I have an account with IB and 50% maintenance margin.
The most common use of margin ist buying stocks with loaned money, for example:
You buy 100 shares for 1$ each, 50% of which is your money, the rest is margin. You owe 50$. Stock price drops by 0.2, your total value is 80$, but you still owe 50$. Now your money is 30$ and the loan is still 50$. in order to get margin called, the price needs to fall below 0.75$. At that point you still owe 50$, but only have 25$ of your own money, so this is the threshold of a margin call correct?
Now imagine a different scenario, where you don't buy stocks with margin but currency, which you then withdraw.
500k in stocks without margin Take out margin loan for 200k, don't buy stocks with it, but simply withdraw it.
If your 500k in stocks drops by 50%, you now have only 250k of stocks, that are yours and you owe 200k for the loan. This shouldn't resutl in a margin call correct?
Only when your initial 500k stocks drops to less than 50% of your loan (100k) do you get margin called, correct?