Abstract: An automated investment system for investment banks which allows their customers to invest idle funds, including odd amounts of funds, throughout the day is disclosed. The cash investment system disclosed is a data processing system which utilizes selected interest bearing and discounted securities and instruments traditionally sold by banks as the basis for a new interest bearing investment vehicle of varying maturities which can be purchased with an odd amount of funds, and without the need to interact with salespeople. The investments and underlying securities and instruments are stored in an inventory file maintained in the bank's data processing facility. A customer reviews the investments being offered on a given day through a terminal located at the customer's facility.