Thanks for your info. I got worried because there is a yellow ! box talking about The Reserve on my Balances and Positions page. I paste here the answer which I got from Customer Services:
Thank you for giving me the opportunity to assist you today. Your sweep vehicle is a Money Market Deposit Account (MMDA) held at TD Bank USA, N.A., an affiliate of TD AMERITRADE, which is insured by The Federal Deposit Insurance Corporation (FDIC) for up to $100,000 in non-retirement accounts and up to $250,000 for IRAs and certain other retirement accounts. The MMDA is not invested in The Reserve.
Thank you for contacting TD AMERITRADE. I hope that this information is helpful to you. If you have any additional questions, feel free to e-mail us again or call us at 1-888-871-9007.
Robert W. Apex Client Services, TD AMERITRADE Division of TD AMERITRADE, Inc.