Quote from IBj:
Competely disclosed, actually.
http://www.interactivebrokers.com/en/accounts/fees/interestMethods.php
You just need to be willing to spend a few minutes working through an example. If it is important to you, spend the time to learn, say 5-10 minutes depending on math aptitude (interest calculations are math, after all). If it isn't important to you, then it is a non-issue anyway.
That's it, make condescending remarks to your clients about their math skills, that's a good start.
Quote from IBj:
What the Wikipedia entry omits to say are the following:
* IB's approach to tiered rates is intended to discourage small accounts. Small capital usually means less trading and we want traders of the semi-pro and pro variety, not hobbyist investors. If you have 15K with IB, you get a poor effective rate. If you have 500K, you get a pretty nice one.
I'm going to call bullshit on that. The real reason you do the tiering is to avoid paying interest on the first 10K for any client no matter their acc't size. It doesn't matter if they have a 500K acc't. If they have three different positions across sub-acc'ts, you will refuse interest payments on 30K on a pro-rata basis.
You people at IB are unbelieveable. You patronize and insult the intelligence of your clients and then pull out the "oh, we don't cater to the proletariat" excuse to attempt to explain your overpriced margin interest. IB sickens me.