ABSTRACT This paper examines how firms’ tax policy expectations (TPE) evolve around and relate to their investment responses to changes in tax policy. Using a text‐based approach to measuring TPE, we find that two recent tax policy–changing events—namely, the 2016 U.S. presidential election and the enactment of the Tax Cuts and Jobs Act (TCJA)—spawned considerable between‐ and within‐firm variation in TPE, with aggregate time‐series patterns in TPE occasionally challenging prevailing assumptions in previous research. Further, we observe that event‐induced TPE relate to investment both before and in response to the TCJA's passage in 2017, with offsetting associations between its first and second moments, and that these TPE moderate the TCJA's intended investment‐stimulating effect. Furthermore, we document a difference between domestic and multinational firms in their TPE‐investment response, with the former (latter) more likely to adjust the level (shift the country location) of their investment. Overall, our findings support the idea that TPE can impact investment behavior in the face of a tax policy change and suggest that our methodology can be used by future research to incorporate TPE into analyses of tax policy effects.