In these times of “fake news,” knowledge contexts and knowledge sources should be important to both management practice and theory. Building on strategic sensemaking, this study aims to identify the influence of the type of formal external knowledge source on the strategic interpretation of environmental changes. Therefore, this article adresses formal external knowledge sources in the sensing of threats in comparison to the sensing of opportunities. Using second respondent and objectively validated survey data from top managers of 483 firms, we show that the type of formal external knowledge source influences the strategic interpretation of environmental changes. The results also reveal that the strength of these associations is moderated differently by a firm’s general intensity of gathering and interpreting environmental knowledge.