title: Coupling News Sentiment with Web Browsing Data Improves Prediction of Intra-Day Price Dynamics.
abstract: The new digital revolution of big data is deeply changing our capability of understanding society and forecasting the outcome of many social and economic systems. Unfortunately, information can be very heterogeneous in the importance, relevance, and surprise it conveys, affecting severely the predictive power of semantic and statistical methods. Here we show that the aggregation of web users' behavior can be elicited to overcome this problem in a hard to predict complex system, namely the financial market. Specifically, our in-sample analysis shows that the combined use of sentiment analysis of news and browsing activity of users of Yahoo! Finance greatly helps forecasting intra-day and daily price changes of a set of 100 highly capitalized US stocks traded in the period 2012-2013. Sentiment analysis or browsing activity when taken alone have very small or no predictive power. Conversely, when considering a news signal where in a given time interval we compute the average sentiment of the clicked news, weighted by the number of clicks, we show that for nearly 50% of the companies such signal Granger-causes hourly price returns. Our result indicates a "wisdom-of-the-crowd" effect that allows to exploit users' activity to identify and weigh properly the relevant and surprising news, enhancing considerably the forecasting power of the news sentiment.
authors.affiliation: IMT Institute for Advanced Studies, Piazza San Francesco 19, 55100 Lucca, Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Ranco
authors.affiliation: Yahoo Labs, Barcelona, Spain.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Bordino
authors.affiliation: Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.|QUANTLab, Via Pietrasantina 123, 56122 Pisa, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Bormetti
authors.affiliation: IMT Institute for Advanced Studies, Piazza San Francesco 19, 55100 Lucca, Italy.|ISC-CNR, Via dei Taurini 19, 00185 Roma, Italy.|London Institute for Mathematical Science, South St. 35 Mayfair, London W1K 2XF, United Kingdom.
authors.forename: Guido
authors.initials: G
authors.lastname: Caldarelli
authors.affiliation: Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.|QUANTLab, Via Pietrasantina 123, 56122 Pisa, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Lillo
authors.affiliation: QUANTLab, Via Pietrasantina 123, 56122 Pisa, Italy.|Mediobanca S.p.A, Piazzetta E. Cuccia 1, 20121 Milano, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Treccani
mesh_terms: D003132:Commerce / Q000191:economics*; D006801:Humans; D020407:Internet; D007449:Investments / Q000191:economics*; D018803:Models, Economic