I am getting ready to set up a broker. I was thinking of interactive brokers, which looks like it is a good system and currently used for day traders. However, I also like to trade U.S. penny stocks, so I sometimes buy and sell in excess of 100,000 shares at a time. Does anybody use interactive brokers for this, and if so how does the commission work? If commissions are USD 0.005 per share, a trade of 100,000 shares would be USD $500 in commissions one way. If this is the case I'll just use TD Ameritrade or somebody who will only charge a fixed USD $10 each way.
