http://www.interactivebrokers.com/en/accounts/fees/interest.php?ib_entity=llc#debit https://www.ameritradeplus.com/plus/html/marketing/margin/mm_page.htm looks like if you borrow 250k, you will get 6.293 on IB and 8.25 on Ameritrade. so a saving 2% or 5k a year. Big difference! What does your broker charge?
qll, just2trade's margin rate is "whatever rate is advertised in just2trade's website by default" or "your broker's margin rate"--whichever is lower. Therefore, it cannot be higher than IB's rate.