Remember reading a post yesterday about somone who lost money and blamed it on the commissions being too low causing him to overtrade. Maybe this has some merit. Having an account at a broker with higher commissions might make some traders only choose what appear to be the highest probability trades to them. I'm sure most people have discipline problems at various times. I only look to place on average 3 trades a week and this is when I am the most profitable and most selective. When I trade more frequently looking for lower probability smaller moves the results are worse.