I know a lot of firms in Chicago and none of them have you pay them back if you leave. That is a scam and would not be legal in the US. That is part of the risk of going prop. You give up a large percentage of profit in return they should "teach" you what they are doing and take some risk on you either through draw/salary and loses as you learn to trade. For most companies there are a lot of areas where they make money - commissions, desk fees, and percent of your profits. I don't know why a firm would want to keep you if you were not doing well and decided to leave. You can go in swinging and blow out your acct until they fire you.