I'm looking at opening a trading account for my partnership at one of these three companies and need some advise from those who have used them. My account size will be around 5 million dollars and average number of shares per year will be 3.8 million shares. I will only be trading small cap stocks and some are very thinly traded. There are many times that I have to break a trade down into 10 to 15 seperate orders. Which would be a better fit?