Regarding IB's commission schedule, they have two basic schedules to choose from called "bundled" and "unbundled". If you go to their site you can do a search and get the nitty gritty on both. I use the bundled schedule which, as long as you're not doing anything fancy and sticking with trading U.S. Index stocks, works like the following, which I took right off of their site:
You pay .005 per share. The minimum commission per order is $1.00. The maximum commission per order is 0.5%, (that's a half a percent), of the total monetary value of your trade plus the typical exchange, ECN and specialist fees.
For example...
if you were to buy 100 shares of a $50 stock you would pay $1.00 commission, because .005 x 100 = .50, but the minimum commission you can pay is $1.
If you buy 1000 shares of a $50 stock your commission = $5.00, because 1000 shares x .005 = $5.00
If you buy 1,000,000 shares of a .0005 stock your commission = 2.50, because .005 x 500 = 2.50, where .005 is half a percent multiplied by the total trade value of $500 (1 million shares x .0005).
The basic point here is that IB's commission schedule blows Etrade and Ameritrade away if you're doing a lot of small cap trading.
Rich
Unless otherwise stated, any and all information I post is my opinion which is subject to change. I accept no responsibility for anyone who chooses to take any action based upon anything I post.