When converting LotBack into Balance, the amount redeemed will be mentally added and subtracted from the balance. For example, if there is a balance of -20 and you exchange LotBack for $5, it will make the balance = -15. However, the balance cannot be reset in all cases by exchanging the lot back.
In the section on exchanging to balance, it is recommended to trade only when the balance is equal to 0 or positive. If all orders are closed, the system will immediately reset the balance.