Uniform price auctions in Finnish Treasury auctions from 1992-99 showed average underpricing of 0.041% of face value. The theory of monopsonistic market power as a cause of underpricing was not supported by the data. Bidders' demand did not change as predicted by the theory with increased competition. The Finnish Treasury strategically considers the repeated game with primary dealers. Bond return volatility was the main factor influencing bidder behavior and underpricing, suggesting private information and the winner's curse are significant in these auctions.