In this paper, I study common‐value auctions with a reserve price. First, I consider a static auction in which one bidder has perfect information about the value of the object and the other does not have any private information. Then I consider a dynamic auction in which the informed bidder obtains private information in two consecutive periods, while the other does not have any private information. In both auctions, I derive the optimal reserve price and establish conditions under which the exclusion principle fails. In addition, I compare the dynamic auction with the single‐period auction and provide conditions under which one auction outperforms the other.