Abstract: A method includes receiving first online messages regarding a financial instrument, and first objective quantitative data that reflect respective first values of a target variable associated with the financial instrument. The first messages are analyzed to generate respective first sentiment scores reflecting respective sentiments expressed in the first messages regarding the financial instrument. An initial prediction model is generated for the target variable by analyzing the first sentiment scores and the associated first values of the target variable. Second messages and objective quantitative data are received and analyzed to generate second sentiment scores and an incremental prediction model. A refined prediction model is generated by combining the initial model with the incremental model. Third messages are received and analyzed to generate third sentiment scores, which are used as input to the refined model to predict a future value of the target variable, which is reported to a user.