The TWS API for RTD RTD is a worksheet function provided by Microsoft that allows Excel to retrieve data from a real-time-data server. In this case, the Trader Workstation or IB Gateway is the server that sends data back to Excel. In essence, it allows you to create your own custom watchlist to display quotes in Excel. Each cell will contain a formula that represents a specific market data column of an instrument. If you are using RTD, you must also ensure that the TWS API was installed on the same drive as the operating system which is usually the c drive, or there may be issues.