Next, you’ll want to add market data, or ticker lines, for the products you want to trade. Although you can trade without market data, we don’t recommend it.
To add market data lines to the Quote Monitor
If you choose Smart as the exchange (rather than selecting Directed and then picking a destination) the market data is aggregated and the default order routing is Smart. From a display perspective, ticker lines that use aggregated Smart data do not display Smart in the data line. TWS will only show the exchange if you elect to direct route. When you create an order, regardless of the market data selection you can modify the order routing destination on a per-order basis using the Destination field.
For more information