The "no margin call" policy in overseas forex trading is actually due to the zero-cut system. Even if your account balance goes negative, the broker will cover the negative amount and bring the balance back to zero, limiting your maximum loss to the amount you deposited. However, this doesn't mean it's "guaranteed and unconditionally protected"... Read more: No margin calls in overseas forex trading? Explanation of the zero-cut system and why it's considered a trap.