A method comprises displaying a visible representation of a plurality of stocks in a stock market by a respective plurality of regions that are arranged based on a plurality of similarity values between a respective plurality of pairs of the stocks. Each of the plurality of similarity values is based on a respective correlation between a respective first time series indicating, for each of a plurality of time intervals, an aggregate level of messaging in postings of messages for a respective first stock in its respective pair of the stocks and a respective second time series indicating, for each of the plurality of time intervals, an aggregate level of messaging in postings of messages for a respective second stock in its respective pair of the stocks. Each of the regions is user-selectable to retrieve information from a message board associated with its respective one of the plurality of stocks.