Patent ID: 7797224

Claim:
A method, comprising: identifying a candidate set of buy orders associated with an investment account, wherein the candidate set includes at least a first buy order and a second buy order; determining that total cash required to fund the candidate set of buy orders exceeds net available cash in the investment account; subsequent to determining that the total cash required exceeds the net available cash, linking the buy orders in the candidate set into a chain, wherein the first buy order is linked to the second buy order; determining a back out target value that identifies a fiscal amount by which the candidate set must be reduced; identifying a decrementation amount; decrementing, in accordance with an ordering associated with the chain, a respective asset quantity of two or more non-zero quantity buy orders, including a first asset quantity of the first buy order and a second asset quantity of the second buy order, to a respective final asset quantity until the back out target value is achieved by: decrementing the first asset quantity of the first buy order by a first amount that is either (i) equal to the identified decrementation amount or (ii) derived from the identified decrementation amount and a first asset price associated with a first asset of the first buy order, determining that an impact of the decrementing the first asset quantity of the first buy order is insufficient to achieve the back out target value, subsequent to determining that the impact of decrementing the first asset quantity is insufficient to achieve the back out target value, decrementing the second asset quantity by a second amount that is either (i) equal to the identified decrementation amount or (ii) derived from the identified decrementation amount and a second asset price associated with a second asset of the second buy order, and determining that a cumulative impact of decrementing at least the first asset quantity of the first buy order and the second asset quantity of the second buy order is sufficient to achieve the back out target value; modifying the candidate set of buy orders by (i) excluding any of the buy orders for which the respective final asset quantity is zero or (ii) replacing a respective initial asset quantity with the respective final asset quantity for any of the buy orders for which the respective final asset quantity is different than the respective initial asset quantity; and providing the modified candidate set of buy orders for trade execution, wherein one or more computers associated with a portfolio management system are programmed to perform the prior steps.