Hi Rabbit,
Not specifically commenting on this post, but you seem to have all/most/ of the complete info.

Someone posted the MFG deposit agreement and a comparison (I think TD Ameritrade). I wanted to save them and review them for comparison to what Options Xpress provided. I can no longer find that post as there have been so many on the subject.

Please post a link to that if you know how to find it.

Not to raise a Red Flag on Ox, but Due Diligence says "look at it" !!!!

A little more on a close subject --- Cash sweeps and FDIC insurance.
Ox sweeps, daily, all unused cash into "interest bearing accounts" that are covered by FDIC insurance. (not that the interest is very important today)

Some time ago (couple of years and before the Charles Schwab buyout) Ox increased the amount of FDIC covered cash as follows:

The now standard $250,000 per account/bank has been increased to a huge number (far larger than I have to worry about) by automatically sweeping to separate accounts that qualify for FDIC. I think the total coverage may be about 5 million.

Thanks, Lee