I study a dynamic trading game where a seller and potential buyers start out symmetrically uninformed about the quality of a good, but the seller becomes informed about the quality, so that the asymmetric information between the agents develops over time. The introduction of a widening information gap results in several new phenomena. In particular, the interaction between screening and learning generates nonmonotonic price and trad- ing patterns, contrary to the standard models in which asymmetric information is initially given. If the seller’s effective learning speed is high, the equilibrium features “collapse-and-recovery” behavior: Both the equilibrium price and the probability of a trade drop at a threshold time and then increase later. The seller’s payoff is nonmonotonic in his learning speed, as a slower learning speed can lead to higher payoff for the seller.