This paper examines how heterogeneity in investment horizons determines the demand for safe assets, bidding strategies in auctions, and post-auction price dynamics. We model a uniform-price double auction with resale where long-term investors hold assets to maturity, while dealer banks distribute the asset in secondary markets. Pure private (common) values emerge when only long-term investors (dealers) participate. Using unique data on Swiss Treasury bond auctions revealing bidders' identities, our empirical findings support key predictions: (1) substantial heterogeneity in demand schedules, with steeper demand curves for dealer banks; (2) dealer banks' demand becomes steeper with increased demand risk and bid dispersion; and (3) demand elasticity positively predicts post-auction returns.