverage on investor trading behavior and stock returns. Pacific-Basin Finance Journal, 43, 151-172.
Yang, W., Lin, D., & Yi, Z. (2017). Impacts of the mass media effect on investor sentiment. Finance Research Letters, 22, 1-4.