Response to your Trouble ticket #360499 created on 2008/12/01 08:41 EST. Subject: Cash balance fluctuating Initial Description: Response from maxr at 2008/12/01 11:17 EST: Dear Trader, The Base currency change does only change the display of the account in TWS and the account management but does not convert money for you. So you still have USD 12'332.76 on the account. By the change of quotes between USD and EUR the account shows fluctuation. To avoid this please convert all the money to EUR in TWS. Therefore please type in USD as underlying into TWS, hit enter, choose forex and choose this line here: IDEAL EUR and hit ok. Now you have it as ticker line in the TWS. Please hit the bid price to get a sell order and type in the quantity 12332. now you can change the price and the order type to what you want to have and transmit the order. After execution all the money is in EUR and you won't see any fluctuation in the account. Now please click on view->Account and go to the FX Portfolio section. Please do a right click on the shown position and choose adjust position or average price. Set the position to 0 and hit ok and it is gone. If you have any further questions, please contact us again. Best regards Max Interactive Brokers LLC