Yes, you can log in to your live and paper accounts simultaneously. However, you can only get market data on both if you are logged in on the same computer (assuming you are subscribed to live market data). If you are logged into both accounts on separate computers, you will only receive data on the live account.
Please Note
- To see live quotes on both your paper and live accounts at the same time from different devices, create a second username for your real account, subscribe to live market data quotes with it, and then share its market data subscriptions with your paper account.
Find more information on the Paper Trading Account page of the Client Portal Users' Guide.
Additional Information