I have a Reg-T margin account with Interactive Brokers. I would like to confirm my assumptions about the effect that making a cash withdrawal on margin would have on the account.
Let's say I have $200 worth of securities in the account; all of it paid for with my own cash (no margin balance), and cash balance of $0. Under these parameters, IB shows:
- Maintenance margin of $50
- Buying power of $600
- Excess liquidity of $150
Let's say I withdrew $100 in cash from the account. Because my previous cash balance was $0, that effectively means that the whole $100 is being borrowed on margin. How would that affect the numbers above?
Ultimately, what I'm trying to figure out is by how much the $200 in securities in the account would have to come down in value before triggering a margin call because of the $100 loan.