Interestingly, at some places "overnight" means only the 5:00 p.m. - 6:00 p.m. ET reset. After that you can continue to use "daily" margin requirements. So one could hold from 6:01 PM until 4:59PM the next day using the Daily requirement.
Are they any good? Would be interested to hear from traders who actually make money and taking payments out.
I doubt the brokers care for actual range. They normally use %% of the exchange margin plus some marketing adjustment.
I have been using AMP for 5 years now, and very happy so far. AMP is not a prop firm or bucket shop that trades against you. One thing to note is that AMP ups margin to about $2000 sometimes $4000 or higher during major news events CPI, NFP, FOMC etc. Just something to bear in mind if your main style is trading these events, don't expect $500 & $1000 over major news events. Also when the VIX really spikes eg. to over 50, then don't expect $500 & $1000 at anytime, even during regular trading hours and no economic news is expected.