This work discusses a new possibility of investment analysis, complementing the existing ones, oriented by the strategic information focus as a competitive differential at the financial market, based on the Information Science insight. It begins with a discussion about its own field, surpassing the most orthodox limits, linked to its origin, such as Biblioteconomy, Museoconomy, Documentation and Archivist, moving towards a postmodern and multidiscipline discussion referred to the understandings of Science Information attributions. A synthesis about the financial system comprehension in order to focus on the object of study, information mediation, is necessary. The study starts from the identification of the most significant daily oscillations (consider oscillations greater than 5% - up or down) occurred at Sao Paulo Stock Exchange (BOVESPA), from July/1994 to October/2006, to the Petrobras S.A. shares and the IBOVESPA index. Based on quantitative data and also a qualitative search through documental research, it is sought the information source that is responsible for the financial effects, compiling and organizing them into a database which could allow the development of the mediational analysis, suggested in this work.181133145