Thanks for your responses. I should further explain why I'm asking this question.
I want to start a non-profit, and wanted an in-house funding method. I came up with a system that works, but it incurs around $10,000.00 per month in fees (credit-card processing, margin interest, and (probably) capital gains). Therefore, I figured I needed around $16,000.00 (or 6.4% gross) monthly to cover for trading mistakes and still make it worth doing.