Past attempts to price bull attributes have relied on static marginal valuations due to cross-sectional data limitations. This analysis investigates whether bull buyersÕ marginal valuations of Angus bull attributes have changed over time using 17 years of bull auction data from Indiana. Results indicate statistically significant time effects on some traits (e.g., ribeye area, percentage intermuscular fat, ribeye-area expected progeny difference [EPD], and maternal-milk EPD). Not all of these effects align with prior expectations. Nonetheless, results have important implications for the beef industry in terms of signaling quality ques and incorporating proven information in the form of EPDs.