Use the Short Sale Confirmation box to confirm that the shares you want to short are available at the clearing firm. This confirmation box pops up the first time you elect to short an underlying. If you enter the number of shares available, it will only require input once per underlying/per TWS session (a session lasts until you log out of TWS) as long as you stay within the available shares limit.
To confirm availability of shares for short sale
Select Short sell as the action on a buy/sell order line.
Enter confirmation information in the Short Sale Confirmation box.
Enter the Total Number of Shares available to avoid having to confirm availability each time you short this underlying.
TWS will track the number of shares available based on the short sell orders you submit on the underlying. If the number of available shares does not cover the order quantity, you will be required to confirm availability again.
