An auction result prediction system predicts auction results. The system may determine item, seller, or auction characteristics from prior or pending auctions. The system also obtains item characteristics of an item for which a result prediction is sought, either by a buyer or by a seller. A price predictor in the system accepts the auction and item characteristics and predicts an auction result based on the characteristics. The system also determines insurance parameters for insuring online auctions, and the insurance parameters may be based on predicted auction results. An insurance policy reflecting the insurance parameters may be offered to an online auction buyer, seller, or other market participant. The insurance policy may insure, for example, that an item for sale will obtain at least a price specified by the insurance policy.