Ok, thought I would share an experience re: IBKR. For some unknown reason, IB calculated March as only having 30 days, so the fluctuations in your account on March 31 did not get entered into the calculations for performance fees for the first Q. So, if March 31 was a down day, you were overpaid and vice versa. I have talked to an IB representative about this and their explanation makes no sense. How can their tech change each year, such that they have to change the calendar dates for March? It isn't like March just got its 31st day this year.
My experience with IB is that their tech claims seem completely hogwash when it is about something I can see, fee calculations, customer linking, enrollment process, and there are so many things that I can't see, trading execution, that those same tech claims are seriously in question.