We model the uniform-price US Treasury security auction as a static symmetric game with incomplete information in which each player is a primary dealer who submits a demand schedule given two independent sources of private information: her/his pre-auction short position of the auctioned security and her/his valuation of this security. Under the assumptions of constant marginal value and additive separability of the demand schedule, we obtain closed-form solutions for the dealer’s optimal demand schedule, and we find that her/his pre-auction short position impacts her/his bidding behavior in three ways. First, the primary dealer’s demand for the auctioned security increases with her/his pre-auction short position. Second, the primary dealer’s differential bid shading decreases with her/his pre-auction short position. Third, primary dealers with higher pre-auction short positions assign lower values to the auctioned security. Based on our findings, we propose policy recommendations that would allow the US Treasury to increase taxpayers’ revenue.