This paper documents that firms face upward-sloping supply curves when they repurchase shares in a Dutch auction, and it analyzes the market reaction to these offers. The announcement price increase is highly correlated with the ultimate repurchase premium. Prices decline at expiration only for pro-rated offers. The cumulative return is positive and highly correlated with the repurchase premium, excepting pro-rated offers. Much of this price increase is consistent with movement along an upward-sloping supply curve. Trading volume around the Dutch auction parallels fixed-price repurchases. Supply elasticity is larger for firms with large trading volume, firms included in the S&P 500 Index, and takeover targets.