Abstract: A trading planning apparatus includes an order quantity planning section determining trading quantities with a plurality of trade connections from a trading cumulative quantity and estimated data about future quantities related to demand and the trade connections, a split-time-based split order planning section generating trading and ordering data containing data about an order price or an order quantity related to trading and ordering in each of planned trading periods that are periods into which a trading period, during which trading can be conducted, is subdivided, and a future quantity estimation section estimating estimated quantities of data related to errors in the future quantities estimated from actual record values, the order quantity planning section increasing or reducing the trading quantity of any of the trade connections when a difference between a sum of the trading quantities of all of the trade connections and a future quantity demanded is equal to or greater than a predetermined value.