TWS provides a built-in, dynamic method to transact stock orders using a specified cash value instead of a share quantity. Cash Quantity allows the user to enter a cash amount in the Quantity field, which is then used along with the bid/ask price to drive the number of shares purchased With Cash Quantity, the entered cash value remains constant and the share size varies based on fill price.
To use Cash Quantity, in Mosaic order entry (or in the Classic TWS order line), click in the Quantity field to display the Size Wand. Toggle from "Shares" to "USD" (or the displayed currency of the stock). Enter the cash amount you want to pay. The approximate share equivalent is shown below the cash quantity, based on the current price. When submitted, the order uses the entered cash value + price to drive the number of shares purchased.
For example, for a buy order with a cash quantity of 1000 and current stock price of 10, the estimated share equivalent would be 100. When the order fills, if the average price is 9, the shares purchased would be 111. If the average fill price is 12, the shares purchased would be 83.
If you prefer to trade cash amounts with even more precision, you can enable fractional trading. Once enabled, our system will submit your order to the nearest whole share and with the remaining amount, purchase a fraction of a share to ensure that we use your entire cash amount for the order. Additionally, you can elect to purchase shares directly in fractions. TWS Build Version 979 or later is required to trade fractional shares. See: How do I enable fractional shares?
This feature currently supports most order types. Currently, only BUY orders are supported for Cash Quantity stocks orders.
Additional Information
- Trading in Fractions and Cash Quantity for Stock Orders available in our TWS Release Notes