While several studies find a positive impact of brand value on firm value, we still know very little on the variables moderating the brand value-firm value relation. In this study, we address this gap in the literature by developing and testing a new framework on the contingencies affecting the impact of brand value changes on stock returns. Drawing from branding theory, we hypothesize that stock price reactions to brand value changes are more positive for firms with high cash flow vulnerability, valuable growth opportunities, and high potential for further product or service price increases. We empirically examine the importance of these three moderators through an event study analysis of 503 brand value announcements derived from Interbrand's Best Global Brands lists from 2001 to 2012. We obtain evidence of significant abnormal stock returns on brand value announcement dates, with a brand to firm value conversion rate of approximately 4%. Cross-sectional regression analyses of announcement day abnormal stock returns suggest that shareholders mainly value the potential of brands to reduce cash flow vulnerability to adverse shocks. We obtain only mixed evidence on the importance of brands in generating growth, and no evidence for their role in allowing firms to set higher prices. Our results, which hold under a range of sensitivity tests, yield clear managerial guidelines regarding the types of firms for which strong brands matter most.