To allow many users to easily participate in stock price prediction, and automatically create portfolios related to investment based on predictions of each user.

When receiving user IDs, specifying information on predicting brands and prediction information on stock price changes that users input in user terminals U1 to Un, a central server apparatus 10 included in a stock price prediction evaluation system 1 starts stock price tracking of the predicting brands and creates user personal pages for a web site established on a network NW. In addition, the central server apparatus 10 calculates points that are indicators to objectively compare and evaluate prediction contents of users based on the stock prices acquired by tracking, and creates a ranking table in which user names are arranged in the descending order of the calculated points to create portfolios using the created ranking table.