The presence of computerized agents has become pervasive in everyday live. In this paper, we examine the impact of agency on human bidders’ affective processes and bidding behavior in an electronic auction environment. In particular, we use skin conductance response and heart rate measurements as proxies for the immediate emotions and overall arousal of human bidders in a lab experiment with human and computerized counterparts. Our results show that computerized agents mitigate the intensity of bidders’ immediate emotions in response to discrete auction events, such as submitting a bid and winning or losing an auction, as well as the bidders’ overall arousal levels during the auction. Moreover, bidding behavior and its relation to overall arousal are affected by agency: whereas overall arousal and bids are negatively correlated when competing against human bidders, this relationship is not observable for computerized agents. In other words, lower levels of agency yield less emotional behavior. The results of our study have implications for the design of electronic auction platforms and markets that include both human and computerized actors.