Property valuation that uses multiple transactions in predicting a value for a property. Instead of choosing only one prior transaction, valuation uses multiple transactions for a given property to provide a more accurate mark-to-market value. Preferably, a weighted combination of mark-to-market values provided by an HPI and individual ones of the multiple transaction records provide a predicted value for the given property. Weighting factors recency and transaction type to correct for both sources of potential inaccuracy.