What is the default behavior of "Last Size Extra Decimal"?

To return to integer display, navigate to the Stock Preset settings inTrader Workstation, IBKR Desktop, or IBKR Mobile, and turn off the "Last Size Extra Decimal" setting. Once disabled, Last Size values will again be displayed as integers across all platforms…

The "Last Size Extra Decimal" feature controls how Last Size values are displayed across platforms. By default, Last Size values are displayed as integers. When configured, the feature formats Last Size values to a specified number of decimal places, giving users greater precision in how trade size data appears in the interface. This feature is effective starting February 23, 2026…

There is no direct configuration option for "Last Size Extra Decimal" within Client Portal at this time. However, Client Portal does read and apply the setting you have configured in Trader Workstation, IBKR Desktop, or IBKR Mobile. Your Last Size values in Client Portal will be formatted according to the decimal setting you have established on another platform…

Client Portal includes a dedicated “ON/OFF toggle for "Last Size Extra Decimal" display behavior. It can be accessed from clicking the User icon from top-right corner:

• OFF (default): Client Portal reads the "Last Size Extra Decimal" setting configured in Trader Workstation, IBKR Desktop, or IBKR Mobile and formats the Last Size values accordingly. The tooltip on hover will show the unformatted raw Last Size…