I have used several brokers in my time which have offered "unbundled commisions", where commision depends on the volume traded. In every country and with every broker this was calculated on a continous basis, so that accumulated volume ultimo some month affected commisions primo next month etc. - i.e. a rolling continous volume calculation. On IB it is limited to calendar month volume - meaning that even though you have a continously high volume, you will get ripped off during the first days of every month - with commisions higher than the unbundled offer, and then you will have to "work your way up" every month. I say "ripped off" because the low-volume unbundled commisions are higher than the fixed-rate commisions, so I think there is grounds to actually claim "being ripped off", considering the continously high volume traded. I object to the current way IB is using calendar months for calculation of volume, and think that commissions should be calculated on a continous basis - even intra-day (which it seems to be now as well). A 30-day (and intraday) rolling average for calculating volume for commisions is the only fair pricing in my opinion. If you currently are considering IB unbundled commision: what's your opinion ?