We examine sunshine-induced mood and its impacts on investors' bidding decisions in the primary market where seasoned equities are offered. Analyzing a unique database that records seasoned equity offerings (SEOs) investors' locations, identities, and bidding information, we examine the degree to which sunshine exerts an influence on investors' bidding behaviors (and subsequently SEO discounts) from two dimensions: sunshine intensity and duration. We find that investors exposed to stronger sunshine intensity or longer sunshine duration submit a higher bid price for SEOs, thus leading to lower offer discounts. We also find that mood misattribution and risk-taking act as channels to rationalize such a sunshine effect. Our moderating analyses indicate that the documented impact strengthens in the case of greater uncertainty, less-frequent bidders, retail investors, and lower levels of investment. These sunshine effects impact failed bids, SEO participation and SEOs' long-term performance. Our study provides original evidence that investors in the primary market can be influenced by a sunshine-induced mood, which, in turn, determines the cost of equity financing.